WorldWideScience

Sample records for remarkable rate acceleration

  1. Practical remarks on the heart rate and saturation measurement methodology

    Science.gov (United States)

    Kowal, M.; Kubal, S.; Piotrowski, P.; Staniec, K.

    2017-05-01

    A surface reflection-based method for measuring heart rate and saturation has been introduced as one having a significant advantage over legacy methods in that it lends itself for use in special applications such as those where a person’s mobility is of prime importance (e.g. during a miner’s work) and excluding the use of traditional clips. Then, a complete ATmega1281-based microcontroller platform has been described for performing computational tasks of signal processing and wireless transmission. In the next section remarks have been provided regarding the basic signal processing rules beginning with raw voltage samples of converted optical signals, their acquisition, storage and smoothing. This chapter ends with practical remarks demonstrating an exponential dependence between the minimum measurable heart rate and the readout resolution at different sampling frequencies for different cases of averaging depth (in bits). The following section is devoted strictly to the heart rate and hemoglobin oxygenation (saturation) measurement with the use of the presented platform, referenced to measurements obtained with a stationary certified pulsoxymeter.

  2. Remarkable rates of lightning strike mortality in Malawi.

    Directory of Open Access Journals (Sweden)

    Monique Borgerhoff Mulder

    Full Text Available Livingstone's second mission site on the shore of Lake Malawi suffers very high rates of consequential lightning strikes. Comprehensive interviewing of victims and their relatives in seven Traditional Authorities in Nkhata Bay District, Malawi revealed that the annual rate of consequential strikes was 419/million, more than six times higher than that in other developing countries; the rate of deaths from lightning was 84/million/year, 5.4 times greater than the highest ever recorded. These remarkable figures reveal that lightning constitutes a significant stochastic source of mortality with potential life history consequences, but it should not deflect attention away from the more prominent causes of mortality in this rural area.

  3. Increased enantioselectivity and remarkable acceleration of lipase-catalyzed transesterification by using an imidazolium PEG-alkyl sulfate ionic liquid.

    Science.gov (United States)

    Itoh, Toshiyuki; Matsushita, Yuichi; Abe, Yoshikazu; Han, Shi-Hui; Wada, Shohei; Hayase, Shuichi; Kawatsura, Motoi; Takai, Shigeomi; Morimoto, Minoru; Hirose, Yoshihiko

    2006-12-13

    Several types of imidazolium salt ionic liquids were prepared derived from poly(oxyethylene)alkyl sulfate and used as an additive or coating material for lipase-catalyzed transesterification in an organic solvent. A remarkably increased enantioselectivity was obtained when the salt was added at 3-10 mol % versus substrate in the Burkholderia cepacia lipase (lipase PS-C)-catalyzed transesterification of 1-phenylethanol by using vinyl acetate in diisopropyl ether or a hexane solvent system. In particular, a remarkable acceleration was accomplished by the ionic liquid coating with lipase PS in an iPr(2)O solvent system while maintaining excellent enantioselectivity; it reached approximately 500- to 1000-fold acceleration for some substrates with excellent enantioselectivity. A similar acceleration was also observed for IL 1-coated Candida rugosa lipase. MALDI-TOF mass spectrometry experiments of the ionic-liquid-coated lipase PS suggest that ionic liquid binds with lipase protein.

  4. Exaggerated Claims About Success Rate of Earthquake Predictions: "Amazing Success" or "Remarkably Unremarkable"?

    Science.gov (United States)

    Kafka, A. L.; Ebel, J. E.

    2005-12-01

    On October 1, 2004, NASA announced on its web site, "Earthquake Forecast Program Has Amazing Success Rate." This announcement claimed that the Rundle-Tiampo earthquake forecast method has accurately predicted the locations of 15 of California's 16 largest earthquakes this decade. Since words like "amazing" carry a lot of meaning to consumers of scientific information, claims of "amazing success" should be limited only to cases where the success is truly amazing. We evaluated the statistical likelihood of the reported success rate of the Rundle-Tiampo prediction method by applying a cellular seismology approach to investigate whether proximity to past earthquakes is a sufficient hypothesis to yield the same level of success as the Rundle-Tiampo method. To delineate where to expect future earthquakes, we used the epicenters of the ANSS earthquake catalog for California from 1932 through 1999 with magnitude≥4.0 ("before" earthquakes). We then tested how many of the 15 events that are shown on the NASA web page ("after" earthquakes) occurred near the "before" earthquake epicenters. We found that with only a 4 km radius around each "before" earthquake epicenter, we successfully forecast the locations of 13/15 (87%) of the "after" earthquakes, and with a 7 km radius we successfully forecast 14/15 (93%) of the earthquakes. The zones created by filling in a 7 km radius around the "before" epicenters cover 18% of the study area. The scorecard maps on the JPL "QuakeSim" web site show an 11 km margin of error for the epicenters of the forecast earthquakes. With an 11 km radius around the past epicenters (covering 31% of the map area), we catch 14/15 of the "after" earthquakes. We conclude that the success rate referred to in the NASA announcement is perhaps better characterized as "remarkably unremarkable", rather than "amazing." The 14/15 success rate for the earthquakes listed on the NASA scorecard is not a rigorous test of the Rundle-Tiampo method, since it appears that

  5. Accelerated nail growth rate in HIV patients.

    Science.gov (United States)

    Sánchez-Moreno, Elisa C; Marioni-Manriquez, Selina; Fernández-Martínez, Ramón F; Moreno-Coutiño, Gabriela

    2017-05-01

    Many factors have been noted to alter the growth rate of both finger and toe nails, some with harder evidence than others. Infectious diseases are among the ones reported as slowing the growth rate. However, on previous studies we noticed that patients living with HIV and onychomycosis could be cured without the use of antifungal therapy, only with the immunological improvement provided by the combined antiretroviral therapy, and we wanted to prove that the growth rate is also increased in this group and thus probably contributes to the cure of onychomycosis. This was an observational, descriptive, and prospective study. We marked with a scalpel the nail plate of the first finger of the non-dominant hand and the same foot, and measured the nail growth in the subsequent medical appointments with a magnifying glass and a millimetric scale. Thirteen patients completed the study, and were paired with healthy controls by age and gender. After performing Mann-Whitney U test, our results showed statistical significance among both groups, showing that patients with HIV have faster nail growth rates than those in the HIV negative group. There is little data on HIV nail growth rate to compare our results, but what we see in the clinical practice is that this group of patients shows a faster nail growth rate, as has also been reported for longer eyelashes, and this could be an important factor in the cure rates of onychomycosis. © 2017 The International Society of Dermatology.

  6. Rate acceleration of light-driven rotary molecular motors

    NARCIS (Netherlands)

    Pollard, Michael M.; Klok, Martin; Pijper, Dirk; Feringa, Ben L.

    2007-01-01

    One of the key challenges in taking light-driven unidirectional rotary motors from discovery to application is to increase the rate of rotation. Herein, we review our ongoing efforts to address this issue by meticulous improvement to the molecular design. To accelerate the rotary cycle, we have

  7. C-band disk-loaded-type accelerating structure for a high acceleration gradient and high-repetition-rate operation

    Directory of Open Access Journals (Sweden)

    T. Sakurai

    2017-04-01

    Full Text Available A high-acceleration-gradient linear accelerator (LINAC for an x-ray free electron laser (XFEL offers the advantages of a short accelerator length and low construction costs. In addition, the high pulse repetition rate of the LINAC, which can drive multiple x-ray beam lines, provides additional user opportunities for experiments involving XFEL. A C-band disk-loaded-type accelerating structure was developed to achieve a high acceleration gradient of >50  MV/m and an rf-pulse repetition rate of 120 pps, which is twice as high as that of the XFEL facility, SACLA (60 pps. The structure has a quasiconstant gradient and a traveling wave type with an accelerating mode of TM01−2π/3. To reduce the surface electric fields, we employed a cross section with an ellipsoidal curvature around an iris aperture. The accelerating structure was manufactured for SACLA. High-power rf conditioning was conducted to investigate its performance. Owing to the conditioning, the acceleration gradient reached a value of more than 50.1  MV/m. The structure was operated without any serious issues at a repetition rate of 120 pps. The accelerating structures were installed in the dedicated accelerator for EUV-FEL at SACLA beam line-1. Finally, we obtained accelerated electron beams with the structures operated at an acceleration gradient of 41.4  MV/m.

  8. C -band disk-loaded-type accelerating structure for a high acceleration gradient and high-repetition-rate operation

    Science.gov (United States)

    Sakurai, T.; Ego, H.; Inagaki, T.; Asaka, T.; Suzuki, D.; Miura, S.; Otake, Y.

    2017-04-01

    A high-acceleration-gradient linear accelerator (LINAC) for an x-ray free electron laser (XFEL) offers the advantages of a short accelerator length and low construction costs. In addition, the high pulse repetition rate of the LINAC, which can drive multiple x-ray beam lines, provides additional user opportunities for experiments involving XFEL. A C -band disk-loaded-type accelerating structure was developed to achieve a high acceleration gradient of >50 MV /m and an rf-pulse repetition rate of 120 pps, which is twice as high as that of the XFEL facility, SACLA (60 pps). The structure has a quasiconstant gradient and a traveling wave type with an accelerating mode of TM 01 -2 π /3 . To reduce the surface electric fields, we employed a cross section with an ellipsoidal curvature around an iris aperture. The accelerating structure was manufactured for SACLA. High-power rf conditioning was conducted to investigate its performance. Owing to the conditioning, the acceleration gradient reached a value of more than 50.1 MV /m . The structure was operated without any serious issues at a repetition rate of 120 pps. The accelerating structures were installed in the dedicated accelerator for EUV-FEL at SACLA beam line-1. Finally, we obtained accelerated electron beams with the structures operated at an acceleration gradient of 41.4 MV /m .

  9. The origin of modern frogs (Neobatrachia was accompanied by acceleration in mitochondrial and nuclear substitution rates

    Directory of Open Access Journals (Sweden)

    Irisarri Iker

    2012-11-01

    Full Text Available Abstract Background Understanding the causes underlying heterogeneity of molecular evolutionary rates among lineages is a long-standing and central question in evolutionary biology. Although several earlier studies showed that modern frogs (Neobatrachia experienced an acceleration of mitochondrial gene substitution rates compared to non-neobatrachian relatives, no further characterization of this phenomenon was attempted. To gain new insights on this topic, we sequenced the complete mitochondrial genomes and nine nuclear loci of one pelobatoid (Pelodytes punctatus and five neobatrachians, Heleophryne regis (Heleophrynidae, Lechriodus melanopyga (Limnodynastidae, Calyptocephalella gayi (Calyptocephalellidae, Telmatobius bolivianus (Ceratophryidae, and Sooglossus thomasseti (Sooglossidae. These represent major clades not included in previous mitogenomic analyses, and most of them are remarkably species-poor compared to other neobatrachians. Results We reconstructed a fully resolved and robust phylogeny of extant frogs based on the new mitochondrial and nuclear sequence data, and dated major cladogenetic events. The reconstructed tree recovered Heleophryne as sister group to all other neobatrachians, the Australasian Lechriodus and the South American Calyptocephalella formed a clade that was the sister group to Nobleobatrachia, and the Seychellois Sooglossus was recovered as the sister group of Ranoides. We used relative-rate tests and direct comparison of branch lengths from mitochondrial and nuclear-based trees to demonstrate that both mitochondrial and nuclear evolutionary rates are significantly higher in all neobatrachians compared to their non-neobatrachian relatives, and that such rate acceleration started at the origin of Neobatrachia. Conclusions Through the analysis of the selection coefficient (ω in different branches of the tree, we found compelling evidence of relaxation of purifying selection in neobatrachians, which could (at least

  10. Accelerated evolutionary rates in tropical and oceanic parmelioid lichens (Ascomycota)

    Science.gov (United States)

    2008-01-01

    Background The rate of nucleotide substitutions is not constant across the Tree of Life, and departures from a molecular clock have been commonly reported. Within parmelioid lichens, the largest group of macrolichens, large discrepancies in branch lengths between clades were found in previous studies. Using an extended taxon sampling, we test for presence of significant rate discrepancies within and between these clades and test our a priori hypothesis that such rate discrepancies may be explained by shifts in moisture regime or other environmental conditions. Results In this paper, the first statistical evidence for accelerated evolutionary rate in lichenized ascomycetes is presented. Our results give clear evidence for a faster rate of evolution in two Hypotrachyna clades that includes species occurring in tropical and oceanic habitats in comparison with clades consisting of species occurring in semi-arid and temperate habitats. Further we explore potential links between evolutionary rates and shifts in habitat by comparing alternative Ornstein-Uhlenbeck models. Conclusion Although there was only weak support for a shift at the base of a second tropical clade, where the observed nucleotide substitution rate is high, overall support for a shift in environmental conditions at cladogenesis is very strong. This suggests that speciation in some lichen clades has proceeded by dispersal into a novel environment, followed by radiation within that environment. We found moderate support for a shift in moisture regime at the base of one tropical clade and a clade occurring in semi-arid regions and a shift in minimum temperature at the base of a boreal-temperate clade. PMID:18808710

  11. Accelerated evolutionary rates in tropical and oceanic parmelioid lichens (Ascomycota

    Directory of Open Access Journals (Sweden)

    Blanco Oscar

    2008-09-01

    Full Text Available Abstract Background The rate of nucleotide substitutions is not constant across the Tree of Life, and departures from a molecular clock have been commonly reported. Within parmelioid lichens, the largest group of macrolichens, large discrepancies in branch lengths between clades were found in previous studies. Using an extended taxon sampling, we test for presence of significant rate discrepancies within and between these clades and test our a priori hypothesis that such rate discrepancies may be explained by shifts in moisture regime or other environmental conditions. Results In this paper, the first statistical evidence for accelerated evolutionary rate in lichenized ascomycetes is presented. Our results give clear evidence for a faster rate of evolution in two Hypotrachyna clades that includes species occurring in tropical and oceanic habitats in comparison with clades consisting of species occurring in semi-arid and temperate habitats. Further we explore potential links between evolutionary rates and shifts in habitat by comparing alternative Ornstein-Uhlenbeck models. Conclusion Although there was only weak support for a shift at the base of a second tropical clade, where the observed nucleotide substitution rate is high, overall support for a shift in environmental conditions at cladogenesis is very strong. This suggests that speciation in some lichen clades has proceeded by dispersal into a novel environment, followed by radiation within that environment. We found moderate support for a shift in moisture regime at the base of one tropical clade and a clade occurring in semi-arid regions and a shift in minimum temperature at the base of a boreal-temperate clade.

  12. Concluding Remarks

    African Journals Online (AJOL)

    It is a great honor and pleasure to offer the concluding remarks for this issue of the Rwanda Journal of Medicine and. Health Sciences. The inaugural Global Innovations in Nursing and Midwifery Education, Research, and Practice conference held in Kigali earlier this year, and the resulting journal issue dedicated to nursing ...

  13. Changes in acceleration rate of chloride ions depending on climatic conditions. Influence of rain

    Directory of Open Access Journals (Sweden)

    Corvo, F.

    2003-12-01

    Full Text Available Mild steel, copper and aluminium samples were exposed outdoors in two atmospheric test stations located in Havana, Cuba and Medellín, Colombia. Two parallel group of samples were formed, one for each station. They were submitted to accelerated outdoor test by intermittent spraying of a salt solution (SCAB test according to ISO 11474:98, receiving also the influence of the open atmosphere. The acceleration of corrosion rate of the three metals caused by the presence of chloride ions in both stations was determined. As expected, steel shows the higher corrosion rate and acceleration by chlorides, particularly at Cuban corrosion station. A remarkable difference in the acceleration rate of chloride ions for mild steel and copper between Cuban and Colombian acceleration rate of chloride ions of steel and copper. Steel corrosion products were analyzed by Mössbauer Spectroscopy. Water absorption was also studied. The presence of magnetite, goethite and other Iron compounds was determined.

    Probetas de acero de bajo carbono, cobre y aluminio se expusieron a la intemperie en dos estaciones de ensayo localizadas en la Habana, Cuba y Medellín, Colombia. Se formaron dos grupos paralelos de probetas, tomándose uno para cada estación. Ambos grupos fueron sometidos a ensayos acelerados a la intemperie mediante la aplicación de una niebla salina (SCAB TEST de acuerdo a la Norma ISO 11474:98, recibiendo también la influencia de la atmósfera abierta. Se determinó la aceleración de la velocidad de corrosión de los tres metales causada por la presencia de iones cloruro en ambas estaciones. Como era de esperar, el acero muestra la mayor velocidad de corrosión y aceleración por los iones cloruro, particularmente en la estación de ensayos cubana. Se determinó una notable diferencia en la velocidad de aceleración provocada por los cloruros para el acero de bajo carbono y el cobre entre las estaciones cubana y colombiana. La influencia de la lluvia

  14. Asymmetric acceleration/deceleration dynamics in heart rate variability

    Science.gov (United States)

    Alvarez-Ramirez, J.; Echeverria, J. C.; Meraz, M.; Rodriguez, E.

    2017-08-01

    The heart rate variability (HRV) is an important physiological signal used either to assess the risk of cardiac death or to model the cardiovascular regulatory dynamics. Asymmetries in HRV data have been observed using 2D Poincare plots, which have been linked to a non-equilibrium operation of the cardiac autonomic system. This work further explores the presence of asymmetries but in the serial correlations of the dynamics of HRV data. To this end, detrended fluctuation analysis (DFA) was used to estimate the Hurst exponent both when the heart rate is accelerating and when it is decelerating. The analysis is conducted using data collected from subjects under normal sinus rhythm (NSR), congestive heart failure (CHF) and atrial fibrillation (AF) . For the NSR cases, it was found that correlations are stronger (p behavior was detected for the CHF and AF patients. Possible links between asymmetric correlations in the dynamics and the mechanisms controlling the operation of the heart rate are discussed, as well as their implications for modeling the cardiovascular regulatory dynamics.

  15. Concluding remarks

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, W.C.

    1996-04-01

    This section contains the concluding remarks of the workshop on rock mechanics issues in repository design and performance assessment. Technical issues such as spatial variability of rock properties, rock mass strength, measurement of loads, evaluation of long-term seal performance, and integration of data into design were discussed. Programmatic issues such as development of a coherent and consistent design methodology and implementation of that methodology were also reiterated.

  16. GPU accelerated processing of astronomical high frame-rate videosequences

    Science.gov (United States)

    Vítek, Stanislav; Švihlík, Jan; Krasula, Lukáš; Fliegel, Karel; Páta, Petr

    2015-09-01

    Astronomical instruments located around the world are producing an incredibly large amount of possibly interesting scientific data. Astronomical research is expanding into large and highly sensitive telescopes. Total volume of data rates per night of operations also increases with the quality and resolution of state-of-the-art CCD/CMOS detectors. Since many of the ground-based astronomical experiments are placed in remote locations with limited access to the Internet, it is necessary to solve the problem of the data storage. It mostly means that current data acquistion, processing and analyses algorithm require review. Decision about importance of the data has to be taken in very short time. This work deals with GPU accelerated processing of high frame-rate astronomical video-sequences, mostly originating from experiment MAIA (Meteor Automatic Imager and Analyser), an instrument primarily focused to observing of faint meteoric events with a high time resolution. The instrument with price bellow 2000 euro consists of image intensifier and gigabite ethernet camera running at 61 fps. With resolution better than VGA the system produces up to 2TB of scientifically valuable video data per night. Main goal of the paper is not to optimize any GPU algorithm, but to propose and evaluate parallel GPU algorithms able to process huge amount of video-sequences in order to delete all uninteresting data.

  17. Closing remarks

    Indian Academy of Sciences (India)

    2007-12-12

    Dec 12, 2007 ... in all the three regions worked very hard to bring out reports which discussed in great details the accelerator and detector designs as well as the physics potential of these machines [4]. Since these reports have come out, the process of globalisation, enunciated back in 1993, has now become a reality in ...

  18. Diffusive shock acceleration - Acceleration rate, magnetic-field direction and the diffusion limit

    Science.gov (United States)

    Jokipii, J. R.

    1992-01-01

    This paper reviews the concept of diffusive shock acceleration, showing that the acceleration of charged particles at a collisionless shock is a straightforward consequence of the standard cosmic-ray transport equation, provided that one treats the discontinuity at the shock correctly. This is true for arbitrary direction of the upstream magnetic field. Within this framework, it is shown that acceleration at perpendicular or quasi-perpendicular shocks is generally much faster than for parallel shocks. Paradoxically, it follows also that, for a simple scattering law, the acceleration is faster for less scattering or larger mean free path. Obviously, the mean free path can not become too large or the diffusion limit becomes inapplicable. Gradient and curvature drifts caused by the magnetic-field change at the shock play a major role in the acceleration process in most cases. Recent observations of the charge state of the anomalous component are shown to require the faster acceleration at the quasi-perpendicular solar-wind termination shock.

  19. Reaction mechanism of the acidic hydrolysis of highly twisted amides: Rate acceleration caused by the twist of the amide bond.

    Science.gov (United States)

    Mujika, Jon I; Formoso, Elena; Mercero, Jose M; Lopez, Xabier

    2006-08-03

    We present an ab initio study of the acid hydrolysis of a highly twisted amide and a planar amide analogue. The aim of these studies is to investigate the effect that the twist of the amide bond has on the reaction barriers and mechanism of acid hydrolysis. Concerted and stepwise mechanisms were investigated using density functional theory and polarizable continuum model calculations. Remarkable differences were observed between the mechanism of twisted and planar amide, due mainly to the preference for N-protonation of the former and O-protonation of the latter. In addition, we were also able to determine that the hydrolytic mechanism of the twisted amide will be pH dependent. Thus, there is a preference for a stepwise mechanism with formation of an intermediate in the acid hydrolysis, whereas the neutral hydrolysis undergoes a concerted-type mechanism. There is a nice agreement between the characterized intermediate and available X-ray data and a good agreement with the kinetically estimated rate acceleration of hydrolysis with respect to analogous undistorted amide compounds. This work, along with previous ab initio calculations, describes a complex and rich chemistry for the hydrolysis of highly twisted amides as a function of pH. The theoretical data provided will allow for a better understanding of the available kinetic data of the rate acceleration of amides upon twisting and the relation of the observed rate acceleration with intrinsic differential reactivity upon loss of amide bond resonance.

  20. Sodium diethyldithiocarbamate as accelerator of the rate of copper cementation

    Directory of Open Access Journals (Sweden)

    Abeer A. El-Saharty

    2015-12-01

    Full Text Available The effects of Cu2+ ion concentration and temperature on the cementation rate of copper from copper sulphate on zinc and the effect of additives of the organic compound “sodium diethyldithiocarbamate” (NaDDC were studied. It was noticed that the cementation increases significantly by increasing the concentrations of NaDDC. The rate of cementation increased by 58.58−100.31%. Our data showed that sodium diethyldithiocarbamate reacts with the Cu2+ solution giving a complex of copper diethyldithiocarbamate, which enhances the rate of cementation.

  1. Seven remarkable days

    CERN Multimedia

    This has been a truly remarkable seven days for CERN. Things have moved so fast that it has sometimes been hard to separate fact from fiction – all the more so since facts have often seemed too good to be true. It’s been a week of many firsts. Monday was the first time we’ve had two captured beams in the LHC. It’s the first time the LHC has functioned as a particle accelerator, boosting particles to the highest beam energy so far achieved at CERN. And it’s been a week in which we’ve seen the highest energy proton-proton collisions ever produced at CERN: our last hadron collider, the SPS was a proton-antiproton collider, a technically simpler machine than the LHC. This week’s successes are all the more remarkable precisely because of the complexity of the LHC. Unlike the SPS collider, it is two accelerators not one, making the job of commissioning nearly twice as difficult. I’d like to express my heartfelt thanks and congra...

  2. Increasing Calcium Oxide (Cao) to Accelerate Moulting and Survival Rate Vannamei Shrimp (Litopenaeus Vannamei))

    OpenAIRE

    Erlando, Gito; ', Rusliadi; Mulyadi,

    2016-01-01

    The research about the increasing Calcium Oxide (CaO) to accelerate moulting and survival rate vannamei shrimp (Litopenaeus vannamei) was conducted from Agustus until September 2015 at Balai Perikanan Budidaya Air Payau, Instalasi Pembenihan Udang (IPU) Gelung, Situbondo Provinsi Jawa Timur. The purpose of this research was to investigate optimum doses calcium oxide to accelerate moulting and the survival rate vannamei shrimp (Litopenaeus vannamei). Vannamei shrimp with size PL25 were used in...

  3. Polar organic solvents accelerate the rate of DNA strand replacement reaction.

    Science.gov (United States)

    Zhang, Tianchi; Shang, Chunli; Duan, Ruixue; Hakeem, Abdul; Zhang, Zhenyu; Lou, Xiaoding; Xia, Fan

    2015-03-21

    Herein, we report a novel strategy to accelerate the rate of DNA strand replacement reaction (DSRR) by polar organic solvents. DSRR plays a vital role in DNA nanotechnology but prolonged reaction time limits its further advancement. That is why it is extremely important to speed up the rate of DSRR. In this work, we introduce different polar organic solvents in both simple and complicated DSRR systems and observe that the rate constant is much more than in aqueous buffer. The rate acceleration of DSRR by polar organic solvents is very obvious and we believe that this strategy will extend the application of DNA nanotechnology in future.

  4. Increased rate of acceleration on Pine Island Glacier strongly coupled to changes in gravitational driving stress

    Directory of Open Access Journals (Sweden)

    J. B. T. Scott

    2009-05-01

    Full Text Available Pine Island Glacier, Antarctica, has been undergoing several related changes for at least two decades; these include acceleration, thinning and grounding line retreat. During the first major ground-based study between 2006 and 2008, GPS receivers were used to monitor ice flow from 55 km to 171 km inland, along the central flowline. At four sites both acceleration and thinning rates over the last two years exceeded rates observed at any other time over the last two decades. At the downstream site acceleration was 6.4% over 2007 and thinning was 3.5±0.5 ma−1. Acceleration and thinning have spread rapidly inland with the acceleration 171 km inland at 4.1% over 2007, greater than any measured annual flow increase along the whole glacier prior to 2006. Increases in surface slope, and hence gravitational driving stress, correlate well with the acceleration and no sustained change in longitudinal stress gradient is needed to explain the force balance. There is no indication that the glacier is approaching a new steady state.

  5. Is the strength of implicit alcohol associations correlated with alcohol-induced heart-rate acceleration?

    NARCIS (Netherlands)

    Wildenberg, E. van den; Beckers, M.; Lambaart, F. van; Conrod, P.; Wiers, R.W.H.J.

    2006-01-01

    Background: Heart rate (HR) acceleration during the ascending limb of the blood alcohol curve has proven to be a reliable measure of the sensitivity to the activating effects of alcohol. In this study, we investigated the correlation between an ethanol-induced cardiac change and the strength of

  6. DNA-based asymmetric catalysis : Sequence-dependent rate acceleration and enantioselectivity

    NARCIS (Netherlands)

    Boersma, Arnold J.; Klijn, Jaap E.; Feringa, Ben L.; Roelfes, Gerard

    2008-01-01

    This study shows that the role of DNA in the DNA-based enantioselective Diels-Alder reaction of azachalcone with cyclopentadiene is not limited to that of a chiral scaffold. DNA in combination with the copper complex of 4,4'-dimethyl-2,2'-bipyridine (Cu-L1) gives rise to a rate acceleration of up to

  7. Accelerated high-frame-rate mouse heart cine-MRI using compressed sensing reconstruction

    NARCIS (Netherlands)

    Motaal, Abdallah G.; Coolen, Bram F.; Abdurrachim, Desiree; Castro, Rui M.; Prompers, Jeanine J.; Florack, Luc M. J.; Nicolay, Klaas; Strijkers, Gustav J.

    2013-01-01

    We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensi ng reconstruction. Key to our

  8. Thresholds of sea-level rise rate and sea-level rise acceleration rate in a vulnerable coastal wetland.

    Science.gov (United States)

    Wu, Wei; Biber, Patrick; Bethel, Matthew

    2017-12-01

    Feedbacks among inundation, sediment trapping, and vegetation productivity help maintain coastal wetlands facing sea-level rise (SLR). However, when the SLR rate exceeds a threshold, coastal wetlands can collapse. Understanding the threshold helps address key challenges in ecology-nonlinear response of ecosystems to environmental change, promotes communication between ecologists and resource managers, and facilitates decision-making in climate change policies. We studied the threshold of SLR rate and developed a new threshold of SLR acceleration rate on sustainability of coastal wetlands as SLR is likely to accelerate due to enhanced anthropogenic forces. Deriving these two thresholds depends on the temporal scale, the interaction of SLR with other environmental factors, and landscape metrics, which have not been fully accounted for before this study. We chose a representative marine-dominated estuary in the northern Gulf of Mexico, Grand Bay in Mississippi, to test the concept of SLR thresholds. We developed a mechanistic model to simulate wetland change and then derived the SLR thresholds for Grand Bay. The model results show that the threshold of SLR rate in Grand Bay is 11.9 mm/year for 2050, and it drops to 8.4 mm/year for 2100 using total wetland area as a landscape metric. The corresponding SLR acceleration rate thresholds are 3.02 × 10-4 m/year2 and 9.62 × 10-5 m/year2 for 2050 and 2100, respectively. The newly developed SLR acceleration rate threshold can help quantify the temporal lag before the rapid decline in wetland area becomes evident after the SLR rate threshold is exceeded, and cumulative SLR a wetland can adapt to under the SLR acceleration scenarios. Based on the thresholds, SLR that will adversely impact the coastal wetlands in Grand Bay by 2100 will fall within the likely range of SLR under a high warming scenario (RCP8.5), highlighting the need to avoid RCP8.5 to preserve these marshes.

  9. Using Contact Forces and Robot Arm Accelerations to Automatically Rate Surgeon Skill at Peg Transfer.

    Science.gov (United States)

    Brown, Jeremy D; O Brien, Conor E; Leung, Sarah C; Dumon, Kristoffel R; Lee, David I; Kuchenbecker, Katherine J

    2017-09-01

    Most trainees begin learning robotic minimally invasive surgery by performing inanimate practice tasks with clinical robots such as the Intuitive Surgical da Vinci. Expert surgeons are commonly asked to evaluate these performances using standardized five-point rating scales, but doing such ratings is time consuming, tedious, and somewhat subjective. This paper presents an automatic skill evaluation system that analyzes only the contact force with the task materials, the broad-bandwidth accelerations of the robotic instruments and camera, and the task completion time. We recruited N = 38 participants of varying skill in robotic surgery to perform three trials of peg transfer with a da Vinci Standard robot instrumented with our Smart Task Board. After calibration, three individuals rated these trials on five domains of the Global Evaluative Assessment of Robotic Skill (GEARS) structured assessment tool, providing ground-truth labels for regression and classification machine learning algorithms that predict GEARS scores based on the recorded force, acceleration, and time signals. Both machine learning approaches produced scores on the reserved testing sets that were in good to excellent agreement with the human raters, even when the force information was not considered. Furthermore, regression predicted GEARS scores more accurately and efficiently than classification. A surgeon's skill at robotic peg transfer can be reliably rated via regression using features gathered from force, acceleration, and time sensors external to the robot. We expect improved trainee learning as a result of providing these automatic skill ratings during inanimate task practice on a surgical robot.

  10. GPU accelerated OCT processing at megahertz axial scan rate and high resolution video rate volumetric rendering

    Science.gov (United States)

    Jian, Yifan; Wong, Kevin; Sarunic, Marinko V.

    2013-03-01

    In this report, we describe how to highly optimize a CUDA based platform to perform real time optical coherence tomography data processing and 3D volumetric rendering using commercially-available cost-effective graphic processing units (GPUs). The maximum complete attainable axial scan processing rate (including memory transfer and rendering frame) was 2.2 megahertz for 16 bits pixel depth and 2048 pixels/A-scan, the maximum 3D volumetric rendering speed is 23 volumes/second (size:1024×256×200). To the best of our knowledge, this is the fastest processing rate reported to date with single-chip GPU and the first implementation of real time video rate volumetric OCT processing and rendering that is capable of matching the ultrahigh-speed OCT acquisition rates.

  11. Accelerated high-frame-rate mouse heart cine-MRI using compressed sensing reconstruction.

    Science.gov (United States)

    Motaal, Abdallah G; Coolen, Bram F; Abdurrachim, Desiree; Castro, Rui M; Prompers, Jeanine J; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

    2013-04-01

    We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensing reconstruction. Key to our approach is that we exploit the stochastic nature of the retrospective triggering acquisition scheme to produce an undersampled and random k-t space filling that allows for compressed sensing reconstruction and acceleration. As a standard, a self-gated FLASH sequence with a total acquisition time of 10 min was used to produce single-slice Cine movies of seven mouse hearts with 90 frames per cardiac cycle. Two times (2×) and three times (3×) k-t space undersampled Cine movies were produced from 2.5- and 1.5-min data acquisitions, respectively. The accelerated 90-frame Cine movies of mouse hearts were successfully reconstructed with a compressed sensing algorithm. The movies had high image quality and the undersampling artifacts were effectively removed. Left ventricular functional parameters, i.e. end-systolic and end-diastolic lumen surface areas and early-to-late filling rate ratio as a parameter to evaluate diastolic function, derived from the standard and accelerated Cine movies, were nearly identical. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Recent acceleration in coastal cliff retreat rates on the south coast of Great Britain.

    Science.gov (United States)

    Hurst, Martin D; Rood, Dylan H; Ellis, Michael A; Anderson, Robert S; Dornbusch, Uwe

    2016-11-22

    Rising sea levels and increased storminess are expected to accelerate the erosion of soft-cliff coastlines, threatening coastal infrastructure and livelihoods. To develop predictive models of future coastal change we need fundamentally to know how rapidly coasts have been eroding in the past, and to understand the driving mechanisms of coastal change. Direct observations of cliff retreat rarely extend beyond 150 y, during which humans have significantly modified the coastal system. Cliff retreat rates are unknown in prior centuries and millennia. In this study, we derived retreat rates of chalk cliffs on the south coast of Great Britain over millennial time scales by coupling high-precision cosmogenic radionuclide geochronology and rigorous numerical modeling. Measured (10)Be concentrations on rocky coastal platforms were compared with simulations of coastal evolution using a Monte Carlo approach to determine the most likely history of cliff retreat. The (10)Be concentrations are consistent with retreat rates of chalk cliffs that were relatively slow (2-6 cm⋅y(-1)) until a few hundred years ago. Historical observations reveal that retreat rates have subsequently accelerated by an order of magnitude (22-32 cm⋅y(-1)). We suggest that acceleration is the result of thinning of cliff-front beaches, exacerbated by regional storminess and anthropogenic modification of the coast.

  13. Error-Rate Estimation Based on Multi-Signal Flow Graph Model and Accelerated Radiation Tests.

    Directory of Open Access Journals (Sweden)

    Wei He

    Full Text Available A method of evaluating the single-event effect soft-error vulnerability of space instruments before launched has been an active research topic in recent years. In this paper, a multi-signal flow graph model is introduced to analyze the fault diagnosis and meantime to failure (MTTF for space instruments. A model for the system functional error rate (SFER is proposed. In addition, an experimental method and accelerated radiation testing system for a signal processing platform based on the field programmable gate array (FPGA is presented. Based on experimental results of different ions (O, Si, Cl, Ti under the HI-13 Tandem Accelerator, the SFER of the signal processing platform is approximately 10-3(error/particle/cm2, while the MTTF is approximately 110.7 h.

  14. Accelerated anaerobic hydrolysis rates under a combination of intermittent aeration and anaerobic conditions.

    Science.gov (United States)

    Jensen, T R; Lastra Milone, T; Petersen, G; Andersen, H R

    2017-04-01

    Anaerobic hydrolysis in activated return sludge was investigated in laboratory scale experiments to find if intermittent aeration would accelerate anaerobic hydrolysis rates compared to anaerobic hydrolysis rates under strict anaerobic conditions. The intermittent reactors were set up in a 240 h experiment with intermittent aeration (3 h:3 h) in a period of 24 h followed by a subsequent anaerobic period of 24 h in a cycle of 48 h which was repeated five times during the experiment. The anaerobic reactors were kept under strict anaerobic conditions in the same period (240 h). Two methods for calculating hydrolysis rates based on soluble chemical oxygen demand were compared. Two-way analysis of variance with the Bonferroni post-test was performed in order to register any significant difference between reactors with intermittent aeration and strictly anaerobic conditions respectively. The experiment demonstrated a statistically significant difference in favor of the reactors with intermittent aeration showing a tendency towards accelerated anaerobic hydrolysis rates due to application of intermittent aeration. The conclusion of the work is thus that intermittent aeration applied in the activated return sludge process can improve the treatment capacity further in full scale applications.

  15. Accelerating regional atrophy rates in the progression from normal aging to Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Sluimer, Jasper D. [VU University Medical Centre, Department of Diagnostic Radiology, Amsterdam (Netherlands); VU University Medical Centre, Alzheimer Centre, Amsterdam (Netherlands); VU University Medical Centre, Image Analysis Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Diagnostic Radiology and Alzheimer Centre, PO Box 7057, Amsterdam (Netherlands); Flier, Wiesje M. van der; Scheltens, Philip [VU University Medical Centre, Alzheimer Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Neurology, Amsterdam (Netherlands); Karas, Giorgos B.; Barkhof, Frederik [VU University Medical Centre, Department of Diagnostic Radiology, Amsterdam (Netherlands); VU University Medical Centre, Alzheimer Centre, Amsterdam (Netherlands); VU University Medical Centre, Image Analysis Centre, Amsterdam (Netherlands); Schijndel, Ronald van [VU University Medical Centre, Image Analysis Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Informatics, Amsterdam (Netherlands); Barnes, Josephine; Boyes, Richard G. [UCL, Institute of Neurology, Dementia Research Centre, London (United Kingdom); Cover, Keith S. [VU University Medical Centre, Department of Physics and Medical Technology, Amsterdam (Netherlands); Olabarriaga, Silvia D. [University of Amsterdam, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, Amsterdam (Netherlands); Fox, Nick C. [VU University Medical Centre, Department of Neurology, Amsterdam (Netherlands); UCL, Institute of Neurology, Dementia Research Centre, London (United Kingdom); Vrenken, Hugo [VU University Medical Centre, Alzheimer Centre, Amsterdam (Netherlands); VU University Medical Centre, Image Analysis Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Physics and Medical Technology, Amsterdam (Netherlands)

    2009-12-15

    We investigated progression of atrophy in vivo, in Alzheimer's disease (AD), and mild cognitive impairment (MCI). We included 64 patients with AD, 44 with MCI and 34 controls with serial MRI examinations (interval 1.8 {+-} 0.7 years). A nonlinear registration algorithm (fluid) was used to calculate atrophy rates in six regions: frontal, medial temporal, temporal (extramedial), parietal, occipital lobes and insular cortex. In MCI, the highest atrophy rate was observed in the medial temporal lobe, comparable with AD. AD patients showed even higher atrophy rates in the extramedial temporal lobe. Additionally, atrophy rates in frontal, parietal and occipital lobes were increased. Cox proportional hazard models showed that all regional atrophy rates predicted conversion to AD. Hazard ratios varied between 2.6 (95% confidence interval (CI) = 1.1-6.2) for occipital atrophy and 15.8 (95% CI = 3.5-71.8) for medial temporal lobe atrophy. In conclusion, atrophy spreads through the brain with development of AD. MCI is marked by temporal lobe atrophy. In AD, atrophy rate in the extramedial temporal lobe was even higher. Moreover, atrophy rates also accelerated in parietal, frontal, insular and occipital lobes. Finally, in nondemented elderly, medial temporal lobe atrophy was most predictive of progression to AD, demonstrating the involvement of this region in the development of AD. (orig.)

  16. Effect of strain and strain rate on fatigue-accelerated biodegradation of polyurethane.

    Science.gov (United States)

    Wiggins, Michael J; Anderson, James M; Hiltner, Anne

    2003-09-01

    A diaphragm-type film specimen was used to study in vitro degradation of poly(etherurethane urea) (PEUU) under conditions of dynamic loading. This geometry allowed both uniaxial and biaxial loading in a single experiment. During testing, the film was exposed to a H(2)O(2)/CoCl(2) solution that simulated in vivo oxidation of PEUU. The combination of dynamic loading and biaxial tensile strain accelerated oxidative degradation. The effects of biaxial strain magnitude and strain rate were examined separately by increasing the frequency of fatigue loading from 0 to 1 Hz with constant maximum biaxial strain and by changing the maximum biaxial strain while maintaining constant strain rate. In the ranges of biaxial strain energy (0.17 to 0.55 MPa) and strain rate (0 to 46% s(-1)) tested, the rate of degradation increased with increasing strain rate whereas strain magnitude had essentially no effect on degradation rate. Although loading conditions affected the rate of oxidative degradation, ATR-FTIR analysis suggested that in all cases the mechanism of degradation did not change. Chemical degradation produced a brittle crosslinked surface layer marked by dimpling and pitting, as observed with scanning electron microscopy. Pits served as stress concentrators and initiated environmental stress cracks under dynamic loading but not under static (creep) loading. Small pits were sufficient to initiate cracks at higher strain rates whereas only large pits initiated cracks at lower strain rates. Consequently, a higher strain rate produced more profuse cracking. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 463-475, 2003

  17. High repetition rate laser-driven MeV ion acceleration at variable background pressures

    Science.gov (United States)

    Snyder, Joseph; Ngirmang, Gregory; Orban, Chris; Feister, Scott; Morrison, John; Frische, Kyle; Chowdhury, Enam; Roquemore, W. M.

    2017-10-01

    Ultra-intense laser-plasma interactions (LPI) can produce highly energetic photons, electrons, and ions with numerous potential real-world applications. Many of these applications will require repeatable, high repetition targets that are suitable for LPI experiments. Liquid targets can meet many of these needs, but they typically require higher chamber pressure than is used for many low repetition rate experiments. The effect of background pressure on the LPI has not been thoroughly studied. With this in mind, the Extreme Light group at the Air Force Research Lab has carried out MeV ion and electron acceleration experiments at kHz repetition rate with background pressures ranging from 30 mTorr to >1 Torr using a submicron ethylene glycol liquid sheet target. We present these results and provide two-dimensional particle-in-cell simulation results that offer insight on the thresholds for the efficient acceleration of electrons and ions. This research is supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parra and Dr. Jean-Luc Cambier. Support was also provided by the DOD HPCMP Internship Program.

  18. Acceleration of the alcohol oxidation rate in rats with aloin, a quinone derivative of Aloe.

    Science.gov (United States)

    Chung, J H; Cheong, J C; Lee, J Y; Roh, H K; Cha, Y N

    1996-11-08

    Aloe contains abundant aloin, a C-glycoside derivative of anthraquinone. Based on recent reports indicating that the water extract of Aloe enhances the ethanol oxidation rate and also that quinones, in general, have a functional role in elevating the alcohol oxidation rate in vivo, we have attempted to identify the quinone derivative contained in Aloe that could increase the alcohol oxidation rate. Upon oral administration of aloin (300 mg/kg) given 12 hr prior to the administration of alcohol (3.0 g/kg), the blood alcohol area under the curve (AUC) was found to be decreased significantly (by 40%). This was supported by increases in the rates of blood alcohol elimination and the disappearance of alcohol from the body by 45 and 50%, respectively. Analysis of hepatic triglyceride (TG) levels revealed that both the ethanol and the aloin treatment alone significantly increased the TG levels in a comparable manner; however, the level obtained by the combined treatment of aloin and ethanol was not statistically different from that produced by either treatment alone. The levels of serum L-aspartate:2-oxoglutarate aminotransferase (AST) and L-alanine:2-oxoglutarate aminotransferase (ALT) activities were not increased by acute alcohol intoxication, aloin alone, or by the combined treatment of alcohol and aloin. Pretreatments with aloe-emodin, the anthraquinone aglycone of aloin, resulted in a significantly decreased blood alcohol AUC and an increase in the rate of ethanol disappearance. These results suggested that when the aloin localized primarily in the skin of Aloe is ingested, aloe-emodin (the quinone aglycone) may be released, and the released quinone may produce acceleration of the ethanol metabolism rate in vivo.

  19. Reduced withdrawal and failure rates of accelerated nursing students enrolled in pharmacology is associated with a supportive intervention.

    Science.gov (United States)

    Doggrell, Sheila Anne; Schaffer, Sally

    2016-02-01

    To reduce nursing shortages, accelerated nursing programs are available for domestic and international students. However, the withdrawal and failure rates from these programs may be different than for the traditional programs. The main aim of our study was to improve the retention and experience of accelerated nursing students. The academic background, age, withdrawal and failure rates of the accelerated and traditional students were determined. Data from 2009 and 2010 were collected prior to intervention. In an attempt to reduce the withdrawal of accelerated students, we set up an intervention, which was available to all students. The assessment of the intervention was a pre-post-test design with non-equivalent groups (the traditional and the accelerated students). The elements of the intervention were a) a formative website activity of some basic concepts in anatomy, physiology and pharmacology, b) a workshop addressing study skills and online resources, and c) resource lectures in anatomy/physiology and microbiology. The formative website and workshop was evaluated using questionnaires. The accelerated nursing students were five years older than the traditional students (p nursing students, than for traditional students who have undertaken first year courses in anatomy and physiology (p = 0.04 in 2010). The withdrawing students were predominantly the domestic students with non-university qualifications or equivalent experience. The failure rates were also higher for this group, compared to the traditional students (p = 0.05 in 2009 and 0.03 in 2010). In contrast, the withdrawal rates for the international and domestic graduate accelerated students were very low. After the intervention, the withdrawal and failure rates in pharmacology for domestic accelerated students with non-university qualifications were not significantly different than those of traditional students. The accelerated international and domestic graduate nursing students have low

  20. Optimization of Neutrino Rates from the EURISOL Beta-Beam Accelerator Complex

    CERN Document Server

    Wildner, E; Emelianenko, N; Fabich, A; Hancock, S; Lindroos, M

    2007-01-01

    The beta beam concept for the production of intense (anti-)neutrino beams is now well established. A baseline design has recently been published for a beta-beam facility at CERN. It has the virtue of respecting the known limitations of the CERN PS and SPS synchrotrons, but falls short of delivering the requested annual rate of neutrinos. We report on a first analysis to increase the rate using the baseline ions of 6He and 18 Ne. A powerful method to understand the functional dependence of the many parameters that influence the figure of merit for a given facility is available with modern analytical calculation software. The method requires that a symbolic analytical description is produced of the full accelerator chain. Such a description has been made using Mathematica for the proposed beta beam facility at CERN. The direct access from Mathematica to an ORACLE database for reading basic design parameters and re-injecting derived parameters for completion of the parameter list is both convenient and efficient...

  1. Effect of Heating Rate on Accelerated Carbide Spheroidisation (ASR in 100CrMnSi6-4 Bearing Steel

    Directory of Open Access Journals (Sweden)

    Hauserova D.

    2014-10-01

    Full Text Available Typical processing routes for bearing steels include a soft annealing stage, the purpose of which is to obtain a microstructure containing globular carbides in ferritic matrix. A newly developed process called ASR cuts the carbide spheroidisation times several fold, producing considerably finer globular carbides than conventional soft annealing. The present paper explores the effect of the heating rate and temperature on the accelerated carbide spheroidisation process and on the resulting hardness. Accelerated spheroidisation was achieved by thermal cycling for several minutes around various temperatures close to the transformation temperature at various heating rates applied by induction heating.

  2. Thermal hazard assessment of oxidizer solutions and emulsion explosives utilizing accelerating rate and Dewar calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.E.G.; Lightfoot, P.D.; Fouchard, R.C. [Natural Resources Canada, CANMET, Canadian Explosives Research Laboratory, Ottawa, ON (Canada)

    2002-07-01

    Accelerating rate calorimetry (ARC) and adiabatic Dewar calorimetric experiments were carried out on oxidizers used in the manufacture of emulsion explosives, their aqueous solutions, a bulk explosive matrix and a detonator-sensitive packaged explosive. The experiments were carried out in both closed and vented experimental configurations. The effects of water levels on the oxidizer solutions were investigated and the results obtained by using the two different techniques were compared. The Dewar experiments were found to yield a better direct estimation of bulk onset temperatures due to their greater sensitivity and lower 'phi factor'. Onset temperatures of oxidizer solutions measured using the Dewar calorimeter were found to be about 15 degrees C lower than those measured by ARC. Onset temperatures for the same oxidizer solution are lower for open systems than for closed systems. Results for emulsion explosives appeared complex, but indications are that oxidation of the oil phase in air is the first exothermic step in the runaway reaction. Whether this oxidation reaction can generate enough heat to drive the reaction to runaway, is not clear. Further elucidation of the complex exothermic reactions of emulsion explosives and their constituents, using both ARC and Dewar calorimetric techniques is recommended. 8 refs., 1 tab., 9 figs.

  3. Semiparametric accelerated failure time cure rate mixture models with competing risks.

    Science.gov (United States)

    Choi, Sangbum; Zhu, Liang; Huang, Xuelin

    2018-01-15

    Modern medical treatments have substantially improved survival rates for many chronic diseases and have generated considerable interest in developing cure fraction models for survival data with a non-ignorable cured proportion. Statistical analysis of such data may be further complicated by competing risks that involve multiple types of endpoints. Regression analysis of competing risks is typically undertaken via a proportional hazards model adapted on cause-specific hazard or subdistribution hazard. In this article, we propose an alternative approach that treats competing events as distinct outcomes in a mixture. We consider semiparametric accelerated failure time models for the cause-conditional survival function that are combined through a multinomial logistic model within the cure-mixture modeling framework. The cure-mixture approach to competing risks provides a means to determine the overall effect of a treatment and insights into how this treatment modifies the components of the mixture in the presence of a cure fraction. The regression and nonparametric parameters are estimated by a nonparametric kernel-based maximum likelihood estimation method. Variance estimation is achieved through resampling methods for the kernel-smoothed likelihood function. Simulation studies show that the procedures work well in practical settings. Application to a sarcoma study demonstrates the use of the proposed method for competing risk data with a cure fraction. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Rate acceleration of the heterogeneous reaction of ozone with a model alkene at the air-ice interface at low temperatures.

    Science.gov (United States)

    Ray, Debajyoti; Malongwe, Joseph K'Ekuboni; Klán, Petr

    2013-07-02

    The kinetics of the ozonation reaction of 1,1-diphenylethylene (DPE) on the surface of ice grains (also called "artificial snow"), produced by shock-freezing of DPE aqueous solutions or DPE vapor-deposition on pure ice grains, was studied in the temperature range of 268 to 188 K. A remarkable and unexpected increase in the apparent ozonation rates with decreasing temperature was evaluated using the Langmuir-Hinshelwood and Eley-Rideal kinetic models, and by estimating the apparent specific surface area of the ice grains. We suggest that an increase of the number of surface reactive sites, and possibly higher ozone uptake coefficients are responsible for the apparent rate acceleration of DPE ozonation at the air-ice interface at lower temperatures. The increasing number of reactive sites is probably related to the fact that organic molecules are displaced more to the top of a disordered interface (or quasi-liquid) layer on the ice surface, which makes them more accessible to the gas-phase reactants. The effect of NaCl as a cocontaminant on ozonation rates was also investigated. The environmental implications of this phenomenon for natural ice/snow are discussed. DPE was selected as an example of environmentally relevant species which can react with ozone. For typical atmospheric ozone concentrations in polar areas (20 ppbv), we estimated that its half-life on the ice surface would decrease from ∼5 days at 258 K to ∼13 h at 188 K at submonolayer DPE loadings.

  5. Accelerated forgetting? An evaluation on the use of long-term forgetting rates in patients with memory problems

    NARCIS (Netherlands)

    Geurts, S.; Werf, S.P. van der; Kessels, R.P.C.

    2015-01-01

    The main focus of this review was to evaluate whether long-term forgetting rates (delayed tests, days, to weeks, after initial learning) are more sensitive measures than standard delayed recall measures to detect memory problems in various patient groups. It has been suggested that accelerated

  6. The neurotransmitters serotonin and glutamate accelerate the heart rate of the mosquito Anopheles gambiae.

    Science.gov (United States)

    Hillyer, Julián F; Estévez-Lao, Tania Y; Mirzai, Homa E

    2015-10-01

    Serotonin and glutamate are neurotransmitters that in insects are involved in diverse physiological processes. Both serotonin and glutamate have been shown to modulate the physiology of the dorsal vessel of some insects, yet until the present study, their activity in mosquitoes remained unknown. To test whether serotonin or glutamate regulate dorsal vessel physiology in the African malaria mosquito, Anopheles gambiae, live mosquitoes were restrained, and a video of the contracting heart (the abdominal portion of the dorsal vessel) was acquired. These adult female mosquitoes were then injected with various amounts of serotonin, glutamate, or a control vehicle solution, and additional videos were acquired at 2 and 10 min post-treatment. Comparison of the videos taken before and after treatment revealed that serotonin accelerates the frequency of heart contractions, with the cardioacceleration being significantly more pronounced when the wave-like contractions of cardiac muscle propagate in the anterograde direction (toward the head). Comparison of the videos taken before and after treatment with glutamate revealed that this molecule is also cardioacceleratory. However, unlike serotonin, the activity of glutamate does not depend on whether the contractions propagate in the anterograde or the retrograde (toward the posterior of the abdomen) directions. Serotonin or glutamate induces a minor change or no change in the percentage of contractions and the percentage of the time that the heart contracts in the anterograde or the retrograde directions. In summary, this study shows that the neurotransmitters serotonin and glutamate increase the heart contraction rate of mosquitoes. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Validation of a High Sampling Rate Inertial Measurement Unit for Acceleration During Running.

    Science.gov (United States)

    Provot, Thomas; Chiementin, Xavier; Oudin, Emeric; Bolaers, Fabrice; Murer, Sébastien

    2017-08-25

    The musculo-skeletal response of athletes to various activities during training exercises has become a critical issue in order to optimize their performance and minimize injuries. However, dynamic and kinematic measures of an athlete's activity are generally limited by constraints in data collection and technology. Thus, the choice of reliable and accurate sensors is crucial for gathering data in indoor and outdoor conditions. The aim of this study is to validate the use of the accelerometer of a high sampling rate ( 1344 Hz ) Inertial Measurement Unit (IMU) in the frame of running activities. To this end, two validation protocols are imposed: a classical one on a shaker, followed by another one during running, the IMU being attached to a test subject. For each protocol, the response of the IMU Accelerometer (IMUA) is compared to a calibrated industrial accelerometer, considered as the gold standard for dynamic and kinematic data collection. The repeatability, impact of signal frequency and amplitude (on shaker) as well as the influence of speed (while running) are investigated. Results reveal that the IMUA exhibits good repeatability. Coefficient of Variation CV is 1 % 8.58 ± 0.06 m / s 2 on the shaker and 3 % 26.65 ± 0.69 m / s 2 while running. However, the shaker test shows that the IMUA is affected by the signal frequency (error exceeds 10 % beyond 80 Hz ), an observation confirmed by the running test. Nevertheless, the IMUA provides a reliable measure in the range 0-100 Hz, i.e., the most relevant part in the energy spectrum over the range 0-150 Hz during running. In our view, these findings emphasize the validity of IMUs for the measurement of acceleration during running.

  8. Generalized Temporal Acceleration Scheme for Kinetic Monte Carlo Simulations of Surface Catalytic Processes by Scaling the Rates of Fast Reactions.

    Science.gov (United States)

    Dybeck, Eric C; Plaisance, Craig P; Neurock, Matthew

    2017-04-11

    A novel algorithm is presented that achieves temporal acceleration during kinetic Monte Carlo (KMC) simulations of surface catalytic processes. This algorithm allows for the direct simulation of reaction networks containing kinetic processes occurring on vastly disparate time scales which computationally overburden standard KMC methods. Previously developed methods for temporal acceleration in KMC were designed for specific systems and often require a priori information from the user such as identifying the fast and slow processes. In the approach presented herein, quasi-equilibrated processes are identified automatically based on previous executions of the forward and reverse reactions. Temporal acceleration is achieved by automatically scaling the intrinsic rate constants of the quasi-equilibrated processes, bringing their rates closer to the time scales of the slow kinetically relevant nonequilibrated processes. All reactions are still simulated directly, although with modified rate constants. Abrupt changes in the underlying dynamics of the reaction network are identified during the simulation, and the reaction rate constants are rescaled accordingly. The algorithm was utilized here to model the Fischer-Tropsch synthesis reaction over ruthenium nanoparticles. This reaction network has multiple time-scale-disparate processes which would be intractable to simulate without the aid of temporal acceleration. The accelerated simulations are found to give reaction rates and selectivities indistinguishable from those calculated by an equivalent mean-field kinetic model. The computational savings of the algorithm can span many orders of magnitude in realistic systems, and the computational cost is not limited by the magnitude of the time scale disparity in the system processes. Furthermore, the algorithm has been designed in a generic fashion and can easily be applied to other surface catalytic processes of interest.

  9. Artificial photosynthesis: closing remarks.

    Science.gov (United States)

    Hammarström, Leif

    2017-06-02

    This paper derives from my closing remarks lecture at the 198th Faraday Discussion meeting on Artificial Photosynthesis, Kyoto, Japan, February 28-March 2. The meeting had sessions on biological approaches and fundamental processes, molecular catalysts, inorganic assembly catalysts, and integration of systems for demonstrating realistic devices. The field has had much progress since the previous Faraday Discussion on Artificial Photosynthesis in Edinburgh, UK, in 2011. This paper is a personal account of recent discussions and developments in the field, as reflected in and discussed during the meeting. First it discusses the general directions of artificial photosynthesis and some considerations for a future solar fuels technology. Then it comments on some scientific directions in the area of the meeting.

  10. Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-Gradient Accelerating Structures

    CERN Document Server

    Tecker, F; Kelisani, M; Doebert, S; Grudiev, A; Quirante, J; Riddone, G; Syratchev, I; Wuensch, W; Kononenko, O; Solodko, A; Lebet, S

    2013-01-01

    RF breakdown is a key issue for the multi-TeV highluminosity e+e- Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam.

  11. Thin liquid sheet target capabilities for ultra-intense laser acceleration of ions at a kHz repetition rate

    Science.gov (United States)

    Klim, Adam; Morrison, J. T.; Orban, C.; Feister, S.; Ngirmang, G. K.; Smith, J.; Frische, K.; Peterson, A. C.; Chowdhury, E. A.; Freeman, R. R.; Roquemore, W. M.

    2016-10-01

    The success of laser-accelerated ion experiments depends crucially on a number of factors including how thin the targets can be created. We present experimental results demonstrating extremely thin (under 200 nm) water sheet targets that can be used for ultra-intense laser-accelerated ion experiments conducted at the Air Force Research Laboratory at Wright-Patterson Air Force Base. Importantly, these experiments operate at a kHz repetition rate and the recovery time of the liquid targets is fast enough to allow the laser to interact with a refreshed, thin target on every shot. We present results from liquid water targets which are useful for proton acceleration experiments via the mechanism of Target Normal Sheath Acceleration (TNSA). In future work, we will create thin sheets from deuterated water in order to perform laser-accelerated deuteron experiments. This research was sponsored by the Quantum and Non-Equilibrium Processes Division of the AFOSR, under the management of Dr. Enrique Parra, and support from the DOD HPCMP Internship Program.

  12. Whole body periodic acceleration (pGz) preserves heart rate variability after cardiac arrest.

    Science.gov (United States)

    Adams, Jose A; Uryash, Arkady; Nadkarni, Vinay; Berg, Robert A; Lopez, Jose R

    2016-02-01

    Heart rate variability (HRV) is a measure of the balance between the sympathetic and parasympathetic autonomic nervous system and lack thereof an ominous sign in many cardiac and neurological conditions including post-cardiac arrest syndrome. Whole body periodic acceleration (pGz) has been shown to be cardio protective when applied prior to during and after cardiac arrest (CA). Here, we investigate whether or not pGz pre or post treatment after CA preserves HRV. Eight min of unsupported ventricular fibrillation followed by CPR and defibrillation was carried out in 32 anesthetized and paralyzed male swine who were randomized to pretreatment (1h pGz prior to CA, pre-pGz [n=8]) or post-treatment (pGz beginning at 30min after return of spontaneous circulation ([ROSC], post-pGz [n=8]) or none (CONT [n=8]). pGz was applied together with conventional mechanical ventilation. In a separate group (n=8), infusion of TRIM (nNOS inhibitor) was used to determine the effects of nNOS inhibition on HRV. Time and frequency domain measures of HRV were determined along with measurements of blood gases and hemodynamics, obtained at baseline and at 30, 60, 120 and 180min after ROSC. All animals had ROSC and there were no significant differences for arterial blood gases, mean blood pressure and coronary perfusion pressure after ROSC among the groups. HRV was significantly depressed after cardiac arrest and remained depressed in CONT group. In contrast, both pre and post pGz treated groups had significantly higher and preserved time domain measures of HRV (RMSSD and SDNN) from 60 to 180min after ROSC, and nNOS inhibition markedly reduced HRV. The frequency domain of HRV did not show changes. In a pig model of CA, pre or post treatment with pGz preserves HRV. Inhibition of nNOS markedly reduced HRV. Post-treatment with pGz is a novel therapeutic strategy that might serve as an adjunct to current pharmacological or hypothermia modalities to potentially improve outcomes from post

  13. Acceleration and deceleration capacity of fetal heart rate in an in-vivo sheep model.

    Directory of Open Access Journals (Sweden)

    Massimo W Rivolta

    Full Text Available BACKGROUND: Fetal heart rate (FHR variability is an indirect index of fetal autonomic nervous system (ANS integrity. FHR variability analysis in labor fails to detect early hypoxia and acidemia. Phase-rectified signal averaging (PRSA is a new method of complex biological signals analysis that is more resistant to non-stationarities, signal loss and artifacts. It quantifies the average cardiac acceleration and deceleration (AC/DC capacity. OBJECTIVE: The aims of the study were: (1 to investigate AC/DC in ovine fetuses exposed to acute hypoxic-acidemic insult; (2 to explore the relation between AC/DC and acid-base balance; and (3 to evaluate the influence of FHR decelerations and specific PRSA parameters on AC/DC computation. METHODS: Repetitive umbilical cord occlusions (UCOs were applied in 9 pregnant near-term sheep to obtain three phases of MILD, MODERATE, and SEVERE hypoxic-acidemic insult. Acid-base balance was sampled and fetal ECGs continuously recorded. AC/DC were calculated: (1 for a spectrum of T values (T = 1÷50 beats; the parameter limits the range of oscillations detected by PRSA; (2 on entire series of fetal RR intervals or on "stable" series that excluded FHR decelerations caused by UCOs. RESULTS: AC and DC progressively increased with UCOs phases (MILD vs. MODERATE and MODERATE vs. SEVERE, p<0.05 for DC [Formula: see text] = 2-5, and AC [Formula: see text] = 1-3. The time evolution of AC/DC correlated to acid-base balance (0.4<[Formula: see text]<0.9, p<0.05 with the highest [Formula: see text] for [Formula: see text]. PRSA was not independent from FHR decelerations caused by UCOs. CONCLUSIONS: This is the first in-vivo evaluation of PRSA on FHR analysis. In the presence of acute hypoxic-acidemia we found increasing values of AC/DC suggesting an activation of ANS. This correlation was strongest on time scale dominated by parasympathetic modulations. We identified the best performing [Formula: see text] parameters

  14. Setting accelerated dissolution test for PLGA microspheres containing peptide, investigation of critical parameters affecting drug release rate and mechanism.

    Science.gov (United States)

    Tomic, I; Vidis-Millward, A; Mueller-Zsigmondy, M; Cardot, J-M

    2016-05-30

    The objective of this study was development of accelerated in vitro release method for peptide loaded PLGA microspheres using flow-through apparatus and assessment of the effect of dissolution parameters (pH, temperature, medium composition) on drug release rate and mechanism. Accelerated release conditions were set as pH 2 and 45°C, in phosphate buffer saline (PBS) 0.02M. When the pH was changed from 2 to 4, diffusion controlled phases (burst and lag) were not affected, while release rate during erosion phase decreased two-fold due to slower ester bonds hydrolyses. Decreasing temperature from 45°C to 40°C, release rate showed three-fold deceleration without significant change in release mechanism. Effect of medium composition on drug release was tested in PBS 0.01M (200 mOsm/kg) and PBS 0.01M with glucose (380 mOsm/kg). Buffer concentration significantly affected drug release rate and mechanism due to the change in osmotic pressure, while ionic strength did not have any effect on peptide release. Furthermore, dialysis sac and sample-and-separate techniques were used, in order to evaluate significance of dissolution technique choice on the release process. After fitting obtained data to different mathematical models, flow-through method was confirmed as the most appropriate for accelerated in vitro dissolution testing for a given formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Concept for calculating dose rates from activated groundwater at accelerator sites

    CERN Document Server

    Prolingheuer, N; Vanderborght, J; Schlögl, B; Nabbi, R; Moormann, R

    Licensing of particle accelerators requires the proof that the groundwater outside of the site will not be significantly contaminated by activation products formed below accelerator and target. In order to reduce the effort for this proof, a site independent simplified but conservative method is under development. The conventional approach for calculation of activation of soil and groundwater is shortly described on example of a site close to Forschungszentrum Juelich, Germany. Additionally an updated overview of a data library for partition coefficients for relevant nuclides transported in the aquifer at the site is presented. The approximate model for transport of nuclides with ground water including exemplary results on nuclide concentrations outside of the site boundary and of resulting effective doses is described. Further applications and developments are finally outlined.

  16. Fetal heart rate accelerations and the risk of cerebral lesions and poor neurodevelopmental outcome in very low birthweight neonates.

    Science.gov (United States)

    Vlastos, Emanuel J; Tomlinson, Tracy M; Bildirici, Ibrahim; Sreenarasimhaiah, Sreedevi; Yusuf, Kamran; Sadovsky, Yoel; Levy, Roni

    2007-02-01

    The risk of intraventricular hemorrhage and periventricular leukomalacia correlates with fetal brain immaturity. Given that the appearance of fetal heart rate (FHR) accelerations is associated with brain maturation, we tested the hypothesis that neonatal cerebral lesions and developmental delay in very low birthweight newborns are associated with absent reactivity of the FHR tracing prior to delivery. We analyzed the FHR tracing of 97 fetuses with birthweight < 1200 g who underwent head ultrasound at day 3 and Bayley Scales of Infant Development testing at age 1 year. We used multivariate analysis to adjust for confounding variables. We found that the absence of two FHR accelerations of 10 beats per minute (bpm) for 10 seconds twice in a 20-minute window 1 hour before delivery was associated with intraventricular hemorrhage and/or periventricular leukomalacia ( P < 0.01) and a significant risk for mental and psychomotor delays by Bayley testing ( P < 0.001). The absence of accelerations of 15 bpm for 15 seconds was not associated with these abnormalities. The absence of FHR accelerations before delivery suggests a greater risk for cerebral injury and developmental delay in the very premature neonate.

  17. Lewis Acid Accelerated Aryl Ether Bond Cleavage with Nickel: Orders of Magnitude Rate Enhancement Using AlMe_3

    OpenAIRE

    Kelley, Paul; Edouard, Guy A.; Lin, Sibo; Agapie, Theodor

    2016-01-01

    Study of the kinetics of intramolecular aryl ether C−O bond cleavage by Ni was facilitated by access to a family of metal complexes supported by diphosphines with pendant aryl-methyl ethers. The nature of the aryl substituents was found to have little effect on the rate of cleavage. In contrast, soluble Lewis acidic additives accelerate the aryl ether cleavage dramatically. The effect of AlMe3 was studied in detail, and showed an increase in rate by several orders of magnitude. Low temperatur...

  18. Accelerated forgetting? An evaluation on the use of long-term forgetting rates in patients with memory problems

    Directory of Open Access Journals (Sweden)

    Sofie eGeurts

    2015-06-01

    Full Text Available The main focus of this review was to evaluate whether long-term forgetting rates (delayed tests days to weeks after initial learning are a more sensitive measure to detect memory problems in various patient groups than standard delayed recall measures. It has been suggested that accelerated forgetting might be characteristic for epilepsy patients, but little research has been performed within other populations. Here, we identified ten studies in a wide range of brain injured patient groups, whose long-term forgetting patterns were compared to that of healthy controls. Signs of accelerated forgetting were found within two studies. The results of seven studies showed normal forgetting over time for the patient groups. However, most of the studies used only a recognition procedure, after optimizing initial learning. Based on the results, we discuss recommendations for assessing long-term forgetting and the need for future research to truly evaluate the usefulness for clinical practice.

  19. Graphics processing unit accelerated optical coherence tomography processing at megahertz axial scan rate and high resolution video rate volumetric rendering.

    Science.gov (United States)

    Jian, Yifan; Wong, Kevin; Sarunic, Marinko V

    2013-02-01

    In this report, we describe how to highly optimize a computer unified device architecture based platform to perform real-time processing of optical coherence tomography interferometric data and three-dimensional (3-D) volumetric rendering using a commercially available, cost-effective, graphics processing unit (GPU). The maximum complete attainable axial scan processing rate, including memory transfer and displaying B-scan frame, was 2.24 MHz for 16 bits pixel depth and 2048 fast Fourier transform size; the maximum 3-D volumetric rendering rate, including B-scan, en face view display, and 3-D rendering, was ~23 volumes/second (volume size: 1024×256×200). To the best of our knowledge, this is the fastest processing rate reported to date with a single-chip GPU and the first implementation of real-time video-rate volumetric optical coherence tomography (OCT) processing and rendering that is capable of matching the acquisition rates of ultrahigh-speed OCT.

  20. Graphics processing unit accelerated optical coherence tomography processing at megahertz axial scan rate and high resolution video rate volumetric rendering

    Science.gov (United States)

    Jian, Yifan; Wong, Kevin; Sarunic, Marinko V.

    2013-02-01

    In this report, we describe how to highly optimize a computer unified device architecture based platform to perform real-time processing of optical coherence tomography interferometric data and three-dimensional (3-D) volumetric rendering using a commercially available, cost-effective, graphics processing unit (GPU). The maximum complete attainable axial scan processing rate, including memory transfer and displaying B-scan frame, was 2.24 MHz for 16 bits pixel depth and 2048 fast Fourier transform size; the maximum 3-D volumetric rendering rate, including B-scan, en face view display, and 3-D rendering, was ˜23 volumes/second (volume size: 1024×256×200). To the best of our knowledge, this is the fastest processing rate reported to date with a single-chip GPU and the first implementation of real-time video-rate volumetric optical coherence tomography (OCT) processing and rendering that is capable of matching the acquisition rates of ultrahigh-speed OCT.

  1. The Impact of Prematriculation Admission Characteristics on Graduation Rates in an Accelerated Doctor of Pharmacy Program

    Science.gov (United States)

    Morin, Anna K.

    2015-01-01

    Objective. To evaluate the impact of admission characteristics on graduation in an accelerated doctor of pharmacy (PharmD) program. Methods. Selected prematriculation characteristics of students entering the graduation class years of 2009-2012 on the Worcester and Manchester campuses of MCPHS University were analyzed and compared for on-time graduation. Results. Eighty-two percent of evaluated students (699 of 852) graduated on time. Students who were most likely to graduate on-time attended a 4-year school, previously earned a bachelor’s degree, had an overall prematriculation grade point average (GPA) greater than or equal to 3.6, and graduated in the spring just prior to matriculating to the university. Factors that reduced the likelihood of graduating on time were also identified. Work experience had a marginal impact on graduating on time. Conclusion. Although there is no certainty in college admission decisions, prematriculation characteristics can help predict the likelihood for academic success of students in an accelerated PharmD program. PMID:26689686

  2. The Impact of Prematriculation Admission Characteristics on Graduation Rates in an Accelerated Doctor of Pharmacy Program.

    Science.gov (United States)

    Steinberg, Michael; Morin, Anna K

    2015-10-25

    Objective. To evaluate the impact of admission characteristics on graduation in an accelerated doctor of pharmacy (PharmD) program. Methods. Selected prematriculation characteristics of students entering the graduation class years of 2009-2012 on the Worcester and Manchester campuses of MCPHS University were analyzed and compared for on-time graduation. Results. Eighty-two percent of evaluated students (699 of 852) graduated on time. Students who were most likely to graduate on-time attended a 4-year school, previously earned a bachelor's degree, had an overall prematriculation grade point average (GPA) greater than or equal to 3.6, and graduated in the spring just prior to matriculating to the university. Factors that reduced the likelihood of graduating on time were also identified. Work experience had a marginal impact on graduating on time. Conclusion. Although there is no certainty in college admission decisions, prematriculation characteristics can help predict the likelihood for academic success of students in an accelerated PharmD program.

  3. Terminal pathologies affect rates of decline to different extents and age accelerates the effects of terminal pathology on cognitive decline.

    Science.gov (United States)

    Rabbitt, Patrick; Lunn, Mary; Pendleton, Neil; Yardefagar, Ghasem

    2011-05-01

    To test whether different terminal pathologies are associated with different rates of age-related decline in fluid and crystallized mental abilities and whether pathology-associated declines are accelerated by age. During a 20-year longitudinal study, 6203 participants were quadrennially assessed on the Heim's (Heim, A 1970) The AH4 series of intelligence tests Slough, U.K.: NEP) AH4-1 and AH4-2 tests of fluid intelligence and on the Raven's (Raven, J. C. 1965) The Mill Hill Vocabulary Scale London: H.K. Lewis) Mill Hill A and B tests of recognition and production vocabulary. Dates and proximate causes of death were logged for 2499 participants. Multilevel modelling compared rates of decline after effects of sex, demographics, and practice were taken into consideration. Rates of cognitive decline markedly differed across pathologies, being most rapid for dementias and infections, slower for malignancies, and most prolonged for cardiovascular conditions. Pathologies were associated with faster declines in older individuals. After sex, age, and demographics have also been considered, different terminal pathologies are associated with markedly different rates of decline. Age accelerates pathology-related decline. This raises the further question as to whether any, or how much of, age-related cognitive decline is brought about by other causes than an increasing burden of pathologies.

  4. Insulin accelerates global and mitochondrial protein synthesis rates in neonatal muscle during sepsis

    Science.gov (United States)

    In neonatal pigs, sepsis decreases protein synthesis in skeletal muscle by decreasing translation initiation. However, insulin stimulates muscle protein synthesis despite persistent repression of translation initiation signaling. To determine whether the insulin-induced increase in global rates of m...

  5. CCAP and FMRFamide-like peptides accelerate the contraction rate of the antennal accessory pulsatile organs (auxiliary hearts) of mosquitoes.

    Science.gov (United States)

    Suggs, Julia M; Jones, Talitha H; Murphree, Steven C; Hillyer, Julián F

    2016-08-01

    Insects rely on specialized accessory pulsatile organs (APOs), also known as auxiliary hearts, to propel hemolymph into their antennae. In most insects, this is accomplished via the pulsations of a pair of ampulla located in the head, each of which propels hemolymph across an antenna via an antennal vessel. Once at the distal end of the appendage, hemolymph returns to the head via the antennal hemocoel. Although the structure of the antennal hearts has been elucidated in various insect orders, their hormonal modulation has only been studied in cockroaches and other hemimetabolous insects within the superorder Polyneoptera, where proctolin and FMRFamide-like peptides accelerate the contraction rate of these auxiliary hearts. Here, we assessed the hormonal modulation of the antennal APOs of mosquitoes, a group of holometabolous (Endopterygota) insects within the order Diptera. We show that crustacean cardioactive peptide (CCAP), FMRFamide and SALDKNFMRFamide increase the contraction rate of the antennal APOs and the heart of Anopheles gambiae Both antennal hearts are synchronously responsive to these neuropeptides, but their contractions are asynchronous with the contraction of the heart. Furthermore, we show that these neuropeptides increase the velocity and maximum acceleration of hemolymph within the antennal space, suggesting that each contraction is also more forceful. To our knowledge, this is the first report demonstrating that hormones of a holometabolous insect modulate the contraction dynamics of an auxiliary heart, and the first report that shows that the hormones of any insect accelerate the velocity of hemolymph in the antennal space. © 2016. Published by The Company of Biologists Ltd.

  6. Relict Mountain Permafrost Area (Loess Plateau, China) Exhibits High Ecosystem Respiration Rates and Accelerating Rates in Response to Warming

    Science.gov (United States)

    Mu, Cuicui; Wu, Xiaodong; Zhao, Qian; Smoak, Joseph M.; Yang, Yulong; Hu, Lian; Zhong, Wen; Liu, Guimin; Xu, Haiyan; Zhang, Tingjun

    2017-10-01

    Relict permafrost regions are characterized by thin permafrost and relatively high temperatures. Understanding the ecosystem respiration rate (ERR) and its relationship with soil hydrothermal conditions in these areas can provide knowledge regarding the permafrost carbon cycle in a warming world. In this study, we examined a permafrost area, a boundary area, and a seasonally frozen ground area within a relict permafrost region on the east edge of the Qinghai-Tibetan Plateau, China. Measurements from July 2015 to September 2016 showed that the mean annual ecosystem CO2 emissions for the boundary area were greater than the permafrost area. The Q10 value of the ERRs in the seasonally frozen ground area was greater than the permafrost area, indicating that the carbon emissions in the nonpermafrost areas were more sensitive to warming. The 1 year open-top chamber (OTC) warming increased soil temperatures in both the permafrost and seasonally frozen ground areas throughout the year, and the warming increased the ERRs by 1.18 (0.99-1.38, with interquartile range) and 1.13 (0.75-1.54, with interquartile range) μmol CO2 m-2 s-1 in permafrost and seasonally frozen ground areas, respectively. The OTC warming increased annual ERRs by approximately 50% for both permafrost and seasonally frozen ground areas with half the increase occurring during the nongrowing seasons. These results suggest that the ERRs in relict permafrost are high in comparison with arctic regions, and the carbon balance in relict permafrost areas could be greatly changed by climate warming.

  7. Lewis Acid Accelerated Aryl Ether Bond Cleavage with Nickel: Orders of Magnitude Rate Enhancement Using AlMe3.

    Science.gov (United States)

    Kelley, Paul; Edouard, Guy A; Lin, Sibo; Agapie, Theodor

    2016-11-21

    Study of the kinetics of intramolecular aryl ether C-O bond cleavage by Ni was facilitated by access to a family of metal complexes supported by diphosphines with pendant aryl-methyl ethers. The nature of the aryl substituents was found to have little effect on the rate of cleavage. In contrast, soluble Lewis acidic additives accelerate the aryl ether cleavage dramatically. The effect of AlMe3 was studied in detail, and showed an increase in rate by several orders of magnitude. Low temperature NMR spectroscopy studies demonstrate quantitative coordination of ether to Al. From the Lewis acid-bound precursor, the activation parameters for ether cleavage are significantly lower. These findings provide a mechanistic basis for milder catalyst design for the activation of strong bonds. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Accelerated crack growth rate at low Delta K in a single crystal superalloy

    Science.gov (United States)

    Telesman, Jack; Ghosn, Louis

    1988-01-01

    The low Delta K crack growth behavior of a single crystal of the PWA 1480 nickel-based superalloy was investigated. The crystal was tested in the near (100) orientation with the side faces being in the near (001) orientation. Although in the higher Delta K region the fatigue crack growth (FCG) behavior is rather normal, at Delta K of about 8 MPa sq rt m, a transition occurs where the FCG rate appears to be independent of Delta K. This region is found to continue until Delta K of about 2.5 MPa sq rt m, where the FCG rate again decreases with decreasing Delta K.

  9. Low-to-moderate nitrogen and phosphorus concentrations accelerate microbially driven litter breakdown rates

    Science.gov (United States)

    John S. Kominoski; Amy D. Rosemond; Jonathan P. Benstead; Vladislav Gulis; John C. Maerz; David Manning

    2015-01-01

    Particulate organic matter (POM) processing is an important driver of aquatic ecosystem productivity that is sensitive to nutrient enrichment and drives ecosystem carbon (C) loss. Although studies of single concentrations of nitrogen (N) or phosphorus (P) have shown effects at relatively low concentrations, responses of litter breakdown rates along gradients of low-to-...

  10. Accelerated anaerobic hydrolysis rates under a combination of intermittent aeration and anaerobic conditions

    DEFF Research Database (Denmark)

    Jensen, T. R.; Lastra Milone, T.; Petersen, G.

    2017-01-01

    for calculating hydrolysis rates based on soluble COD were compared. Two-way ANOVA with the Bonferroni post-test was performed in order to register any significant difference between reactors with intermittent aeration and strictly anaerobic conditions respectively. The experiment demonstrated a statistically...

  11. Ancient dates or accelerated rates? Morphological clocks and the antiquity of placental mammals.

    Science.gov (United States)

    Beck, Robin M D; Lee, Michael S Y

    2014-10-22

    Analyses of a comprehensive morphological character matrix of mammals using 'relaxed' clock models (which simultaneously estimate topology, divergence dates and evolutionary rates), either alone or in combination with an 8.5 kb nuclear sequence dataset, retrieve implausibly ancient, Late Jurassic-Early Cretaceous estimates for the initial diversification of Placentalia (crown-group Eutheria). These dates are much older than all recent molecular and palaeontological estimates. They are recovered using two very different clock models, and regardless of whether the tree topology is freely estimated or constrained using scaffolds to match the current consensus placental phylogeny. This raises the possibility that divergence dates have been overestimated in previous analyses that have applied such clock models to morphological and total evidence datasets. Enforcing additional age constraints on selected internal divergences results in only a slight reduction of the age of Placentalia. Constraining Placentalia to less than 93.8 Ma, congruent with recent molecular estimates, does not require major changes in morphological or molecular evolutionary rates. Even constraining Placentalia to less than 66 Ma to match the 'explosive' palaeontological model results in only a 10- to 20-fold increase in maximum evolutionary rate for morphology, and fivefold for molecules. The large discrepancies between clock- and fossil-based estimates for divergence dates might therefore be attributable to relatively small changes in evolutionary rates through time, although other explanations (such as overly simplistic models of morphological evolution) need to be investigated. Conversely, dates inferred using relaxed clock models (especially with discrete morphological data and MrBayes) should be treated cautiously, as relatively minor deviations in rate patterns can generate large effects on estimated divergence dates. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  12. UVB Exposure Does Not Accelerate Rates of Litter Decomposition in a Semiarid Riparian Ecosystem

    Science.gov (United States)

    Uselman, S. M.; Snyder, K. A.; Blank, R. R.; Jones, T. J.

    2010-12-01

    Aboveground litter decomposition is controlled mainly by substrate quality and climate factors across terrestrial ecosystems, but photodegradation from exposure to high-intensity ultraviolet-B (UVB) radiation may also be important in arid and semi-arid environments. We investigated the interactive effects of UVB exposure and litter quality on decomposition in a Tamarix-invaded riparian ecosystem during the establishment of an insect biological control agent in northern Nevada. Feeding by the northern tamarisk beetle (Diorhabda carinulata) on Tamarix spp. trees leads to altered leaf litter quality and increased exposure to solar UVB radiation from canopy opening. In addition, we examined the dynamics of litter decomposition of the invasive exotic Lepidium latifolium, because it is well-situated to invade beetle-infested Tamarix sites. Three leaf litter types (natural Tamarix, beetle-affected Tamarix, and L. latifolium) differing in substrate quality were decomposed in litterbags for one year in the field. Litterbags were subjected to one of three treatments: (1) Ambient UVB or (2) Reduced UVB (where UVB was manipulated by using clear plastic films that transmit or block UVB), and (3) No Cover (a control used to test for the effect of using the plastic films, i.e. a cover effect). Results showed a large cover effect on rates of decomposition and nutrient release, and our findings suggested that frequent cycles of freeze-thaw, and possibly rainfall intensity, influenced decomposition at this site. Contrary to our expectations, greater UVB exposure did not result in faster rates of decomposition. Greater UVB exposure resulted in decreased rates of decomposition and P release for the lower quality litter and no change in rates of decomposition and nutrient release for the two higher quality litter types, possibly due to a negative effect of UVB on soil microbes. Among litter types, rates of decomposition and net release of N and P followed this ranking: L. latifolium

  13. Cyclodextrin-based artificial oxidases with high rate accelerations and selectivity

    DEFF Research Database (Denmark)

    Zhou, You; Lindbäck, Emil Anders; Pedersen, Christian Marcus

    2014-01-01

    Three cyclodextrin derivatives with one to four 2-O-formylmethyl groups attached to the secondary rim were prepared and investigated as catalysts for the oxidation of aminophenols in buffered dilute hydrogen peroxide. The derivatives were found to be Michaelis-Menten catalysts and to give rate ac....... The ability of one of the new artificial enzymes to oxidize selectively one aminophenol from a mixture of two was investigated giving substrate selectivities of up to 16:1....

  14. Particle Rate and Host Accelerator Beam Loss on the MICE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dobbs, Adam James [Imperial College, London (United Kingdom)

    2011-10-01

    A study is presented of particle rates in the MICE Muon Beamline and their relationship to beam loss produced in ISIS. A brief overview of neutrino physics is presented, together with a discussion on the Neutrino Factory as a motivation for MICE. An overview of MICE itself is then presented, highlighting the need for a systematic understanding of the relationship between the MICE target parameters, ISIS beam loss, and MICE particle rate. The variation of beam loss with target depth is examined and observed to be non-linear. The variation of beam loss with respect to the target dip time in the ISIS cycle is examined and observed to be approximately linear for dip times between 11.1 ms and 12.6 ms after ISIS injection, before tailing at earlier dip times. The variation of beam loss with particle rate is also observed to follow an approximately linear relationship from 0.05 V.ms to 4.7 V.ms beam loss, with a further strong indication that this continues up to 7.1 V.ms. Particle identification using time-of-flight data is used to give an insight into the relative abundances of each particle species present in the MICE beam. Estimates of muon rate are then produced as a function of beam loss. At a level of 2 V.ms beam loss ~10.9 muons per spill for a 3.2 ms spill with negative π → μ optics, and ~31.1 muons per 1 ms spill with positive π → μ optics are observed. Simulations using the ORBIT particle tracking code of the beam loss distributions around the ISIS ring, caused by the MICE target, are also presented and the implications for MICE running discussed.

  15. The complete plastid genome sequence of Welwitschia mirabilis: an unusually compact plastome with accelerated divergence rates

    Directory of Open Access Journals (Sweden)

    Boore Jeffrey L

    2008-05-01

    Full Text Available Abstract Background Welwitschia mirabilis is the only extant member of the family Welwitschiaceae, one of three lineages of gnetophytes, an enigmatic group of gymnosperms variously allied with flowering plants or conifers. Limited sequence data and rapid divergence rates have precluded consensus on the evolutionary placement of gnetophytes based on molecular characters. Here we report on the first complete gnetophyte chloroplast genome sequence, from Welwitschia mirabilis, as well as analyses on divergence rates of protein-coding genes, comparisons of gene content and order, and phylogenetic implications. Results The chloroplast genome of Welwitschia mirabilis [GenBank: EU342371] is comprised of 119,726 base pairs and exhibits large and small single copy regions and two copies of the large inverted repeat (IR. Only 101 unique gene species are encoded. The Welwitschia plastome is the most compact photosynthetic land plant plastome sequenced to date; 66% of the sequence codes for product. The genome also exhibits a slightly expanded IR, a minimum of 9 inversions that modify gene order, and 19 genes that are lost or present as pseudogenes. Phylogenetic analyses, including one representative of each extant seed plant lineage and based on 57 concatenated protein-coding sequences, place Welwitschia at the base of all seed plants (distance, maximum parsimony or as the sister to Pinus (the only conifer representative in a monophyletic gymnosperm clade (maximum likelihood, bayesian. Relative rate tests on these gene sequences show the Welwitschia sequences to be evolving at faster rates than other seed plants. For these genes individually, a comparison of average pairwise distances indicates that relative divergence in Welwitschia ranges from amounts about equal to other seed plants to amounts almost three times greater than the average for non-gnetophyte seed plants. Conclusion Although the basic organization of the Welwitschia plastome is typical, its

  16. Dependence of neutron rate production with accelerator beam profile and energy range in an ADS-TRIGA RC1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Firoozabadi, M.M.; Karimi, J. [Birjand Univ. (Iran, Islamic Republic of). Dept. of Physics; Zangian, M. [Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Nuclear Engineering Dept.

    2016-12-15

    Lead, mercury, tantalum and tungsten were used as target material for calculation of spallation processes in an ADS-TRIGA RC1 reactor. The results show that tungsten has the highest neutron production rate. Therefore it was selected as target material for further calculations. The sensitivity of neutron parameters of the ADS reactor core relative to a change of beam profile and proton energy was determined. The core assembly and parameters of the TRIGA RC1 demonstration facility were used for the calculation model. By changing the proton energy from 115 to 1 400 MeV by using the intra-nuclear cascade model of Bertini (INC-Bertini), the quantity of the relative difference in % for energy gain (G) and spallation neutron yield (Y{sub n/p}), increases to 289.99 % and 5199.15 % respectively. These changes also reduce the amount of relative difference for the proton beam current (I{sub p}) and accelerator power (P{sub acc}), 99.81 % and 81.28 % respectively. In addition, the use of a Gaussian distribution instead of a uniform distribution in the accelerator beam profile increases the quantity of relative difference for energy gain (G), net neutron multiplication (M) and spallation neutron yield (Y{sub n/p}), up to 4.93 %, 4.9 % and 5.55 % respectively.

  17. Emission from accelerating jets in gamma-ray bursts: radiation-dominated flows with increasing mass outflow rates

    Science.gov (United States)

    Ryde, Felix; Lundman, Christoffer; Acuner, Zeynep

    2017-12-01

    We study the narrowest spectra expected from gamma-ray bursts. We present an analytical function for the spectrum that is emitted from the photosphere of a radiation-dominated flow that is under acceleration. This is the narrowest possible spectrum and it differs from a Planck function. We also present numerical spectra from photospheres occurring during the transition into the coasting phase of the flow. Using these spectral models, we reanalyse Fermi observations of GRB 100507 and GRB 101219, which both have been reported to have very narrow spectra. The bursts can be fitted by the spectral models: for GRB 101219 the spectrum is consistent with the photosphere occurring below or close to the saturation radius, while for GRB 100507 the photosphere position relative to the saturation radius can be determined as a function of time. In the latter case, we find that the photosphere initially occurs in the acceleration phase and thereafter transitions into the coasting phase. We also find that this transition occurs at the same time as the change in observed cooling behaviour: the temperature is close to constant before the break and decays after. We argue that such a transition can be explained by an increasing mass outflow rate. Both analysed bursts thus give strong evidence that the jets are (initially) radiation dominated.

  18. Experimental Platform for Ultra-high Dose Rate FLASH Irradiation of Small Animals Using a Clinical Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Schüler, Emil; Trovati, Stefania; King, Gregory; Lartey, Frederick; Rafat, Marjan; Villegas, Manuel; Praxel, A. Joe [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Loo, Billy W., E-mail: BWLoo@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Maxim, Peter G., E-mail: PMaxim@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States)

    2017-01-01

    Purpose: A key factor limiting the effectiveness of radiation therapy is normal tissue toxicity, and recent preclinical data have shown that ultra-high dose rate irradiation (>50 Gy/s, “FLASH”) potentially mitigates this effect. However, research in this field has been strongly limited by the availability of FLASH irradiators suitable for small animal experiments. We present a simple methodologic approach for FLASH electron small animal irradiation with a clinically available linear accelerator (LINAC). Methods and Materials: We investigated the FLASH irradiation potential of a Varian Clinac 21EX in both clinical mode and after tuning of the LINAC. We performed detailed FLUKA Monte Carlo and experimental dosimetric characterization at multiple experimental locations within the LINAC head. Results: Average dose rates of ≤74 Gy/s were achieved in clinical mode, and the dose rate after tuning exceeded 900 Gy/s. We obtained 220 Gy/s at 1-cm depth for a >4-cm field size with 90% homogeneity throughout a 2-cm-thick volume. Conclusions: We present an approach for using a clinical LINAC for FLASH irradiation. We obtained dose rates exceeding 200 Gy/s after simple tuning of the LINAC, with excellent dosimetric properties for small animal experiments. This will allow for increased availability of FLASH irradiation to the general research community.

  19. Do Higher 20th Century Sea-cliff Retreat Rates Necessarily Imply Recent Acceleration in Sea-cliff Retreat?

    Science.gov (United States)

    Mushkin, Amit; Katz, Oded; Porat, Naomi

    2017-04-01

    Inland retreat of sea cliffs in response to post LGM (last glacial maximum) sea-level rise is an ongoing process that affects coastal environments and communities worldwide. Here, we examine a globally recurring pattern where reported sea-cliff retreat rates since the 20th century often appear to exceed longer-term millennial-scale ('background') rates that rarely exceed 0.1 m/yr. Focusing on Israel's 30-km-long Mediterranean 'Sharon' sea-cliff as a case study we demonstrate that such apparent increase in rates may also reflect a widely acknowledged sampling bias in geologic rate estimates inferred from observation time windows ('OTW') shorter than process episodicity. We show that this possible bias leads to an ambiguity in conventional rate estimates obtained by averaging observed retreat distances over OTW, and that as a result despite ubiquitous and robust observations of cliff retreat since the 20th century (e.g., aerial photographs) recent/current retreat rates for many of the world's episodically retreating sea cliffs remain essentially unknown. To address this present limitation in our ability to detect and quantify recent changes in sea-cliff retreat rates we use airborne LiDAR to measure the continuous wave-driven volumetric erosion of collapsed material from the cliff base as an effective upper-bound constraint for the m/yr rate of episodic retreat of the cliff itself. We find that while conventional retreat rate estimates since the 20th century along the Sharon sea cliff artefactually increase up to several m/yr as an inverse function of OTW, the LiDAR-constrained retreat rates are not susceptible to this sampling bias, are comparable to the cliff's background retreat rate of 0.03-0.07 m/yr since the mid Holocene and thus indicate no recent acceleration in retreat. This ability to unambiguously constrain sea-cliff retreat rates with annual to decadal-scale observations directly impacts the global-scale push to quantify, better understand and ultimately

  20. Accelerating rate calorimetry study on the thermal stability of interpenetrating network type poly(siloxane-g-ethylene oxide) polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Bookeun; Hyung, Yoo-Eup; Vissers, Donald R.; Amine, Khalil

    2003-06-30

    Safety study regarding an exothermic reaction at elevated temperature of comb-shaped siloxane polymer and its interpenetrating network type solid polymer electrolyte (SPE) are investigated. Accelerating rate calorimetry (ARC) is used to examine exothermic reactions. The thermal stability of the polymer electrolyte in the presence of charged electrodes is also monitored. Resulting data were compared with those of 1.0 M LiPF{sub 6} in ethylene carbonate:ethyl methyl carbonate (3:7 by wt.) electrolyte. The self-heating exothermic reaction of mono comb-shaped siloxane polymer electrolyte starts at approximately 300 deg. C. Comparison of the heat generation profiles from ARC tests indicates that SPE reduces the intensity of exothermic reactions resulting from charged electrodes and electrolyte.

  1. Digital holographic interferometry accelerated with GPU: application in mechanical micro-deformation measurement operating at video rate

    Science.gov (United States)

    Múnera Ortiz, N.; Trujillo, C. A.; García-Sucerquia, J.

    2013-11-01

    The quantification of the deformations presented by mechanical parts is a useful tool for several applications in engineering; regularly this quantification is performed a posteriori. In this work, a digital holographic interferometer for measuring micro-deformation at video rate is presented. The interferometer is developed with the use of the parallel paradigm of CUDA™ (Compute Unified Device Architecture). A commercial Graphics Processor Unit (GPU) is used to accelerate phase processing from the recorded holograms. The proposed method can process record holograms of 1024x1024 pixels in 48 milliseconds. At the best performance of the method, it processes 21 frames per second (FPS). This benchmark surpasses 133-times the best performance of the method on a regular CPU.

  2. A dose verification tool for high-dose-rate interstitial brachytherapy treatment planning in accelerated partial breast irradiation.

    Science.gov (United States)

    Marqa, Mohamad Feras; Caudrelier, Jean-Michel; Betrouni, Nacim

    2012-01-01

    To develop a dose verification tool for high-dose-rate interstitial brachytherapy treatment planning in accelerated partial breast irradiation. We have developed a software tool for interstitial brachytherapy treatment planning assessment. The software contains a database of seven (192)Ir source models and is able to estimate the dose distribution using the Task Group 43 and the Sievert integral algorithms. Dose-volume histogram analysis and dose quality assurance (QA) criteria including conformity (COnformal INdex [COIN] and conformation number [CN]), homogeneity (homogeneity index [HI]) parameters were implemented in the software to evaluate and to compare between the doses estimated by the two algorithms and a dose extracted from an external treatment planning system (TPS). The tool was evaluated and validated on four clinical cases treated by high-dose-rate interstitial brachytherapy. The doses provided by the Task Group 43 and the Sievert integral algorithms were evaluated by establishing the dose-volume histogram analysis and then by calculating the QA criteria. The algorithms were validated by comparing the dose at different anatomic points with their corresponding dose points provided from TPS. The differences were considered in good agreement (within 5%). Pretreatment dose verification is an important step in the QA of brachytherapy accelerated partial breast irradiation. A simple, fast, and accurate method of dose verification is therefore needed. The software proposed in this study could fulfill these requirements. In addition, it is freely available for using by anyone wishing to do a QA on any TPS. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  3. Accelerated Growth Rate and Increased Drought Stress Resilience of the Model Grass Brachypodium distachyon Colonized by Bacillus subtilis B26.

    Directory of Open Access Journals (Sweden)

    François Gagné-Bourque

    Full Text Available Plant growth-promoting bacteria (PGB induce positive effects in plants, for instance, increased growth and reduced abiotic stresses susceptibility. The mechanisms by which these bacteria impact the host plant are numerous, diverse and often specific. Here, we studied the agronomical, molecular and biochemical effects of the endophytic PGB Bacillus subtilis B26 on the full life cycle of Brachypodium distachyon Bd21, an established model species for functional genomics in cereal crops and temperate grasses. Inoculation of Brachypodium with B. subtilis strain B26 increased root and shoot weights, accelerated growth rate and seed yield as compared to control plants. B. subtilis strain B26 efficiently colonized the plant and was recovered from roots, stems and blades as well as seeds of Brachypodium, indicating that the bacterium is able to migrate, spread systemically inside the plant, establish itself in the aerial plant tissues and organs, and is vertically transmitted to seeds. The presence of B. subtilis strain B26 in the seed led to systemic colonization of the next generation of Brachypodium plants. Inoculated Brachypodium seedlings and mature plants exposed to acute and chronic drought stress minimized the phenotypic effect of drought compared to plants not harbouring the bacterium. Protection from the inhibitory effects of drought by the bacterium was linked to upregulation of the drought-response genes, DREB2B-like, DHN3-like and LEA-14-A-like and modulation of the DNA methylation genes, MET1B-like, CMT3-like and DRM2-like, that regulate the process. Additionally, total soluble sugars and starch contents increased in stressed inoculated plants, a biochemical indication of drought tolerance. In conclusion, we show a single inoculation of Brachypodium with a PGB affected the whole growth cycle of the plant, accelerating its growth rates, shortening its vegetative period, and alleviating drought stress effects. These effects are relevant to

  4. Application of Overall Dynamic Body Acceleration as a Proxy for Estimating the Energy Expenditure of Grazing Farm Animals: Relationship with Heart Rate

    Science.gov (United States)

    Miwa, Masafumi; Oishi, Kazato; Nakagawa, Yasuhiro; Maeno, Hiromichi; Anzai, Hiroki; Kumagai, Hajime; Okano, Kanji; Tobioka, Hisaya; Hirooka, Hiroyuki

    2015-01-01

    Estimating the energy expenditure of farm animals at pasture is important for efficient animal management. In recent years, an alternative technique for estimating energy expenditure by measuring body acceleration has been widely performed in wildlife and human studies, but the availability of the technique in farm animals has not yet been examined. In the present study, we tested the potential use of an acceleration index, overall dynamic body acceleration (ODBA), as a new proxy for estimating the energy expenditure of grazing farm animals (cattle, goats and sheep) at pasture with the simultaneous evaluation of a conventional proxy, heart rate. Body accelerations in three axes and heart rate for cows (n = 8, two breeds), goats (n = 6) and sheep (n = 5) were recorded, and the effect of ODBA calculated from the body accelerations on heart rate was analyzed. In addition, the effects of the two other activity indices, the number of steps and vectorial dynamic body acceleration (VeDBA), on heart rate were also investigated. The results of the comparison among three activity indices indicated that ODBA was the best predictor for heart rate. Although the relationship between ODBA and heart rate was different between the groups of species and breeds and between individuals (Pweights; a common equation could be established by correcting the body weights (M: kg): heart rate (beats/min) = 147.263∙M-0.141 + 889.640∙M-0.179∙ODBA (g). Combining this equation with the previously reported energy expenditure per heartbeat, we estimated the energy expenditure of the tested animals, and the results indicated that ODBA is a good proxy for estimating the energy expenditure of grazing farm animals across species and breeds. The utility and simplicity of the procedure with acceleration loggers could make the accelerometry technique a worthwhile option in field research and commercial farm use. PMID:26030931

  5. Monte Carlo dose calculations for high-dose-rate brachytherapy using GPU-accelerated processing.

    Science.gov (United States)

    Tian, Z; Zhang, M; Hrycushko, B; Albuquerque, K; Jiang, S B; Jia, X

    2016-01-01

    Current clinical brachytherapy dose calculations are typically based on the Association of American Physicists in Medicine Task Group report 43 (TG-43) guidelines, which approximate patient geometry as an infinitely large water phantom. This ignores patient and applicator geometries and heterogeneities, causing dosimetric errors. Although Monte Carlo (MC) dose calculation is commonly recognized as the most accurate method, its associated long computational time is a major bottleneck for routine clinical applications. This article presents our recent developments of a fast MC dose calculation package for high-dose-rate (HDR) brachytherapy, gBMC, built on a graphics processing unit (GPU) platform. gBMC-simulated photon transport in voxelized geometry with physics in (192)Ir HDR brachytherapy energy range considered. A phase-space file was used as a source model. GPU-based parallel computation was used to simultaneously transport multiple photons, one on a GPU thread. We validated gBMC by comparing the dose calculation results in water with that computed TG-43. We also studied heterogeneous phantom cases and a patient case and compared gBMC results with Acuros BV results. Radial dose function in water calculated by gBMC showed GPU-based MC dose calculation package, gBMC, for HDR brachytherapy make it attractive for clinical applications. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  6. Effect of predictive sign of acceleration on heart rate variability in passive translation situation: preliminary evidence using visual and vestibular stimuli in VR environment

    Directory of Open Access Journals (Sweden)

    Watanabe Hiroshi

    2007-09-01

    Full Text Available Abstract Objective We studied the effects of the presentation of a visual sign that warned subjects of acceleration around the yaw and pitch axes in virtual reality (VR on their heart rate variability. Methods Synchronization of the immersive virtual reality equipment (CAVE and motion base system generated a driving scene and provided subjects with dynamic and wide-ranging depth information and vestibular input. The heart rate variability of 21 subjects was measured while the subjects observed a simulated driving scene for 16 minutes under three different conditions. Results When the predictive sign of the acceleration appeared 3500 ms before the acceleration, the index of the activity of the autonomic nervous system (low/high frequency ratio; LF/HF ratio of subjects did not change much, whereas when no sign appeared the LF/HF ratio increased over the observation time. When the predictive sign of the acceleration appeared 750 ms before the acceleration, no systematic change occurred. Conclusion The visual sign which informed subjects of the acceleration affected the activity of the autonomic nervous system when it appeared long enough before the acceleration. Also, our results showed the importance of the interval between the sign and the event and the relationship between the gradual representation of events and their quantity.

  7. Effect of predictive sign of acceleration on heart rate variability in passive translation situation: preliminary evidence using visual and vestibular stimuli in VR environment.

    Science.gov (United States)

    Watanabe, Hiroshi; Teramoto, Wataru; Umemura, Hiroyuki

    2007-09-29

    We studied the effects of the presentation of a visual sign that warned subjects of acceleration around the yaw and pitch axes in virtual reality (VR) on their heart rate variability. Synchronization of the immersive virtual reality equipment (CAVE) and motion base system generated a driving scene and provided subjects with dynamic and wide-ranging depth information and vestibular input. The heart rate variability of 21 subjects was measured while the subjects observed a simulated driving scene for 16 minutes under three different conditions. When the predictive sign of the acceleration appeared 3500 ms before the acceleration, the index of the activity of the autonomic nervous system (low/high frequency ratio; LF/HF ratio) of subjects did not change much, whereas when no sign appeared the LF/HF ratio increased over the observation time. When the predictive sign of the acceleration appeared 750 ms before the acceleration, no systematic change occurred. The visual sign which informed subjects of the acceleration affected the activity of the autonomic nervous system when it appeared long enough before the acceleration. Also, our results showed the importance of the interval between the sign and the event and the relationship between the gradual representation of events and their quantity.

  8. Editorial - a remark you made

    OpenAIRE

    Yngve Nordkvelle

    2007-01-01

    ”A remark you made” is the title of a wonderful tune by the famous jazz-rock group “Weather Report”, issued on the influential “Heavy weather” LP some 30 years ago. In an age where planning and rationalizing is the main issue in most contexts, whether it’s a matter of studying, teaching, doing research or using a diet, “A remark you made” is a symbol of attending to the unplanned, unforeseen and often, unwanted. In most accounts on cognitive development one is overtly focused on the manageabl...

  9. Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase

    Directory of Open Access Journals (Sweden)

    Martínez-Valencia María Asunción

    2015-06-01

    Full Text Available Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak, a peak rate of force development (RFDpeak and time to RFD (TRFD in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001 in sprint times (20 and 30 m sprint for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s−1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s−1, p ≤ 0.01. Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.

  10. Ivabradine Prevents Heart Rate Acceleration in Patients with Chronic Obstructive Pulmonary Disease and Coronary Heart Disease after Salbutamol Inhalation

    Directory of Open Access Journals (Sweden)

    Uta C. Hoppe

    2012-04-01

    Full Text Available Accelerated sinus rhythm is an important side effect of inhaled salbutamol which is especially harmful in patients with chronic obstructive pulmonary disease (COPD and coronary heart disease (CHD. Cross-over, randomized, open label study design. 20 patients (18 males and two females with COPD stage II–IV and comorbide CHD NYHA class I–III were included. Spirometry with 400 mg salbutamol inhalation was performed at two consecutive days of the study. Patients in group I were prescribed 5 mg ivabradine per os 3 h before salbutamol inhalation solely on the first day of the study and patients of group II received 5 mg ivabradine only on the second day of the study. Salbutamol caused a significant increase of HR by 5.5 bpm (95% CI 0.8; 10.2, p < 0.03. After ivabradine ingestion salbutamol did not change HR significantly by −2.4 bpm (−7.0; 2.3, p = 0.33. The attenuation of HR elevation by ivabradine was significant, p < 0.01. Salbutamol alone increased FEV1 by 6.0% (2.7; 9.3, p < 0.01. This effect was not impaired by ivabradine (FEV1 increase by 7.7% (2.8; 12.6, p < 0.01 versus baseline, p = 0.5 versus no ivabradine. Ivabradine 5 mg per os prevents heart rate acceleration after inhalation of 400 mg salbutamol. Ivabradine has no impact on lung function in patients with moderate-to-very-severe COPD and CHD comorbidity.

  11. Oscillations and accelerations of ice crystal growth rates in microgravity in presence of antifreeze glycoprotein impurity in supercooled water

    Science.gov (United States)

    Furukawa, Yoshinori; Nagashima, Ken; Nakatsubo, Shun-Ichi; Yoshizaki, Izumi; Tamaru, Haruka; Shimaoka, Taro; Sone, Takehiko; Yokoyama, Etsuro; Zepeda, Salvador; Terasawa, Takanori; Asakawa, Harutoshi; Murata, Ken-Ichiro; Sazaki, Gen

    2017-03-01

    The free growth of ice crystals in supercooled bulk water containing an impurity of glycoprotein, a bio-macromolecule that functions as ‘antifreeze’ in living organisms in a subzero environment, was observed under microgravity conditions on the International Space Station. We observed the acceleration and oscillation of the normal growth rates as a result of the interfacial adsorption of these protein molecules, which is a newly discovered impurity effect for crystal growth. As the convection caused by gravity may mitigate or modify this effect, secure observations of this effect were first made possible by continuous measurements of normal growth rates under long-term microgravity condition realized only in the spacecraft. Our findings will lead to a better understanding of a novel kinetic process for growth oscillation in relation to growth promotion due to the adsorption of protein molecules and will shed light on the role that crystal growth kinetics has in the onset of the mysterious antifreeze effect in living organisms, namely, how this protein may prevent fish freezing.

  12. Remarks on the clump theory

    Energy Technology Data Exchange (ETDEWEB)

    Krommes, J.A.

    1986-07-01

    Further details are provided of a soon-to-be published dialog (Phys. Fluids 29 (July, 1986)) which discussed the role of the small scales in fluid clump theory. It is argued that the approximation of the clump lifetime which is compatible with exponentially rapid separation of adjacent orbits is inappropriate for the description of the dynamically important large scales. Various other remarks are made relating to the analytic treatment of strong drift-wave-like turbulence.

  13. Self-accelerating sulfur reduction via polysulfide to realize a high-rate sulfidogenic reactor for wastewater treatment.

    Science.gov (United States)

    Zhang, Liang; Zhang, Zefeng; Sun, Rongrong; Liang, Shuang; Chen, Guang-Hao; Jiang, Feng

    2017-11-28

    Sulfur reduction is a promising alternative to sulfate reduction as it can generate sulfide at a low cost for the precipitation of heavy metals or autotrophic denitrification in wastewater treatment. However, the extremely low water solubility of elemental sulfur limits its bioavailability and results in a low sulfur-reduction rate. Polysulfide, which is naturally generated through reactions between sulfur and sulfide, can enhance the bioavailability of sulfur and thus contribute to high-rate sulfur reduction. Based on this principle, a laboratory-scale sulfur-reducing bioreactor was designed in this study for wastewater treatment. After 164 days of operation, the sulfide production rate (SPR) in the bioreactor reached 126 mg S/L-h, which is significantly higher than those of other sulfate-reducing systems. Moreover, dissolved zero-valent sulfur (referred to as polysulfide) was detected in the sulfur-reducing reactor when the organics were completely depleted, indicating that polysulfide can form naturally and be readily reduced to sulfide in the bioreactor. We found that the produced sulfide promoted the formation of more polysulfide, which enabled a self-accelerating chain reaction of sulfur reduction via polysulfide. This stimulation effect was further validated by the 7-h batch tests. In the batch test without sulfide addition initially, a continuous increase in the hourly SPR was observed with increasing sulfide concentration. Furthermore, in the batch tests with the addition of 50-200 mg S/L sulfide at the beginning, the average SPR in the first 3 h increased with elevating initial sulfide concentration due to more polysulfide formation and reduction. However, high sulfide concentration (>250 mg S/L) hindered the continuous increase in SPR. Additionally, when polysulfide formation was prevented through the addition of Fe2+, the SPR dropped by 97.6% compared to that in the presence of polysulfide. This validates the key role of polysulfide in the high-rate

  14. Accelerating Rate Calorimetry Tests of Lithium-Ion Cells Before and After Storage Degradation at High Temperature

    Directory of Open Access Journals (Sweden)

    Mendoza-Hernandez Omar Samuel

    2017-01-01

    Full Text Available Understanding the behavior of Li-ion cells during thermal runaway is critical to evaluate the safety of these energy storage devices under outstanding conditions. Li-ion cells possess a high energy density and are used to store and supply energy to many aerospace applications. Incidents related to the overheating or thermal runaway of these cells can cause catastrophic damages that could end up costly space missions; therefore, thermal studies of Li-ion cells are very important for ensuring safety and reliability of space missions. This work evaluates the thermal behavior of Li-ion cells before and after storage degradation at high temperature using accelerating rate calorimeter (ARC equipment to analyze the thermal behavior of Li-ion cells under adiabatic conditions. Onset temperature points of self-heating and thermal runaway reactions are obtained. The onset points are used to identify non-self-heating, self-heating and thermal runaway regions as a function of state of charge. The results obtained can be useful to develop accurate thermo-electrochemical models of Li-ion cells.

  15. Experience-dependent enhancement of pitch-specific responses in the auditory cortex is limited to acceleration rates in normal voice range.

    Science.gov (United States)

    Krishnan, A; Gandour, J T; Suresh, C H

    2015-09-10

    The aim of this study is to determine how pitch acceleration rates within and outside the normal pitch range may influence latency and amplitude of cortical pitch-specific responses (CPR) as a function of language experience (Chinese, English). Responses were elicited from a set of four pitch stimuli chosen to represent a range of acceleration rates (two each inside and outside the normal voice range) imposed on the high rising Mandarin Tone 2. Pitch-relevant neural activity, as reflected in the latency and amplitude of scalp-recorded CPR components, varied depending on language-experience and pitch acceleration of dynamic, time-varying pitch contours. Peak latencies of CPR components were shorter in the Chinese than the English group across stimuli. Chinese participants showed greater amplitude than English for CPR components at both frontocentral and temporal electrode sites in response to pitch contours with acceleration rates inside the normal voice pitch range as compared to pitch contours with acceleration rates that exceed the normal range. As indexed by CPR amplitude at the temporal sites, a rightward asymmetry was observed for the Chinese group only. Only over the right temporal site was amplitude greater in the Chinese group relative to the English. These findings may suggest that the neural mechanism(s) underlying processing of pitch in the right auditory cortex reflect experience-dependent modulation of sensitivity to acceleration in just those rising pitch contours that fall within the bounds of one's native language. More broadly, enhancement of native pitch stimuli and stronger rightward asymmetry of CPR components in the Chinese group is consistent with the notion that long-term experience shapes adaptive, distributed hierarchical pitch processing in the auditory cortex, and reflects an interaction with higher order, extrasensory processes beyond the sensory memory trace. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Rotational IMRT delivery using a digital linear accelerator in very high dose rate 'burst mode'

    Energy Technology Data Exchange (ETDEWEB)

    Salter, Bill J; Sarkar, Vikren; Wang, Brian; Szegedi, Martin; Rassiah-Szegedi, Prema [Department of Radiation Oncology, University of Utah, Salt Lake City, UT (United States); Shukla, Himanshu, E-mail: bill.salter@hci.utah.edu [Oncology Care Systems Group, Siemens Medical Solutions (USA), 4040 Nelson Avenue, Concord, CA (United States)

    2011-04-07

    Recently, there has been a resurgence of interest in arc-based IMRT, through the use of 'conventional' multileaf collimator (MLC) systems that can treat large tumor volumes in a single, or very few pass(es) of the gantry. Here we present a novel 'burst mode' modulated arc delivery approach, wherein 2000 monitor units per minute (MU min{sup -1}) high dose rate bursts of dose are facilitated by a flattening-filter-free treatment beam on a Siemens Artiste (Oncology Care Systems, Siemens Medical Solutions, Concord, CA, USA) digital linear accelerator in a non-clinical configuration. Burst mode delivery differs from continuous mode delivery, used by Elekta's VMAT (Elekta Ltd, Crawley, UK) and Varian's RapidArc (Varian Medical Systems, Palo Alto, CA, USA) implementations, in that dose is not delivered while MLC leaves are moving. Instead, dose is delivered in bursts over very short arc angles and only after an MLC segment shape has been completely formed and verified by the controller. The new system was confirmed to be capable of delivering a wide array of clinically relevant treatment plans, without machine fault or other delivery anomalies. Dosimetric accuracy of the modulated arc platform, as well as the Prowess (Prowess Inc., Concord, CA, USA) prototype treatment planning version utilized here, was quantified and confirmed, and delivery times were measured as significantly brief, even with large hypofractionated doses. The burst mode modulated arc approach evaluated here appears to represent a capable, accurate and efficient delivery approach.

  17. Editorial - a remark you made

    Directory of Open Access Journals (Sweden)

    Yngve Nordkvelle

    2007-12-01

    Full Text Available ”A remark you made” is the title of a wonderful tune by the famous jazz-rock group “Weather Report”, issued on the influential “Heavy weather” LP some 30 years ago. In an age where planning and rationalizing is the main issue in most contexts, whether it’s a matter of studying, teaching, doing research or using a diet, “A remark you made” is a symbol of attending to the unplanned, unforeseen and often, unwanted. In most accounts on cognitive development one is overtly focused on the manageable, on the predictable and expected, and not so attentive to the opposite. “A remark you made” makes us think again and reconsider what might be of value, in what we otherwise might neglect. A remark made by Terry Anderson at a conference last year (2006 was rather telling. Anderson is the renown distance educator from Athabasca University, Alberta Canada, and editor of our fellow e-journal “The International Review of Research in Open and Distance Learning”. I recite it here totally from my own memory, and I have never approached him to have it verified, falsified or commented. That doesn’t matter in this context. Standing on the podium, he lowered his voice and asked if any Danes were present in the room. There weren’t! Then he explained that his argument might be presented differently with Danes present: “You see – Danes seem to think that learning alone is no longer possible!” That remark caused quite a good laugh, not the least because any comment – good or bad – about fellow Scandinavians generally is considered to be a good joke. But it was also a comment on how not only distance education, or open and flexible learning, but learning theory in general is driven by the sociocultural learning theory, - and according to Anderson, particularly so in Denmark! Our first contribution in this issue is about the theory of media theory developed by one of our editors: Lars Qvortrup. Lars is now the rector of the Danish

  18. Procedure to estimate maximum ground acceleration from macroseismic intensity rating: application to the Lima, Perú data from the October-3-1974-8.1-Mw earthquake

    Directory of Open Access Journals (Sweden)

    L. Ocola

    2008-01-01

    Full Text Available Post-disaster reconstruction management of urban areas requires timely information on the ground response microzonation to strong levels of ground shaking to minimize the rebuilt-environment vulnerability to future earthquakes. In this paper, a procedure is proposed to quantitatively estimate the severity of ground response in terms of peak ground acceleration, that is computed from macroseismic rating data, soil properties (acoustic impedance and predominant frequency of shear waves at a site. The basic mathematical relationships are derived from properties of wave propagation in a homogeneous and isotropic media. We define a Macroseismic Intensity Scale IMS as the logarithm of the quantity of seismic energy that flows through a unit area normal to the direction of wave propagation in unit time. The derived constants that relate the IMS scale and peak acceleration agree well with coefficients derived from a linear regression between MSK macroseismic rating and peak ground acceleration for historical earthquakes recorded at a strong motion station, at IGP's former headquarters, since 1954. The procedure was applied to 3-October-1974 Lima macroseismic intensity data at places where there was geotechnical data and predominant ground frequency information. The observed and computed peak acceleration values, at nearby sites, agree well.

  19. Procedure to estimate maximum ground acceleration from macroseismic intensity rating: application to the Lima, Perú data from the October-3-1974-8.1-Mw earthquake

    Science.gov (United States)

    Ocola, L.

    2008-01-01

    Post-disaster reconstruction management of urban areas requires timely information on the ground response microzonation to strong levels of ground shaking to minimize the rebuilt-environment vulnerability to future earthquakes. In this paper, a procedure is proposed to quantitatively estimate the severity of ground response in terms of peak ground acceleration, that is computed from macroseismic rating data, soil properties (acoustic impedance) and predominant frequency of shear waves at a site. The basic mathematical relationships are derived from properties of wave propagation in a homogeneous and isotropic media. We define a Macroseismic Intensity Scale IMS as the logarithm of the quantity of seismic energy that flows through a unit area normal to the direction of wave propagation in unit time. The derived constants that relate the IMS scale and peak acceleration agree well with coefficients derived from a linear regression between MSK macroseismic rating and peak ground acceleration for historical earthquakes recorded at a strong motion station, at IGP's former headquarters, since 1954. The procedure was applied to 3-October-1974 Lima macroseismic intensity data at places where there was geotechnical data and predominant ground frequency information. The observed and computed peak acceleration values, at nearby sites, agree well.

  20. Cycle-Powered Short Radius (1.9 m) Centrifuge: Effect of Exercise Versus Passive Acceleration on Heart Rate in Humans

    Science.gov (United States)

    Greenleaf, J. E.; Gundo, D. P.; Watenpaugh, D. E.; Mulenburg, G. M.; Mckenzie, M. A.; Looft-Wilson, R.; Hargens, A. R.

    1997-01-01

    In addition to extensive use of lower extremity physical exercise training as a countermeasure for the work capacity component of spaceflight deconditioning, some form of additional head-to-foot (+Gz) gravitational (orthostatic) stress may be required to further attenuate or prevent the signs and symptoms (nausea, vertigo, instability, fatigue) of the general reentry syndrome (GRS) that can reduce astronaut performance during landing. Orthostatic (head-to-foot) stress can be induced by standing, by lower body negative pressure, and by +Gz acceleration. One important question is whether acceleration training alone or with concurrent leg exercise would provide sufficient additive stimulation to attenuate the GRS. Use of a new human-powered centrifuge may be the answer. Thus, the purpose for this study was to compare heart rate (HR), i.e., a stress response during human-powered acceleration, in four men (35-62 yr) and two women (30-31 yr) during exercise acceleration versus passive acceleration (by an off-board operator) at 100% (maximal acceleration = A(max)), and at 25%, 50%, and 75% of A(max). Mean (+/-SE) A(max) was 43.7 +/- 1.3 rpm (+3.9 +/- 0.2Gz). Mean HR at exercise A(max) was 189 +/- 13 b/min (50-70 sec run time), and 142 +/- 22 b/min at passive A(max) (40-70 sec run time). Regression of mean HR on the various +Gz levels indicated explained variance (correlations squared) of r(exp 2) = 0.88 (exercise) and r(exp 2) = 0.96 (passive): exercise HR of 107 +/- 4 (25%) to 189 +/- 13 (100%) b/min were 43-50 b/min higher (p less than 0.05) than comparable passive HR of 64 +/- 2 to 142 +/- 22 b/min. Thus, exercise adds significant physiological stress during +Gz acceleration. Inflight use of this combined exercise and acceleration countermeasure may maintain work capacity as well as normalize acceleration and orthostatic tolerances which could attenuate or perhaps eliminate the GRS.

  1. Die degradation effect on aging rate in accelerated cycling tests of SiC power MOSFET modules

    DEFF Research Database (Denmark)

    Luo, Haoze; Baker, Nick; Iannuzzo, Francesco

    2017-01-01

    In order to distinguish the die and bond wire degradations, in this paper both the die and bond wire resistances of SiC MOSFET modules are measured and tested during the accelerated cycling tests. It is proved that, since the die degradation under specific conditions increases the temperature swing...

  2. Procedure to estimate maximum ground acceleration from macroseismic intensity rating: application to the Lima, Perú data from the October-3-1974-8.1-Mw earthquake

    OpenAIRE

    L. Ocola

    2008-01-01

    Post-disaster reconstruction management of urban areas requires timely information on the ground response microzonation to strong levels of ground shaking to minimize the rebuilt-environment vulnerability to future earthquakes. In this paper, a procedure is proposed to quantitatively estimate the severity of ground response in terms of peak ground acceleration, that is computed from macroseismic rating data, soil properties (acoustic impedance) and predominant frequency of shear waves at a si...

  3. High-dose-rate interstitial brachytherapy for accelerated partial breast irradiation – trial results of Azerbaijan National Center of Oncology

    Directory of Open Access Journals (Sweden)

    Jamil A. Aliyev

    2017-04-01

    Full Text Available Purpose : To describe early results of two cohorts of patients with low and intermediate risk of early breast cancer treated with accelerated partial breast irradiation (APBI using different schedules of multicatheter brachytherapy. Material and methods: Patients with early stage breast cancer after breast conserving surgery were enrolled for a prospective analysis. The APBI, using multicatheter brachytherapy, was delivered either eight times 4 Gy in five days with a planned total dose of 32 Gy, or seven times 5 Gy in four days with a planned total dose of 35 Gy. Primary endpoints were side effects. Results : Forty-eight patients were enrolled between 2012 and 2014. Patients characteristics were as follow: median age of patients was 55 years, early breast cancer was defined according GEC-ESTRO recommendations. With a median follow-up period of 37 months, no significant differences regarding late side effects and cosmesis between two cohorts of patients were documented. In total, cosmesis was excellent in 13/48 (27.1% patients, good in 34/48 (70.8% patients, and moderate in 1/48 patient (2.1%. Conclusions : Accelerated partial breast irradiation using multicatheter brachytherapy with 32 Gy/8 fractions and 35 Gy/7 fractions for early breast cancer seems to be similar in terms of late side effects. According to our findings, APBI was also feasible for intermediate-risk of early breast cancer patients.

  4. Studies on the radicidation of natural food colorants. Effects of electron energy (accelerating voltages) and dose rate of ionizing radiation on functional properties of beet red colorant

    Energy Technology Data Exchange (ETDEWEB)

    Higashimura, Yutaka; Tada, Mikiro [Okayama Univ. (Japan). Graduate School of Natural Science and Technology; Furuta, Masakazu [Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology

    2003-01-01

    In order to the practical use of radicidation of beet red, natural food colorant with low heat stability and high possibility of microbe contamination, we studied on the energy dependency and dose rate effect for the influence on functional properties of the beet red colorant. For the elucidation of energy dependency, the {gamma}-ray (1.33 MeV) and electron beams with different accelerating voltages (0.75, 1, 2.5, 5 and 10 MeV) were used. The dose rate effect was studied under the different dose rate by using {gamma}-ray (0.723, 1.91 and 4.55 kGy/h) and electron beams with accelerating voltage of 10 MeV (1.0 x 10{sup 3}, 2.6 x 10{sup 3}, 7.0 x 10{sup 3}, 7.0 x 10{sup 3}, 2.0 x 10{sup 4} and 5.0 x 10{sup 4} kGy/h). The results obtained in this study showed that regardness of these energy and dose rate, the functional properties of the beet red colorant were little affected by irradiation less than 25 kGy of ionizing radiations. (author)

  5. Metabolic syndrome but not obesity measures are risk factors for accelerated age-related glomerular filtration rate decline in the general population.

    Science.gov (United States)

    Stefansson, Vidar T N; Schei, Jørgen; Solbu, Marit D; Jenssen, Trond G; Melsom, Toralf; Eriksen, Bjørn O

    2018-01-22

    Rapid age-related glomerular filtration rate (GFR) decline increases the risk of end-stage renal disease, and a low GFR increases the risk of mortality and cardiovascular disease. High body mass index and the metabolic syndrome are well-known risk factors for patients with advanced chronic kidney disease, but their role in accelerating age-related GFR decline independent of cardiovascular disease, hypertension and diabetes is not adequately understood. We studied body mass index, waist circumference, waist-hip ratio and metabolic syndrome as risk factors for accelerated GFR decline in 1261 middle-aged people representative of the general population without diabetes, cardiovascular disease or kidney disease. GFR was measured as iohexol clearance at baseline and repeated after a median of 5.6 years. Metabolic syndrome was defined as fulfilling three out of five criteria, based on waist circumference, blood pressure, glucose, high-density lipoprotein cholesterol and triglycerides. The mean GFR decline rate was 0.95 ml/min/year. Neither the body mass index, waist circumference nor waist-hip ratio predicted statistically significant changes in age-related GFR decline, but individuals with baseline metabolic syndrome had a significant mean of 0.30 ml/min/year faster decline than individuals without metabolic syndrome in a multivariable adjusted linear regression model. This association was mainly driven by the triglyceride criterion of metabolic syndrome, which was associated with a significant 0.36 ml/min/year faster decline when analyzed separately. Results differed significantly when GFR was estimated using creatinine and/or cystatin C. Thus, metabolic syndrome, but not the body mass index, waist circumference or waist-hip ratio, is an independent risk factor for accelerated age-related GFR decline in the general population. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  6. The Rate of Success of the Accelerated Solvent Extraction (Ase of Fat and Organochlorine Pesticides from Dried Fish Meat Samples

    Directory of Open Access Journals (Sweden)

    Ana Andreea CIOCA

    2017-05-01

    Full Text Available The replacement of conventional sample preparation techniques with newer techniques which are automated, faster and more eco-friendly, is nowadays desired in every analytical laboratory. One of the techniques with the attributes mentioned above is the Accelerated Solvent Extraction. In order to evaluate how successful this method is for the extraction of fat and organochlorine pesticides (OCPs from dried fish meat samples, we have tested two series of diverse fish using Dionex™ 350 ASE provided by Thermo Scientific™ (Germany. For a more interesting approach, we added to our investigation 7 polychlorinated biphenyl (PCBs, 3 thricholorobenzenes, 2 tetrachlorobenzenes, 1 pentachlorobenzenes and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD. The study focused on comparing the recoveries of these analytes from different fish samples, after replacing the conventional reference method of the laboratory with ASE. The ASE parameters tested were previously used for the extraction of fat and polybrominated diphenyl ethers (PBDE from fish samples: temperature: 120 ° C; static time: 5 min; number of cycles: 3; flushing volume: 25%; rinse with nitrogen: 90 s; solvent: cyclohexane/ethyl acetate (ratio 1:1. The ASE method provided similar and in some cases better results when compared to the standard reference method, more rapidly, eco-friendly and safer. Any high or low recoveries of the analytes taken into study are attributed to random or systematic errors during the Clean-up step of the extracts and the quantification with Gas Chromatography coupled with Tandem Mass-Spectrometry (GC MS/MS.

  7. Accelerated Partial Breast Irradiation With Low-Dose-Rate Interstitial Implant Brachytherapy After Wide Local Excision: 12-Year Outcomes From a Prospective Trial

    Energy Technology Data Exchange (ETDEWEB)

    Hattangadi, Jona A. [Harvard Radiation Oncology Program, Boston, MA (United States); Powell, Simon N. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); MacDonald, Shannon M.; Mauceri, Thomas; Ancukiewicz, Marek [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Freer, Phoebe [Department of Radiology, Massachusetts General Hospital, Boston, MA (United States); Lawenda, Brian [21st Century Oncology, Las Vegas, NV (United States); Alm El-Din, Mohamed A. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Clinical Oncology, Tanta University Hospital, Tanta (Egypt); Gadd, Michele A.; Smith, Barbara L. [Department of Surgical Oncology, Massachusetts General Hospital, Boston, MA (United States); Taghian, Alphonse G., E-mail: ataghian@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

    2012-07-01

    Purpose: To evaluate the long-term toxicity, cosmesis, and local control of accelerated partial breast irradiation with implant brachytherapy after wide local excision for Stage T1N0 breast cancer (BCa). Materials and Methods: Between 1997 and 2001, 50 patients with Stage T1N0M0 BCa were treated in a Phase I-II protocol using low-dose-rate accelerated partial breast irradiation with implant brachytherapy after wide local excision and lymph node surgery. The total dose was escalated in three groups: 50 Gy (n = 20), 55 Gy (n = 17), and 60 Gy (n = 13). Patient- and physician-assessed breast cosmesis, patient satisfaction, toxicity, mammographic abnormalities, repeat biopsies, and disease status were prospectively evaluated at each visit. Kendall's tau ({tau}{sub {beta}}) and logistic regression analyses were used to correlate outcomes with dose, implant volume, patient age, and systemic therapy. Results: The median follow-up period was 11.2 years (range, 4-14). The patient satisfaction rate was 67%, 67% reported good-excellent cosmesis, and 54% had moderate-severe fibrosis. Higher dose was correlated with worse cosmetic outcome ({tau}{sub {beta}} 0.6, p < .0001), lower patient satisfaction ({tau}{sub {beta}} 0.5, p < .001), and worse fibrosis ({tau}{sub {beta}} 0.4, p = .0024). Of the 50 patients, 35% had fat necrosis and 34% developed telangiectasias {>=}1 cm{sup 2}. Grade 3-4 late skin and subcutaneous toxicities were seen in 4 patients (9%) and 6 patients (13%), respectively, and both correlated with higher dose ({tau}{sub {beta}} 0.3-0.5, p {<=} .01). One patient had Grade 4 skin ulceration and fat necrosis requiring surgery. Mammographic abnormalities were seen in 32% of the patients, and 30% underwent repeat biopsy, of which 73% were benign. Six patients had ipsilateral breast recurrence: five elsewhere in the breast, and one at the implant site. One patient died of metastatic BCa after recurrence. The 12-year actuarial local control, recurrence

  8. Accelerated HF-rTMS Protocol has a Rate-Dependent Effect on dACC Activation in Alcohol-Dependent Patients: An Open-Label Feasibility Study.

    Science.gov (United States)

    Herremans, Sarah C; De Raedt, Rudi; Van Schuerbeek, Peter; Marinazzo, Daniele; Matthys, Frieda; De Mey, Johan; Baeken, Chris

    2016-01-01

    located at the ventral cortical aspects in 6 of our participants, reliable data were only obtained for the ACC. Our data indicate that higher baseline dACC activation may serve as a protective mechanism regarding relapse. For the first time, it is demonstrated that accelerated HF-rTMS treatment influences dACC activation in a rate-dependent manner: the lower the baseline dACC activation, the more dACC activity was increased after HF-rTMS treatment. Copyright © 2016 by the Research Society on Alcoholism.

  9. Accelerated Stem Growth Rates and Improved Fiber Properties of Loblolly Pine: Functional Analysis Of CyclinD from Pinus taeda

    Energy Technology Data Exchange (ETDEWEB)

    Dr. John Cairney, School of Biology and Institute of Paper Science and Technology @ Georgia Tech, Georgia Institute of Technology; Dr. Gary Peter, University of Florida; Dr. Ulrika Egertsdotter, Dept. of Forestry, Virgina Tech; Dr. Armin Wagner, New Zealand Forest Research Institute Ltd. (Scion Research.)

    2005-11-30

    A sustained supply of low-cost, high quality raw materials is essential for the future success of the U.S. forest products industry. To maximize stem (trunk) growth, a fundamental understanding of the molecular mechanisms that regulate cell divisions within the cambial meristem is essential. We hypothesize that auxin levels within the cambial meristem regulate cyclin gene expression and this in turn controls cell cycle progression as occurs in all eukaryotic cells. Work with model plant species has shown that ectopic overexpression of cyclins promotes cell division thereby increasing root growth > five times. We intended to test whether ectopic overexpression of cambial cyclins in the cambial zone of loblolly pine also promotes cell division rates that enhance stem growth rates. Results generated in model annual angiosperm systems cannot be reliably extrapolated to perennial gymnosperms, thus while the generation and development of transgenic pine is time consuming, this is the necessary approach for meaningful data. We succeeded in isolating a cyclin D gene and Clustal analysis to the Arabidopsis cyclin D gene family indicates that it is more closely related to cyclin D2 than D1 or D3 Using this gene as a probe we observed a small stimulation of cyclin D expression in somatic embryo culture upon addition of auxin. We hypothesized that trees with more cells in the vascular cambial and expansion zones will have higher cyclin mRNA levels. We demonstrated that in trees under compressive stress where the rates of cambial divisions are increased on the underside of the stem relative to the top or opposite side, there was a 20 fold increase in the level of PtcyclinD1 mRNA on the compressed side of the stem relative to the opposite. This suggests that higher secondary growth rates correlate with PtcyclinD1 expression. We showed that larger diameter trees show more growth during each year and that the increased growth in loblolly pine trees correlates with more cell

  10. The Complete Plastid Genome Sequence of the Secondarily Nonphotosynthetic Alga Cryptomonas paramecium: Reduction, Compaction, and Accelerated Evolutionary Rate

    Science.gov (United States)

    Donaher, Natalie; Tanifuji, Goro; Onodera, Naoko T.; Malfatti, Stephanie A.; Chain, Patrick S. G.; Hara, Yoshiaki

    2009-01-01

    The cryptomonads are a group of unicellular algae that acquired photosynthesis through the engulfment of a red algal cell, a process called secondary endosymbiosis. Here, we present the complete plastid genome sequence of the secondarily nonphotosynthetic species Cryptomonas paramecium CCAP977/2a. The ∼78 kilobase pair (Kbp) C. paramecium genome contains 82 predicted protein genes, 29 transfer RNA genes, and a single pseudogene (atpF). The C. paramecium plastid genome is approximately 50 Kbp smaller than those of the photosynthetic cryptomonads Guillardia theta and Rhodomonas salina; 71 genes present in the G. theta and/or R. salina plastid genomes are missing in C. paramecium. The pet, psa, and psb photosynthetic gene families are almost entirely absent. Interestingly, the ribosomal RNA operon, present as inverted repeats in most plastid genomes (including G. theta and R. salina), exists as a single copy in C. paramecium. The G + C content (38%) is higher in C. paramecium than in other cryptomonad plastid genomes, and C. paramecium plastid genes are characterized by significantly different codon usage patterns and increased evolutionary rates. The content and structure of the C. paramecium plastid genome provides insight into the changes associated with recent loss of photosynthesis in a predominantly photosynthetic group of algae and reveals features shared with the plastid genomes of other secondarily nonphotosynthetic eukaryotes. PMID:20333213

  11. Gene duplication and an accelerated evolutionary rate in 11S globulin genes are associated with higher protein synthesis in dicots as compared to monocots

    Directory of Open Access Journals (Sweden)

    Li Chun

    2012-01-01

    Full Text Available Abstract Background Seed storage proteins are a major source of dietary protein, and the content of such proteins determines both the quantity and quality of crop yield. Significantly, examination of the protein content in the seeds of crop plants shows a distinct difference between monocots and dicots. Thus, it is expected that there are different evolutionary patterns in the genes underlying protein synthesis in the seeds of these two groups of plants. Results Gene duplication, evolutionary rate and positive selection of a major gene family of seed storage proteins (the 11S globulin genes, were compared in dicots and monocots. The results, obtained from five species in each group, show more gene duplications, a higher evolutionary rate and positive selections of this gene family in dicots, which are rich in 11S globulins, but not in the monocots. Conclusion Our findings provide evidence to support the suggestion that gene duplication and an accelerated evolutionary rate may be associated with higher protein synthesis in dicots as compared to monocots.

  12. Climate change accelerates local disease extinction rates in a long-term wild host-pathogen association.

    Science.gov (United States)

    Zhan, Jiasui; Ericson, Lars; Burdon, Jeremy J

    2018-02-27

    Pathogens are a significant component of all plant communities. In recent years the potential for existing and emerging pathogens of agricultural crops to cause increased yield losses as a consequence of changing climatic patterns has raised considerable concern. In contrast, the response of naturally occurring, endemic pathogens to a warming climate has received little attention. Here we report on the impact of a signature variable of global climate change - increasing temperature - on the long-term epidemiology of a natural host-pathogen association involving the rust pathogen Triphragmium ulmariae and its host plant Filipendula ulmaria. In a host-pathogen metapopulation involving approximately 230 host populations growing on an archipelago of islands in the Gulf of Bothnia we assessed changes in host population size and pathogen epidemiological measures over a 25-year period. We show how the incidence of disease and its severity declines over that period and most importantly demonstrate a positive association between a long-term trend of increasing extinction rates in individual pathogen populations of the metapopulation and increasing temperature. Our results are highly suggestive that changing climatic patterns, particularly mean monthly growing season (April-November) temperature, are markedly influencing the epidemiology of plant disease in this host-pathogen association. Given the important role plant pathogens have in shaping the structure of communities, changes in the epidemiology of pathogens have potentially far-reaching impacts on ecological and evolutionary processes. For these reasons, it is essential to increase understanding of pathogen epidemiology, its response to warming, and to invoke these responses in forecasts for the future. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Future accelerators (?)

    Energy Technology Data Exchange (ETDEWEB)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  14. Characterisation of the interactions between substrate, copper(II) complex and DNA and their role in rate acceleration in DNA-based asymmetric catalysis.

    Science.gov (United States)

    Draksharapu, Apparao; Boersma, Arnold J; Browne, Wesley R; Roelfes, Gerard

    2015-02-28

    Interactions of the azachalcone derived substrate Aza with copper(II) complexes in the presence and absence of st-DNA were studied in detail by UV/Vis absorption, EPR and Raman and (UV and vis) resonance Raman spectroscopies. The binding of Aza to the Lewis acidic copper(II) complexes, which results in activation of the substrate, was established spectroscopically. It was shown that the binding of Aza differs between Cu(II)dmbpy and Cu(II)terpy, consistent with the observed differences in catalytic asymmetric Diels-Alder reactions with regard to both the rate and enantiomeric preference. Finally, it was shown that DNA has a major beneficial effect on the binding of Aza to the copper(II) complex due to the fact that both bind to the DNA. The result is a high effective molarity of both the copper complexes and the Aza substrate, which leads to a significant increase in binding of Aza to the copper(II) complex. This effect is a key reason for the observed rate acceleration in the catalyzed reactions brought about by the presence of DNA.

  15. Remarkable evolutionary conservation of SOX14 orthologues

    Indian Academy of Sciences (India)

    PCR based approach was used to identify Sox14 of goat, cow and rat, while nucleotide and amino acid sequence alignments and mapping were performed using information currently available in public database. Comparative sequence analysis revealed remarkable identity among Sox14 orthologues and helped us to ...

  16. Remarks on the extended characteristic uncertainty relations

    Energy Technology Data Exchange (ETDEWEB)

    Trifonov, D.A. [Institute for Nuclear Research, Sofia (Bulgaria)

    2001-03-09

    Three remarks concerning the form and the range of validity of the state-extended characteristic uncertainty relations (URs) are presented. A more general definition of the uncertainty matrix for pure and mixed states is suggested. Some new URs are provided. (author). Letter-to-the-editor.

  17. Remarkable NO oxidation on single supported platinum atoms

    Science.gov (United States)

    Narula, Chaitanya K.; Allard, Lawrence F.; Stocks, G. M.; Moses-DeBusk, Melanie

    2014-01-01

    Our first-principles density functional theoretical modeling suggests that NO oxidation is feasible on fully oxidized single θ-Al2O3 supported platinum atoms via a modified Langmuir-Hinshelwood pathway. This is in contrast to the known decrease in NO oxidation activity of supported platinum with decreasing Pt particle size believed to be due to increased platinum oxidation. In order to validate our theoretical study, we evaluated single θ-Al2O3 supported platinum atoms and found them to exhibit remarkable NO oxidation activity. A comparison of turnover frequencies (TOF) of single supported Pt atoms with those of platinum particles for NO oxidation shows that single supported Pt atoms are as active as fully formed platinum particles. Thus, the overall picture of NO oxidation on supported Pt is that NO oxidation activity decreases with decreasing Pt particle size but accelerates when Pt is present only as single atoms. PMID:25429995

  18. Remarkable NO oxidation on single supported platinum atoms.

    Science.gov (United States)

    Narula, Chaitanya K; Allard, Lawrence F; Stocks, G M; Moses-DeBusk, Melanie

    2014-11-28

    Our first-principles density functional theoretical modeling suggests that NO oxidation is feasible on fully oxidized single θ-Al2O3 supported platinum atoms via a modified Langmuir-Hinshelwood pathway. This is in contrast to the known decrease in NO oxidation activity of supported platinum with decreasing Pt particle size believed to be due to increased platinum oxidation. In order to validate our theoretical study, we evaluated single θ-Al2O3 supported platinum atoms and found them to exhibit remarkable NO oxidation activity. A comparison of turnover frequencies (TOF) of single supported Pt atoms with those of platinum particles for NO oxidation shows that single supported Pt atoms are as active as fully formed platinum particles. Thus, the overall picture of NO oxidation on supported Pt is that NO oxidation activity decreases with decreasing Pt particle size but accelerates when Pt is present only as single atoms.

  19. Flame spread over electrical wire with AC electric fields: Internal circulation, fuel vapor-jet, spread rate acceleration, and molten insulator dripping

    KAUST Repository

    Lim, Seungjae

    2015-04-01

    The effect of electric field on the characteristics of flame spread along a polyethylene (PE) insulated electrical wire was investigated experimentally by varying the AC frequency and voltage applied to the wire. The results showed that the flame spread rate was accelerated due to the convergence of electric flux near the end of wire, having three distinct regimes depending on applied voltage. In each regime, several subregimes could be identified depending on AC frequency. Flame shape (height and width) and slanted direction of the spreading flame were influenced differently. Fuel-vapor jets were ejected from the molten PE surface even for the baseline case without the application of an electric field; this could be attributed to the bursting of fuel vapor bubbles generated from internal boiling at the molten PE surface. An internal circulation of molten-PE was also observed as a result of non-uniform heating by the spreading flame. In the high voltage regime with a high AC frequency, excessive dripping of molten PE led to flame extinction.

  20. Concluding Remarks on the Planetary Rings Conference

    OpenAIRE

    Stone, E. C.

    1982-01-01

    In the past five years ring systems have been discovered around Uranus and Jupiter and a wealth of new data acquired about Saturn's rings. This vigorous observational program has been accompanied by renewed theoretical interest in ring systems. Although all of these topics have been addressed in papers at this first conference on planetary rings, these concluding remarks are focused on some of the key aspects of Saturn's rings about which more needs to be understood throu...

  1. Electrostatic accelerators

    OpenAIRE

    Hinterberger, F.

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We ...

  2. Electrostatic accelerators

    CERN Document Server

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We sketch possible applications and the progress in the development of electrostatic accelerators.

  3. Some Remarks on the Extended Galilean Transformation.

    Science.gov (United States)

    Greenberger, Daniel M.

    1979-01-01

    The extended Galilean transformation carries an inertial frame into a rigid frame with uniform spatial, but arbitrary translational acceleration. Besides being useful in discussing the equivalence principle, this transformation provides a physical interpretation for the theorem in nonrelativistic quantum mechanics, that we cannot coherently…

  4. Accelerating Value Creation with Accelerators

    DEFF Research Database (Denmark)

    Jonsson, Eythor Ivar

    2015-01-01

    accelerator programs. Microsoft runs accelerators in seven different countries. Accelerators have grown out of the infancy stage and are now an accepted approach to develop new ventures based on cutting-edge technology like the internet of things, mobile technology, big data and virtual reality. It is also...... an approach to facilitate implementation and realization of business ideas and is a lucrative approach to transform research into ventures and to revitalize regions and industries in transition. Investors have noticed that the accelerator approach is a way to increase the possibility of success by funnelling...... with the traditional audit and legal universes and industries are examples of emerging potentials both from a research and business point of view to exploit and explore further. The accelerator approach may therefore be an Idea Watch to consider, no matter which industry you are in, because in essence accelerators...

  5. LIBO accelerates

    CERN Multimedia

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  6. Some remarks on PM2.5

    Directory of Open Access Journals (Sweden)

    A. Piano

    2003-06-01

    Full Text Available Since 1970, the General Physics Department of «Università degli Studi di Torino» has carried out a project research, on inorganic solid particulate matter. The special issue of Annals of Geophysics, published for Professor Giorgio Fiocco?s 70th birthday, gives us the possibility to make some important remarks on this topic, focusing on PM2.5. This has been possible using all the old and new experimental data of the measures made by the authors of this paper since 1970.

  7. Accelerating Inspire

    CERN Document Server

    AUTHOR|(CDS)2266999

    2017-01-01

    CERN has been involved in the dissemination of scientific results since its early days and has continuously updated the distribution channels. Currently, Inspire hosts catalogues of articles, authors, institutions, conferences, jobs, experiments, journals and more. Successful orientation among this amount of data requires comprehensive linking between the content. Inspire has lacked a system for linking experiments and articles together based on which accelerator they were conducted at. The purpose of this project has been to create such a system. Records for 156 accelerators were created and all 2913 experiments on Inspire were given corresponding MARC tags. Records of 18404 accelerator physics related bibliographic entries were also tagged with corresponding accelerator tags. Finally, as a part of the endeavour to broaden CERN's presence on Wikipedia, existing Wikipedia articles of accelerators were updated with short descriptions and links to Inspire. In total, 86 Wikipedia articles were updated. This repo...

  8. Induction accelerators

    CERN Document Server

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  9. Chemical physics of electroactive materials: concluding remarks.

    Science.gov (United States)

    Rutland, Mark W

    2017-07-01

    It is an honour to be charged with providing the concluding remarks for a Faraday Discussion. As many have remarked before, it is nonetheless a prodigious task, and what follows is necessarily a personal, and probably perverse, view of a watershed event in the Chemical Physics of Electroactive materials. The spirit of the conference was captured in a single sentence during the meeting itself."It is the nexus between rheology, electrochemistry, colloid science and energy storage". The current scientific climate is increasingly dominated by a limited number of global challenges, and there is thus a tendency for research to resemble a football match played by 6 year olds, where everyone on the field chases the (funding) ball instead of playing to their "discipline". It is thus reassuring to see how the application of rigorous chemical physics is leading to ingenious new solutions for both energy storage and harvesting, via, for example, nanoactuation, electrowetting, ionic materials and nanoplasmonics. In fact, the same language of chemical physics allows seamless transition between applications as diverse as mechano-electric energy generation, active moisture transport and plasmonic shutters - even the origins of life were addressed in the context of electro-autocatalysis!

  10. Cosmic Acceleration

    Science.gov (United States)

    Bean, Rachel

    2011-03-01

    In this series of lectures we review observational evidence for, and theoretical investigations into, cosmic acceleration and dark energy. The notes are in four sections. First I review the basic cosmological formalism to describe the expansion history of the universe and how distance measures are defined. The second section covers the evidence for cosmic acceleration from cosmic distance measurements. Section 3 discusses the theoretical avenues being considered to explain the cosmological observations. Section 4 discusses how the growth of inhomogeneities and large scale structure observations might help us pin down the theoretical origin of cosmic acceleration.

  11. Remarkable connections between extended magnetohydrodynamics models

    Energy Technology Data Exchange (ETDEWEB)

    Lingam, M., E-mail: manasvi@physics.utexas.edu; Morrison, P. J., E-mail: morrison@physics.utexas.edu; Miloshevich, G., E-mail: gmilosh@physics.utexas.edu [Department of Physics and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-07-15

    Through the use of suitable variable transformations, the commonality of all extended magnetohydrodynamics (MHD) models is established. Remarkable correspondences between the Poisson brackets of inertialess Hall MHD and inertial MHD (which has electron inertia, but not the Hall drift) and extended MHD (which has both effects) are established. The helicities (two in all) for each of these models are obtained through these correspondences. The commonality of all the extended MHD models is traced to the existence of two Lie-dragged 2-forms, which are closely associated with the canonical momenta of the two underlying species. The Lie-dragging of these 2-forms by suitable velocities also leads to the correct equations of motion. The Hall MHD Poisson bracket is analyzed in detail, the Jacobi identity is verified through a detailed proof, and this proof ensures the Jacobi identity for the Poisson brackets of all the models.

  12. Horizontal Accelerator

    Data.gov (United States)

    Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

  13. Accelerated construction

    Science.gov (United States)

    2004-01-01

    Accelerated Construction Technology Transfer (ACTT) is a strategic process that uses various innovative techniques, strategies, and technologies to minimize actual construction time, while enhancing quality and safety on today's large, complex multip...

  14. LINEAR ACCELERATOR

    Science.gov (United States)

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  15. Comparison of the Effects of Two Auditory Methods by Mother and Fetus on the Results of Non-Stress Test (Baseline Fetal Heart Rate and Number of Accelerations in Pregnant Women: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Roghaie Khoshkholgh

    2016-05-01

    Full Text Available Objective: To compare the effects of two auditory methods by mother and fetus on the results of NST in 2011-2012.Materials and methods: In this single-blind clinical trial, 213 pregnant women with gestational age of 37-41 weeks who had no pregnancy complications were randomly divided into 3 groups (auditory intervention for mother, auditory intervention for fetus, and control each containing 71 subjects. In the intervention groups, music was played through the second 10 minutes of NST. The three groups were compared regarding baseline fetal heart rate and number of accelerations in the first and second 10 minutes of NST. The data were analyzed using one-way ANOVA, Kruskal-Wallis, and paired T-test.Results: The results showed no significant difference among the three groups regarding baseline fetal heart rate in the first (p = 0.945 and second (p = 0.763 10 minutes. However, a significant difference was found among the three groups concerning the number of accelerations in the second 10 minutes. Also, a significant difference was observed in the number of accelerations in the auditory intervention for mother (p = 0.013 and auditory intervention for fetus groups (p < 0.001. The difference between the number of accelerations in the first and second 10 minutes was also statistically significant (p = 0.002.Conclusion: Music intervention was effective in the number of accelerations which is the indicator of fetal health. Yet, further studies are required to be conducted on the issue.

  16. The end of a remarkable era

    CERN Multimedia

    2011-01-01

    An important era in particle physics is coming to an end: the US Department of Energy announced on Monday that it will not fund an extension to Tevatron running beyond 2011. It is a poignant moment for particle physics as we prepare to bid farewell to a machine that has changed our view of the Universe, and played a significant role in paving the way for the new era that is opening up with the LHC.   The Tevatron has been at the high-energy frontier of particle physics for over a quarter of a century. That’s a remarkable achievement by any account, and the physics results are there to prove it. As well as bringing us the discovery of the top quark in 1995, the Tevatron’s experiments have provided vitally important precision measurements covering the full spectrum of Standard Model physics, not to mention hints of what may lie beyond. With several months of running still to come, it would be a foolish gambler who bet against further new physics emerging before the Teva...

  17. Thomas Edison Accelerated Elementary School.

    Science.gov (United States)

    Levin, Henry M.; Chasin, Gene

    This paper describes early outcomes of a Sacramento, California, elementary school that participated in the Accelerated Schools Project. The school, which serves many minority and poor students, began training for the project in 1992. Accelerated Schools were designed to advance the learning rate of students through a gifted and talented approach,…

  18. Laser acceleration

    Science.gov (United States)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  19. Fermi Acceleration in driven relativistic billiards

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Rafael S., E-mail: rsoaresp@ifi.unicamp.br [Instituto de Fisica ' Gleb Wataghin' , Universidade Estadual de Campinas, 13083-970, Campinas, SP (Brazil); Letelier, Patricio S. [Departamento de Matematica Aplicada, Instituto de Matematica, Estatistica e Computacao Cientifica, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil)

    2011-08-29

    We show numerical experiments of driven billiards using special relativity. We have the remarkable fact that for the relativistic driven circular and annular concentric billiards, depending on initial conditions and parameters, we observe Fermi Acceleration, absent in the Newtonian case. The velocity for these cases tends to the speed of light very quickly. We find that for the annular eccentric billiard the initial velocity grows for a much longer time than the concentric annular billiard until it asymptotically reach c. -- Highlights: → Fermi Acceleration is studied for relativistic driven billiards. → We studied regular and chaotic billiards with different parameters. → Fermi Acceleration is present even for static regular billiards.

  20. Opening Remarks: SciDAC 2007

    Science.gov (United States)

    Strayer, Michael

    2007-09-01

    Good morning. Welcome to Boston, the home of the Red Sox, Celtics and Bruins, baked beans, tea parties, Robert Parker, and SciDAC 2007. A year ago I stood before you to share the legacy of the first SciDAC program and identify the challenges that we must address on the road to petascale computing—a road E E Cummins described as `. . . never traveled, gladly beyond any experience.' Today, I want to explore the preparations for the rapidly approaching extreme scale (X-scale) generation. These preparations are the first step propelling us along the road of burgeoning scientific discovery enabled by the application of X- scale computing. We look to petascale computing and beyond to open up a world of discovery that cuts across scientific fields and leads us to a greater understanding of not only our world, but our universe. As part of the President's America Competitiveness Initiative, the ASCR Office has been preparing a ten year vision for computing. As part of this planning the LBNL together with ORNL and ANL hosted three town hall meetings on Simulation and Modeling at the Exascale for Energy, Ecological Sustainability and Global Security (E3). The proposed E3 initiative is organized around four programmatic themes: Engaging our top scientists, engineers, computer scientists and applied mathematicians; investing in pioneering large-scale science; developing scalable analysis algorithms, and storage architectures to accelerate discovery; and accelerating the build-out and future development of the DOE open computing facilities. It is clear that we have only just started down the path to extreme scale computing. Plan to attend Thursday's session on the out-briefing and discussion of these meetings. The road to the petascale has been at best rocky. In FY07, the continuing resolution provided 12% less money for Advanced Scientific Computing than either the President, the Senate, or the House. As a consequence, many of you had to absorb a no cost extension for your

  1. ACCELERATORS: ENGINES FOR TRAVERSING A LARGE AND OFTEN DIFFICULT LANDSCAPE

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, Andrew M.

    2012-08-17

    The many applications of accelerators are presented, with pictures and comments, upon the machines and the results obtained with them. Attention is then given to possible future applications, and some remarks are made on the future development of accelerators. In short, the presentation should serve as an introduction to the Conference itself where there shall be many - wonderfully detailed - contributions to all of this.

  2. Accelerators and the Accelerator Community

    Energy Technology Data Exchange (ETDEWEB)

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  3. [Several remarks apropos of quantitative psychopathology].

    Science.gov (United States)

    Guelfi, J D

    1985-01-01

    There is no contradiction between rating scales and clinical judgment: the former represent only a codification of the latter. There is no contradiction either between clinical judgment and statistical judgment. Rating scales are elaborated with hopes of quantifying symptomatology and its change under treatment. In the field of comprehensive scales, let us mention the AMDP, the BPRS/BPHF, the IMPS and the PSE. Among depression scales, the HAMD is being superseded by the MADRS; our Department has also made an extensive use of the Overall Depression scale. Mania scales insufficiently discriminate between manic mood and agitation. As regards anxiety scales, the HAMA is an excellent one. In the field of somatic scales, we have developed the CHESS, which appears promising. In the field of diagnostic typology, the recent criteria by Pull might bring better results that previous research. Adequate scales are missing in mania, in the distinction between the psychostimulant and the antidepressant effects, in the field of vigilance-attention-memory and in the measurement of psychotherapeutic change.

  4. Remarkable Stability of Myelinating Oligodendrocytes in Mice

    Directory of Open Access Journals (Sweden)

    Richa B. Tripathi

    2017-10-01

    Full Text Available New myelin-forming oligodendrocytes (OLs are generated in the mouse central nervous system during adulthood. These adult-born OLs might augment the existing population, contributing to neural plasticity, or else replace OLs that die in use (turnover. To distinguish between these alternatives, we induced genetic labeling of mature myelinating OLs in young adult mice and tracked their subsequent survival. OL survival rates were region dependent, being higher in corpus callosum (∼90% survival over 20 months and motor cortex (∼70% survival than in corticospinal tract or optic nerve (50%–60% survival. Survival rates over the first 8 months were 90%–100% in all regions except the optic nerve. In the corpus callosum, new OLs accumulate during young adulthood and are therefore likely to participate in adaptive myelination. We also found that the number of myelin internodes maintained by individual cortical OLs is stable for at least 8 months but declines ∼12% in the following year.

  5. accelerating cavity

    CERN Multimedia

    On the inside of the cavity there is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  6. Laser-plasma booster for ion post acceleration

    Directory of Open Access Journals (Sweden)

    Satoh D.

    2013-11-01

    Full Text Available A remarkable ion energy increase is demonstrated for post acceleration by a laser-plasma booster. An intense short-pulse laser generates a strong current by high-energy electrons accelerated, when this intense short-pulse laser illuminates a plasma target. The strong electric current creates a strong magnetic field along the high-energy electron current in plasma. During the increase phase in the magnetic field, a longitudinal inductive electric field is induced for the forward ion acceleration by the Faraday law. Our 2.5-dimensional particle-in-cell simulations demonstrate a remarkable increase in ion energy by several tens of MeV.

  7. Lung cancer, brucellosis and tuberculosis: remarkable togetherness

    Directory of Open Access Journals (Sweden)

    Muhammed Emin Akkoyunlu

    2013-08-01

    Full Text Available A 68 years old male farmer referred with cough, expectorating sputum, intermittant fever, night sweats, fatigue and anorexia persisting for two weeks. There was a history of 80 packs each year of smoking and he was still an active smoker. Pneumonectomy was performed because of pulmonary epidermoid cancer and he received chemotherapy. He was diagnosed lung tuberculosis and using anti-tuberculous treatment for 4 months. He had a weight loss of 8 kg in last month. His body tempereature was 38.5 °C. Heart rate was 100/min. ESR was 51mm/h and CRP was 5.6 mg/ dL. There was no proliferation in blood and sputum cultures. Three sputum specimens were examined and AFB wasn’t detected. Fibronodular infiltration was seen in right lower zone of chest X-ray. In thorax CT, fibronodular densities were seen in lower lobe anterior and posterior segments. Brucella melitensis was isolated in blood culture. Second bronchoscopy was performed with suspect of brucellosis pneumonia. Brucella tube agglutination test was positive at titer 1/320 in the bronchial lavage fluid and 1/640 in concurrent serum sample. In cases with chronic cough or pneumonia which is irresponsive to nonspecific antibiotherapy, respiratory brucellosis must be rememberred in endemic areas.

  8. Evaluation of color and radon exhalation rate in granite rocks between accelerated aging cycles; Avaliacao da cor e taxa de exalacao de radonio em rochas graniticas entre ciclos de envelhecimento acelerado

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Francisco Diones Oliveira

    2016-07-01

    Data used for the assessment of the analyzes performed on three types of dimension stone (Juparana Bordeaux, Branco Nevasca and Golden Artico), in natural state and after several cycles of accelerated aging are presented, correlating them with the gas exhalation rate radon issued by the analyzed lithologies. In the samples were conducted permeability, porosity, colorimetry, image analysis, petrographic and exhalation rate of radon, accompanied by aging tests on climate simulation chamber which simulates change situations of materials by weathering agents, accelerating wear and tear samples. The measurements were performed on samples in natural state, with 50 and 100 cycles of aging acceleration, where each cycle corresponds to variations in temperature and humidity in climatic simulation chamber, with the addition of an internal atmosphere of SO{sub 2} with 25 concentration ppm. The results obtained during the tests were related to better analysis of the changes observed on the samples and the variation rate of exhalation radon emitted. The rocks have radon concentration values above the limits suggested by relevant international agencies (200-400 Bq/m³), with average values in the natural state, in 6149, 1619 and 866 Bq/m³ for Juparana Bordeaux, Branco Nevasca and Golden Arctic, respectively. The other aging cycles (50 and 100 cycles) showed an average increase of 0.8% for Juparana Bordeaux, 6.9% for White Blizzard and -23.87% for the Golden Arctic, with 50 cycles. From 50 to 100 cycles, there was reduction of 3.43% for Juparana Bordeaux and 22.15% for Branco Nevasca and an increase of 13.82% in the Golden Artico. The porosity results in the natural state obtained values an average of 0.696% for Juparana Bordeaux, 0.919% for Branco Nevasca and 0.830% for Golden Artico, and after 50 cycles of accelerated aging, obtained 0.621% to Juparana Bordeaux, 0.910% for Branco Nevasca and 0.840% for Golden Artico. The permeability of the samples showed values in the natural

  9. Preface: Introductory Remarks: Linear Scaling Methods

    Science.gov (United States)

    Bowler, D. R.; Fattebert, J.-L.; Gillan, M. J.; Haynes, P. D.; Skylaris, C.-K.

    2008-07-01

    It has been just over twenty years since the publication of the seminal paper on molecular dynamics with ab initio methods by Car and Parrinello [1], and the contribution of density functional theory (DFT) and the related techniques to physics, chemistry, materials science, earth science and biochemistry has been huge. Nevertheless, significant improvements are still being made to the performance of these standard techniques; recent work suggests that speed improvements of one or even two orders of magnitude are possible [2]. One of the areas where major progress has long been expected is in O(N), or linear scaling, DFT, in which the computer effort is proportional to the number of atoms. Linear scaling DFT methods have been in development for over ten years [3] but we are now in an exciting period where more and more research groups are working on these methods. Naturally there is a strong and continuing effort to improve the efficiency of the methods and to make them more robust. But there is also a growing ambition to apply them to challenging real-life problems. This special issue contains papers submitted following the CECAM Workshop 'Linear-scaling ab initio calculations: applications and future directions', held in Lyon from 3-6 September 2007. A noteworthy feature of the workshop is that it included a significant number of presentations involving real applications of O(N) methods, as well as work to extend O(N) methods into areas of greater accuracy (correlated wavefunction methods, quantum Monte Carlo, TDDFT) and large scale computer architectures. As well as explicitly linear scaling methods, the conference included presentations on techniques designed to accelerate and improve the efficiency of standard (that is non-linear-scaling) methods; this highlights the important question of crossover—that is, at what size of system does it become more efficient to use a linear-scaling method? As well as fundamental algorithmic questions, this brings up

  10. Acceleration Modes and Transitions in Pulsed Plasma Accelerators

    Science.gov (United States)

    Polzin, Kurt A.; Greve, Christine M.

    2018-01-01

    accelerators was developed by Cheng, et al. The Coaxial High ENerGy (CHENG) thruster operated on the 10-microseconds timescales of pulsed plasma thrusters, but claimed high thrust density, high efficiency and low electrode erosion rates, which are more consistent with the deflagration mode of acceleration. Separate work on gas-fed pulsed plasma thrusters (PPTs) by Ziemer, et al. identified two separate regimes of performance. The regime at higher mass bits (termed Mode I in that work) possessed relatively constant thrust efficiency (ratio of jet kinetic energy to input electrical energy) as a function of mass bit. In the second regime at very low mass bits (termed Mode II), the efficiency increased with decreasing mass bit. Work by Poehlmann et al. and by Sitaraman and Raja sought to understand the performance of the CHENG thruster and the Mode I / Mode II performance in PPTs by modeling the acceleration using the Hugoniot Relation, with the detonation and deflagration modes representing two distinct sets of solutions to the relevant conservation laws. These works studied the proposal that, depending upon the values of the various controllable parameters, the accelerator would operate in either the detonation or deflagration mode. In the present work, we propose a variation on the explanation for the differences in performance between the various pulsed plasma accelerators. Instead of treating the accelerator as if it were only operating in one mode or the other during a pulse, we model the initial stage of the discharge in all cases as an accelerating current sheet (detonation mode). If the current sheet reaches the exit of the accelerator before the discharge is completed, the acceleration mode transitions to the deflagration mode type found in the quasi-steady MPD thrusters. This modeling method is used to demonstrate that standard gas-fed pulsed plasma accelerators, the CHENG thruster, and the quasi-steady MPD accelerator are variations of the same device, with the overall

  11. Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields.

    Science.gov (United States)

    Stewart, Alexandra J; O'Farrell, Desmond A; Cormack, Robert A; Hansen, Jorgen L; Khan, Atif J; Mutyala, Subhakar; Devlin, Phillip M

    2008-11-19

    To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite applicator and compare to those produced by whole breast external beam radiotherapy (WBRT). Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10) and the dose received by 20 cc of the structure (D20), were calculated as well as the maximum and mean doses received. Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925-1380 cc. Cardiac volumes ranged from 337-551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction. This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets.

  12. Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields

    Directory of Open Access Journals (Sweden)

    Mutyala Subhakar

    2008-11-01

    Full Text Available Abstract Purpose To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite™ applicator and compare to those produced by whole breast external beam radiotherapy (WBRT. Materials and methods Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10 and the dose received by 20 cc of the structure (D20, were calculated as well as the maximum and mean doses received. Results Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925–1380 cc. Cardiac volumes ranged from 337–551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction. Conclusion This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets. Trial registration Dana Farber Trial Registry number 03-179

  13. Microstructural evolution and mechanical properties of a novel FeCrNiBSi advanced high-strength steel: Slow, accelerated and fast casting cooling rates

    Energy Technology Data Exchange (ETDEWEB)

    Askari-Paykani, Mohsen; Shahverdi, Hamid Reza, E-mail: shahverdi@modares.ac.ir; Miresmaeili, Reza

    2016-06-21

    In the current work, three different solidification routes and a two-step heat treatment process were applied to a novel FeCrNiBSi alloy system to introduce a new candidate for advanced high-strength steels. The evolution of the microstructure after solidification, heat treatment, and tensile deformation was characterized using optical and electron microscopy techniques, as well as hardness and room temperature uniaxial tensile tests. The effects of the different solidification routes and heat treatment parameters on the deformation and fracture mechanisms of this steel are discussed. Grain refinement, precipitation hardening, and solid solution as a result of the fast casting cooling rate led to an increase in strength at improved ductility. This result can be explained partly by the less severe stress/strain partitioning at the matrix grain/M{sub 2}B interfaces and better interface cohesion. Moreover, the stress/strain partitioning characteristics between the matrix grains and M{sub 2}B led to a higher initial strain hardening rate. The fast casting cooling rate further promoted ductile fracture mechanisms, which is a result of increased cleavage fracture stress. The higher casting cooling rate and two-step heat treatment resulted in a strong increase in formability index, from 8 GPa% to 24 GPa%, at which the mechanical properties occupy the TRIP envelope. Heat treatment of the fast-cooling specimens led to a small reduction in yield and tensile strength and 22% total elongation percentage improvement (from 10% to 32%).

  14. Estimation of precipitation rates by measurements of {sup 36}Cl in the GRIP ice core with the PSI/ETH tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, G.; Baumgartner, S.; Beer, J. [EAWAG, Duebendorf (Switzerland); Synal, H.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Suter, M. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Within the European Greenland ice core project (GRIP) {sup 36}Cl AMS measurements have been performed on ice core samples from Summit (Greenland, 73{sup o}N, 37{sup o}W). Most data analysed so far are from the lower part of the ice core. The {sup 36}Cl concentration is well correlated with {delta}{sup 18}O, which is considered as a proxy for paleotemperatures. Assuming that the deposition rate of radionuclides is independent of {delta}{sup 18}O, {sup 36}Cl is used to estimate the relationship between accumulation and {delta}{sup 18}O. The results confirm that the rapid changes of {delta}{sup 18}O, the so-called Dansgaard-Oeschger events, are also reflected in the precipitation rate. (author) 1 fig., 3 refs.

  15. Particle Acceleration in the Heliosphere: Implications for Astrophysics

    Science.gov (United States)

    Fisk, L. A.; Gloeckler, G.

    2012-11-01

    There has been a remarkable discovery concerning particles that are accelerated in the solar wind. At low energies, in the region where the particles are being accelerated, the spectrum of the accelerated particles is always the same: when expressed as a distribution function, the spectrum is a power law in particle speed with a spectral index of -5, and a rollover at higher particle speeds that can often be described as exponential. This common spectral shape cannot be accounted for by any conventional acceleration mechanism, such as diffusive shock acceleration or traditional stochastic acceleration. It has thus been necessary to invent a new acceleration mechanism to account for these observations, a pump mechanism in which particles are pumped up in energy through a series of adiabatic compressions and expansions. The conditions under which the pump acceleration is the dominant acceleration mechanism are quite general and are likely to occur in other astrophysical plasmas. In this paper, the most compelling observations of the -5 spectra are reviewed; the governing equation of the pump acceleration mechanism is derived in detail; the pump acceleration mechanism is applied to acceleration at shocks; and, as an illustration of the potential applicability of the pump acceleration mechanism to other astrophysical plasmas, the pump mechanism is applied to the acceleration of galactic cosmic rays in the interstellar medium.

  16. A High-Fat Diet Containing Lard Accelerates Prostate Cancer Progression and Reduces Survival Rate in Mice: Possible Contribution of Adipose Tissue-Derived Cytokines

    Directory of Open Access Journals (Sweden)

    Han Jin Cho

    2015-04-01

    Full Text Available To examine the effects of high-fat diet (HFD containing lard on prostate cancer development and progression and its underlying mechanisms, transgenic adenocarcinoma mouse prostate (TRAMP and TRAMP-C2 allograft models, as well as in vitro culture models, were employed. In TRAMP mice, HFD feeding increased the incidence of poorly differentiated carcinoma and decreased that of prostatic intraepithelial neoplasia in the dorsolateral lobes of the prostate, which was accompanied by increased expression of proteins associated with proliferation and angiogenesis. HFD feeding also led to increased metastasis and decreased survival rate in TRAMP mice. In the allograft model, HFD increased solid tumor growth, the expression of proteins related to proliferation/angiogenesis, the number of lipid vacuoles in tumor tissues, and levels of several cytokines in serum and adipose tissue. In vitro results revealed that adipose tissue-conditioned media from HFD-fed mice stimulated the proliferation and migration of prostate cancer cells and angiogenesis compared to those from control-diet-fed mice. These results indicate that the increase of adipose tissue-derived soluble factors by HFD feeding plays a role in the growth and metastasis of prostate cancer via endocrine and paracrine mechanisms. These results provide evidence that a HFD containing lard increases prostate cancer development and progression, thereby reducing the survival rate.

  17. Heart rate and pulmonary function while wearing the launch-entry crew escape suit (LES) during + Gx acceleration and simulated Shuttle launch

    Science.gov (United States)

    Krutz, Robert W., Jr.; Bagian, James P.; Burton, Russell R.; Meeker, Larry J.

    1990-01-01

    Space shuttle crewmembers have been equipped with a launch-entry crew escape system (LES) since the Challenger accident in 1986. Some crewmembers, wearing the new pressure suit, have reported breathing difficulties and increased effort to achieve the desired range of motion. This study was conducted to quantify the reported increased physical workloads and breathing difficulty associated with wearing the LES. Both veteran astronauts and centrifuge panel members were exposed to various + Gx profiles (including simulated shuttle launch) + Gx on the USAF School of Aerospace Medicine (USAFSAM) human-use centrifuge. Maximum heart rate data showed no increased workload associated with arm and head movement in the LES when compared to the flight suit/helmet ensemble (LEH). However, the LES did impose a significant increase in breathing difficulty beginning at +2.5 Gx which was demonstrated by a decrease in forced vital capacity and subjected questionnaries.

  18. Extracting Realistic Kinetics of Rare Activated Processes from Accelerated Molecular Dynamics Using Kramers' Theory.

    Science.gov (United States)

    Doshi, Urmi; Hamelberg, Donald

    2011-03-08

    The cis-trans isomerization of peptide bonds is very slow, occurring in hundreds of seconds. Kinetic studies of such processes using straightforward molecular dynamics are currently not possible. Here, we use Kramers' rate theory in the high friction regime in combination with accelerated molecular dynamics in explicit solvent to successfully retrieve the normal rate of cis to trans switching in the glycyl-prolyl dipeptide. Our approach bypasses the time-reweighting problem of the hyperdynamics scheme, wherein the addition of the bias potential alters the transition state regions and avoids an accurate estimation of kinetics. By performing accelerated molecular dynamics at a few different levels of acceleration, the rate of isomerization is enhanced as much as 10(10) to 10(11) times. Remarkably, the normal rates obtained by simply extrapolating to zero bias are within an order of experimental estimates. This provides validation from a kinetic standpoint of the ω torsional parameters of the AMBER force field that were recently revised by matching to experimentally measured equilibrium properties. We also provide a comparative analysis of the performance of the widely used water models, i.e., TIP3P and SPC/E, in estimating the kinetics of cis-trans isomerization. Furthermore, we show that the dynamic properties of bulk water can be corrected by adjusting the collision frequency in a Langevin thermostat, which then allows for better reproduction of cis-trans isomerization kinetics and a closer agreement of rates between experiments and simulations.

  19. Seismic-induced accelerations detected by two parallel gravity meters in continuous recording with a high sampling rate at Etna volcano

    Directory of Open Access Journals (Sweden)

    P. Stefanelli

    2008-06-01

    Full Text Available We analyse a microgravity data set acquired from two spring LaCoste & Romberg gravity meters operated in parallel at the same site on Etna volcano (Italy for about two months (August – September 2005. The high sampling rate acquisition (2Hz allowed the correlation of short-lasting gravity fluctuations with seismic events. After characterizing the oscillation behavior of the meters, through the study of spectral content and the background noise level of both sequences, we recognized fluctuations in the gravity data, spanning a range of periods from 1 second to about 30 seconds dominated by components with a period of about 15 ÷ 25 seconds, during time intervals encompassing both local seismic events and large worldwide earthquakes. The data analyses demonstrate that observed earthquake-induced gravity fluctuations have some differences due to diverse spectral content of the earthquakes. When local seismic events which present high frequency content excite the meters, the correlation between the two gravity signals is poor (factor < 0.3. Vice versa, when large worldwide earthquakes occur and low frequency seismic waves dominate the ensuing seismic wavefield, the resonance frequencies of the meters are excited and they react according to more common features. In the latter case, the signals from the two instruments are strongly correlated to each other (up to 0.9. In this paper the behaviors of spring gravimeters in the frequency range of the disturbances produced by local and large worldwide earthquakes are presented and discussed.

  20. Unusual accelerated rate of deletions and insertions in toxin genes in the venom glands of the pygmy copperhead (Austrelaps labialis) from Kangaroo island.

    Science.gov (United States)

    Doley, Robin; Tram, Nguyen Ngoc Bao; Reza, Md Abu; Kini, R Manjunatha

    2008-02-28

    Toxin profiling helps in cataloguing the toxin present in the venom as well as in searching for novel toxins. The former helps in understanding potential pharmacological profile of the venom and evolution of toxins, while the latter contributes to understanding of novel mechanisms of toxicity and provide new research tools or prototypes of therapeutic agents. The pygmy copperhead (Austrelaps labialis) is one of the less studied species. In this present study, an attempt has been made to describe the toxin profile of A. labialis from Kangaroo Island using the cDNA library of its venom glands. We sequenced 658 clones which represent the common families of toxin genes present in snake venom. They include (a) putative long-chain and short-chain neurotoxins, (b) phospholipase A2, (c) Kunitz-type protease inhibitor, (d) CRISPs, (e) C-type lectins and (f) Metalloproteases. In addition, we have also identified a novel protein with two Kunitz-type domains in tandem similar to bikunin. Interestingly, the cDNA library reveals that most of the toxin families (17 out of 43 toxin genes; approximately 40%) have truncated transcripts due to insertion or deletion of nucleotides. These truncated products might not be functionally active proteins. However, cellular transcripts from the same venom glands are not affected. This unusual higher rate of deletion and insertion of nucleotide in toxin genes may be responsible for the lower toxicity of A. labialis venom of Kangroo Island and have significant effect on evolution of toxin genes.

  1. Mechanical Design of Superconducting Accelerator Magnets

    CERN Document Server

    Toral, Fernando

    2014-07-17

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, costheta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a compact superconducting cyclotron summarizes the main steps and the guidelines that should be followed for a proper mechanical design. Finally, we present some remarks on the measurement techniques.

  2. Application of electron accelerator worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Sueo [Japan Atomic Industrial Forum, Inc., Tokyo (Japan)

    2003-02-01

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  3. Unusual accelerated rate of deletions and insertions in toxin genes in the venom glands of the pygmy copperhead (Austrelaps labialis from kangaroo island

    Directory of Open Access Journals (Sweden)

    Kini R Manjunatha

    2008-02-01

    Full Text Available Abstract Background Toxin profiling helps in cataloguing the toxin present in the venom as well as in searching for novel toxins. The former helps in understanding potential pharmacological profile of the venom and evolution of toxins, while the latter contributes to understanding of novel mechanisms of toxicity and provide new research tools or prototypes of therapeutic agents. Results The pygmy copperhead (Austrelaps labialis is one of the less studied species. In this present study, an attempt has been made to describe the toxin profile of A. labialis from Kangaroo Island using the cDNA library of its venom glands. We sequenced 658 clones which represent the common families of toxin genes present in snake venom. They include (a putative long-chain and short-chain neurotoxins, (b phospholipase A2, (c Kunitz-type protease inhibitor, (d CRISPs, (e C-type lectins and (f Metalloproteases. In addition, we have also identified a novel protein with two Kunitz-type domains in tandem similar to bikunin. Conclusion Interestingly, the cDNA library reveals that most of the toxin families (17 out of 43 toxin genes; ~40% have truncated transcripts due to insertion or deletion of nucleotides. These truncated products might not be functionally active proteins. However, cellular trancripts from the same venom glands are not affected. This unusual higher rate of deletion and insertion of nucleotide in toxin genes may be responsible for the lower toxicity of A. labialis venom of Kangroo Island and have significant effect on evolution of toxin genes.

  4. A remarkable climate warming hiatus over Northeast China since 1998

    Science.gov (United States)

    Sun, Xiubao; Ren, Guoyu; Ren, Yuyu; Fang, Yihe; Liu, Yulian; Xue, Xiaoying; Zhang, Panfeng

    2017-07-01

    Characteristics and causes of global warming hiatus (GWH) phenomenon have received much attention in recent years. Monthly mean data of land surface air maximum temperature (Tmax), minimum temperature (Tmin), and mean temperature (Tmean) of 118 national stations since 1951 in Northeast China are used in this paper to analyze the changes of land surface air temperature in recent 64 years with an emphasis on the GWH period. The results show that (1) from 1951 to 2014, the warming trends of Tmax, Tmin, and Tmean are 0.20, 0.42, and 0.34 °C/decade respectively for the whole area, with the warming rate of Tmin about two times of Tmax, and the upward trend of Tmean obviously higher than mainland China and global averages; (2) in the period 1998-2014, the annual mean temperature consistently exhibits a cooling phenomenon in Northeast China, and the trends of Tmax, Tmin, and Tmean are -0.36, -0.14, and -0.28 °C/decade respectively; (3) in the GWH period, seasonal mean cooling mainly occurs in northern winter (DJF) and spring (MAM), but northern summer (JJA) and autumn (SON) still experience a warming, implying that the annual mean temperature decrease is controlled by the remarkable cooling of winter and spring; (4) compared to the global and mainland China averages, the hiatus phenomenon is more evident in Northeast China, and the cooling trends are more obvious in the cold season; (5) the Northeast China cooling trend occurs under the circulation background of the negative phase Arctic Oscillation (AO), and it is also closely related to strengthening of the Siberia High (SH) and the East Asian Trough (EAT), and the stronger East Asian winter monsoon (EAWM) over the GWH period.

  5. Calorimetry at industrial electron accelerators

    DEFF Research Database (Denmark)

    Miller, Arne; Kovacs, A.

    1985-01-01

    Calorimetry is a convenient way to measure doses at industrial electron accelerators, where high absorbed doses (1-100 kGy) are delivered at dose rates of 102-105 Gy s-1 or even higher. Water calorimeters have been used for this purpose for several years, but recently other materials such as grap......Calorimetry is a convenient way to measure doses at industrial electron accelerators, where high absorbed doses (1-100 kGy) are delivered at dose rates of 102-105 Gy s-1 or even higher. Water calorimeters have been used for this purpose for several years, but recently other materials...

  6. Piezoelectric particle accelerator

    Science.gov (United States)

    Kemp, Mark A.; Jongewaard, Erik N.; Haase, Andrew A.; Franzi, Matthew

    2017-08-29

    A particle accelerator is provided that includes a piezoelectric accelerator element, where the piezoelectric accelerator element includes a hollow cylindrical shape, and an input transducer, where the input transducer is disposed to provide an input signal to the piezoelectric accelerator element, where the input signal induces a mechanical excitation of the piezoelectric accelerator element, where the mechanical excitation is capable of generating a piezoelectric electric field proximal to an axis of the cylindrical shape, where the piezoelectric accelerator is configured to accelerate a charged particle longitudinally along the axis of the cylindrical shape according to the piezoelectric electric field.

  7. A Remarkable Recent Transition in the Solar Dynamo

    NARCIS (Netherlands)

    de Jager, C.; Akasofu, S.-I.; Duhau, S.; Livingston, W.C.; Nieuwenhuijzen, H.; Potgieter, M.S.

    2016-01-01

    We summarize the major aspects of the remarkable, fairly long lasting period(∼ 2005 to ∼ 2010) of low solar activity, that we will call the Transition. It is the transitionalstage between the Grand Maximum of the 20th century and a forthcoming (most probablyRegular) episode of solar activity. The

  8. Remark on an infinite semipositone problem with indefinite weight ...

    Indian Academy of Sciences (India)

    (Math. Sci.) Vol. 123, No. 1, February 2013, pp. 145–150. c Indian Academy of Sciences. Remark on an infinite semipositone problem with indefinite weight and falling zeros ... 1Department of Mathematics, Faculty of Mathematical Sciences,. University of ... where 0 0 and c > 0 are constants, is a bounded domain ...

  9. Initial remarks on Sur la genèse

    Directory of Open Access Journals (Sweden)

    G. M. Goshgarian

    2012-01-01

    Full Text Available G. M. Goshgarian describes historical and theoretical context in whichAlthusser’s note On Genesis has been written. Goshgarian indicated theoreticalsources of althusserian remarks in the theme of genesis. He invokes – next to Marx– such names as Montaigne or Spinoza.

  10. Bounding the number of remarkable values via Jouanolou's theorem

    OpenAIRE

    Chèze, Guillaume

    2015-01-01

    In this article we bound the number of remarkable values of a polynomial vector field. The proof is short and based on Jouanolou's theorem about rational first integrals of planar polynomial derivations. Our bound is given in term of the size of a Newton polygon associated to the vector field. We prove that this bound is almost reached.

  11. Bounding the number of remarkable values via Jouanolou's theorem

    Science.gov (United States)

    Chèze, Guillaume

    2015-05-01

    In this article we bound the number of remarkable values of a polynomial vector field. The proof is short and based on Jouanolou's theorem about rational first integrals of planar polynomial derivations. Our bound is given in term of the size of a Newton polygon associated to the vector field. We prove that this bound is almost reached.

  12. Remarkable visual recovery after severe open globe injury

    Directory of Open Access Journals (Sweden)

    Yewlin E. Chee

    2016-10-01

    Conclusions and importance: Poor presenting acuity is a known risk factor for poor visual outcome after open globe injury. We hypothesize this remarkable visual recovery could be attributable to the presence of a massive choroidal hemorrhage and limited intraocular hemorrhage elsewhere. In rare cases, vision can improve from the no light perception level after secondary vitreoretinal surgery.

  13. Discussant Remarks on Session: Statistical Aspects of Measuring the Internet

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, Les

    1999-04-02

    These remarks will briefly summarize what we learn from the talks in this session, and add some more areas in Internet Measurement that may provide challenges for statisticians. It will also point out some reasons why statisticians may be interested in working in this area.

  14. Some Remarks on Iterated Maps of Natural Numbers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 11. Some Remarks on Iterated Maps of Natural Numbers. Agnes M Herzberg M Ram Murty. General Article Volume 19 Issue 11 November 2014 pp 1038-1046. Fulltext. Click here to view fulltext PDF. Permanent link:

  15. Polypyridyl iron(II) complexes showing remarkable photocytotoxicity ...

    Indian Academy of Sciences (India)

    aditya

    Polypyridyl iron(II) complexes showing remarkable photocytotoxicity in visible light. ADITYA GARAI a. , UTTARA BASU a. , ILA PANT b. , PATURU KONDAIAH*. ,b. AND. AKHIL R. CHAKRAVARTY*. ,a a. Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore. 560012, India. E-mail: ...

  16. Carbon nanocages: A new support material for Pt catalyst with remarkably high durability

    Science.gov (United States)

    Wang, Xiao Xia; Tan, Zhe Hua; Zeng, Min; Wang, Jian Nong

    2014-01-01

    Low durability is the major challenge hindering the large-scale implementation of proton exchange membrane fuel cell (PEMFC) technology, and corrosion of carbon support materials of current catalysts is the main cause. Here, we describe the finding of remarkably high durability with the use of a novel support material. This material is based on hollow carbon nanocages developed with a high degree of graphitization and concurrent nitrogen doping for oxidation resistance enhancement, uniform deposition of fine Pt particles, and strong Pt-support interaction. Accelerated degradation testing shows that such designed catalyst possesses a superior electrochemical activity and long-term stability for both hydrogen oxidation and oxygen reduction relative to industry benchmarks of current catalysts. Further testing under conditions of practical fuel cell operation reveals almost no degradation over long-term cycling. Such a catalyst of high activity, particularly, high durability, opens the door for the next-generation PEMFC for “real world” application. PMID:24658614

  17. Application of Plasma Waveguides to High Energy Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Milchberg, Howard [Univ. of Maryland, College Park, MD (United States)

    2016-07-01

    This grant supported basic experimental, theoretical and computer simulation research into developing a compact, high pulse repetition rate laser accelerator using the direct laser acceleration mechanism in plasma-based slow wave structures.

  18. DOE-HEP Final Report for 2013-2016: Studies of plasma wakefields for high repetition-rate plasma collider, and Theoretical study of laser-plasma proton and ion acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Katsouleas, Thomas C. [Duke Univ., Durham, NC (United States). Dept. of Electrical and Computer Engineering; Sahai, Aakash A. [Imperial College, London (United Kingdom). Dept. of Physics

    2016-08-08

    There were two goals for this funded project: 1. Studies of plasma wakefields for high repetition-rate plasma collider, and 2. Theoretical study of laser-plasma proton and ion acceleration. For goal 1, an analytical model was developed to determine the ion-motion resulting from the interaction of non-linear “blow-out” wakefields excited by beam-plasma and laser-plasma interactions. This is key to understanding the state of the plasma at timescales of 1 picosecond to a few 10s of picoseconds behind the driver-energy pulse. More information can be found in the document. For goal 2, we analytically and computationally analyzed the longitudinal instabilities of the laser-plasma interactions at the critical layer. Specifically, the process of “Doppler-shifted Ponderomotive bunching” is significant to eliminate the very high-energy spread and understand the importance of chirping the laser pulse frequency. We intend to publish the results of the mixing process in 2-D. We intend to publish Chirp-induced transparency. More information can be found in the document.

  19. 2014 CERN Accelerator Schools: Plasma Wake Acceleration

    CERN Multimedia

    2014-01-01

    A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

  20. Acceleration effects on atomic clocks

    CERN Document Server

    Dahia, F

    2014-01-01

    We consider a free massive particle inside a box which is dragged by Rindler observers. Admitting that the particle obeys the Klein-Gordon equation, we find the frequencies of the stationary states of this system. Transitions between the stationary states are employed to set a standard frequency for a toy atomic clock. Comparing the energy spectrum of the accelerated system with the energy spectrum of an identical system in an inertial frame, we determine the influence of the instantaneous acceleration on the rate of atomic clocks. We argue that our result does not violate the clock hypothesis.

  1. Objective and Longitudinal Assessment of Dermatitis After Postoperative Accelerated Partial Breast Irradiation Using High-Dose-Rate Interstitial Brachytherapy in Patients With Breast Cancer Treated With Breast Conserving Therapy: Reduction of Moisture Deterioration by APBI

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Eiichi [Department of Radiation Oncology, National Hospital Organization, Osaka National Hospital, Osaka (Japan); Yamazaki, Hideya, E-mail: hideya10@hotmail.com [Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Yoshida, Ken; Takenaka, Tadashi [Department of Radiation Oncology, National Hospital Organization, Osaka National Hospital, Osaka (Japan); Masuda, Norikazu [Department of Surgery and Breast Oncology, National Hospital Organization, Osaka National Hospital, Osaka (Japan); Kotsuma, Tadayuki; Yoshioka, Yasuo; Inoue, Takehiro [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita (Japan)

    2011-11-15

    Purpose: To objectively evaluate the radiation dermatitis caused by accelerated partial breast irradiation (APBI) using high-dose-rate interstitial brachytherapy. Patients and Methods: The skin color and moisture changes were examined using a newly installed spectrophotometer and corneometer in 22 patients who had undergone APBI using open cavity implant high-dose-rate interstitial brachytherapy (36 Gy in six fractions) and compared with the corresponding values for 44 patients in an external beam radiotherapy (EBRT) control group (50-60 Gy in 25-30 fractions within 5-6 weeks) after breast conserving surgery. Results: All values changed significantly as a result of APBI. The extent of elevation in a Asterisk-Operator (reddish) and reduction in L Asterisk-Operator (black) values caused by APBI were similar to those for EBRT, with slightly delayed recovery for 6-12 months after treatment owing to the surgical procedure. In contrast, only APBI caused a change in the b Asterisk-Operator values, and EBRT did not, demonstrating that the reduction in b Asterisk-Operator values (yellowish) depends largely on the surgical procedure. The changes in moisture were less severe after APBI than after EBRT, and the recovery was more rapid. The toxicity assessment using the Common Toxicity Criteria, version 3, showed that all dermatitis caused by APBI was Grade 2 or less. Conclusion: An objective analysis can quantify the effects of APBI procedures on color and moisture cosmesis. The radiation dermatitis caused by APBI using the present schedule showed an equivalent effect on skin color and a less severe effect on moisture than the effects caused by standard EBRT.

  2. Growth depression and recovery: the remarkable case of American slaves.

    Science.gov (United States)

    Steckel, R H

    1987-01-01

    Legislation designed to prevent slave smuggling after 1807 created an extra-ordinary set of documents identifying slaves transported in the coastwise trade by name, age, sex height and colour. Slaves fell below the first or second centile of modern height standards as children but recovered during and after adolescence to exceed the 25th centile as adults. This profile differs remarkably from other populations. Poor pre-natal care, early weaning, food supplements that were nutritionally poor and often contaminated, and a heavy disease load thwarted growth during childhood, but the diet improved substantially when young adolescents entered the labour force. The results show that humans have remarkable capacity for catch-up growth.

  3. Virtual gap dielectric wall accelerator

    Science.gov (United States)

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  4. High Energy Particle Accelerators

    CERN Multimedia

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  5. Improved plasma accelerator

    Science.gov (United States)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  6. Metabolic acceleration in Mediterranean Perciformes

    Science.gov (United States)

    Lika, Konstadia; Kooijman, Sebastiaan A. L. M.; Papandroulakis, Nikos

    2014-11-01

    Larval stages are considered the most critical of fish development. During a very short period of time (2 to 3 months), larvae undergo major morphoanatomical and functional changes in order to transform into juveniles while remaining functioning (developing, eating, surviving). Depending on species and environmental conditions, patterns in larval development may vary. We study the patterns of larval development for nine fish species of Perciformes reared under aquaculture conditions and compare them in terms of species-specific parameters derived from DEB theory. We extended the standard DEB model to include metabolic acceleration during the larval period, where maximum specific assimilation and energy conductance increase with length between birth and metabolic metamorphosis. Metabolic acceleration has as a consequence that larvae initially grow slower than juveniles and adults. Our results indicate that the species with higher acceleration have lower growth rates at birth and they also suggest that metabolic acceleration is related to spawning season. High metabolic acceleration of demersal species is associated with summer-autumn spawning in the Mediterranean, where temperature is high and food availability is low.

  7. Highly charged ion injector in the terminal of tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, M; Asozu, T; Nakanoya, T; Kutsukake, K; Hanashima, S; Takeuchi, S, E-mail: matsuda.makoto@jaea.go.j [Japan Atomic Energy Agency, Tokai Research and Development Center, Nuclear Science Research Institute, Tandem Accelerator Section 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki, 319-1195 (Japan)

    2009-04-01

    A highly charged heavy ion injector using an all permanent magnet type electron cyclotron resonance ion source (ECRIS) has been constructed in the high voltage terminal of the vertical and folded type 20UR Pelletron tandem accelerator at Japan Atomic Energy Agency at Tokai. The new in-terminal injector made it possible to accelerate highly charged heavy ions which have not been obtained from the tandem accelerator. Beam energy and beam intensity have been remarkably increased and the noble gas ion beams have become available.

  8. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics The CERN Accelerator School: Introduction to Accelerator Physics, which should have taken place in Istanbul, Turkey, later this year has now been relocated to Budapest, Hungary.  Further details regarding the new hotel and dates will be made available as soon as possible on a new Indico site at the end of May.

  9. Accelerators and Dinosaurs

    CERN Multimedia

    Turner, Michael Stanley

    2003-01-01

    Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

  10. Remarks on Hawking radiation as tunneling from a uniformly ...

    Indian Academy of Sciences (India)

    Abstract. Motivated by the Hamilton–Jacobi method of Angheben et al, we investigate the Hawking tunneling radiation from a uniformly accelerating rectilinear black hole for which the horizons and entropy are functions of θ. After several coordinate transforma- tions, we conclude that when the self-gravitational interaction ...

  11. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  12. Accelerated corrosion of stainless steel in thiocyanate-containing solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pistorius, P Chris; Li, Wen

    2012-09-19

    It is known that reduced sulfur compounds (such as thiocyanate and thiosulfate) can accelerate active corrosion of austenitic stainless steel in acid solutions, but before we started this project the mechanism of acceleration was largely unclear. This work combined electrochemical measurements and analysis using scanning electron microscopy (SEM) and X-ray photo-electron spectroscopy (XPS), which provided a comprehensive understanding of the catalytic effect of reduced sulfur species on the active corrosion of stainless steel. Both the behavior of the pure elements and the steel were studied and the work focused on the interaction between the pure elements of the steel, which is the least understood area. Upon completion of this work, several aspects are now much clearer. The main results from this work can be summarized as follows: The presence of low concentrations (around 0.1 mM) of thiocyanate or tetrathionate in dilute sulfuric acid greatly accelerates the anodic dissolution of chromium and nickel, but has an even stronger effect on stainless steels (iron-chromium-nickel alloys). Electrochemical measurements and surface analyses are in agreement with the suggestion that accelerated dissolution really results from suppressed passivation. Even well below the passivation potential, the electrochemical signature of passivation is evident in the electrode impedance; the electrode impedance shows clearly that this pre-passivation is suppressed in the presence of thiocyanate. For the stainless steels, remarkable changes in the morphology of the corroded metal surface and in the surface concentration of chromium support the suggestion that pre-passivation of stainless steels is suppressed because dissolution of chromium is accelerated. Surface analysis confirmed that adsorbed sulfur / sulfide forms on the metal surfaces upon exposure to solutions containing thiocyanate or thiosulfate. For pure nickel, and steels containing nickel (and residual copper), bulk sulfide

  13. Industrial Application of Accelerators

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    At CERN, we are very familiar with large, high energy particle accelerators. However, in the world outside CERN, there are more than 35000 accelerators which are used for applications ranging from treating cancer, through making better electronics to removing harmful micro-organisms from food and water. These are responsible for around $0.5T of commerce each year. Almost all are less than 20 MeV and most use accelerator types that are somewhat different from what is at CERN. These lectures will describe some of the most common applications, some of the newer applications in development and the accelerator technology used for them. It will also show examples of where technology developed for particle physics is now being studied for these applications. Rob Edgecock is a Professor of Accelerator Science, with a particular interest in the medical applications of accelerators. He works jointly for the STFC Rutherford Appleton Laboratory and the International Institute for Accelerator Applications at the Univer...

  14. Industrial Application of Accelerators

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    At CERN, we are very familiar with large, high energy particle accelerators. However, in the world outside CERN, there are more than 35000 accelerators which are used for applications ranging from treating cancer, through making better electronics to removing harmful micro-organisms from food and water. These are responsible for around $0.5T of commerce each year. Almost all are less than 20 MeV and most use accelerator types that are somewhat different from what is at CERN. These lectures will describe some of the most common applications, some of the newer applications in development and the accelerator technology used for them. It will also show examples of where technology developed for particle physics is now being studied for these applications. Rob Edgecock is a Professor of Accelerator Science, with a particular interest in the medical applications of accelerators. He works jointly for the STFC Rutherford Appleton Laboratory and the International Institute for Accelerator Applications at the Uni...

  15. Accelerated Extra-Gradient Descent: A Novel Accelerated First-Order Method

    OpenAIRE

    Diakonikolas, Jelena; Orecchia, Lorenzo

    2018-01-01

    We provide a novel accelerated first-order method that achieves the asymptotically optimal convergence rate for smooth functions in the first-order oracle model. To this day, Nesterov's Accelerated Gradient Descent (AGD) and variations thereof were the only methods achieving acceleration in this standard blackbox model. In contrast, our algorithm is significantly different from AGD, as it relies on a predictor-corrector approach similar to that used by Mirror-Prox [Nemirovski, 2004] and Extra...

  16. REMARKS ON INTENSIFIERS AND INTENSIFICATION IN ENGLISH AND ROMANIAN

    Directory of Open Access Journals (Sweden)

    Constantin MANEA

    2014-05-01

    Full Text Available The aim of the present paper is to briefly illustrate and assess the main uses of intensifiers and intensification in English and Romanian, trying to hint at the complexity of the phenomenon in the two languages, while sketchily suggesting ways to improve the teaching and learning activities in Romanian schools, as well as much of the activity of translators in this country. The authors’s illustrative treatment tackles the broader sphere of intensification, not only such intensifiers as very, terribly, awfully, really, definitely, kind of. The main subsections of the paper deal, respectively, with semantic aspects, word formation, syntactic aspects, stylistic issues, and a few remarks on usage.

  17. Concluding remarks: Faraday Discussion on chemistry in the urban atmosphere.

    Science.gov (United States)

    Jimenez, Jose L

    2016-07-18

    This article summarises the Concluding remarks from the Faraday Discussion on Chemistry in the Urban Atmosphere. The following themes are addressed: (a) new results that inform our understanding of the evolving sources and composition of the urban atmosphere ("News"); (b) results that identify gaps in our understanding that necessitate further work ("Gaps"); (c) the emerging instrumentation revolution and some of the challenges that it brings; (d) the structural issues of insufficient support for the analysis of field campaigns; and (e) some important areas that were missing from this Faraday Discussion and that should receive an increasing focus in the future.

  18. RTX Correction Accuracy and Real-Time Data Processing of the New Integrated SeismoGeodetic System with Real-Time Acceleration and Displacement Measurements for Earthquake Characterization Based on High-Rate Seismic and GPS Data

    Science.gov (United States)

    Zimakov, L. G.; Raczka, J.; Barrientos, S. E.

    2016-12-01

    We will discuss and show the results obtained from an integrated SeismoGeodetic System, model SG160-09, installed in the Chile (Chilean National Network), Italy (University of Naples Network), and California. The SG160-09 provides the user high rate GNSS and accelerometer data, full epoch-by-epoch measurement integrity and the ability to create combined GNSS and accelerometer high-rate (200Hz) displacement time series in real-time. The SG160-09 combines seismic recording with GNSS geodetic measurement in a single compact, ruggedized case. The system includes a low-power, 220-channel GNSS receiver powered by the latest Trimble-precise Maxwell™6 technology and supports tracking GPS, GLONASS and Galileo signals. The receiver incorporates on-board GNSS point positioning using Real-Time Precise Point Positioning (PPP) technology with satellite clock and orbit corrections delivered over IP networks. The seismic recording includes an ANSS Class A, force balance accelerometer with the latest, low power, 24-bit A/D converter, producing high-resolution seismic data. The SG160-09 processor acquires and packetizes both seismic and geodetic data and transmits it to the central station using an advanced, error-correction protocol providing data integrity between the field and the processing center. The SG160-09 has been installed in three seismic stations in different geographic locations with different Trimble global reference stations coverage The hardware includes the SG160-09 system, external Zephyr Geodetic-2 GNSS antenna, both radio and high-speed Internet communication media. Both acceleration and displacement data was transmitted in real-time to the centralized Data Acquisition Centers for real-time data processing. Command/Control of the field station and real-time GNSS position correction are provided via the Pivot platform. Data from the SG160-09 system was used for seismic event characterization along with data from traditional seismic and geodetic stations

  19. Characteristics of diffusion flames with accelerated motion

    Directory of Open Access Journals (Sweden)

    Lou Bo

    2016-01-01

    Full Text Available The aim of this work is to present an experiment to study the characteristics of a laminar diffusion flame under acceleration. A Bunsen burner (nozzle diameter 8 mm, using liquefied petroleum gas as its fuel, was ignited under acceleration. The temperature field and the diffusion flame angle of inclination were visualised with the assistance of the visual display technology incorporated in MATLAB™. Results show that the 2-d temperature field under different accelerations matched the variation in average temperatures: they both experience three variations at different time and velocity stages. The greater acceleration has a faster change in average temperature with time, due to the accumulation of combustion heat: the smaller acceleration has a higher average temperature at the same speed. No matter what acceleration was used, in time, the flame angle of inclination increased, but the growth rate decreased until an angle of 90°: this could be explained by analysis of the force distribution within the flame. It is also found that, initially, the growth rate of angle with velocity under the greater acceleration was always smaller than that at lower accelerations; it was also different in flames with uniform velocity fire conditions.

  20. Harmonic ratcheting for fast acceleration

    Directory of Open Access Journals (Sweden)

    N. Cook

    2014-04-01

    Full Text Available A major challenge in the design of rf cavities for the acceleration of medium-energy charged ions is the need to rapidly sweep the radio frequency over a large range. From low-power medical synchrotrons to high-power accelerator driven subcritical reactor systems, and from fixed focus alternating gradient accelerators to rapid cycling synchrotrons, there is a strong need for more efficient, and faster, acceleration of protons and light ions in the semirelativistic range of hundreds of MeV/u. A conventional way to achieve a large, rapid frequency sweep (perhaps over a range of a factor of 6 is to use custom-designed ferrite-loaded cavities. Ferrite rings enable the precise tuning of the resonant frequency of a cavity, through the control of the incremental permeability that is possible by introducing a pseudoconstant azimuthal magnetic field. However, rapid changes over large permeability ranges incur anomalous behavior such as the “Q-loss” and “f-dot” loss phenomena that limit performance while requiring high bias currents. Notwithstanding the incomplete understanding of these phenomena, they can be ameliorated by introducing a “harmonic ratcheting” acceleration scheme in which two or more rf cavities take turns accelerating the beam—one turns on when the other turns off, at different harmonics—so that the radio frequency can be constrained to remain in a smaller range. Harmonic ratcheting also has straightforward performance advantages, depending on the particular parameter set at hand. In some typical cases it is possible to halve the length of the cavities, or to double the effective gap voltage, or to double the repetition rate. This paper discusses and quantifies the advantages of harmonic ratcheting in general. Simulation results for the particular case of a rapid cycling medical synchrotron ratcheting from harmonic number 9 to 2 show that stability and performance criteria are met even when realistic engineering details

  1. Remarks to the risk assessment for abandoned mine sites

    Directory of Open Access Journals (Sweden)

    Klaus Maas

    2007-06-01

    Full Text Available The authors give some remarks to the term risk regarding its use for the assessment of abandoned mine sites. These remarks are based on the recommendation Geotechnical Investigation and Evaluation of Abandoned Mine Sites developed by the working committee Abandoned Mining of the German Society for Geotechnical Engineering (DGGT and the German Society for Mine Surveying (DMV, published in 2004.By this recommendation, the risk is defined as a product of the occurrence probability and the extent of damage of an unwanted event. The occurrence probability for each unwanted event is described by the linguistic terms in all probability, probable, less probable or practically impossible. The extent of damage for each unwanted event is described by the linguistic terms insignificant, small, high or very high. A matrix out of these terms is used to define schematically an explicit limiting risk for each unwanted event.The authors point out that a schematic determination of limiting risk should be supported by an unique and comprehensible evaluation of all significant risk factors and parameters influencing the extent of damage. Fuzzy sets can be used instead of a discreet classification leading to more plausible results. The processing of linguistic terms by a fuzzy logic system is demonstrated.

  2. Computational investigation of 99Mo, 89Sr, and 131I production rates in a subcritical UO2(NO32 aqueous solution reactor driven by a 30-MeV proton accelerator

    Directory of Open Access Journals (Sweden)

    Z. Gholamzadeh

    2015-12-01

    Full Text Available The use of subcritical aqueous homogenous reactors driven by accelerators presents an attractive alternative for producing 99Mo. In this method, the medical isotope production system itself is used to extract 99Mo or other radioisotopes so that there is no need to irradiate common targets. In addition, it can operate at much lower power compared to a traditional reactor to produce the same amount of 99Mo by irradiating targets. In this study, the neutronic performance and 99Mo, 89Sr, and 131I production capacity of a subcritical aqueous homogenous reactor fueled with low-enriched uranyl nitrate was evaluated using the MCNPX code. A proton accelerator with a maximum 30-MeV accelerating power was used to run the subcritical core. The computational results indicate a good potential for the modeled system to produce the radioisotopes under completely safe conditions because of the high negative reactivity coefficients of the modeled core. The results show that application of an optimized beam window material can increase the fission power of the aqueous nitrate fuel up to 80%. This accelerator-based procedure using low enriched uranium nitrate fuel to produce radioisotopes presents a potentially competitive alternative in comparison with the reactor-based or other accelerator-based methods. This system produces ∼1,500 Ci/wk (∼325 6-day Ci of 99Mo at the end of a cycle.

  3. Accelerator and radiation physics

    CERN Document Server

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  4. Nonparaxial accelerating Talbot effect

    CERN Document Server

    Zhang, Yiqi; Belić, Milivoj R; Li, Changbiao; Zhang, Zhaoyang; Wen, Feng; Zhang, Yanpeng; Xiao, Min

    2016-01-01

    We demonstrate the Talbot effect of nonpraxial accelerating beams, theoretically and numerically. It is based on the interference of nonparaxial accelerating solutions of the Helmholtz equation in two dimensions. The effect originates from the interference of such solutions that accelerate along concentric semicircular trajectories with different radii. The Talbot images form along certain central angles, which are referred to as the Talbot angles. These angles are inversely proportional to the radial differences between the nearest beams, which are equal and fixed. A single nonparaxial accelerating beam possesses duality - it can be viewed as a Talbot effect of itself with an infinite or zero Talbot angle. By choosing the coefficient for each beam component properly, we also obtain the fractional nonparaxial accelerating Talbot effect. These results improve the understanding of nonparaxial accelerating beams and the Talbot effect among them.

  5. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  6. Experiments on Gradient Limits for Normal Conducting Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Dolgashev, Valery A.

    2003-08-11

    The accelerating gradient is one of the crucial parameters affecting the design, construction and cost of next-generation linear accelerators. For a specified final energy, the gradient sets the accelerator length, and for a given accelerating structure and pulse repetition rate, it determines power consumption. In this paper experimental results and problems related to breakdown damage, pulsed heating, application of new materials, as well as difference between standing wave (SW) and traveling wave (TW) structures will be discussed.

  7. Miniaturization Techniques for Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, James E.

    2003-05-27

    The possibility of laser driven accelerators [1] suggests the need for new structures based on micromachining and integrated circuit technology because of the comparable scales. Thus, we are exploring fully integrated structures including sources, optics (for both light and particle) and acceleration in a common format--an accelerator-on-chip (AOC). Tests suggest a number of preferred materials and techniques but no technical or fundamental roadblocks at scales of order 1 {micro}m or larger.

  8. Power Converters for Accelerators

    CERN Document Server

    Visintini, R.

    2015-06-15

    Particle accelerators use a great variety of power converters for energizing their sub-systems; while the total number of power converters usually depends on the size of the accelerator or combination of accelerators (including the experimental setup), the characteristics of power converters depend on their loads and on the particle physics requirements: this paper aims to provide an overview of the magnet power converters in use in several facilities worldwide.

  9. On the structure of acceleration in turbulence

    DEFF Research Database (Denmark)

    Liberzon, A.; Lüthi, B.; Holzner, M.

    2012-01-01

    Acceleration and spatial velocity gradients are obtained simultaneously in an isotropic turbulent flow via three dimensional particle tracking velocimetry. We observe two distinct populations of intense acceleration events: one in flow regions of strong strain and another in regions of strong...... vorticity. Geometrical alignments with respect to vorticity vector and to the strain eigenvectors, curvature of Lagrangian trajectories and of streamlines for total acceleration, and for its convective part, , are studied in detail. We discriminate the alignment features of total and convective acceleration...... statistics, which are genuine features of turbulent nature from those of kinematic nature. We find pronounced alignment of acceleration with vorticity. Similarly, and especially are predominantly aligned at 45°with the most stretching and compressing eigenvectors of the rate of the strain tensor...

  10. High Gradient Accelerator Research

    Energy Technology Data Exchange (ETDEWEB)

    Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics. Plasma Science and Fusion Center

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  11. Accelerator Review Report 2014

    OpenAIRE

    Tovey, Dan; Appleby, Rob; Bartolini, Riccardo; Bruning, Oliver; Clarke, Jim; Flint, Jonathan; Kilcoyne, Susan H.; Thomason, John; Jamieson, Charlotte; The Accelerator Science and Technology Centre (ASTeC); The Cockcroft Institute (CI); The John Adams Institute for Accelerator Science (JAI)

    2014-01-01

    The panel was created to review the accelerator programme and provide information on the breadth and scope of the STFC’s current accelerator R&D portfolio. The review’s prime driver is to underpin the development of the STFC accelerator landscape and strategy. The panel’s report will go to SB for comment and development of a high-level accelerator strategy, taking into account information from parallel reviews on neutron and photon activities. The ASB will then establish a more detailed accel...

  12. The Social Interplay of Disciplinarity and Interdisciplinarity. Some Introductory Remarks

    Directory of Open Access Journals (Sweden)

    Reinhold Hedtke

    2006-12-01

    Full Text Available Social Science Education as a subject field in schools is an intrinsic pluridisciplinary feature, whatever disciplines are included, however it may be organised and wherever it may be institutionalised. Civic education, economic education, social education and historical education each comprise several academic disciplines even if they are thought to be completely independent subjects. From the start on, disciplinarity and interdisciplinarity are on the agenda for any subject related to social science education and are one of its main problems. For these introductory remarks interdisciplinarity can be simply defined as relating two or more academic disciplines or school subjects to each other if this is done in a purposeful, systematic, explicit and reflective way. The overarching goal is to improve education that is to enhance students' understandings of the worlds and their abilities to act within and towards them. A relationship between disciplines or subjects which misses one or more of the four characteristics can be called pluridisciplinary or multidisciplinary (cf. Audigier 2006. In the following I first want to discuss some aspects of disciplinarity and interdisciplinarity at schools and at universities and the weakness of interdisciplinarity. I sketch some social science based ideas on the interrelationship between the subject structure of the academic world and the world of schools (3. and of some tendency to commonalities or even unification of social sciences and related competencies (4.. I conclude with some remarks on different kinds of knowledge (5.. Last but not least, I'll give an overview on the papers in this issue of the Journal of Social Science Education (6..

  13. Evaluation of the environmental equivalent dose rate using area monitors for neutrons in clinical linear accelerators; Avaliacao da taxa de equivalente de dose ambiente utilizando monitores de area para neutrons em aceleradores lineares clinicos

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Ana Paula; Pereira, Walsan Wagner; Patrao, Karla C. de Souza; Fonseca, Evaldo S. da, E-mail: asalgado@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Batista, Delano V.S. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The Neutron Laboratory of the Radioprotection and Dosimetry Institute - IRD/CNEN, Rio de Janeiro, Brazil, initiated studies on the process of calibration of neutron area monitors and the results of the measurements performed at radiotherapy treatment rooms, containing clinical accelerators

  14. Beam Diagnostics for Accelerators

    CERN Document Server

    Koziol, Heribert

    2005-01-01

    This introductory course aims at a reasonably complete coverage of beam diagnostic devices used in linear and circular accelerators and in primary beam lines. The weight is on the concepts and the indication of variants, while for technical details the reader is referred to the literature. The present updated version replaces those from previous General Accelerator Physics Courses.

  15. Accelerators Beyond The Tevatron?

    Energy Technology Data Exchange (ETDEWEB)

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  16. Asia honours accelerator physicists

    CERN Multimedia

    2010-01-01

    "Steve Meyers of Cern and Jie Wei of Beijing's Tsinghua University are the first recipients of a new prize for particle physics. The pair were honoured for their contributions to numerous particle-accelerator projects - including Cern's Large Hadron Collider - by the Asian Committee for Future Accelerators (ACFA)..." (1 paragraph)

  17. KEK digital accelerator

    Directory of Open Access Journals (Sweden)

    T. Iwashita

    2011-07-01

    Full Text Available The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  18. Remarks from Congressional Leaders: Congresswoman Zoe Lofgren (2011 EFRC Summit)

    Energy Technology Data Exchange (ETDEWEB)

    Lofgren, Zoe (Congresswoman, California)

    2011-05-25

    Congresswoman Zoe Lofgren (D-California) spoke during the opening session of the EFRC Summit. The 2011 EFRC Summit and Forum brought together the EFRC community and science and policy leaders from universities, national laboratories, industry and government to discuss "Science for our Nation's Energy Future." In August 2009, the Office of Science established 46 Energy Frontier Research Centers. The EFRCs are collaborative research efforts intended to accelerate high-risk, high-reward fundamental research, the scientific basis for transformative energy technologies of the future. These Centers involve universities, national laboratories, nonprofit organizations, and for-profit firms, singly or in partnerships, selected by scientific peer review. They are funded at $2 to $5 million per year for a total planned DOE commitment of $777 million over the initial five-year award period, pending Congressional appropriations. These integrated, multi-investigator Centers are conducting fundamental research focusing on one or more of several “grand challenges” and use-inspired “basic research needs” recently identified in major strategic planning efforts by the scientific community. The purpose of the EFRCs is to integrate the talents and expertise of leading scientists in a setting designed to accelerate research that transforms the future of energy and the environment.

  19. Remarks from Congressional Leaders: Congressman Daniel Lipinski (2011 EFRC Summit)

    Energy Technology Data Exchange (ETDEWEB)

    Lipinski, Daniel

    2011-05-25

    Congressman Daniel Lipinski (D-Illinois) spoke during the opening session of the EFRC Summit. The 2011 EFRC Summit and Forum brought together the EFRC community and science and policy leaders from universities, national laboratories, industry and government to discuss "Science for our Nation's Energy Future." In August 2009, the Office of Science established 46 Energy Frontier Research Centers. The EFRCs are collaborative research efforts intended to accelerate high-risk, high-reward fundamental research, the scientific basis for transformative energy technologies of the future. These Centers involve universities, national laboratories, nonprofit organizations, and for-profit firms, singly or in partnerships, selected by scientific peer review. They are funded at $2 to $5 million per year for a total planned DOE commitment of $777 million over the initial five-year award period, pending Congressional appropriations. These integrated, multi-investigator Centers are conducting fundamental research focusing on one or more of several “grand challenges” and use-inspired “basic research needs” recently identified in major strategic planning efforts by the scientific community. The purpose of the EFRCs is to integrate the talents and expertise of leading scientists in a setting designed to accelerate research that transforms the future of energy and the environment.

  20. Remarks from Congressional Leaders: Senator Jeff Bingaman (2011 EFRC Summit)

    Energy Technology Data Exchange (ETDEWEB)

    Bingaman, Jeff

    2011-05-25

    During the opening session of the EFRC Summit, Senator Jeff Bingaman (D-NM) explained how the EFRCs play an important role in the U.S. energy innovation ecosystem. The 2011 EFRC Summit and Forum brought together the EFRC community and science and policy leaders from universities, national laboratories, industry and government to discuss "Science for our Nation's Energy Future." In August 2009, the Office of Science established 46 Energy Frontier Research Centers. The EFRCs are collaborative research efforts intended to accelerate high-risk, high-reward fundamental research, the scientific basis for transformative energy technologies of the future. These Centers involve universities, national laboratories, nonprofit organizations, and for-profit firms, singly or in partnerships, selected by scientific peer review. They are funded at $2 to $5 million per year for a total planned DOE commitment of $777 million over the initial five-year award period, pending Congressional appropriations. These integrated, multi-investigator Centers are conducting fundamental research focusing on one or more of several “grand challenges” and use-inspired “basic research needs” recently identified in major strategic planning efforts by the scientific community. The purpose of the EFRCs is to integrate the talents and expertise of leading scientists in a setting designed to accelerate research that transforms the future of energy and the environment.

  1. Ultra accelerated testing of PV module components

    Science.gov (United States)

    Pitts, J. R.; King, D. E.; Bingham, C.; Czanderna, A. W.

    1999-03-01

    Using concentrated natural sunlight at the NREL High Flux Solar Furnace, we have exposed several materials to acceleration factors of up to 400 times the normal outdoor UV exposure dose. This accelerated rate allows the exposure of materials such that a year of outdoor exposure can be simulated in about 5 hours. We have studied the solarization of cerium containing glass, the degradation of ethylene vinyl acetate laminated between borosilicate glass, and the yellowing of standard polystyrene test coupons. The first two candidates are of interest to the photovoltaics (PV) program, and the last candidate material is a widely used dosimeter for ultra violet (UV) exposure in accelerated weathering chambers.

  2. Ultra Accelerated Testing of PV Module Components

    Energy Technology Data Exchange (ETDEWEB)

    Pitts, J. R.; King, D. E.; Bingham, C.; Czanderna, A. W.

    1998-10-28

    Using concentrated natural sunlight at the NREL High Flux Solar Furnace, we have exposed several materials to acceleration factors of up to 400 times the normal outdoor UV exposure dose. This accelerated rate allows the exposure of materials such that a year of outdoor exposure can be simulated in about 5 hours. We have studied the solarization of cerium containing glass, the degradation of ethylene vinyl acetate laminated between borosilicate glass, and the yellowing of standard polystyrene test coupons. The first two candidates are of interest to the photovoltaics (PV) program, and the last candidate material is a widely used dosimeter for ultra violet (UV) exposure in accelerated weathering chambers

  3. LHC Dipoles Accelerate

    CERN Multimedia

    2001-01-01

    Andrezej Siemko (left), Peter Sievers (centre), and Lucio Rossi (right), have the exciting challenge of preparing and testing 2000 magnets for the LHC. The LHC is going to require a lot of powerful magnets by the time it begins operation in 2006. More specifically, it is going to need 130 special magnets, 400 quadrupoles, and a whopping 1250 dipoles! Preparing and testing these magnets for the conditions they will encounter in the LHC is not an easy task. But evaluation of the most recently received magnet, from the German company Noell, is showing that while the monumental task of receiving and testing nearly 2000 magnets is going to be exhausting, the goals are definitely attainable. At the moment and over the next year, pre-series magnets (the magnets that CERN uses to fine tune performance) are arriving slowly (90 in total will arrive), but by 2003 the rate of series magnet arrival will accelerate to 9 per week, that's over 450 in a single year! And working with these magnets when they arrive is tough. ...

  4. The Atomki accelerator center

    Science.gov (United States)

    Vajda, I.; Fülöp, Zs.; Biri, S.

    2017-06-01

    Particle accelerators are the driving forces of nuclear physics laboratories and MTA Atomki, the Institute for Nuclear Research of the Hungarian Academy of Sciences is no exception. The Atomki Accelerator Center (AAC) incorporates several low-energy charged-particle accelerators, offering the possibility of choosing ions with various charge states, energies and beam intensities. Currently, the AAC has six main facilities: a cyclotron (K=20), two Van de Graaff accelerators (1 MV, 5 MV), an ECR ion source, an electromagnetic isotope separator and a 2 MV Tandetron installed in 2015. The accelerators, spanning a range of beam energies from 50 eV to 27 MeV, have been designed for a broad range of research projects and applications in various fields - mainly in nuclear and atomic physics, materials science, environmental research and archaeology. The structure of the laboratory with a short description of the most important topics, education and outreach activities are presented.

  5. Neutron induced activation in the EVEDA accelerator materials: Implications for the accelerator maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, J. [Department of Power Engineering, Universidad Nacional de Educacion a Distancia (UNED), C/Juan del Rosal 12, 28040 Madrid (Spain); Institute of Nuclear Fusion, UPM, 28006 Madrid (Spain)], E-mail: jsanz@ind.uned.es; Garcia, M.; Sauvan, P.; Lopez, D. [Department of Power Engineering, Universidad Nacional de Educacion a Distancia (UNED), C/Juan del Rosal 12, 28040 Madrid (Spain); Institute of Nuclear Fusion, UPM, 28006 Madrid (Spain); Moreno, C.; Ibarra, A.; Sedano, L. [CIEMAT, 28040 Madrid (Spain)

    2009-04-30

    The Engineering Validation and Engineering Design Activities (EVEDA) phase of the International Fusion Materials Irradiation Facility project should result in an accelerator prototype for which the analysis of the dose rates evolution during the beam-off phase is a necessary task for radioprotection and maintenance feasibility purposes. Important aspects of the computational methodology to address this problem are discussed, and dose rates for workers inside the accelerator vault are assessed and found to be not negligible.

  6. Neutron induced activation in the EVEDA accelerator materials: Implications for the accelerator maintenance

    Science.gov (United States)

    Sanz, J.; García, M.; Sauvan, P.; López, D.; Moreno, C.; Ibarra, A.; Sedano, L.

    2009-04-01

    The Engineering Validation and Engineering Design Activities (EVEDA) phase of the International Fusion Materials Irradiation Facility project should result in an accelerator prototype for which the analysis of the dose rates evolution during the beam-off phase is a necessary task for radioprotection and maintenance feasibility purposes. Important aspects of the computational methodology to address this problem are discussed, and dose rates for workers inside the accelerator vault are assessed and found to be not negligible.

  7. Deuteron and neutron induced activation in the Eveda accelerator materials: implications for the accelerator maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.; Sanz, J.; Garcia, N.; Cabellos, O. [Madrid Univ. Politecnica, C/ Jose Gutierrez Abascal, lnstituto de Fusion Nuclear (Spain); Sauvan, R. [Universidad Nacional de Educacion a Distancia (UNED), Madrid (Spain); Moreno, C.; Sedano, L.A. [CIEMAT-Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Association Euratom-CIEMAT, Madrid (Spain)

    2007-07-01

    Full text of publication follows: The IFMIF (International Fusion Materials Irradiation Facility) is an accelerator-based DLi neutron source designed to test fusion reactor candidate materials for high fluence neutrons. Before deciding IFMIF construction, an engineering design and associated experimental data acquisition, defined as EVEDA, has been proposed. Along the EVEDA accelerator, deuteron beam losses collide with the accelerator materials, producing activation and consequent radiations responsible of dose. Calculation of the dose rates in the EVEDA accelerator room is necessary in order to analyze the feasibility for manual maintenance. Dose rates due to the activation produced by the deuteron beam losses interaction with the accelerator materials, will be calculated with the ACAB activation code, using EAF2007 library for deuteron activation cross-sections. Also, dose rates from the activation induced by the neutron source produced by the interaction of deuteron beam losses with the accelerator materials and the deuterium implanted in the structural lattice, will be calculated with the SRIM2006, TMAP7, DROSG2000/NEUYIE, MCNPX and ACAB codes. All calculations will be done for the EVEDA accelerator with the room temperature DTL structure, which is based on copper cavities for the DTL. Some calculations will be done for the superconducting DTL structure, based on niobium cavities for the DTL working at cryogenic temperature. Final analysis will show the dominant mechanisms and major radionuclides contributing to the surface dose rates. (authors)

  8. Acceleration of oxidation-reduction reactions in freezing solution

    OpenAIRE

    Takenaka,Norimichi; Ueda,Akihiro; Maeda,Yasuaki

    1993-01-01

    In general, most chemical reactions are accelerated at higher temperature, while reactions of which activation energy is negative are accelerated at lower temperature. The reaction rates, however, become much slower in the ice phase because molecule cannot move easily. It was found that a few reactions of which activation energies were positive were accelerated in freezing aqueous solution. The reaction rates in the freezing process were 10 to (10)^5 times faster than those in solution at 25℃...

  9. Preliminary remarks for a study of urban motilities

    Directory of Open Access Journals (Sweden)

    Andrea Mubi Brighenti

    2009-03-01

    1. a dromology of displacements. This includes the study of speeds of material and immaterial (informational transfers, kinetic energy in relation to the type of propulsion or fuel (animal, mechanic, fossil, electric etc. and the type of medium (earth, water, air, wires, aether; average and instantaneous speed of transport, coefficients of velocity (= speed + directional vector, thus considering movements of entrance, exit, turning, etc., accelerations, decelerations, queues, jams, accidents, collisions, and their consequences; the study of transfer vectors, i.e. means of displacement (in relation to the different speeds each type of vehicle ensures, be it private, public, or hybrid transport and the infrastructures for displacement (in relation to the different speeds they ensure, impose or invite; description of distances and travel durations, daily and weekly overall time spent on travelling etc

  10. The miniature accelerator

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    The image that most people have of CERN is of its enormous accelerators and their capacity to accelerate particles to extremely high energies. But thanks to some cutting-edge studies on beam dynamics and radiofrequency technology, along with innovative construction techniques, teams at CERN have now created the first module of a brand-new accelerator, which will be just 2 metres long. The potential uses of this miniature accelerator will include deployment in hospitals for the production of medical isotopes and the treatment of cancer. It’s a real David-and-Goliath story.   Serge Mathot, in charge of the construction of the "mini-RFQ", pictured with the first of the four modules that will make up the miniature accelerator. The miniature accelerator consists of a radiofrequency quadrupole (RFQ), a component found at the start of all proton accelerator chains around the world, from the smallest to the largest. The LHC is designed to produce very high-intensity beams ...

  11. Multicavity proton cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    J. L. Hirshfield

    2002-08-01

    Full Text Available A mechanism for acceleration of protons is described, in which energy gain occurs near cyclotron resonance as protons drift through a sequence of rotating-mode TE_{111} cylindrical cavities in a strong nearly uniform axial magnetic field. Cavity resonance frequencies decrease in sequence from one another with a fixed frequency interval Δf between cavities, so that synchronism can be maintained between the rf fields and proton bunches injected at intervals of 1/Δf. An example is presented in which a 122 mA, 1 MeV proton beam is accelerated to 961 MeV using a cascade of eight cavities in an 8.1 T magnetic field, with the first cavity resonant at 120 MHz and with Δf=8 MHz. Average acceleration gradient exceeds 40 MV/m, average effective shunt impedance is 223 MΩ/m, but maximum surface field in the cavities does not exceed 7.2 MV/m. These features occur because protons make many orbital turns in each cavity and thus experience acceleration from each cavity field many times. Longitudinal and transverse stability appear to be intrinsic properties of the acceleration mechanism, and an example to illustrate this is presented. This acceleration concept could be developed into a proton accelerator for a high-power neutron spallation source, such as that required for transmutation of nuclear waste or driving a subcritical fission burner, provided a number of significant practical issues can be addressed.

  12. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea

    Directory of Open Access Journals (Sweden)

    Crandall Keith A

    2009-04-01

    Full Text Available Abstract Background The Thecostraca are arguably the most morphologically and biologically variable group within the Crustacea, including both suspension feeders (Cirripedia: Thoracica and Acrothoracica and parasitic forms (Cirripedia: Rhizocephala, Ascothoracida and Facetotecta. Similarities between the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups. Results To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305, 28S rRNA (2,402, Histone H3 (328] and 41 larval characters in seven facetotectans, five ascothoracidans, three acrothoracicans, 25 rhizocephalans and 39 thoracicans (ingroup and 12 Malacostraca and 10 Copepoda (outgroup. Maximum parsimony, maximum likelihood and Bayesian analyses showed the Facetotecta, Ascothoracida and Cirripedia each as monophyletic. The better resolved and highly supported DNA maximum likelihood and morphological-DNA Bayesian analysis trees depicted the main phylogenetic relationships within the Thecostraca as (Facetotecta, (Ascothoracida, (Acrothoracica, (Rhizocephala, Thoracica. Conclusion Our analyses indicate a convergent evolution of the very similar and highly reduced slug-shaped stages found during metamorphosis of both the Rhizocephala and the Facetotecta. This provides a remarkable case of convergent evolution and implies that the advanced endoparasitic mode of life known from the Rhizocephala and strongly indicated for the Facetotecta had no common origin. Future analyses are needed to determine whether the most recent common ancestor of the Thecostraca was free-living or some primitive form of ectoparasite.

  13. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea)

    Science.gov (United States)

    Pérez-Losada, Marcos; Høeg, Jens T; Crandall, Keith A

    2009-01-01

    Background The Thecostraca are arguably the most morphologically and biologically variable group within the Crustacea, including both suspension feeders (Cirripedia: Thoracica and Acrothoracica) and parasitic forms (Cirripedia: Rhizocephala, Ascothoracida and Facetotecta). Similarities between the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups. Results To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305), 28S rRNA (2,402), Histone H3 (328)] and 41 larval characters in seven facetotectans, five ascothoracidans, three acrothoracicans, 25 rhizocephalans and 39 thoracicans (ingroup) and 12 Malacostraca and 10 Copepoda (outgroup). Maximum parsimony, maximum likelihood and Bayesian analyses showed the Facetotecta, Ascothoracida and Cirripedia each as monophyletic. The better resolved and highly supported DNA maximum likelihood and morphological-DNA Bayesian analysis trees depicted the main phylogenetic relationships within the Thecostraca as (Facetotecta, (Ascothoracida, (Acrothoracica, (Rhizocephala, Thoracica)))). Conclusion Our analyses indicate a convergent evolution of the very similar and highly reduced slug-shaped stages found during metamorphosis of both the Rhizocephala and the Facetotecta. This provides a remarkable case of convergent evolution and implies that the advanced endoparasitic mode of life known from the Rhizocephala and strongly indicated for the Facetotecta had no common origin. Future analyses are needed to determine whether the most recent common ancestor of the Thecostraca was free-living or some primitive form of ectoparasite. PMID:19374762

  14. Directional selection in temporally replicated studies is remarkably consistent.

    Science.gov (United States)

    Morrissey, Michael B; Hadfield, Jarrod D

    2012-02-01

    Temporal variation in selection is a fundamental determinant of evolutionary outcomes. A recent paper presented a synthetic analysis of temporal variation in selection in natural populations. The authors concluded that there is substantial variation in the strength and direction of selection over time, but acknowledged that sampling error would result in estimates of selection that were more variable than the true values. We reanalyze their dataset using techniques that account for the necessary effect of sampling error to inflate apparent levels of variation and show that directional selection is remarkably constant over time, both in magnitude and direction. Thus we cannot claim that the available data support the existence of substantial temporal heterogeneity in selection. Nonetheless, we conject that temporal variation in selection could be important, but that there are good reasons why it may not appear in the available data. These new analyses highlight the importance of applying techniques that estimate parameters of the distribution of selection, rather than parameters of the distribution of estimated selection (which will reflect both sampling error and "real" variation in selection); indeed, despite availability of methods for the former, focus on the latter has been common in synthetic reviews of the aspects of selection in nature, and can lead to serious misinterpretations. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  15. Shared Voyage: Learning and Unlearning from Remarkable Projects

    Science.gov (United States)

    Laufer, Alexander; Post, Todd; Hoffman, Edward J.

    2005-01-01

    Shared Voyage is about four remarkable projects: the Advanced Composition Explorer (NASA), the Joint Air-to-Surface Standoff Missile (U.S. Air Force), the Pathfinder Solar-Powered Airplane (NASA), and the Advanced Medium Range Air-to-Air Missile (U.S.Air Force). Each project is presented as a case study comprised of stories collected from key members of the project teams. The stories found in the book are included with the purpose of providing an effective learning source for project management, encouraging the unlearning of outdated project management concepts, and enhancing awareness of the contexts surrounding different projects. Significantly different from project concepts found in most project management literature, Shared Voyage highlights concepts like a will to win, a results-oriented focus, and collaboration through trust. All four project teams researched in this study applied similar concepts; however, they applied them differently, tailoring them to fit the context of their own particular projects. It is clear that the one best way approach which is still the prevailing paradigm in project management literature should be replaced by a new paradigm: Even though general project management principles exist, their successful application depends on the specifics of the situation.

  16. Aging, longevity, and diet: historical remarks on calorie intake reduction.

    Science.gov (United States)

    Schafer, Daniel

    2005-01-01

    The link between longevity and diet is of great interest to biological and gerontological research. The fact that relevant knowledge has generally been available for many centuries is often not remarked upon. This article examines three aspects of early modern Western medicine which thematize the following links between the elderly, longevity and caloric intake: (1) the question of a diet specifically tailored to old age as background to certain theories of aging; (2) the transfer of these dietetic concepts to younger patients in order to improve health and extend life, and (3) the promotion of dieting in order to avoid the consequences of plethora and to retard the aging process. A number of Latin texts from premodern medical and health literature will be examined and their contents will be analyzed for material relating to diet for the elderly and longevity in their historic contexts. We will clearly indicate fundamental parallels as well as differences between historic and modern scientific thought. We will thereby show that although a modern understanding of hormones and molecular genetics was obviously lacking, basic knowledge of the influence of nutrition on old age was prevalent. In contrast, the early modern lay concept of longevity through calorie reduction was based on coincidental observation. These premodern, but nonetheless rational ideas must be integrated into the socio-cultural setting and the question must be raised as to the link between contemporary research aims and social reality. Copyright (c) 2005 S. Karger AG, Basel.

  17. Preliminary simulation of implants breast through the accelerated partial irradiation technique: coverage rates and homogeneity; Simulacion previa de implates de mama mediante la tecnica de irradiacion parcial acelerada: indices de cubrimiento y homegeneidad

    Energy Technology Data Exchange (ETDEWEB)

    Moral Sanchez, S. C.; Paula Carranza, B. de; Erzibengoa, M.; Bragado Alvarez, L.; Guisasola Berasetegui, A.

    2013-07-01

    In this work we present and evaluate the process of pre-simulation we have drawn up when it comes to treatments of accelerated partial irradiation of breast. Previous simulation that we will allow you to have greater control over the location of catheters with respect to the area to radiate. The goodness of this procedure is evaluated through representative quality indexes of the implant. (Author)

  18. Direct Laser Acceleration in Laser Wakefield Accelerators

    Science.gov (United States)

    Shaw, J. L.; Froula, D. H.; Marsh, K. A.; Joshi, C.; Lemos, N.

    2017-10-01

    The direct laser acceleration (DLA) of electrons in a laser wakefield accelerator (LWFA) has been investigated. We show that when there is a significant overlap between the drive laser and the trapped electrons in a LWFA cavity, the accelerating electrons can gain energy from the DLA mechanism in addition to LWFA. The properties of the electron beams produced in a LWFA, where the electrons are injected by ionization injection, have been investigated using particle-in-cell (PIC) code simulations. Particle tracking was used to demonstrate the presence of DLA in LWFA. Further PIC simulations comparing LWFA with and without DLA show that the presence of DLA can lead to electron beams that have maximum energies that exceed the estimates given by the theory for the ideal blowout regime. The magnitude of the contribution of DLA to the energy gained by the electron was found to be on the order of the LWFA contribution. The presence of DLA in a LWFA can also lead to enhanced betatron oscillation amplitudes and increased divergence in the direction of the laser polarization. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  19. RF linear accelerators

    CERN Document Server

    Wangler, Thomas P

    2008-01-01

    Thomas P. Wangler received his B.S. degree in physics from Michigan State University, and his Ph.D. degree in physics and astronomy from the University of Wisconsin. After postdoctoral appointments at the University of Wisconsin and Brookhaven National Laboratory, he joined the staff of Argonne National Laboratory in 1966, working in the fields of experimental high-energy physics and accelerator physics. He joined the Accelerator Technology Division at Los Alamos National Laboratory in 1979, where he specialized in high-current beam physics and linear accelerator design and technology. In 2007

  20. Confronting Twin Paradox Acceleration

    Science.gov (United States)

    Murphy, Thomas W.

    2016-05-01

    The resolution to the classic twin paradox in special relativity rests on the asymmetry of acceleration. Yet most students are not exposed to a satisfactory analysis of what exactly happens during the acceleration phase that results in the nonaccelerated observer's more rapid aging. The simple treatment presented here offers both graphical and quantitative solutions to the problem, leading to the correct result that the acceleration-induced age gap is 2Lβ years when the one-way distance L is expressed in light-years and velocity β ≡v/c .

  1. Accelerator Production of Radionuclides

    Science.gov (United States)

    Schlyer, David J.; Ruth, Thomas J.

    2012-06-01

    While many radioactive isotopes in use today are found in nature, many more are artificially produced by irradiating target materials with nuclear particles. Two different technologies can provide the energetic particles needed: nuclear reactors, which produce a flux of neutrons, and particle accelerators, which produce a flux of charged particles. This chapter will deal with the important aspects of the production of radionuclides with accelerators, along with some details on their applications, commercially-available accelerator systems used for this purpose, and the size of the equipment business.

  2. Acceleration of runaway electrons and Joule heating in solar flares

    Science.gov (United States)

    Holman, G. D.

    1985-01-01

    The electric field acceleration of electrons out of a thermal plasma and the simultaneous Joule heating of the plasma are studied. Acceleration and heating timescales are derived and compared, and upper limits are obtained on the acceleration volume and the rate at which electrons can be accelerated. These upper limits, determined by the maximum magnetic field strength observed in flaring regions, place stringent restrictions upon the acceleration process. The role of the plasma resistivity in these processes is examined, and possible sources of anomalous resistivity are summarized. The implications of these results for the microwave and hard X-ray emission from solar flares are examined.

  3. Characterization of remarkable floods in France, a transdisciplinary approach applied on generalized floods of January 1910

    Science.gov (United States)

    Boudou, Martin; Lang, Michel; Vinet, Freddy; Coeur, Denis

    2014-05-01

    emphasize one flood typology or one flood dynamic (for example flash floods are often over-represented than slow dynamic floods in existing databases). Thus, the selected criteria have to introduce a general overview of flooding risk in France by integrating all typologies: storm surges, torrential floods, rising groundwater level and resulting to flood, etc. The methodology developed for the evaluation grid is inspired by several scientific works related to historical hydrology (Bradzil, 2006; Benito et al., 2004) or extreme floods classification (Kundzewics et al. 2013; Garnier E., 2005). The referenced information are mainly issued from investigations realized for the PFRA (archives, local data),from internet databases on flooding disasters, and from a complementary bibliography (some scientists such as Maurice Pardé a geographer who largely documented French floods during the 20th century). The proposed classification relies on three main axes. Each axis is associated to a set of criteria, each one related to a score (from 0.5 to 4 points), and pointing out a final remarkability score. • The flood intensity characterizing the flood's hazard level. It is composed of the submersion duration, important to valorize floods with slow dynamics as flooding from groundwater, the event peak discharge's return period, and the presence of factors increasing significantly the hazard level (dykes breaks, log jam, sediment transport…) • The flood severity focuses on economic damages, social and political repercussions, media coverage of the event, fatalities number or eventual flood warning failures. Analyzing the flood consequences is essential in order to evaluate the vulnerability of society at disaster date. • The spatial extension of the flood, which contributes complementary information to the two first axes. The evaluation grid was tested and applied on the sample of 176 remarkable events. Around twenty events (from 1856 to 2010) come out with a high remarkability rate

  4. Non-accelerator experiments

    Energy Technology Data Exchange (ETDEWEB)

    Goldhaber, M.

    1986-01-01

    This report discusses several topics which can be investigated without the use of accelerators. Topics covered are: (1) proton decay, (2) atmospheric neutrinos, (3) neutrino detection, (4) muons from Cygnus X-3, and (5) the double-beta decay.

  5. Macromolecular ion accelerator.

    Science.gov (United States)

    Hsu, Yun-Fei; Lin, Jung-Lee; Lai, Szu-Hsueh; Chu, Ming-Lee; Wang, Yi-Sheng; Chen, Chung-Hsuan

    2012-07-03

    Presented herein are the development of macromolecular ion accelerator (MIA) and the results obtained by MIA. This new instrument utilizes a consecutive series of planar electrodes for the purpose of facilitating stepwise acceleration. Matrix-assisted laser desorption/ionization (MALDI) is employed to generate singly charged macromolecular ions. A regular Z-gap microchannel plate (MCP) detector is mounted at the end of the accelerator to record the ion signals. In this work, we demonstrated the detection of ions with the mass-to-charge (m/z) ratio reaching 30,000,000. Moreover, we showed that singly charged biomolecular ions can be accelerated with the voltage approaching 1 MV, offering the evidence that macromolecular ions can possess much higher kinetic energy than ever before.

  6. The next big accelerator

    CERN Multimedia

    Cramer, J G

    2002-01-01

    Accelerator physics in the US has been devastated by the cancellation of two high-energy physics colliders facilities. However there are future plans. A suggestion is made to build the new collider in the Australian outback.

  7. Accelerated learning in Afghanistan

    Directory of Open Access Journals (Sweden)

    Christine Capacci Carneal

    2005-01-01

    Full Text Available Most accelerated learning (AL programmes are ‘catch up’ initiatives to assist out-of-school youth into formal education. But what happens when adults join and complete AL classes?

  8. DIELECTRIC WALL ACCELERATOR TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Sampayan, S; Caporaso, G; Chen, Y; Harris, J; Hawkins, S; Holmes, C; Nelson, S; Poole, B; Rhodes, M; Sanders, D; Sullivan, J; Wang, L; Watson, J

    2007-10-18

    The dielectric wall accelerator (DWA) is a compact pulsed power device where the pulse forming lines, switching, and vacuum wall are integrated into a single compact geometry. For this effort, we initiated a extensive compact pulsed power development program and have pursued the study of switching (gas, oil, laser induced surface flashover and photoconductive), dielectrics (ceramics and nanoparticle composites), pulse forming line topologies (asymmetric and symmetric Blumleins and zero integral pulse forming lines), and multilayered vacuum insulator (HGI) technology. Finally, we fabricated an accelerator cell for test on ETAII (a 5.5 MeV, 2 kA, 70 ns pulsewidth electron beam accelerator). We review our past results and report on the progress of accelerator cell testing.

  9. Rejuvenating CERN's Accelerators

    CERN Multimedia

    2004-01-01

    In the coming years and especially in 2005, CERN's accelerators are going to receive an extensive renovation programme to ensure they will perform reliably and effectively when the LHC comes into service.

  10. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    View towards the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138.

  11. Linear Accelerator (LINAC)

    Science.gov (United States)

    ... View full size with caption Related Articles and Media External Beam Therapy (EBT) Intensity-Modulated Radiation Therapy (IMRT) Image-guided Radiation Therapy (IGRT) Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiotherapy (SBRT) Images related to Linear Accelerator Sponsored ...

  12. Joint International Accelerator School

    CERN Multimedia

    CERN Accelerator School

    2014-01-01

    The CERN and US Particle Accelerator Schools recently organised a Joint International Accelerator School on Beam Loss and Accelerator Protection, held at the Hyatt Regency Hotel, Newport Beach, California, USA from 5-14 November 2014. This Joint School was the 13th in a series of such schools, which started in 1985 and also involves the accelerator communities in Japan and Russia.   Photo courtesy of Alfonse Pham, Michigan State University.   The school attracted 58 participants representing 22 different nationalities, with around half from Europe and the other half from Asia and the Americas. The programme comprised 26 lectures, each of 90 minutes, and 13 hours of case study. The students were given homework each day and had an opportunity to sit a final exam, which counted towards university credit. Feedback from the participants was extremely positive, praising the expertise and enthusiasm of the lecturers, as well as the high standard and quality of their lectures. Initial dis...

  13. Amps particle accelerator definition study

    Science.gov (United States)

    Sellen, J. M., Jr.

    1975-01-01

    The Particle Accelerator System of the AMPS (Atmospheric, Magnetospheric, and Plasmas in Space) payload is a series of charged particle accelerators to be flown with the Space Transportation System Shuttle on Spacelab missions. In the configuration presented, the total particle accelerator system consists of an energetic electron beam, an energetic ion accelerator, and both low voltage and high voltage plasma acceleration devices. The Orbiter is illustrated with such a particle accelerator system.

  14. LHCb GPU Acceleration Project

    CERN Document Server

    AUTHOR|(SzGeCERN)744808; Campora Perez, Daniel Hugo; Neufeld, Niko; Vilasis Cardona, Xavier

    2016-01-01

    The LHCb detector is due to be upgraded for processing high-luminosity collisions, which will increase the load on its computation infrastructure from 100 GB/s to 4 TB/s, encouraging us to look for new ways of accelerating the Online reconstruction. The Coprocessor Manager is our new framework for integrating LHCb’s existing computation pipelines with massively parallel algorithms running on GPUs and other accelerators. This paper describes the system and analyzes its performance.

  15. Accelerating News Issue 2

    CERN Document Server

    Kahle, K; Wildner, E

    2012-01-01

    In this summer issue we look at how developments in collimator materials could have applications in aerospace and beyond, and how Polish researchers are harnessing accelerators for medical and industrial uses. We see how the LHC luminosity upgrade is linking with European industry and US researchers, and how the neutrino oscillation community is progressing. We find out the mid-term status of TIARA-PP and how it is mapping European accelerator education resources.

  16. Accelerated Evidence Search Report

    Science.gov (United States)

    2014-07-01

    Accelerated Evidence Search Report IMPORTANT INFORMATIVE STATEMENTS Accelerated Multi-Camera Evidence Search and Retrieval CSSP Project #: CSSP -2013...CD-1063 was supported by the Canadian Safety and Security Program ( CSSP ) which is led by Defence Research and Development Canada’s Centre for...Border Technology Division The CSSP is a federally-funded program to strengthen Canada’s ability to anticipate, prevent/mitigate, prepare for, respond to

  17. Laser acceleration... now with added fibre

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    Laser acceleration technology is plagued by two main issues: efficiency and repetition rates. In other words, lasers consume too much power and cannot sustain accelerating particles long enough to produce collisions. ICAN, a new EU-funded project, is examining how fibre lasers may help physicists tackle these issues.   A diode-pumped fibre laser. (Image courtesy of Laser Zentrum Hannover.) The International Coherent Amplification Network (ICAN) is studying the potential of lasers for collision physics. CERN is a beneficiary of the project and will collaborate with 15 other institutes from around the world, including KEK in Japan, Fermilab in the USA, and DESY in Germany. “The network is looking into existing fibre laser technology, which we believe has fantastic potential for accelerators,” says Gerard Mourou, ICAN co-ordinator at the École Polytechnique in France. “The hope is to make laser acceleration competitive with traditional radio-fre...

  18. BOOK REVIEW: Electron acceleration in the aurora and beyond

    Science.gov (United States)

    McClements, K. G.

    1999-08-01

    measurements of flare accelerated electrons at the Earth's orbit, despite acknowledging that uncertainties in propagation effects make it very difficult to reconstruct conditions at the Sun from such measurements. Similar remarks apply to the final chapter, on acceleration of cosmic ray electrons. Again, attention is focused almost exclusively on measurements of particles rather than the radiation signature of those particles, in this case synchrotron radiation by ultrarelativistic electrons. No mention is made of radio and X ray data, indicating that electrons with energies of up to around 1014eV are being accelerated at shocks associated with shell type supernova remnants. Interestingly, resonant acceleration of electrons by lower hybrid waves has been invoked by A.A. Galeev [Sov. Phys.-JETP 59 (1984) 965] as a mechanism for the production of cosmic ray electrons: although Galeev's paper is not cited in this book, the process he describes is very similar to that proposed by Dr Bryant for electron acceleration in the aurora and other near Earth plasma environments. The book contains a number of physics errors. For example, on page 17 the time derivative of a magnetic field is equated to an induced electric field, rather than the curl of one. On page 21, the author invokes Larmor's formula for the power radiated by a non-relativistic charged particle, and then combines it with the relativistic relation between acceleration and energy to estimate the maximum acceleration rate. The book has also been badly proofread. For example, Figure 1.15 appears twice: where it is first used, on page 8, it is clear that the accompanying caption and text refer to a different figure. I found several errors in the reference list (one of my own publications is cited as two separate papers, with both citations containing inaccuracies). Having said that, the reference list is impressively comprehensive and eclectic. It includes, for example, Swift's `Gulliver's Travels': a spacecraft in the

  19. Experiments on heat pipes submitted to strong accelerations; Experimentation de caloducs soumis a de fortes accelerations

    Energy Technology Data Exchange (ETDEWEB)

    Labuthe, A. [Dassault Aviation, 92 - Saint Cloud (France)

    1996-12-31

    In order to evaluate the possibility to use heat pipes as efficient heat transfer devices in aircrafts, a study of their behaviour during strong accelerations is necessary. This study has been jointly carried out by the Laboratory of Thermal Studies of Poitiers (France) and Dassault Aviation company. It is based on a series of tests performed with an experimental apparatus that uses the centrifugal effect to simulate the acceleration fields submitted to the heat pipe. Un-priming - priming cycles have been performed under different power and acceleration levels and at various functioning temperatures in order to explore the behaviour of heat pipes: rate of un-priming and re-priming, functioning in blocked mode etc.. This preliminary study demonstrates the rapid re-priming of the tested heat pipes when submitted to favourable acceleration situations and the possibility to use them under thermosyphon conditions despite the brief unfavourable acceleration periods encountered. (J.S.)

  20. Small type accelerator. Try for accelerator driven system

    CERN Document Server

    Mori, Y

    2003-01-01

    FFAG (Fixed-field alternating gradient) accelerator for accelerator driven subcritical reactor, which aims to change from long-lived radioactive waste to short-lived radioactivity, is introduced. It is ring accelerator. The performance needed is proton as accelerator particle, 10MW (total) beam power, about 1GeV beam energy, >30% power efficiency and continuous beam. The feature of FFAG accelerator is constant magnetic field. PoP (Proof-of-principle)-FFAG accelerator, radial type, was run at first in Japan in 2000. The excursion is about some ten cm. In principle, beam can be injected and extracted at any place of ring. The 'multi-fish' acceleration can accelerate beams to 100% duty by repeating acceleration. 150MeV-FFAG accelerator has been started since 2001. It tried to practical use, for example, treatment of cancer. (S.Y.)

  1. Some Remarks on the Problem of Dollar Scarcity

    NARCIS (Netherlands)

    J. Tinbergen (Jan)

    1949-01-01

    textabstractAt the prevailing exchange rates and price levels it appears that, considering the current items of the balance of payments of the United States, demand for dollars surpasses their supply. Or in other terms: American exports to the rest of the world (taking goods and services

  2. Accelerators in Science and Technology

    CERN Document Server

    Kailas, S

    2002-01-01

    Accelerators built for basic research in frontier areas of science have become important and inevitable tools in many areas of science and technology. Accelerators are examples of science driven high technology development. Accelerators are used for a wide ranging applications, besides basic research. Accelerator based multidisciplinary research holds great promise

  3. Plasma-based accelerator structures

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Carl B. [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas.

  4. Particle accelerator physics

    CERN Document Server

    Wiedemann, Helmut

    2007-01-01

    Particle Accelerator Physics is an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. Part I gathers the basic tools, recalling the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part II is an extensive primer in beam dynamics, followed in Part III by the introduction and description of the main beam parameters. Part IV is devoted to the treatment of perturbations in beam dynamics. Part V discusses the details of charged particle accleration. Part VI and Part VII introduce the more advanced topics of coupled beam dynamics and the description of very intense beams. Part VIII is an exhaustive treatment of radiation from accelerated charges and introduces important sources of coherent radiation such as synchrotrons and free-electron lasers. Part IX collects the appendices gathering useful mathematical and physical formulae, parameters and units. Solutions to many end-of-chapter problems are give...

  5. Quasar Jet Acceleration

    Science.gov (United States)

    Polito, Nicholas; Hough, David

    2009-10-01

    We observed radio jets in six lobe-dominated quasars (LDQs) from 1995 to 2008 using the NRAO VLBA at 8.4 and 15 GHz. These observations have tracked jet component positions and velocities over that time period. There is a correlation between apparent jet speed and projected core distance in these LDQs at greater than 99 per cent confidence levels (Hough 2008, Extragalactic Jets, eds: Rector and DeYoung, ASP, p. 274). Four of our sources show this effect particularly strongly. We only tracked single jet components over relatively short distances, but the assumption of a unique velocity profile allows us to study component motion on an effective timescale of approximately 20-50 years. Results for 3C207 and 3C263 show a good fit using a constant acceleration model. The cause of such acceleration is still unknown, though ``magnetic acceleration'' by a gradient in magnetic field pressure is one possibility.

  6. Superconducting Accelerator Magnets

    CERN Document Server

    Mess, K H; Wolff, S

    1996-01-01

    The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements ...

  7. Accelerating the culture change!

    Science.gov (United States)

    Klunk, S W; Panetta, J; Wooten, J

    1996-11-01

    Exide Electronics, a major supplier of uninterruptible power system equipment, embarked on a journey of changing a culture to improve quality, enhance customer responsiveness, and reduce costs. This case study examines the evolution of change over a period of seven years, with particular emphasis on the most recent years, 1992 through 1995. The article focuses on the Raleigh plant operations and describes how each succeeding year built on the successes and fixed the shortcomings of the prior years to accelerate the culture change, including corrective action and continuous improvement processes, organizational structures, expectations, goals, achievements, and pitfalls. The real challenge to changing the culture was structuring a dynamic approach to accelerate change! The presentation also examines how the evolutionary process itself can be created and accelerated through ongoing communication, regular feedback of progress and goals, constant evaluation and direction of the process, and measuring and paying for performance.

  8. Artificial seismic acceleration

    Science.gov (United States)

    Felzer, Karen R.; Page, Morgan T.; Michael, Andrew J.

    2015-01-01

    In their 2013 paper, Bouchon, Durand, Marsan, Karabulut, 3 and Schmittbuhl (BDMKS) claim to see significant accelerating seismicity before M 6.5 interplate mainshocks, but not before intraplate mainshocks, reflecting a preparatory process before large events. We concur with the finding of BDMKS that their interplate dataset has significantly more fore- shocks than their intraplate dataset; however, we disagree that the foreshocks are predictive of large events in particular. Acceleration in stacked foreshock sequences has been seen before and has been explained by the cascade model, in which earthquakes occasionally trigger aftershocks larger than themselves4. In this model, the time lags between the smaller mainshocks and larger aftershocks follow the inverse power law common to all aftershock sequences, creating an apparent acceleration when stacked (see Supplementary Information).

  9. Microelectromechanical acceleration-sensing apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Robb M. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM); Polosky, Marc A. (Albuquerque, NM); Hoke, Darren A. (Albuquerque, NM); Vernon, George E. (Rio Rancho, NM)

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  10. (Fe, Cr)3O4 Spinel Layer as the Key to Solving the Accelerated Oxidation of High Cr Iron Alloy in High-temperature Steam

    National Research Council Canada - National Science Library

    Murata, Yoshinori; Minai, Hideyuki; Nagai, Kensuke; Shiraki, Atsuhiro; Morinaga, Masahiko

    2008-01-01

    ...)3O4 spinel layer formed on the alloy surface. This result is related closely to the fact that oxidation of high Cr ferritic steels is accelerated remarkably by the existence of steam at elevated temperatures...

  11. [Fifty years of nutrition counseling. Remarks and perspectives].

    Science.gov (United States)

    Pudel, V; Ellrott, T

    2004-08-01

    Fifty years of nutrition information and education did not reach their goals. Nutrition-dependent diseases, obesity, and misinformation are still increasing. Cognitive information about nutrition does not induce changes in primary emotion-controlled eating habits. Better knowledge of nutrition on the part of consumers mainly activates their bad conscience when they rate their own eating habits. Future prevention campaigns, which clearly address consumer needs using social marketing principles, will be better able to change eating behavior.

  12. Monoenergetic laser wakefield acceleration

    Directory of Open Access Journals (Sweden)

    N. E. Andreev

    2000-02-01

    Full Text Available Three dimensional test particle simulations are applied to optimization of the plasma-channeled laser wakefield accelerator (LWFA operating in a weakly nonlinear regime. Electron beam energy spread, emittance, and luminosity depend upon the proportion of the electron bunch size to the plasma wavelength. This proportion tends to improve with the laser wavelength increase. We simulate a prospective two-stage ∼1GeV LWFA with controlled energy spread and emittance. The input parameters correspond to realistic capabilities of the BNL Accelerator Test Facility that features a picosecond-terawatt CO_{2} laser and a high-brightness electron gun.

  13. Shielding high energy accelerators

    CERN Document Server

    Stevenson, Graham Roger

    2001-01-01

    After introducing the subject of shielding high energy accelerators, point source, line-of-sight models, and in particular the Moyer model. are discussed. Their use in the shielding of proton and electron accelerators is demonstrated and their limitations noted. especially in relation to shielding in the forward direction provided by large, flat walls. The limitations of reducing problems to those using it cylindrical geometry description are stressed. Finally the use of different estimators for predicting dose is discussed. It is suggested that dose calculated from track-length estimators will generally give the most satisfactory estimate. (9 refs).

  14. Accelerating News Issue 4

    CERN Document Server

    Szeberenyi, A; Wildner, E

    2012-01-01

    In this winter issue, we are very pleased to announce the approval of EuCARD-2 by the European Commission. We look at the conclusions of EUROnu in proposing future neutrino facilities at CERN, a new milestone reached by CLIC and progress on the SPARC upgrade using C-band technology. We also report on recent events: second Joint HiLumi LHC-LARP Annual Meeting and workshop on Superconducting technologies for the Next Generation of Accelerators aiming at closer collaboration with industry. The launch of the Accelerators for Society brochure is also highlighted.

  15. A New Paradigm for Flare Particle Acceleration

    Science.gov (United States)

    Guidoni, Silvina E.; Karpen, Judith T.; DeVore, C. Richard

    2017-08-01

    The mechanism that accelerates particles to the energies required to produce the observed high-energy impulsive emission and its spectra in solar flares is not well understood. Here, we propose a first-principle-based model of particle acceleration that produces energy spectra that closely resemble those derived from hard X-ray observations. Our mechanism uses contracting magnetic islands formed during fast reconnection in solar flares to accelerate electrons, as first proposed by Drake et al. (2006) for kinetic-scale plasmoids. We apply these ideas to MHD-scale islands formed during fast reconnection in a simulated eruptive flare. A simple analytic model based on the particles’ adiabatic invariants is used to calculate the energy gain of particles orbiting field lines in our ultrahigh-resolution, 2.5D, MHD numerical simulation of a solar eruption (flare + coronal mass ejection). Then, we analytically model electrons visiting multiple contracting islands to account for the observed high-energy flare emission. Our acceleration mechanism inherently produces sporadic emission because island formation is intermittent. Moreover, a large number of particles could be accelerated in each macroscopic island, which may explain the inferred rates of energetic-electron production in flares. We conclude that island contraction in the flare current sheet is a promising candidate for electron acceleration in solar eruptions. This work was supported in part by the NASA LWS and H-SR programs..

  16. Ion Acceleration in the Madison Helicon Experiment

    Science.gov (United States)

    Wiebold, Matt; Sung, Yung-Ta; Scharer, John

    2011-10-01

    The Madison Helicon Experiment consists of a 150 cm long, 10 cm inner diameter Pyrex tube connected to a stainless steel expansion chamber 60 cm long and 45 cm in diameter with an axial magnetic field, variable up to 1 kG at the source region with a nozzle profile. Supersonic ion acceleration up to Ei = 160 eV at 500 W, 13.56 MHz RF power have been observed in the expanding region of the source. The effect of flow rate/pressure, RF power and magnetic field strength on the ion beam acceleration and the spatial variation of the plasma potential, electron density and temperature are explored. The ion energy distribution function is obtained by a two-grid RPA, while probe diagnostics determine Vp, ne, and Te. The effect of the operating mode of the helicon source (E, H or W) is explored. RF plasma potential fluctuations are observed which electrons can respond to but ions cannot, leading to time-averaged acceleration of the ions and time-dependent ``neutralization'' of the beam. Ion acceleration occurs over ~ 400 λD, and the accelerated population persists for several ion charge exchange mean free paths. Both double layer and Boltzmann expansion are considered as mechanisms responsible for the acceleration. Research supported by AFOSR Grant FA9550-10-1-0396 and in part by AFOSR Grant FA9550-09-1-0357.

  17. Considerations of acceleration effects in relativistic kinematics

    Science.gov (United States)

    Caviness, Kenneth Edwin

    An extended special-relativistic formalism incorporating non-inertial frames undergoing constant proper acceleration is developed as a natural outgrowth of Einstein's 1905 and 1907 treatises. Based on the so-called clock hypothesis, tacitly used by Einstein, and enunciated by von Laue in 1913, which states that the rate of a ideal clock is independent of its momentary acceleration, extended special relativity (ESR) makes use of the Moeller transformation and generalizes the work of Brehme to form a consistent mathematical framework, revealing a number of hitherto hidden features. From this basis, a number of highly interesting kinematic phenomena are considered, among which are: the nonconstancy of the speed of light and the variation of time rates within an accelerated system; the Doppler shift and aberration of light in a noninertial system, viewed by an inertial observer; the curved path of a light signal, preparatory to a treatment of the spatial and temporal Terrell effects in the ESR formalism. The ensuing equations are compared with special relativistic results, and in each case the role of acceleration in the formulae is defined. Quantitative calculations were made, and the results shown in graph form. The ESR formalism is then shown to be a particular case of the general-relativistic formalism. The limits of the accelerated observer's universe and the limits of the theory are discussed.

  18. Remarks on a technique of measuring CP phase {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, N.G.; Oh, S. [Oregon Univ., Eugene, OR (United States). Inst. of Theoretical Science; He, X.G. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-02-01

    We present a method to measure the CKM phase {alpha} and the tree and penguin (strong and electroweak) amplitudes in B{yields} {pi} {pi} decays, based on isospin consideration and the weak assumption that all tree amplitudes have a common strong phase and all penguin amplitudes have a different common phase. The method needs only the time-independent measurements of the relevant decay rates in B{yields} {pi} {pi}. We also propose a method to experimentally examine the validity of the assumption that all penguin amplitudes have the same strong phases, and to extract detailed information about the hadronic matrix elements. (authors). 14 refs., 1 fig.

  19. Laser Wakefield Accelerators

    OpenAIRE

    Najmudin, Z.

    2017-01-01

    The one-dimensional wakefield generation equations are solved for increasing levels of non-linearity, to demonstrate how they contribute to the overall behaviour of a non-linear wakefield in a plasma. The effect of laser guiding is also studied as a way to increase the interaction length of a laser wakefield accelerator.

  20. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

      Introduction to accelerator physics This course will take place in Istanbul, Turkey, from 18 to 30 September 2016. It is now open for registration, and further information can be found here: http://cas.web.cern.ch/cas/Turkey-2016/Turkey-advert.html

  1. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    See photo 8302397: View from the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138. Giacomo Primadei stands on the left.

  2. The CERN accelerator complex

    CERN Multimedia

    Mobs, Esma Anais

    2016-01-01

    The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  3. The CERN accelerator complex

    CERN Multimedia

    Haffner, Julie

    2013-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  4. The CERN accelerator complex

    CERN Multimedia

    Christiane Lefèvre

    2008-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  5. Dissociation by acceleration

    NARCIS (Netherlands)

    Peeters, K.; Zamaklar, m.

    2008-01-01

    We show that mesons, described using rotating relativistic strings in a holographic setup, undergo dissociation when their acceleration 'a' exceeds a value which scales with the angular momentum 'J' as a_max ~ \\sqrt{T_s/J}, where 'T_s' is the string tension.

  6. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    One of the SPS acceleration cavities (200 MHz, travelling wave structure). On the ceiling one sees the coaxial transmission line which feeds the power from the amplifier, located in a surface building above, to the upstream end of the cavity. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8104138, 8302397.

  7. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    One of the SPS accelerating cavities (200 MHz, travelling wave structure). The power that is fed into the upstream end of the cavity is extracted at the downstream end and sent into a dump load. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8011289, 8302397.

  8. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics This course will take place in Budapest, Hungary, from 2 to 14 October 2016. It is now open for registration and further information can be found at: http://cas.web.cern.ch/cas/Hungary2016/Hungary-advert.html and http://indico.cern.ch/event/532397/.

  9. Angular Accelerating White Light

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2015-08-01

    Full Text Available Significant interest has been devoted to tailoring optical fields that transversely accelerate during propagation in the form of Airy, Weber and Mathieu beams. In this work, the authors introduce a new type of optical field that exhibits controlled...

  10. Neurodegeneration in accelerated aging.

    Science.gov (United States)

    Scheibye-Knudsen, Moren

    2016-11-01

    The growing proportion of elderly people represents an increasing economic burden, not least because of age-associated diseases that pose a significant cost to the health service. Finding possible interventions to age-associated disorders therefore have wide ranging implications. A number of genetically defined accelerated aging diseases have been characterized that can aid in our understanding of aging. Interestingly, all these diseases are associated with defects in the maintenance of our genome. A subset of these disorders, Cockayne syndrome, Xeroderma pigmentosum group A and ataxia-telangiectasia, show neurological involvement reminiscent of what is seen in primary human mitochondrial diseases. Mitochondria are the power plants of the cells converting energy stored in oxygen, sugar, fat, and protein into ATP, the energetic currency of our body. Emerging evidence has linked this organelle to aging and finding mitochondrial dysfunction in accelerated aging disorders thereby strengthens the mitochondrial theory of aging. This theory states that an accumulation of damage to the mitochondria may underlie the process of aging. Indeed, it appears that some accelerated aging disorders that show neurodegeneration also have mitochondrial dysfunction. The mitochondrial alterations may be secondary to defects in nuclear DNA repair. Indeed, nuclear DNA damage may lead to increased energy consumption, alterations in mitochondrial ATP production and defects in mitochondrial recycling, a term called mitophagy. These changes may be caused by activation of poly-ADP-ribose-polymerase 1 (PARP1), an enzyme that responds to DNA damage. Upon activation PARP1 utilizes key metabolites that attenuate pathways that are normally protective for the cell. Notably, pharmacological inhibition of PARP1 or reconstitution of the metabolites rescues the changes caused by PARP1 hyperactivation and in many cases reverse the phenotypes associated with accelerated aging. This implies that modulation

  11. Relativity and accelerator engineering

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Schenefeld (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-09-15

    From a geometrical viewpoint, according to the theory of relativity, space and time constitute a four-dimensional continuum with pseudo-Euclidean structure. This has recently begun to be a practically important statement in accelerator physics. An X-ray Free Electron Laser (XFEL) is in fact the best, exciting example of an engineering system where improvements in accelerator technology makes it possible to develop ultrarelativistic macroscopic objects with an internal fine structure, and the theory of relativity plays an essential role in their description. An ultrarelativistic electron bunch modulated at nanometer-scale in XFELs has indeed a macroscopic finite-size of order of 10 μm. Its internal, collective structure is characterized in terms of a wave number vector. Here we will show that a four-dimensional geometrical approach, unusual in accelerator physics, is needed to solve problems involving the emission of radiation from an ultrarelativistic modulated electron beam accelerating along a curved trajectory. We will see that relativistic kinematics enters XFEL physics in a most fundamental way through the so-called Wigner rotation of the modulation wave number vector, which is closely associated to the relativity of simultaneity. If not taken into account, relativistic kinematics effects would lead to a strong qualitative disagreement between theory and experiments. In this paper, several examples of relativistic kinematics effects, which are important for current and future XFEL operation, are studied. The theory of relativity is applied by providing details of the clock synchronization procedure within the laboratory frame. This approach, exploited here but unusual in literature, is rather ''practical'', and should be acceptable to accelerator physicists.

  12. Real and virtual propagation dynamics of angular accelerating white light beams

    CSIR Research Space (South Africa)

    Vetter, C

    2017-08-01

    Full Text Available manipulation and laser plasma interactions. Here we create angular accelerating light beams with a potentially unlimited acceleration rate. By employing wavelength independent digital holograms for the creation and propagation of white light beams, we are able...

  13. Accelerated Tests of Soft Errors in Network Systems Using a Compact Accelerator- Driven Neutron Source

    Science.gov (United States)

    Iwashita, Hidenori; Sato, Hirotaka; Arai, Kaoru; Kotanigawa, Takashi; Kino, Koichi; Kamiyama, Takashi; Hiraga, Fujio; Koda, Katsutoshi; Furusaka, Michihiro; Kiyanagi, Yoshiaki

    2017-01-01

    The frequency of neutron-induced soft errors is increasing as devices become more integrated and miniaturized. Therefore, it has become more important recently to check reliability of a recovery system from the soft errors in network systems. For accelerated test, first we have examined possibility of the acceleration tests at a compact accelerator-driven neutron source, which is easy to adjust for soft-error tests and which also has low experimental costs. We selected the electron accelerator-driven neutron source at Hokkaido University as the compact accelerator-driven neutron source. We prepared a new target-reflector assembly composed of heavy metals to provide the fast neutrons, and conducted neutron-induced soft-error experiments on network equipments. As a result, we found that an accelerated rate of soft errors was about 106 times compared with that of the natural environment. We also investigated network equipment soft-error tolerance, fault detection and backup switching processes. Performing such testing before network equipment is actually deployed is critical for development of future network systems. Hence, the compact accelerator-based neutron source is a very useful tool.

  14. Concentrated Light for Accelerated Photo Degradation of Polymer Materials

    DEFF Research Database (Denmark)

    Madsen, Morten Vesterager; Tromholt, Thomas; Norrman, Kion

    2013-01-01

    Concentrated light is used to perform photochemical degradation of polymer solar cell materials with acceleration factors up to 1200. At constant temperature the photon efficiency in regards to photo degradation is constant for 1–150 suns and oxygen diffusion rates are not a limiting factor....... Accelerated degradation by concentrated light thus allows for rapid and precise evaluations of one sun polymer stabilities....

  15. Nonlinear dynamics in particle accelerators

    CERN Document Server

    Dilão, Rui

    1996-01-01

    This book is an introductory course to accelerator physics at the level of graduate students. It has been written for a large audience which includes users of accelerator facilities, accelerator physicists and engineers, and undergraduates aiming to learn the basic principles of construction, operation and applications of accelerators.The new concepts of dynamical systems developed in the last twenty years give the theoretical setting to analyse the stability of particle beams in accelerator. In this book a common language to both accelerator physics and dynamical systems is integrated and dev

  16. M31N 2008-12a — The Remarkable Recurrent Nova in M31

    Science.gov (United States)

    Darnley, M. J.

    2017-03-01

    M31N 2008-12a is a remarkable recurrent nova within the Andromeda Galaxy. With eleven eruptions now identified, including eight in the past eight years, the system exhibits a recurrence period of one year, and possibly just six months. This short inter eruption period is driven by the combination of a high mass white dwarf (1.38 M⊙) and high mass accretion rate (˜1.6×10-7 M⊙ yr-1). Such a high accretion rate appears to be provided by the stellar wind of a red giant companion. Deep Hα observations have revealed the presence of a vastly extended nebula around the system, which could be the ‘super-remnant' of many thousands of past eruptions. With a prediction of the white dwarf reaching the Chandrasekhar mass in less than a mega-year, M31N 2008-12a has become the leading pre-explosion type Ia supernova candidate. The 2016 eruption - to be the twelfth detected eruption - is expected imminently, and a vast array of follow-up observations are already planned.

  17. heavy ion acceleration at shocks

    Science.gov (United States)

    Shevchenko, V. I.; Galinsky, V.

    2009-12-01

    The theoretical study of alpha particle acceleration at a quasi-parallel shock due to interaction with Alfven waves self-consistently excited in both upstream and downstream regions was conducted using a scale-separation model [1]. The model uses conservation laws and resonance conditions to find where waves will be generated or dumped and hence particles will be pitch--angle scattered as well as the change of the wave energy due to instability or damping. It includes in consideration the total distribution function (the bulk plasma and high energy tail), so no any assumptions (e.g. seed populations, or some ad-hoc escape rate of accelerated particles) are required. In previous studies heavy ions were treated as perfect test particles, they only experienced the Alfven turbulence excited by protons and didn’t contribute to turbulence generation. In contrast to this approach, we consider the ion scattering on hydromagnetic turbulence generated by both protons and ions themselves. It is important for alpha particles with their relatively large mass-loading parameter that defines efficiency of the wave excitation by alpha particles. The energy spectra of alpha particles is found and compared with those obtained in test particle approximation. [1] Galinsky, V.L., and V.I. Shevchenko, Astrophys. J., 669, L109, 2007.

  18. Accelerator research studies

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks.

  19. Accelerating time to benefit

    DEFF Research Database (Denmark)

    Svejvig, Per; Geraldi, Joana; Grex, Sara

    Despite the ubiquitous pressure for speed, our approaches to accelerate projects remain constrained to the old-fashioned understanding of the project as a vehicle to deliver products and services, not value. This article explores an attempt to accelerate time to benefit. We describe and deconstruct...... of the time. Although all cases valued speed and speed to benefit, and implemented most practices proposed by the methodology, only three of the five projects were more successful in decreasing time to speed. Based on a multi-case study comparison between these five different projects and their respective...... the implementation of a large intervention undertaken in five project-based organizations in Denmark – the Project Half Double where the same project methodology has been applied in five projects, each of them in five distinct organizations in Denmark, as a bold attempt to realize double the benefit in half...

  20. accelerating cavity from LEP

    CERN Multimedia

    This is an accelerating cavity from LEP, with a layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities are now used in LEP to double the energy of the particle beams.

  1. Acceleration of microparticle

    CERN Document Server

    Shibata, H

    2002-01-01

    A microparticle (dust) ion source has been installed at the high voltage terminal of the 3.75 MV single ended Van de Graaff electrostatic accelerator and a beam line for microparticle experiments has been build at High Fluence Irradiation Facility (HIT) of Research Center for Nuclear Science and Technology, the University of Tokyo. Microparticle acceleration has been successful in obtaining expected velocities of 1-20 km/s or more for micron or submicron sized particles. Development of in situ dust detectors and analyzers on board satellites and spacecraft in the expected mass and velocity range of micrometeoroids and investigation of hypervelocity impact phenomena by using time of flight mass spectrometry, impact flash or luminescence measurement and scanning electron or laser microscope observation for metals, ceramics, polymers and semiconductors bombarded by micron-sized particles were started three years ago. (author)

  2. Lectures in accelerator theory

    CERN Document Server

    Month, M

    1981-01-01

    Accelerator theory is a broad area of study involving the behaviour of particle beams. Out of the many categories, the author has chosen to describe three phenomena taken from (1) the theory of single particle motion in nonlinear fields; (2) the theory of high intensity coherent motion and; (3) the theory of current accumulation. He deals with the behaviour of particles in the nonlinear field arising from the electromagnetic interaction of colliding beams. An analysis of the development of traveling waves on particle beams is presented. The situation studied is that of a uniform beam current in a circular accelerator and the excitation for the coherent motion is induced by the resistivity of the vacuum chamber wall. A description of the current accumulation process used at the proton storage rings at CERN (ISR) is given. (0 refs).

  3. Accelerators for Cancer Therapy

    Science.gov (United States)

    Lennox, Arlene J.

    2000-05-30

    The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy.

  4. Hardware Accelerated Simulated Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Laney, D; Callahan, S; Max, N; Silva, C; Langer, S; Frank, R

    2005-04-12

    We present the application of hardware accelerated volume rendering algorithms to the simulation of radiographs as an aid to scientists designing experiments, validating simulation codes, and understanding experimental data. The techniques presented take advantage of 32 bit floating point texture capabilities to obtain validated solutions to the radiative transport equation for X-rays. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedra that produces simulated radiographs in the absorption-only regime. A sorted tetrahedral projection algorithm is presented that simulates radiographs of emissive materials. We apply the tetrahedral projection algorithm to the simulation of experimental diagnostics for inertial confinement fusion experiments on a laser at the University of Rochester. We show that the hardware accelerated solution is faster than the current technique used by scientists.

  5. Particle accelerator physics

    CERN Document Server

    Wiedemann, Helmut

    2015-01-01

    This book by Helmut Wiedemann is a well-established, classic text, providing an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. The present 4th edition has been significantly revised, updated and expanded. The newly conceived Part I is an elementary introduction to the subject matter for undergraduate students. Part II gathers the basic tools in preparation of a more advanced treatment, summarizing the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part III is an extensive primer in beam dynamics, followed, in Part IV, by an introduction and description of the main beam parameters and including a new chapter on beam emittance and lattice design. Part V is devoted to the treatment of perturbations in beam dynamics. Part VI then discusses the details of charged particle acceleration. Parts VII and VIII introduce the more advanced topics of coupled beam dynamics and describe very intense bea...

  6. [Some remarks on the present discussion on underdevelopment].

    Science.gov (United States)

    Khalatbari, P

    1989-01-01

    Along with the threat of atomic war, the chronic poverty of 3/4 of the world's population is a further aspect of the crisis of today's civilization. Underdevelopment and backwardness are not identical concepts, as the latter is rooted in traditional, manual agricultural production that over 300 years of colonial capitalistic production upset without transforming by using colonies for raw material production and eventually after the First World War for industrial production. Today 75% of peasant families in Latin America and 97% in Africa cultivate their land using backward traditional methods, and 60% of land in developing countries is owned by large estate landlords. Vaccination against epidemics and public health measures of new independent countries lowered mortality without a corresponding reduction of fertility resulting in increasing population and a youthful structure. The number of women in reproductive age was 397 million in 1956, rose to 812 million in 1985, and is expected to soar to over 1.7 billion by 2025. Even if the birth rate were to drop to 18.6/1000 by 2025 as the UN estimates, this will continue the increase of world population for decades. The disturbance of the demoeconomical balance, the inability to absorb the ever increasing population is the dilemma of developing countries. The number of unemployed will rise to 800 million by 2000 from 500 million in 1989. There are 600 million malnourished people, and every year 14-15 million die because of deficient diet and hunger. The shortage of land leads to deforestation: 12% of tropical forests will be cut down by 2000 and desert areas will triple. Peasants displaced by modern agricultural mass production and landlessness flock to cities expanding the numbers of paupers that are easy to radicalize by adventurers who could resort to solutions by atomic blackmail.

  7. Electrophysical Systems Based On Charged Particle Accelerators

    CERN Document Server

    Vorogushin, M F

    2004-01-01

    The advancement of the charged particle accelerator engineering affects appreciably the modern tendencies of the scientific and technological progress in the world. In a number of advanced countries, this trend is one of the most dynamically progressing in the field of applied science and high-technology production. Such internationally known firms as VARIAN, SIEMENS, PHILIPS, ELECTA, IBA, HITACHI, etc., with an annual budget of milliards of dollars and growth rate of tens of percent may serve as an example. Although nowadays the projects of new large-scale accelerators for physical research are not implemented so quickly and frequently as desired, accelerating facilities are finding ever-widening application in various fields of human activities. The contribution made by Russian scientists into high-energy beams physics is generally known. High scientific and technical potential in this field, qualified personnel with a high creative potential, modern production and test facilities and state-of-the-art techn...

  8. Distributed representations accelerate evolution of adaptive behaviours.

    Directory of Open Access Journals (Sweden)

    James V Stone

    2007-08-01

    Full Text Available Animals with rudimentary innate abilities require substantial learning to transform those abilities into useful skills, where a skill can be considered as a set of sensory-motor associations. Using linear neural network models, it is proved that if skills are stored as distributed representations, then within-lifetime learning of part of a skill can induce automatic learning of the remaining parts of that skill. More importantly, it is shown that this "free-lunch" learning (FLL is responsible for accelerated evolution of skills, when compared with networks which either 1 cannot benefit from FLL or 2 cannot learn. Specifically, it is shown that FLL accelerates the appearance of adaptive behaviour, both in its innate form and as FLL-induced behaviour, and that FLL can accelerate the rate at which learned behaviours become innate.

  9. Accelerated plate tectonics.

    Science.gov (United States)

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  10. Accelerating regular polygon beams.

    Science.gov (United States)

    Barwick, Shane

    2010-12-15

    Beams that possess high-intensity peaks that follow curved paths of propagation under linear diffraction have recently been shown to have a multitude of interesting uses. In this Letter, a family of phase-only masks is derived, and each mask gives rise to multiple accelerating intensity maxima. The curved paths of the peaks can be described by the vertices of a regular polygon that is centered on the optic axis and expands with propagation.

  11. Accelerating News Issue 3

    CERN Document Server

    Kahle, K; Tanguy, C; Wildner, E

    2012-01-01

    This summer saw CERN announce to a worldwide audience the discovery of a Higgs-like boson, so this issue takes a look at the machine behind the discovery, the LHC, as well as future plans for a possible Higgs factory in the form of LEP3. Looking ahead too are European strategies for particle physics and accelerator-based neutrino physics. In addition, taking stock of the work so far, HiLumi LHC and EuCARD showcase their latest results.

  12. Particle Accelerator Focus Automation

    Science.gov (United States)

    Lopes, José; Rocha, Jorge; Redondo, Luís; Cruz, João

    2017-08-01

    The Laboratório de Aceleradores e Tecnologias de Radiação (LATR) at the Campus Tecnológico e Nuclear, of Instituto Superior Técnico (IST) has a horizontal electrostatic particle accelerator based on the Van de Graaff machine which is used for research in the area of material characterization. This machine produces alfa (He+) and proton (H+) beams of some μA currents up to 2 MeV/q energies. Beam focusing is obtained using a cylindrical lens of the Einzel type, assembled near the high voltage terminal. This paper describes the developed system that automatically focuses the ion beam, using a personal computer running the LabVIEW software, a multifunction input/output board and signal conditioning circuits. The focusing procedure consists of a scanning method to find the lens bias voltage which maximizes the beam current measured on a beam stopper target, which is used as feedback for the scanning cycle. This system, as part of a wider start up and shut down automation system built for this particle accelerator, brings great advantages to the operation of the accelerator by turning it faster and easier to operate, requiring less human presence, and adding the possibility of total remote control in safe conditions.

  13. The Silicon Lattice Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, J

    2003-11-24

    Previously, the generalized luminosity L was defined and calculated for all incident channels based on an NLC e{sup +}e{sup -} design. Alternatives were then considered to improve the differing beam-beam effects in the e{sup -}e{sup -}, e{gamma} and {gamma}{gamma} channels. One example was tensor beams composed of bunchlets n{sub ijk} implemented with a laser-driven, silicon accelerator based on micromachining techniques. Problems were considered and expressions given for radiative broadening due to bunchlet manipulation near the final focus to optimize luminosity via charge enhancement, neutralization or bunch shaping. Because the results were promising, we explore fully integrated structures that include sources, optics (for both light and particles) and acceleration in a common format--an accelerator-on-chip. Acceptable materials (and wavelengths) must allow velocity synchronism between many laser and electron pulses with optimal efficiency in high radiation environments. There are obvious control and cost advantages that accrue from using silicon structures if radiation effects can be made acceptable and the structures fabricated. Tests related to deep etching, fabrication and radiation effects on candidate amorphous and crystalline materials indicate Si(1.2 < {lambda}{sub L} < 10 {micro}m) and fused c-SiO{sub 2}(0.3 < {lambda}{sub L} < 4 {micro}m) to be ideal.

  14. Acceleration during magnetic reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Beresnyak, Andrey [Los Alamos National Laboratory; Li, Hui [Los Alamos National Laboratory

    2015-07-16

    The presentation begins with colorful depictions of solar x-ray flares and references to pulsar phenomena. Plasma reconnection is complex, could be x-point dominated or turbulent, field lines could break due to either resistivity or non-ideal effects, such as electron pressure anisotropy. Electron acceleration is sometimes observed, and sometimes not. One way to study this complex problem is to have many examples of the process (reconnection) and compare them; the other way is to simplify and come to something robust. Ideal MHD (E=0) turbulence driven by magnetic energy is assumed, and the first-order acceleration is sought. It is found that dissipation in big (length >100 ion skin depths) current sheets is universal and independent on microscopic resistivity and the mean imposed field; particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. One example of such flow is spontaneous reconnection. This explains hot electrons with a power-law tail in solar flares, as well as ultrashort time variability in some astrophysical sources.

  15. Particle Accelerator Focus Automation

    Directory of Open Access Journals (Sweden)

    Lopes José

    2017-08-01

    Full Text Available The Laboratório de Aceleradores e Tecnologias de Radiação (LATR at the Campus Tecnológico e Nuclear, of Instituto Superior Técnico (IST has a horizontal electrostatic particle accelerator based on the Van de Graaff machine which is used for research in the area of material characterization. This machine produces alfa (He+ and proton (H+ beams of some μA currents up to 2 MeV/q energies. Beam focusing is obtained using a cylindrical lens of the Einzel type, assembled near the high voltage terminal. This paper describes the developed system that automatically focuses the ion beam, using a personal computer running the LabVIEW software, a multifunction input/output board and signal conditioning circuits. The focusing procedure consists of a scanning method to find the lens bias voltage which maximizes the beam current measured on a beam stopper target, which is used as feedback for the scanning cycle. This system, as part of a wider start up and shut down automation system built for this particle accelerator, brings great advantages to the operation of the accelerator by turning it faster and easier to operate, requiring less human presence, and adding the possibility of total remote control in safe conditions.

  16. Optimizing accelerator technology

    CERN Document Server

    Katarina Anthony

    2012-01-01

    A new EU-funded research and training network, oPAC, is bringing together 22 universities, research centres and industry partners to optimize particle accelerator technology. CERN is one of the network’s main partners and will host 5 early-stage researchers in the BE department.   A diamond detector that will be used for novel beam diagnostics applications in the oPAC project based at CIVIDEC. (Image courtesy of CIVIDEC.) As one of the largest Marie Curie Initial Training Networks ever funded by the EU – to the tune of €6 million – oPAC extends well beyond the particle physics community. “Accelerator physics has become integral to research in almost every scientific discipline – be it biology and life science, medicine, geology and material science, or fundamental physics,” explains Carsten P. Welsch, oPAC co-ordinator based at the University of Liverpool. “By optimizing the operation of accelerators, all of these...

  17. Gamma-Ray Attenuation Measurements as a Laboratory Experiment: Some Remarks

    Science.gov (United States)

    Adamides, E.; Koutroubas, S. K.; Moshonas, N.; Yiasemides, K.

    2011-01-01

    In this article we make some significant remarks on the experimental study of the absorption of gamma radiation passing through matter. These remarks have to do with the seemingly unexpected trend of the measured intensity of radiation versus the thickness of the absorber, which puzzles students and its explanation eludes many laboratory…

  18. Accelerated Characterization of Polymer Properties

    Energy Technology Data Exchange (ETDEWEB)

    R. Wroczynski; l. Brewer; D. Buckley; M. Burrell; R. Potyrailo

    2003-07-30

    This report describes the efforts to develop a suite of microanalysis techniques that can rapidly measure a variety of polymer properties of industrial importance, including thermal, photo-oxidative, and color stability; as well as ductility, viscosity, and mechanical and antistatic properties. Additional goals of the project were to direct the development of these techniques toward simultaneous measurements of multiple polymer samples of small size in real time using non-destructive and/or parallel or rapid sequential measurements, to develop microcompounding techniques for preparing polymers with additives, and to demonstrate that samples prepared in the microcompounder could be analyzed directly or used in rapid off-line measurements. These enabling technologies are the crucial precursors to the development of high-throughput screening (HTS) methodologies for the polymer additives industry whereby the rate of development of new additives and polymer formulations can be greatly accelerated.

  19. Neuroscience and Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Palmblad, M N; Buchholz, B A; Hillegonds, D J; Vogel, J S

    2004-08-02

    Accelerator mass spectrometry (AMS) is a mass spectrometric method for quantifying rare isotopes. It has had great impact in geochronology and archaeology and is now being applied in biomedicine. AMS measures radioisotopes such as {sup 3}H, {sup 14}C, {sup 26}Al, {sup 36}Cl and {sup 41}Ca, with zepto- or attomole sensitivity and high precision and throughput, enabling safe human pharmacokinetic studies involving: microgram doses, agents having low bioavailability, or toxicology studies where administered doses must be kept low (<1 {micro}g/kg). It is used to study long-term pharmacokinetics, to identify biomolecular interactions, to determine chronic and low-dose effects or molecular targets of neurotoxic substances, to quantify transport across the blood-brain barrier and to resolve molecular turnover rates in the human brain on the timescale of decades. We will here review how AMS is applied in neurotoxicology and neuroscience.

  20. Introduction to Microwave Linear [Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Whittum, David H

    1999-01-04

    The elements of microwave linear accelerators are introduced starting with the principles of acceleration and accelerating structures. Considerations for microwave structure modeling and design are developed from an elementary point of view. Basic elements of microwave electronics are described for application to the accelerator circuit and instrumentation. Concepts of beam physics are explored together with examples of common beamline instruments. Charged particle optics and lattice diagnostics are introduced. Considerations for fixed-target and colliding-beam experimentation are summarized.

  1. Particle drift, diffusion, and acceleration at shocks

    Science.gov (United States)

    Jokipii, J. R.

    1982-01-01

    The gradient and curvature drifts implicit in change of the ambient magnetic field at a hydromagnetic shock wave are incorporated into the diffusive theory of shock acceleration of charged particles. The conventional jump condition at the shock is modified by a term incorporating the large drift along the shock plane. This term vanished identically for one-dimensional systems, but must be included in general for shocks which are finite in transverse extent or which have transverse structure. It is found that the effect of the drift is such that the transverse drift rate is proportional to the acceleration rate, and for perpendicular shocks is exactly equal to the rate of change of energy in the V x B electric field observed in the shock frame. This establishes a connection with the 'shock drift' models which neglect diffusion.

  2. Remarks at Opening Press Conference, IMF/World Bank Spring Meetings, Washington, D.C., April 18, 2013

    OpenAIRE

    Kim, Jim Yong

    2013-01-01

    Jim Yong Kim, President of the World Bank Group, discusses the issues to end extreme poverty in the World, promoting shared prosperity, and taking bold action on climate change. He speaks about accelerating the high growth rate in the developing world, and to translate this into poverty reduction and job creation. It must be inclusive to curb inequality. He insists that we must avert or mitigate potential shocks such as climate disas...

  3. Tuning the rotation rate of light-driven molecular motors.

    Science.gov (United States)

    Bauer, Jurica; Hou, Lili; Kistemaker, Jos C M; Feringa, Ben L

    2014-05-16

    Overcrowded alkenes are among the most promising artificial molecular motors because of their ability to undergo repetitive light-driven unidirectional rotary motion around the central C═C bond. The exceptional features of these molecules render them highly useful for a number of applications in nanotechnology. Many of these applications, however, would benefit from higher rotation rates. To this end, a new molecular motor was designed, and the isomerization processes were studied in detail. The new motor comprises a fluorene lower half and a five-membered-ring upper half; the upper-half ring is fused to a p-xylyl moiety and bears a tert-butyl group at the stereogenic center. The kinetics of the thermal isomerization was studied by low-temperature UV-vis spectroscopy as well as by transient absorption spectroscopy at room temperature. These studies revealed that the tert-butyl and p-xylyl groups in the five-membered-ring upper half may be introduced simultaneously in the molecular design to achieve an acceleration of the rotation rate of the molecular motor that is larger than the acceleration obtained by using either one of the two groups individually. Furthermore, the new molecular motor retains unidirectional rotation while showing remarkably high photostationary states.

  4. Microfabricated pseudocapacitors using Ni(OH)2 electrodes exhibit remarkable volumetric capacitance and energy density

    KAUST Repository

    Kurra, Narendra

    2014-09-10

    Metal hydroxide based microfabricated pseudocapacitors with impressive volumetric stack capacitance and energy density are demonstrated. A combination of top-down photolithographic process and bottom-up chemical synthesis is employed to fabricate the micro-pseudocapacitors (μ-pseudocapacitors). The resulting Ni(OH)2-based devices show several excellent characteristics including high-rate redox activity up to 500 V s-1 and an areal cell capacitance of 16 mF cm-2 corresponding to a volumetric stack capacitance of 325 F cm-3. This volumetric capacitance is two-fold higher than carbon and metal oxide based μ-supercapacitors with interdigitated electrode architecture. Furthermore, these μ-pseudocapacitors show a maximum energy density of 21 mWh cm-3, which is superior to the Li-based thin film batteries. The heterogeneous growth of Ni(OH)2 over the Ni surface during the chemical bath deposition is found to be the key parameter in the formation of uniform monolithic Ni(OH)2 mesoporous nanosheets with vertical orientation, responsible for the remarkable properties of the fabricated devices. Additionally, functional tandem configurations of the μ-pseudocapacitors are shown to be capable of powering a light-emitting diode.

  5. Remarkable shape memory effect of a natural biopolymer in aqueous environment.

    Science.gov (United States)

    Liu, Z Q; Jiao, D; Zhang, Z F

    2015-10-01

    Remarkable water-stimulated shape memory effect was revealed in a natural biopolymer of peacock's tail covert feathers of which the innate shape can almost be fully recovered after severe deformation by a short hydration step. The shape memory effect manifests a good stability of high recovery rate and ratio during cycles of deformation and subsequent recovery. Both strength and energy absorption efficiency of medullary foam can be recovered despite the apparent decrease in the first deformation stroke caused by structural damage. A kinetic model developed from non-equilibrium thermodynamic fluctuation theory was adopted to describe the shape recovery process by considering the viscoelastic relaxation. The effects of hydration on mechanical properties, recovery kinetics, activation process and dynamic mechanical behaviors were also evaluated. Mechanisms were explored based on the lubrication, swelling effect and structural changes of macromolecular chains or segments in terms of their mobility. This study is expected to aid in understanding the responses of natural biological materials to environmental stimuli and to provide useful information for synthetic shape memory materials from the bio-inspiration perspective. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. APT accelerator. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, G.; Rusthoi, D. [comp.] [ed.

    1995-03-01

    The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation`s stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century.

  7. VLHC accelerator physics

    Energy Technology Data Exchange (ETDEWEB)

    Michael Blaskiewicz et al.

    2001-11-01

    A six-month design study for a future high energy hadron collider was initiated by the Fermilab director in October 2000. The request was to study a staged approach where a large circumference tunnel is built that initially would house a low field ({approx}2 T) collider with center-of-mass energy greater than 30 TeV and a peak (initial) luminosity of 10{sup 34} cm{sup -2}s{sup -1}. The tunnel was to be scoped, however, to support a future upgrade to a center-of-mass energy greater than 150 TeV with a peak luminosity of 2 x 10{sup 34} cm{sup -2} sec{sup -1} using high field ({approx} 10 T) superconducting magnet technology. In a collaboration with Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, a report of the Design Study was produced by Fermilab in June 2001. 1 The Design Study focused on a Stage 1, 20 x 20 TeV collider using a 2-in-1 transmission line magnet and leads to a Stage 2, 87.5 x 87.5 TeV collider using 10 T Nb{sub 3}Sn magnet technology. The article that follows is a compilation of accelerator physics designs and computational results which contributed to the Design Study. Many of the parameters found in this report evolved during the study, and thus slight differences between this text and the Design Study report can be found. The present text, however, presents the major accelerator physics issues of the Very Large Hadron Collider as examined by the Design Study collaboration and provides a basis for discussion and further studies of VLHC accelerator parameters and design philosophies.

  8. Cysteine-Accelerated Methanogenic Propionate Degradation in Paddy Soil Enrichment.

    Science.gov (United States)

    Zhuang, Li; Ma, Jinlian; Tang, Jia; Tang, Ziyang; Zhou, Shungui

    2017-05-01

    Propionate degradation is a critical step during the conversion of complex organic matter under methanogenic conditions, and it requires a syntrophic cooperation between propionate-oxidizing bacteria and methanogenic archaea. Increasing evidences suggest that interspecies electron transfer for syntrophic metabolism is not limited to the reducing equivalents of hydrogen and formate. This study tested the ability of an electron shuttle to mediate interspecies electron transfer in syntrophic methanogenesis. We found that cysteine supplementation (100, 400, and 800 μM) accelerated CH 4 production from propionate in paddy soil enrichments. Of the concentrations tested, 100 μM cysteine was the most effective at enhancing propionate degradation to CH 4 , and the rates of CH 4 production and propionate degradation were increased by 109 and 79%, respectively, compared with the cysteine-free control incubations. We eliminated the possibility that the stimulatory effect of cysteine on methanogenesis was attributable to the function of cysteine as a methanogenic substrate in the presence of propionate. The potential catalytic effect involved cysteine serving as an electron carrier to mediate interspecies electron transfer in syntrophic propionate oxidization. The redox potential of cystine/cysteine, which is dependent on the concentration, might be more suitable to facilitate interspecies electron transfer between syntrophic partners at a concentration of 100 μM. Pelotomaculum, obligately syntrophic, propionate-oxidizing bacteria, and hydrogenotrophic methanogens of the family Methanobacteriaceae are predominant in cysteine-mediated methanogenic propionate degradation. The stimulatory effect of cysteine on syntrophic methanogenesis offers remarkable potential for improving the performance of anaerobic digestion and conceptually broaden strategies for interspecies electron transfer in syntrophic metabolism.

  9. Accelerated Innovation Pilot

    Science.gov (United States)

    Davis, Jeffrey

    2012-01-01

    Opportunities: I. Engage NASA team (examples) a) Research and technology calls . provide suggestions to AES, HRP, OCT. b) Use NASA@Work to solicit other ideas; (possibly before R+D calls). II. Stimulate collaboration (examples) a) NHHPC. b) Wharton Mack Center for Technological Innovation (Feb 2013). c) International ] DLR ] :envihab (July 2013). d) Accelerated research models . NSF, Myelin Repair Foundation. III. Engage public Prizes (open platform: InnoCentive, yet2.com, NTL; Rice Business Plan, etc.) IV. Use same methods to engage STEM.

  10. Accelerating abelian gauge dynamics

    CERN Document Server

    Adler, Stephen Louis

    1991-01-01

    In this paper, we suggest a new acceleration method for Abelian gauge theories based on linear transformations to variables which weight all length scales equally. We measure the autocorrelation time for the Polyakov loop and the plaquette at β=1.0 in the U(1) gauge theory in four dimensions, for the new method and for standard Metropolis updates. We find a dramatic improvement for the new method over the Metropolis method. Computing the critical exponent z for the new method remains an important open issue.

  11. Introduction to Accelerator Dynamics

    Science.gov (United States)

    Peggs, Stephen; Satogata, Todd

    2017-08-01

    Preface; 1. Introduction; 2. Linear motion; 3. Strong focusing transverse optics; 4. Longitudinal and off-momentum motion; 5. Action and emittance - one particle or many?; 6. Magnets; 7. RF cavities; 8. Linear errors and their correction; 9. Sextupoles, chromaticity and the Hénon map; 10. Octupoles, detuning and slow extraction; 11. Synchrotron radiation - classical damping; 12. Synchrotron radiation - quantum excitation; 13. Linacs - protons and ions; 14. Linacs - electrons; 15. The beam-beam interaction and 1-D resonances; 16. Routes to chaos; Appendix: selected formulae for accelerator design; References; Index.

  12. 2014 CERN Accelerator Schools

    CERN Multimedia

    2014-01-01

    A specialised school on Power Converters will be held in Baden, Switzerland, from 7 to 14 May 2014. Please note that the deadline for applications is 7 FEBRUARY 2014. A course on Introduction to Accelerator Physics will be held in Prague, Czech Republic, from 31 August to 12 September 2014. Applications are now open for this school; the application deadline is 25 APRIL 2014. Further information on these schools and other CAS events can be found on the CAS website and on the Indico page. For further information please contact Barbara.strasser@cern.ch

  13. Preparation and Performance of a New-Type Alkali-Free Liquid Accelerator for Shotcrete

    Directory of Open Access Journals (Sweden)

    Yanping Sheng

    2017-01-01

    Full Text Available A new type of alkali-free liquid accelerator for shotcrete was prepared. Specifically, the setting time and strength and shrinkage performance of two kinds of Portland cement with the accelerator were fully investigated. Moreover, the accelerating mechanism of alkali-free liquid accelerator and the hydration process of the shotcrete with accelerator were explored. Results show that alkali-free liquid accelerator significantly shortened the setting time of cement paste, where the initial setting time of cement paste with 8 wt% of the accelerator was about 3 min and the final setting time was about 7 min. Compressive strength at 1 day of cement mortar with the accelerator could reach 23.4 MPa, which increased by 36.2% compared to the strength of cement mortar without the accelerator, and the retention rate of 28-day compressive strength reached 110%. In addition, the accelerator still shows a good accelerating effect under low temperature conditions. However, the shrinkage rate of the concrete increased with the amount of the accelerator. 5~8% content of accelerator is recommended for shotcrete in practice. XRD and SEM test results showed that the alkali-free liquid accelerator promoted the formation of ettringite crystals due to the increase of Al3+ and SO42- concentration.

  14. Acceleration of clinician hand movements during spinal manipulative therapy.

    Science.gov (United States)

    Gelley, Geoffrey M; Passmore, Steven R; MacNeil, Brian J

    2015-04-01

    This study used an observational design to examine the kinematics of spinal manipulative therapy (SMT) by determining the acceleration characteristics of the manipulative input at the cervical, thoracic, and lumbar spinal regions. Studies of SMT have been restricted to measuring the forces that result from the manipulative input. Several studies have indicated the rate of force development is a key parameter of clinically delivered SMT. Despite this, the movement strategies employed during SMT, including acceleration, have not been directly measured. Participants (n = 29) were recruited from a private practice chiropractic clinic. A wireless accelerometer attached to the clinician's hand was used to characterize the thrust phase of the SMT treatments. Significant differences were found across each spinal region for acceleration amplitude parameters (p < 0.0001). Post-hoc analysis indicated that amplitudes significantly increased in order from thoracic to cervical to lumbar regions (p < 0.0001). Spinal level was also a significant factor in determining the temporal parameters of hand acceleration during SMT (p < 0.0005). This study provides a description of the acceleration properties of clinically delivered SMT. Consistent with that reported for SMT forces, acceleration amplitudes varied significantly across spinal regions with relatively little differences in acceleration latencies. Notably, acceleration amplitudes and latencies were not associated with each other within spinal regions. These findings indicate that changes in acceleration amplitude, rather than latency, are used to tailor SMT to individuals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Simulating autonomous driving styles: Accelerations for three road profiles

    Directory of Open Access Journals (Sweden)

    Karjanto Juffrizal

    2017-01-01

    Full Text Available This paper presents a new experimental approach to simulate projected autonomous driving styles based on the accelerations at three road profiles. This study was focused on the determination of ranges of accelerations in triaxial direction to simulate the autonomous driving experience. A special device, known as the Automatic Acceleration and Data controller (AUTOAccD, has been developed to guide the designated driver to accomplish the selected accelerations based on the road profiles and the intended driving styles namely assertive, defensive and light rail transit (LRT. Experimental investigations have been carried out at three different road profiles (junction, speed hump, and corner with two designated drivers with five trials on each condition. A driving style with the accelerations of LRT has also been included in this study as it is significant to the present methodology because the autonomous car is predicted to accelerate like an LRT, in such a way that it enables the users to conduct activities such as working on a laptop, using personal devices or eating and drinking while travelling. The results demonstrated that 92 out of 110 trials of the intended accelerations for autonomous driving styles could be achieved and simulated on the real road by the designated drivers. The differences between the two designated drivers were negligible, and the rates of succeeding in realizing the intended accelerations were high. The present approach in simulating autonomous driving styles focusing on accelerations can be used as a tool for experimental setup involving autonomous driving experience and acceptance.

  16. Accelerator School Success

    CERN Multimedia

    2004-01-01

    Accelerator specialists don't grow on trees: training them is the job of the CERN Accelerator School (CAS). Group photo during visit to the Daresbury Laboratory. CAS and the CCLRC Daresbury Laboratory jointly organised a specialised school on Power Converters in Warrington, England from 12-18 May 2004. The last CAS Power Converter course was in 1990, so there was plenty of ground to cover. The challenging programme proposed a review of the state of the art and the latest developments in the field, including 30 hours of tuition. The school also included a visit to the CCLRC Daresbury laboratory, a one-day excursion to Liverpool and Chester and a themed (Welsh medieval) dinner at the school's closure. A record attendance of 91 students of more than 20 different nationalities included not only participants from Europe and North America but also from Armenia, Taiwan, India, Turkey, Iran and for the first time, fee-paying students from China and Australia. European industry showed a welcome and solid interest in...

  17. Broadband accelerator control network

    Energy Technology Data Exchange (ETDEWEB)

    Skelly, J.; Clifford, T.; Frankel, R.

    1983-01-01

    A broadband data communications network has been implemented at BNL for control of the Alternating Gradient Synchrotron (AG) proton accelerator, using commercial CATV hardware, dual coaxial cables as the communications medium, and spanning 2.0 km. A 4 MHz bandwidth Digital Control channel using CSMA-CA protocol is provided for digital data transmission, with 8 access nodes available over the length of the RELWAY. Each node consists of an rf modem and a microprocessor-based store-and-forward message handler which interfaces the RELWAY to a branch line implemented in GPIB. A gateway to the RELWAY control channel for the (preexisting) AGS Computerized Accelerator Operating system has been constructed using an LSI-11/23 microprocessor as a device in a GPIB branch line. A multilayer communications protocol has been defined for the Digital Control Channel, based on the ISO Open Systems Interconnect layered model, and a RELWAY Device Language defined as the required universal language for device control on this channel.

  18. Concluding Remarks.

    NARCIS (Netherlands)

    Ziegele, Frank; van Vught, Franciscus A.; Ziegele, Frank

    2012-01-01

    In this book we have addressed the general topic of rankings in higher education and research as well as the development of a new multidimensional ranking tool. We looked at the various issues surrounding the ranking debates, and analyzed current practices and their impact. We have been critical of

  19. Concluding Remarks

    Science.gov (United States)

    Bonnet, Roger M.

    2010-01-01

    Let me first express my warmest acknowledgements to Cesare Barbieri for having taken the initiative of convening this symposium. These two days offered a unique opportunity to celebrate the scientific achievements and the legacy of Galileo Galilei. It allowed not only celebrating the scientist but also the philosopher and the human being. It was a fantastic journey in the past, present and future exploration of our universe and a fantastic retrospection into the Renaissance world which no better city than Padova would be able to offer. During these two days we could listen to a well balanced and well prepared set of excellent papers and presentations. All participants should be congratulated for their very active interactions during the discussions in the aula and also during coffee and lunch breaks.

  20. Concluding remarks

    Science.gov (United States)

    Gustafsson, Bengt

    Attempts are made to summarize some main points and results discussed at the IAU Symposium No. 228 in Paris, May 2005. It is concluded that, although the situation in areas pioneered by F. and M. Spite is nowdays rather complex, some important progress has recently been made, and more is expected to occur within the next few years if the level of ambition in the astronomical community is kept at the high level set by the pioneers.

  1. Remarkable Reframing

    OpenAIRE

    Schütte, Brendan

    2015-01-01

    This paper arises from a presentation at the International Mediation and Restorative Practice Conference held at the National University of Ireland, Maynooth on 5th September 2014. The topic is the technique known as reframing. To reframe is to bring about a change in someone’s mental perspective by altering their tacit underlying viewpoint to create different meaning. It is an attempt to release the parties from a blame and counter-blame cycle, and to focus on more useful ways of viewing ...

  2. Zoogeographical remarks

    NARCIS (Netherlands)

    NN,

    1940-01-01

    Much has been said of the geographical relations and the origin of the West Indian fauna, especially as to that of its vertebrates and mollusks. Mostly the islands off the Venezuelan coast, for the greater part within sight of the South American continent, remained out of question, although obvious

  3. Introductory Remarks

    NARCIS (Netherlands)

    T-D. Truong (Thanh-Dam); D.R. Gasper (Des)

    2011-01-01

    textabstractDriven by diverse forces – economic pressures and opportunities, climate change, war, conquest, and transformation of political regimes – human migration has been central to circulation of knowledge and values, goods and labour. Yet, it has been subject to mainly disciplinary inquiries

  4. Concluding remarks

    Directory of Open Access Journals (Sweden)

    Lynas-Gray A.E.

    2013-03-01

    Full Text Available Precision asteroseismic observations with the Kepler and CoRot satellites enable the internal structure and evolution of pulsating stars to be more exhaustively studied than has hitherto been possible. It is particularly important to study the evolutionary links between white dwarfs and subdwarf-B stars with stars considered to have been their progenitors, those on the Red Giant and Asymptotic Giant Branches. Though observations present challenges for existing stellar evolution and pulsation models, and the data (atomic, molecular and nuclear on which they are based, excellent prospects for development are identified which will in turn facilitate studies of the Galaxy and extra-solar planets.

  5. Concluding remarks

    OpenAIRE

    Pelletier, J.-P.; Lequesne, M.

    2017-01-01

    International audience; The focus of this Symposium was on bifidobacteria and propionibacteria for dairy and probiotic applications.Both genera have many similarities: being phylogenetically closely grouped within the Actinobacteria, they are high G+C branch Gram-positive bacteria, and share several physiological properties, despite having different industrial applications. It was highlighted in this Symposium that, from the point of view of consumers, consumer organizations, and government a...

  6. Concluding remarks

    OpenAIRE

    Lerayer, Alda

    2005-01-01

    International audience; The focus of this Symposium was on bifidobacteria and propionibacteria for dairy and probiotic applications.Both genera have many similarities: being phylogenetically closely grouped within the Actinobacteria, they are high G+C branch Gram-positive bacteria, and share several physiological properties, despite having different industrial applications. It was highlighted in this Symposium that, from the point of view of consumers, consumer organizations, and government a...

  7. ETYMOLOGICAL REMARKS

    Directory of Open Access Journals (Sweden)

    Tatiana Goryacheva

    2016-01-01

    Full Text Available The paper deals with the etymological research of five East.-Slav. dialectal words: баланцы, воронéць, забуглáть, щáя и малофéйки, regarding all the scope of their phonetic and semantic variants. The word баланцы was analyzed in the meanings ‘chatter’ and ‘small icicles’. In the former meaning it is either onomatopoetic word, or it could be deduced from protoslav. *bal- ‘speak’; the latter one is, probably, derivative from the former, which could be confirmed with the typological data. Ukr. воронéць in the meaning ‘drink produced with vodka or horilka’ is motivated by the horse colour. Despite the drinks, the paper observes some features of herbs and plants, described by means of other horse-suit words. Rus. dial. забуглáть, meaning ‘cover with snow flakes’ is attributed to the root *bug- < i.-e. *bheug(h-/*bhoug(h ‘bend, bow’, ‘oppress, bring to ruin’, known with its semantic capacity. Ukr. слово щáя ‘time before dawn’ is connected with the verb щавити ‘press, oppress’. The meaning of Russ. dial. малофéйки ‘waves, ripple on a water surface’ is deduced from the Russ. slang малафья ‘cum, wet dreem’, descending from the Greek μαλακία. 

  8. Introductory remarks

    NARCIS (Netherlands)

    Kiefer, Friedemann; Schulte-Merker, Stefan

    2014-01-01

    This introductory section briefly highlights the subsequent chapters in the context of recent findings and open questions in lymphatic vessel biology. It aims to provide a quick overview and orientation in the contents of this monograph collection.

  9. Acceleration in Linear and Circular Motion

    Science.gov (United States)

    Kellington, S. H.; Docherty, W.

    1975-01-01

    Describes the construction of a simple accelerometer and explains its use in demonstrating acceleration, deceleration, constant speed, measurement of acceleration, acceleration and the inclined plane and angular and radial acceleration. (GS)

  10. Accelerator Technology: Geodesy and Alignment for Particle Accelerators

    CERN Document Server

    Missiaen, D

    2013-01-01

    This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '8.9 Geodesy and Alignment for Particle Accelerators' of the Chapter '8 Accelerator Technology' with the content: 8.9 Geodesy and Alignment for Particle Accelerators 8.9.1 Introduction 8.9.2 Reference and Co-ordinate Systems 8.9.3 Definition of the Beam Line on the Accelerator Site 8.9.4 Geodetic Network 8.9.5 Tunnel Preliminary Works 8.9.6 The Alignment References 8.9.7 Alignment of Accelerator Components 8.9.8 Permanent Monitoring and Remote Alignment of Low Beta Quadrupoles 8.9.9 Alignment of Detector Components

  11. 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection

    CERN Document Server

    JAS - Joint US-CERN-Japan-Russia Accelerator School

    2016-01-01

    Many particle accelerators operate with very high beam power and very high energy stored in particle beams as well as in magnet systems. In the future, the beam power in high intensity accelerators will further increase. The protection of the accelerator equipment from the consequences of uncontrolled release of the energy is essential. This was the motivation for organizing a first school on beam losses and accelerator protection (in general referred to as machine protection). During the school the methods and technologies to identify, mitigate, monitor and manage the technical risks associated with the operation of accelerators with high-power beams or subsystems with large stored energy were presented. At the completion of the school the participants should have been able to understand the physical phenomena that can damage machine subsystems or interrupt operations and to analyze an accelerator facility to produce a register of technical risks and the corresponding risk mitigation and management strategie...

  12. CERN Accelerator School: Registration open for Advanced Accelerator Physics course

    CERN Multimedia

    2015-01-01

    Registration is now open for the CERN Accelerator School’s Advanced Accelerator Physics course to be held in Warsaw, Poland from 27 September to 9 October 2015.   The course will be of interest to physicists and engineers who wish to extend their knowledge of accelerator physics. The programme offers core lectures on accelerator physics in the mornings and a practical course with hands-on tuition in the afternoons.  Further information can be found at: http://cas.web.cern.ch/cas/Poland2015/Warsaw-advert.html http://indico.cern.ch/event/361988/

  13. CERN Accelerator School: Registration open for Advanced Accelerator Physics course

    CERN Multimedia

    2015-01-01

    Registration is now open for the CERN Accelerator School’s Advanced Accelerator Physics course to be held in Warsaw, Poland from 27 September to 9 October 2015.   The course will be of interest to physicists and engineers who wish to extend their knowledge of Accelerator Physics. The programme offers core lectures on accelerator physics in the mornings and a practical course with hands-on tuition in the afternoons.  Further information can be found at: http://cas.web.cern.ch/cas/Poland2015/Warsaw-advert.html http://indico.cern.ch/event/361988/

  14. SATURDAY: EPA Administrator to Deliver Remarks at Third Annual Broccoli Festival

    Science.gov (United States)

    WASHINGTON - On Saturday, April 25, EPA Administrator Gina McCarthy will give remarks at the Third Annual Broccoli City Festival's Earth Day celebration. Administrator McCarthy will speak about EPA's efforts to implement President Obama's Climate Ac

  15. Academy of Program/Project & Engineering Leadership: Shared Voyage: Learning and Unlearning from Remarkable Projects

    Data.gov (United States)

    National Aeronautics and Space Administration — Shared Voyage is about four remarkable projects:the Advanced Composition Explorer (NASA), the Joint Air-to-Surface Standoff Missile (U.S. Air Force), the Pathfinder...

  16. Issues in American psychiatry reflected in remarks of APA presidents, 1844-1994.

    Science.gov (United States)

    Geller, J L

    1994-10-01

    The author reviewed the history of American psychiatry for the first 150 years of the American Psychiatric Association's existence (1844-1994) as reflected in remarks of the association's presidents. Presidential addresses or remarks from alternative sources were located for the 120 presidents who served the association between 1844 and 1994. The presidents' remarks on six topics-psychiatric practice, etiology of mental illness, public mental hospitals, alternatives to state hospitals (deinstitutionalization), biologic treatments, and fiscal issues were sampled and arranged chronologically. American psychiatry's history--its innovations, cyclical repetitions, and self-assessments-can be gleaned from this form of data. The presidents' remarks appear to refute the claim that organized American psychiatry has been negligent in criticizing itself.

  17. Rings and filaments: The remarkable detached CO shell of U Antliae

    Science.gov (United States)

    Kerschbaum, F.; Maercker, M.; Brunner, M.; Lindqvist, M.; Olofsson, H.; Mecina, M.; De Beck, E.; Groenewegen, M. A. T.; Lagadec, E.; Mohamed, S.; Paladini, C.; Ramstedt, S.; Vlemmings, W. H. T.; Wittkowski, M.

    2017-09-01

    Aims: Our goal is to characterize the intermediate age, detached shell carbon star U Antliae morphologically and physically in order to study the mass-loss evolution after a possible thermal pulse. Methods: High spatial resolution ALMA observations of unprecedented quality in thermal CO lines allow us to derive first critical spatial and temporal scales and constrain modeling efforts to estimate mass-loss rates for both the present day as well as the ejection period of the detached shell. Results: The detached shell is remarkably thin, overall spherically symmetric, and shows a barely resolved filamentary substructure possibly caused by instabilities in the interaction zone of winds with different outflow velocities. The expansion age of the detached shell is of the order of 2700 yr and its overall width indicates a high expansion-velocity and high mass-loss period of only a few hundred years at an average mass-loss rate of ≈10-5 M⊙ yr-1. The post-high-mass-loss-rate-epoch evolution of U Ant shows a significant decline to a substantially lower gas expansion velocity and a mass-loss rate amounting to 4 × 10-8 M⊙ yr-1, at present being consistent with evolutionary changes as predicted for the period between thermal pulses. This paper makes use of the following ALMA data: ADS/JAO.ALMA2015.1.00007.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ.The reduced ALMA FITS data cubes are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A116The movie is available at http://www.aanda.org

  18. Electrostatic accelerators fundamentals and applications

    CERN Document Server

    2005-01-01

    Electrostatic accelerators are an important and widespread subgroup within the broad spectrum of modern, large particle acceleration devices. They are specifically designed for applications that require high-quality ion beams in terms of energy stability and emittance at comparatively low energies (a few MeV). Their ability to accelerate virtually any kind of ion over a continuously tunable range of energies make them a highly versatile tool for investigations in many research fields including, but not limited to, atomic and nuclear spectroscopy, heavy ion reactions, accelerator mass spectroscopy as well as ion-beam analysis and modification. The book is divided into three parts. The first part concisely introduces the field of accelerator technology and techniques that emphasize their major modern applications. The second part treats the electrostatic accelerator per se: its construction and operational principles as well as its maintenance. The third part covers all relevant applications in which electrosta...

  19. PREFACE: Introductory remarks Introductory remarks

    Science.gov (United States)

    Bowler, D. R.; Alfe, D.

    2010-02-01

    This special issue contains papers related to the 2009 Thomas Young Centre Workshop at University College London 'Accessing large length and time scales with accurate quantum methods', in celebration of Professor Michael Gillan's 65th birthday. Mike Gillan won the 2006 Institute of Physics Dirac Medal and Prize, the citation reading: 'For his contributions to the development of atomic-scale computer simulations, which have greatly extended their power and effectiveness over an immense range of applications'. This rightly highlights Mike's seminal work on materials modelling, but misses out some of the many other areas he has enriched. After taking his PhD at the Department of Theoretical Physics, Oxford University, Mike went as a post-doc to Minneapolis. He then joined the Statistical Physics Group in the Theoretical Physics Division, Harwell, where he stayed for over 20 years, with a brief interlude in Saclay. In the late 1980s, Mike made a transition to become Professor of Physics at the University of Keele, where he stayed for a decade until University College London was fortunate in being able to tempt him to join the Condensed Matter and Material Physics Group, where there was already a significant materials modelling initiative. Over the years, Mike has made many important contributions, some with impact on other areas of science, others with significance in technology areas such as nuclear safety. Thus, he developed a form of quantum transition-state theory, generalizing Eyring's well-known classical transition-state theory to the case of quantum particles, such as hydrogen, diffusing in condensed matter. He pioneered quantum methods for calculating defect energetics in solids, and then molecular processes on surfaces. He synthesised these approaches into very general ways to calculate thermodynamic free energies of condensed matter from first principles, drawing on his early experience of statistical physics. These methods led to rapid advances in the study of matter under extreme conditions, as in the Earth's core. A further powerful development has been his input to linear-scaling quantum techniques for the properties of very large complex systems. In recent years, his attention has shifted towards increasing accuracy, touching areas such as quantum Monte Carlo and hierarchical quantum chemical techniques. In this journal issue, we have papers which both reflect topics from the workshop and address a number of areas which are directly in Mike's interests or which have been influenced by his work or assistance. There are papers addressing accuracy in quantum simulations [1-5], methods for applying quantum techniques to large systems [6, 7] and applications of quantum simulations to important problems [8-10]. We also have a viewpoint on magnetism in oxides and carbon [11], prompted by Mike's innovative work on oxides. References [1] Nolan S J, Bygrave P J, Allan N L and Manby F R 2010 J. Phys.: Condens. Matter 22 074201 [2] Badinski A, Haynes P D, Trail J R and Needs R J 2010 J. Phys.: Condens. Matter 22 074202 [3] Klimeš J, Bowler D R and Michaelides A 2010 J. Phys.: Condens. Matter 22 074203 [4] Baroni S, Gebauer R, Malcιoğlu O B, Saad Y, Umari P and Xian J 2010 J. Phys.: Condens. Matter 22 074204 [5] Toton D, Lorenz C D, Rompotis N, Martsinovich N and Kantorovich L 2010 J. Phys.: Condens. Matter 22 074205 [6] Fujiwara T, Hoshi T, Yamamoto S, Sogabe T and Zhang S-L 2010 J. Phys.: Condens. Matter 22 074206 [7] Bowler D R and Miyazari T 2010 J. Phys.: Condens. Matter 22 074207 [8] Er S, van Setten M J, de Wijs G A and Brocks G 2010 J. Phys.: Condens. Matter 22 074208 [9] Pan D, Liu L-M, Tribello G A, Slater B, Michaelides A and Wang E 2010 J. Phys.: Condens. Matter 22 074209 [10] Choudhury R, Gattinoni C, Makov G and De Vita A 2010 J. Phys.: Condens. Matter 22 074210 [11] Stoneham M 2010 J. Phys.: Condens. Matter 22 074211

  20. Network acceleration techniques

    Science.gov (United States)

    Crowley, Patricia (Inventor); Awrach, James Michael (Inventor); Maccabe, Arthur Barney (Inventor)

    2012-01-01

    Splintered offloading techniques with receive batch processing are described for network acceleration. Such techniques offload specific functionality to a NIC while maintaining the bulk of the protocol processing in the host operating system ("OS"). The resulting protocol implementation allows the application to bypass the protocol processing of the received data. Such can be accomplished this by moving data from the NIC directly to the application through direct memory access ("DMA") and batch processing the receive headers in the host OS when the host OS is interrupted to perform other work. Batch processing receive headers allows the data path to be separated from the control path. Unlike operating system bypass, however, the operating system still fully manages the network resource and has relevant feedback about traffic and flows. Embodiments of the present disclosure can therefore address the challenges of networks with extreme bandwidth delay products (BWDP).

  1. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The SPS started up with 2 accelerating cavities (each consisting of 5 tank sections) in LSS3. They have a 200 MHz travelling wave structure (see 7411032 and 7802190) and 750 kW of power is fed to each of the cavities from a 1 MW tetrode power amplifier, located in a surface building above, via a coaxial transmission line. Clemens Zettler, builder of the SPS RF system, is standing at the side of one of the cavities. In 1978 and 1979 another 2 cavities were added and entered service in 1980. These were part of the intensity improvement programme and served well for the new role of the SPS as proton-antiproton collider. See also 7411032, 8011289, 8104138, 8302397.

  2. ACCELERATING NANO-TECHNOLOGICAL

    DEFF Research Database (Denmark)

    Jensen, Jens Stissing; Koch, Christian

    2007-01-01

    By viewing the construction industry as a technological innovation system (TIS) this paper discusses possible initiatives to accelerate nanotechnological innovations. The point of departure is a recent report on the application of nano-technology in the Danish construction industry, which concludes...... that opportunities are generally poorly appreciated by the industry and research communities alike. It is found that the construction industry is characterized by low-tech trajectories where dedicated innovation networks are often too fragile for innovations to stabilize and diffuse. The institutional features...... of the system are furthermore poorly equipped at identifying potentials within high-tech areas. In order to exploit the potentials of nano-technology it is thus argued that an alternative TIS needs to be established. Initiatives should identify and support “incubation rooms” or marked niches in order...

  3. GPU Accelerated Prognostics

    Science.gov (United States)

    Gorospe, George E., Jr.; Daigle, Matthew J.; Sankararaman, Shankar; Kulkarni, Chetan S.; Ng, Eley

    2017-01-01

    Prognostic methods enable operators and maintainers to predict the future performance for critical systems. However, these methods can be computationally expensive and may need to be performed each time new information about the system becomes available. In light of these computational requirements, we have investigated the application of graphics processing units (GPUs) as a computational platform for real-time prognostics. Recent advances in GPU technology have reduced cost and increased the computational capability of these highly parallel processing units, making them more attractive for the deployment of prognostic software. We present a survey of model-based prognostic algorithms with considerations for leveraging the parallel architecture of the GPU and a case study of GPU-accelerated battery prognostics with computational performance results.

  4. HIGH ENERGY PARTICLE ACCELERATOR

    Science.gov (United States)

    Courant, E.D.; Livingston, M.S.; Snyder, H.S.

    1959-04-14

    An improved apparatus is presented for focusing charged particles in an accelerator. In essence, the invention includes means for establishing a magnetic field in discrete sectors along the path of moving charged particles, the magnetic field varying in each sector in accordance with the relation. B = B/ sub 0/ STAln (r-r/sub 0/)/r/sub 0/!, where B/sub 0/ is the value of the magnetic field at the equilibrium orbit of radius r/sub 0/ of the path of the particles, B equals the magnetic field at the radius r of the chamber and n equals the magnetic field gradient index, the polarity of n being abruptly reversed a plurality of times as the particles travel along their arcuate path. With this arrangement, the particles are alternately converged towards the axis of their equillbrium orbit and diverged therefrom in successive sectors with a resultant focusing effect.

  5. ISOLDE - Accelerating Future

    CERN Multimedia

    CERN. Geneva

    2003-01-01

    Isotope Separation On-Line (ISOL) was first developed in Copenhagen in the late 50s. The technique was taken to CERN in the 60s and the CERN facility was given the name ISOLDE. The method is based on energetic protons hitting a solid target. The reaction products produced through spallation, fission and fragmentation are heated out in the form of an electrically neutral gas. In the subsequent steps the gas is ionized, accelerated and magnetically separated to produce isotopically pure beams for experiments in nuclear physics, atomic physics, astrophysics, solid state physics and for medical applications. An overview will be given of the physics at ISOLDE as well as over the techniques used to produce the necessary isotopes. Furthermore, a part of the talk will be dedicated to the future plans at ISOLDE including the proposal to build a next generation radioactive beam facility at CERN. The talk ends with a guided visit to the ISOLDE facility. Prerequisite knowledge: None.

  6. Interstellar Mapping and Acceleration Probe (IMAP)

    Science.gov (United States)

    Schwadron, Nathan

    2016-04-01

    Our piece of cosmic real-estate, the heliosphere, is the domain of all human existence - an astrophysical case-history of the successful evolution of life in a habitable system. By exploring our global heliosphere and its myriad interactions, we develop key physical knowledge of the interstellar interactions that influence exoplanetary habitability as well as the distant history and destiny of our solar system and world. IBEX was the first mission to explore the global heliosphere and in concert with Voyager 1 and Voyager 2 is discovering a fundamentally new and uncharted physical domain of the outer heliosphere. In parallel, Cassini/INCA maps the global heliosphere at energies (~5-55 KeV) above those measured by IBEX. The enigmatic IBEX ribbon and the INCA belt were unanticipated discoveries demonstrating that much of what we know or think we understand about the outer heliosphere needs to be revised. The next quantum leap enabled by IMAP will open new windows on the frontier of Heliophysics at a time when the space environment is rapidly evolving. IMAP with 100 times the combined resolution and sensitivity of IBEX and INCA will discover the substructure of the IBEX ribbon and will reveal in unprecedented resolution global maps of our heliosphere. The remarkable synergy between IMAP, Voyager 1 and Voyager 2 will remain for at least the next decade as Voyager 1 pushes further into the interstellar domain and Voyager 2 moves through the heliosheath. The "A" in IMAP refers to acceleration of energetic particles. With its combination of highly sensitive pickup and suprathermal ion sensors, IMAP will provide the species and spectral coverage as well as unprecedented temporal resolution to associate emerging suprathermal tails with interplanetary structures and discover underlying physical acceleration processes. These key measurements will provide what has been a critical missing piece of suprathermal seed particles in our understanding of particle acceleration to high

  7. Accelerator based fusion reactor

    Science.gov (United States)

    Liu, Keh-Fei; Chao, Alexander Wu

    2017-08-01

    A feasibility study of fusion reactors based on accelerators is carried out. We consider a novel scheme where a beam from the accelerator hits the target plasma on the resonance of the fusion reaction and establish characteristic criteria for a workable reactor. We consider the reactions d+t\\to n+α,d+{{}3}{{H}\\text{e}}\\to p+α , and p+{{}11}B\\to 3α in this study. The critical temperature of the plasma is determined from overcoming the stopping power of the beam with the fusion energy gain. The needed plasma lifetime is determined from the width of the resonance, the beam velocity and the plasma density. We estimate the critical beam flux by balancing the energy of fusion production against the plasma thermo-energy and the loss due to stopping power for the case of an inert plasma. The product of critical flux and plasma lifetime is independent of plasma density and has a weak dependence on temperature. Even though the critical temperatures for these reactions are lower than those for the thermonuclear reactors, the critical flux is in the range of {{10}22}-{{10}24}~\\text{c}{{\\text{m}}-2}~{{\\text{s}}-1} for the plasma density {ρt}={{10}15}~\\text{c}{{\\text{m}}-3} in the case of an inert plasma. Several approaches to control the growth of the two-stream instability are discussed. We have also considered several scenarios for practical implementation which will require further studies. Finally, we consider the case where the injected beam at the resonance energy maintains the plasma temperature and prolongs its lifetime to reach a steady state. The equations for power balance and particle number conservation are given for this case.

  8. Cast dielectric composite linear accelerator

    Science.gov (United States)

    Sanders, David M [Livermore, CA; Sampayan, Stephen [Manteca, CA; Slenes, Kirk [Albuquerque, NM; Stoller, H M [Albuquerque, NM

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  9. Collective accelerator for electron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, R.J.

    1985-05-13

    A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch.

  10. NIIEFA accelerators for applied purposes

    Science.gov (United States)

    Vorogushin, M. F.; Strokach, A. P.; Filatov, O. G.

    2016-12-01

    Since the foundation of the institute, we have designed and delivered more than three hundred different accelerators to Russia and abroad: cyclotrons, linear accelerators, and neutron generators. The technical characteristics of our equipment makes it competitive on the international market. Here we present the application, main parameters, and status of accelerators manufactured by NIIEFA, as well as prospects for the development of electrophysical systems for applied purposes.

  11. Motion Representation with Acceleration Images

    OpenAIRE

    Kataoka, Hirokatsu; He, Yun; Shirakabe, Soma; Satoh, Yutaka

    2016-01-01

    Information of time differentiation is extremely important cue for a motion representation. We have applied first-order differential velocity from a positional information, moreover we believe that second-order differential acceleration is also a significant feature in a motion representation. However, an acceleration image based on a typical optical flow includes motion noises. We have not employed the acceleration image because the noises are too strong to catch an effective motion feature ...

  12. Particle Acceleration by MHD Turbulence

    OpenAIRE

    Cho, Jungyeon; Lazarian, A.

    2005-01-01

    Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of particle acceleration. We make use of the recently established scaling of slow and fast MHD modes in strong and weak MHD turbulence to provide a systematic study of particle acceleration in magnetic pressure (low-$\\beta$) and gaseous pressure (high-$\\beta$) dominated plasmas. We consider the acceleration by large scale compressions in both slow and fast particle diffusion limits. We c...

  13. Helium-neon laser irradiation at fluences of 1, 2, and 4 J/cm2 failed to accelerate wound healing as assessed by both wound contracture rate and tensile strength.

    Science.gov (United States)

    Allendorf, J D; Bessler, M; Huang, J; Kayton, M L; Laird, D; Nowygrod, R; Treat, M R

    1997-01-01

    Reports in the literature indicate that low energy laser irradiation has a biostimulatory effect on wound healing; however, no mechanism of this effect has been elucidated. We attempted to establish a model from which to study the mechanism of biostimulation. The effects of low energy helium-neon irradiation on wound healing were observed in two rat models. In the first model, 1.5 cm diameter full thickness excisional skin defects were created in the dorsal midline of rats (n = 32). All animals were anesthetized and all eschars were debrided daily. Wound area was determined by caliper measurements for 2 weeks postoperatively. Rats that received a treatment of 1 J/cm2 had two defects in the dorsal skin. One wound was treated and the second was used as its own control. These measurements were not blinded. Rats that received 2 J/cm2, 4 J/cm2, or anesthesia alone had one defect on the dorsal skin. Caliper measurements of these wounds were blinded. We were unable to demonstrate any difference in the rate of wound contracture in rats that received a daily dose of 1 J/cm2, 2 J/cm2, 4 J/cm2, or anesthesia alone (P > 0.8 by student's t-test). In the second model, a single 2 cm longitudinal full thickness skin incision was created in the dorsal midline of each rat (n = 24). No difference was found between rats that received anesthesia alone and those treated daily with 2 J/cm2 as assessed by tensile strength measurements on postoperative days 7 and 14 (P > 0.8 by student's t-test between groups at both time points). These determinations were blinded. Despite our intentions of studying the mechanism of low energy HeNe biostimulation, we were unable to demonstrate a beneficial effect. In this study, helium-neon laser irradiation produced no measurable benefit on wound healing.

  14. Accelerated epigenetic aging in Werner syndrome.

    Science.gov (United States)

    Maierhofer, Anna; Flunkert, Julia; Oshima, Junko; Martin, George M; Haaf, Thomas; Horvath, Steve

    2017-04-01

    Individuals suffering from Werner syndrome (WS) exhibit many clinical signs of accelerated aging. While the underlying constitutional mutation leads to accelerated rates of DNA damage, it is not yet known whether WS is also associated with an increased epigenetic age according to a DNA methylation based biomarker of aging (the "Epigenetic Clock"). Using whole blood methylation data from 18 WS cases and 18 age matched controls, we find that WS is associated with increased extrinsic epigenetic age acceleration (p=0.0072) and intrinsic epigenetic age acceleration (p=0.04), the latter of which is independent of age-related changes in the composition of peripheral blood cells. A multivariate model analysis reveals that WS is associated with an increase in DNA methylation age (on average 6.4 years, p=0.011) even after adjusting for chronological age, gender, and blood cell counts. Further, WS might be associated with a reduction in naïve CD8+ T cells (p=0.025) according to imputed measures of blood cell counts. Overall, this study shows that WS is associated with an increased epigenetic age of blood cells which is independent of changes in blood cell composition. The extent to which this alteration is a cause or effect of WS disease phenotypes remains unknown.

  15. Multi-Mode Cavity Accelerator Structure

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yong [Yale Univ., New Haven, CT (United States); Hirshfield, Jay Leonard [Omega-P R& D, Inc., New Haven, CT (United States)

    2016-11-10

    This project aimed to develop a prototype for a novel accelerator structure comprising coupled cavities that are tuned to support modes with harmonically-related eigenfrequencies, with the goal of reaching an acceleration gradient >200 MeV/m and a breakdown rate <10-7/pulse/meter. Phase I involved computations, design, and preliminary engineering of a prototype multi-harmonic cavity accelerator structure; plus tests of a bimodal cavity. A computational procedure was used to design an optimized profile for a bimodal cavity with high shunt impedance and low surface fields to maximize the reduction in temperature rise ΔT. This cavity supports the TM010 mode and its 2nd harmonic TM011 mode. Its fundamental frequency is at 12 GHz, to benchmark against the empirical criteria proposed within the worldwide High Gradient collaboration for X-band copper structures; namely, a surface electric field Esurmax< 260 MV/m and pulsed surface heating ΔTmax< 56 °K. With optimized geometry, amplitude and relative phase of the two modes, reductions are found in surface pulsed heating, modified Poynting vector, and total RF power—as compared with operation at the same acceleration gradient using only the fundamental mode.

  16. Mechanisms of cardiovascular disease in accelerated aging syndromes.

    Science.gov (United States)

    Capell, Brian C; Collins, Francis S; Nabel, Elizabeth G

    2007-07-06

    In the past several years, remarkable progress has been made in the understanding of the mechanisms of premature aging. These rare, genetic conditions offer valuable insights into the normal aging process and the complex biology of cardiovascular disease. Many of these advances have been made in the most dramatic of these disorders, Hutchinson-Gilford progeria syndrome. Although characterized by features of normal aging such as alopecia, skin wrinkling, and osteoporosis, patients with Hutchinson-Gilford progeria syndrome are affected by accelerated, premature arteriosclerotic disease that leads to heart attacks and strokes at a mean age of 13 years. In this review, we highlight recent advances in the biology of premature aging uncovered in Hutchinson-Gilford progeria syndrome and other accelerated aging syndromes, advances that provide insight into the mechanisms of cardiovascular diseases ranging from atherosclerosis to arrhythmias.

  17. Accelerators for research and applications

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, J.R.

    1990-06-01

    The newest particle accelerators are almost always built for extending the frontiers of research, at the cutting edge of science and technology. Once these machines are operating and these technologies mature, new applications are always found, many of which touch our lives in profound ways. The evolution of accelerator technologies will be discussed, with descriptions of accelerator types and characteristics. The wide range of applications of accelerators will be discussed, in fields such as nuclear science, medicine, astrophysics and space-sciences, power generation, airport security, materials processing and microcircuit fabrication. 13 figs.

  18. Compact accelerator for medical therapy

    Energy Technology Data Exchange (ETDEWEB)

    Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

    2010-05-04

    A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

  19. Superconducting Radiofrequency (SRF) Acceleration Technology

    Data.gov (United States)

    Federal Laboratory Consortium — SRF cavities enable accelerators to increase particle beam energy levels while minimizing the use of electrical power by all but eliminating electrical resistance....

  20. Short Acceleration Times from Superdiffusive Shock Acceleration in the Heliosphere

    Science.gov (United States)

    Perri, S.; Zimbardo, G.

    2015-12-01

    The analysis of time profiles of particles accelerated at interplanetary shocks allows particle transport properties to be inferred. The frequently observed power-law decay upstream, indeed, implies a superdiffusive particle transport when the level of magnetic field variance does not change as the time interval from the shock front increases. In this context, a superdiffusive shock acceleration (SSA) theory has been developed, allowing us to make predictions of the acceleration times. In this work we estimate for a number of interplanetary shocks, including the solar wind termination shock, the acceleration times for energetic protons in the framework of SSA and we compare the results with the acceleration times predicted by standard diffusive shock acceleration. The acceleration times due to SSA are found to be much shorter than in the classical model, and also shorter than the interplanetary shock lifetimes. This decrease of the acceleration times is due to the scale-free nature of the particle displacements in the framework of superdiffusion. Indeed, very long displacements are possible, increasing the probability for particles far from the front of the shock to return, and short displacements have a high probability of occurrence, increasing the chances for particles close to the front to cross the shock many times.

  1. Accelerant-related burns and drug abuse: Challenging combination.

    Science.gov (United States)

    Leung, Leslie T F; Papp, Anthony

    2017-10-31

    Accelerants are flammable substances that may cause explosion when added to existing fires. The relationships between drug abuse and accelerant-related burns are not well elucidated in the literature. Of these burns, a portion is related to drug manufacturing, which have been shown to be associated with increased burn complications. 1) To evaluate the demographics and clinical outcomes of accelerant-related burns in a Provincial Burn Centre. 2) To compare the clinical outcomes with a control group of non-accelerant related burns. 3) To analyze a subgroup of patients with history of drug abuse and drug manufacturing. Retrospective case control study. Patient data associated with accelerant-related burns from 2009 to 2014 were obtained from the British Columbia Burn Registry. These patients were compared with a control group of non-accelerant related burns. Clinical outcomes that were evaluated include inhalational injury, ICU length of stay, ventilator support, surgeries needed, and burn complications. Chi-square test was used to evaluate categorical data and Student's t-test was used to evaluate mean quantitative data with the p value set at 0.05. A logistic regression model was used to evaluate factors affecting burn complications. Accelerant-related burns represented 28.2% of all burn admissions (N=532) from 2009 to 2014. The accelerant group had higher percentage of patients with history of drug abuse and was associated with higher TBSA burns, ventilator support, ICU stay and pneumonia rates compared to the non-accelerant group. Within the accelerant group, there was no difference in clinical outcomes amongst people with or without history of drug abuse. Four cases were associated with methamphetamine manufacturing, all of which underwent ICU stay and ventilator support. Accelerant-related burns cause significant burden to the burn center. A significant proportion of these patients have history of drug abuse. Copyright © 2017 Elsevier Ltd and ISBI. All rights

  2. Contemporary crustal deformations in the Izu peninsula, Honshu, Japan and acceleration of plate bending in the northernmost part of the Philippine Sea plate

    Science.gov (United States)

    Fujii, Yoichiro

    1991-07-01

    Since the beginning of the anomalous vertical crustal movement in the Izu peninsul, Honshu, Japan, many repeated precise levellings have been carried out by the Geographical Survey Institute. Trilaterations covering the entire Izu peninsula have also been carried out by the Geographical Survey Institute. A new technique is developed to adjust the results of levellings, because they had been carried out for different epochs along each levelling route and because of rapid vertical crustal movements. In conventional least-squares adjustment of levelling network, only corrections to the approximate height are assumed to be unknown, while in the present analysis a special model in which rates of vertical deformation at any bench marks are also assumed to be unknown, is adopted. In addition, tidal stations along the coast of the Izu peninsula yield the rate of vertical crustal movement from analysis of tidal data independent of levelling data. We select several special bench marks in which rates of vertical movement are determined by tidal analysis, thereafter special adjustment is applied according to the type of network. The results show that the peninsula is inclined to the south-west. Uplift in the northeastern part of the peninsula is accompanied by remarkable subsidence in the southwest. The rate of contemporary inclination is many times higher than the rate during the period from 1929 to 1972. The deformation is concentrated in the area where Nakamura (1979, 1980) pointed out the bending of the Philippine Sea plate. The mode and rate of the detected crustal deformation suggest the accelerated bending of the peninsula. There are some local “uplift” that deviate from the general pattern of deformation. The most remarkable land uplift was observed near Ito, a city within the peninsula, and the focus of this uplift migrated with time. The accelerated plate bending will produce an extension at the earth's surface and contraction in the deeper part of the subcrustal

  3. High Field Studies for CLIC Accelerating Structures Development

    CERN Document Server

    Profatilova, I

    2017-01-01

    Compact Linear Collider RF structures need to be able to achieve the very high average accelerating gradient of 100 MV/m. One of the main challenges in reaching such high accelerating gradients is to avoid vacuum electrical breakdown within CLIC accelerating structures. Accelerating structure tests are carried out in the klystron-based test stands known as the XBoxes. In order to investigate vacuum breakdown phenomena and its statistical characteristics in a simpler system and get results in a faster way, pulsed dc systems have been developed at CERN. To acquire sufficient breakdown data in a reasonable period of time, high repetition rate pulse generators are used in the systems for breakdown studies, so-called pulsed dc system. This paper describes the pulsed dc systems and the two high repetition rate circuits, which produce high-voltage pulses for it, available at CERN.

  4. COMPASS Accelerator Design Technical Overview

    Energy Technology Data Exchange (ETDEWEB)

    Nanni, Emilio; Dolgashev, Valery; Tantawi, Sami; Neilson, Jeff; /SLAC

    2016-03-14

    This report is a survey of technical options for generating a MeV-class accelerator for space based science applications. The survey was performed focusing on the primary technical requirements of the accelerator in the context of a satellite environment with its unique challenges of limited electrical power (PE), thermal isolation, dimensions, payload requirement and electrical isolation.

  5. Natural Acceleration: Supporting Creative Trajectories

    Science.gov (United States)

    Cohen, LeoNora M.

    2011-01-01

    "Natural acceleration" happens through an internal fire that burns to learn and may transcend school boundaries. Based on their passionate interests and connections with a domain, children who hunger for domain understandings outside school curricula require different types of acceleration, motivated by these interests. The lifeworks,…

  6. Accelerating Topical Anaesthesia Using Microneedles.

    Science.gov (United States)

    Davies, Lleucu B; Gateley, Christopher; Holland, Phillip; Coulman, Siôn A; Birchall, James C

    2017-09-08

    Topical anaesthetics reduce pain during venous access procedures in children. However, clinical use is hindered by a significant anaesthetic onset time. Restricted diffusion of the topical anaesthetic through the stratum corneum barrier is the principal reason for the delayed onset. Microneedles can painlessly pierce the skin. This study evaluated microneedle pre-treatment of ex vivo human skin as a means to increase the rate of tetracaine permeation, in order to accelerate the onset of anaesthesia. Franz-type diffusion cells were used to determine permeation of a commercial tetracaine formulation, Ametop gel, through human skin epidermis. Microneedle-assisted permeation was compared to untreated epidermis. Upon completion of the permeation studies, the epidermal membranes were visually characterised. At 30 min, 5.43 µg/cm2 of tetracaine had permeated through the untreated membrane compared to 12.13 µg/cm2 through the microneedle-treated membrane. Insertion of a hypodermic needle created a large single channel in the epidermis (approx. 4,250 μm2) whilst the punctured surface area following microneedle treatments was estimated to be 75,000 μm2. Pre-treatment of skin with microneedles significantly enhances the permeation of tetracaine. Microneedles have the potential to more than halve the onset time for anaesthesia when applying Ametop gel. © 2017 S. Karger AG, Basel.

  7. The art of acceleration

    CERN Multimedia

    2005-01-01

    "They invented the World Wide Web. Now, they are building the most powerful, most complex scientific machine in the world. But the scientists at CERN near Geneva have other talents: they are first-rate managers" (8 pages)

  8. Industrial accelerators and their applications

    CERN Document Server

    Hamm, Marianne E

    2012-01-01

    This unique new book is a comprehensive review of the many current industrial applications of particle accelerators, written by experts in each of these fields. Readers will gain a broad understanding of the principles of these applications, the extent to which they are employed, and the accelerator technology utilized. The book also serves as a thorough introduction to these fields for non-experts and laymen. Due to the increased interest in industrial applications, there is a growing interest among accelerator physicists and many other scientists worldwide in understanding how accelerators are used in various applications. The government agencies that fund scientific research with accelerators are also seeking more information on the many commercial applications that have been or can be developed with the technology developments they are funding. Many industries are also doing more research on how they can improve their products or processes using particle beams.

  9. Accelerators for high intensity beams

    CERN Document Server

    Chou, Weiren

    2014-01-01

    As particle accelerators strive forever increasing performance, high intensity particle beams become one of the critical demands requested across the board by a majority of accelerator users (proton, electron and ion) and for most applications. Much effort has been made by our community to pursue high intensity accelerator performance on a number of fronts. Recognizing its importance, we devote this volume to Accelerators for High Intensity Beams. High intensity accelerators have become a frontier and a network for innovation. They are responsible for many scientific discoveries and technological breakthroughs that have changed our way of life, often taken for granted. A wide range of topics is covered in the fourteen articles in this volume.

  10. Energy Innovation Acceleration Program

    Energy Technology Data Exchange (ETDEWEB)

    Wolfson, Johanna [Fraunhofer USA Inc., Center for Sustainable Energy Systems, Boston, MA (United States)

    2015-06-15

    The Energy Innovation Acceleration Program (IAP) – also called U-Launch – has had a significant impact on early stage clean energy companies in the Northeast and on the clean energy economy in the Northeast, not only during program execution (2010-2014), but continuing into the future. Key results include: Leverage ratio of 105:1; $105M in follow-on funding (upon $1M investment by EERE); At least 19 commercial products launched; At least 17 new industry partnerships formed; At least $6.5M in revenue generated; >140 jobs created; 60% of assisted companies received follow-on funding within 1 year of program completion; In addition to the direct measurable program results summarized above, two primary lessons emerged from our work executing Energy IAP:; Validation and demonstration awards have an outsized, ‘tipping-point’ effect for startups looking to secure investments and strategic partnerships. An ecosystem approach is valuable, but an approach that evaluates the needs of individual companies and then draws from diverse ecosystem resources to fill them, is most valuable of all.

  11. SPS RF Accelerating Cavity

    CERN Multimedia

    1979-01-01

    This picture shows one of the 2 new cavities installed in 1978-1979. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X

  12. The entangled accelerating universe

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Diaz, Pedro F. [Colina de los Chopos, Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain); Estacion Ecologica de Biocosmologia, Pedro de Alvarado, 14, 06411-Medellin (Spain)], E-mail: p.gonzalezdiaz@imaff.cfmac.csic.es; Robles-Perez, Salvador [Colina de los Chopos, Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain); Estacion Ecologica de Biocosmologia, Pedro de Alvarado, 14, 06411-Medellin (Spain)

    2009-08-31

    Using the known result that the nucleation of baby universes in correlated pairs is equivalent to spacetime squeezing, we show in this Letter that there exists a T-duality symmetry between two-dimensional warp drives, which are physically expressible as localized de Sitter little universes, and two-dimensional Tolman-Hawking and Gidding-Strominger baby universes respectively correlated in pairs, so that the creation of warp drives is also equivalent to spacetime squeezing. Perhaps more importantly, it has been also seen that the nucleation of warp drives entails a violation of the Bell's inequalities, and hence the phenomena of quantum entanglement, complementarity and wave function collapse. These results are generalized to the case of any dynamically accelerating universe filled with dark or phantom energy whose creation is also physically equivalent to spacetime squeezing and to the violation of the Bell's inequalities, so that the universe we are living in should be governed by essential sharp quantum theory laws and must be a quantum entangled system.

  13. Cosmic transparency and acceleration

    Science.gov (United States)

    Holanda, R. F. L.; Pereira, S. H.; Jain, Deepak

    2018-01-01

    In this paper, by considering an absorption probability independent of photon wavelength, we show that current type Ia supernovae (SNe Ia) and gamma-ray burst (GRB) observations plus high-redshift measurements of the cosmic microwave background (CMB) radiation temperature support cosmic acceleration regardless of the transparent-universe assumption. Two flat scenarios are considered in our analyses: the Λ CDM model and a kinematic model. We consider τ (z )=2 ln (1 +z )ɛ, where τ (z ) denotes the opacity between an observer at z =0 and a source at z . This choice is equivalent to deforming the cosmic distance duality relation as DLDA-1=(1 +z )2+ɛ and, if the absorption probability is independent of photon wavelength, the CMB temperature evolution law is TCMB(z )=T0(1 +z )1+2 ɛ /3. By marginalizing on the ɛ parameter, our analyses rule out a decelerating universe at 99.99% C.L. for all scenarios considered. Interestingly, by considering only SNe Ia and GRBs observations, we obtain that a decelerated universe—indicated by ΩΛ≤0.33 and q0>0 —is ruled out around 1.5 σ C.L. and 2 σ C.L., respectively, regardless of the transparent-universe assumption.

  14. Hot Spot Cosmic Accelerators

    Science.gov (United States)

    2002-11-01

    length of more than 3 million light-years, or no less than one-and-a-half times the distance from the Milky Way to the Andromeda galaxy, this structure is indeed gigantic. The region where the jets collide with the intergalactic medium are known as " hot spots ". Superposing the intensity contours of the radio emission from the southern "hot spot" on a near-infrared J-band (wavelength 1.25 µm) VLT ISAAC image ("b") shows three distinct emitting areas; they are even better visible on the I-band (0.9 µm) FORS1 image ("c"). This emission is obviously associated with the shock front visible on the radio image. This is one of the first times it has been possible to obtain an optical/near-IR image of synchrotron emission from such an intergalactic shock and, thanks to the sensitivity and image sharpness of the VLT, the most detailed view of its kind so far . The central area (with the strongest emission) is where the plasma jet from the galaxy centre hits the intergalactic medium. The light from the two other "knots", some 10 - 15,000 light-years away from the central "hot spot", is also interpreted as synchrotron emission. However, in view of the large distance, the astronomers are convinced that it must be caused by electrons accelerated in secondary processes at those sites . The new images thus confirm that electrons are being continuously accelerated in these "knots" - hence called "cosmic accelerators" - far from the galaxy and the main jets, and in nearly empty space. The exact physical circumstances of this effect are not well known and will be the subject of further investigations. The present VLT-images of the "hot spots" near 3C 445 may not have the same public appeal as some of those beautiful images that have been produced by the same instruments during the past years. But they are not less valuable - their unusual importance is of a different kind, as they now herald the advent of fundamentally new insights into the mysteries of this class of remote and active

  15. EXHIBITION: Accelerated Particles

    CERN Multimedia

    2004-01-01

    http://www.cern.ch/cern50/ An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's fiftieth anniversary celebrations. The fiftieth anniversary of a world famous organization like CERN, an international laboratory specializing in fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting two "salons" consisting of an exhibition of plastic arts and evenings of music and visual arts performances with the collective title of "Accelerated Particles". Several works will be exhibited and performed. Salon des matières: An exhibition of plastic arts Until Wednesday 3 November 2004. Tuesdays to Fridays: 4.00 p.m. to 7.00 p.m. Saturdays: 2.00 p.m. to 6.00 p.m. Doors open late on the evening of the performances. Salon des ...

  16. EXHIBITION: Accelerated Particles

    CERN Multimedia

    2004-01-01

    An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's 50th anniversary celebrations. Fifty candles for CERN, an international laboratory renowned for fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting exhibitions of plastic arts and performances entitled: Accelerated Particles. Several works will be exhibited and performed in two 'salons'. Salon des matières: An exhibition of plastic arts From Tues 12 October to Wed 3 November 2004 Tuesdays to Fridays: 16:00 to 19:00 Saturdays: 14:00 to 18:00 Exhibition open late on performance nights, entrance free Salon des particules: Musical and visual performances Tues 12 and Mon 25 October from 20:00 to 23:00 Preview evening for both events: Tues 12 October from 18:...

  17. Behavior of susceptible-vaccinated--infected--recovered epidemics with diversity in the infection rate of the individuals

    CERN Document Server

    Cai, Chao-Ran; Guan, Jian-Yue

    2013-01-01

    We study a susceptible-vaccinated--infected--recovered (SVIR) epidemic-spreading model with diversity of infection rate of the individuals. By means of analytical arguments as well as extensive computer simulations, we demonstrate that the heterogeneity in infection rate can either impede or accelerate the epidemic spreading, which depends on the amount of vaccinated individuals introduced in the population as well as the contact pattern among the individuals. Remarkably, as long as the individuals with different capability of acquiring the disease interact with unequal frequency, there always exist a cross point for the fraction of vaccinated, below which the diversity of infection rate hinders the epidemic spreading and above which expedites it. The overall results are robust to the SVIR dynamics defined on different population models; the possible applications of the results are discussed.

  18. Induced activity in accelerator structures, air and water

    CERN Document Server

    Stevenson, Graham Roger

    2001-01-01

    A summary is given of several 'rules of thumb' which can be used to predict the formation and decay of radionuclides in the structure of accelerators together with the dose rates from the induced radioactivity. Models are also given for the activation of gases (air of the accelerator vault) and liquids (in particular cooling water), together with their transport front the activation region to the release point. (18 refs).

  19. Demographic and Competitiveness Acceleration and Government Sustainable Advantage in Indonesia

    OpenAIRE

    Samosir, Omas Bulan; Rajagukguk, Wilson

    2017-01-01

    The objective of this research is to investigate the effects of demographic and competitiveness acceleration on sustainable advantage in government areas in Indonesia. The research is done at district level (kabupaten/kota) in Indonesia. The sustainable advantage variable is the gross domestic product (GDP), while the demographic and competitiveness acceleration variables are the dependency ratio growth rate, capital investment, percentage share of agriculture in the economy, and percentage o...

  20. A GPU Accelerated Spring Mass System for Surgical Simulation

    DEFF Research Database (Denmark)

    Mosegaard, Jesper; Sørensen, Thomas Sangild

    2005-01-01

    There is a growing demand for surgical simulators to dofast and precise calculations of tissue deformation to simulateincreasingly complex morphology in real-time. Unfortunately, evenfast spring-mass based systems have slow convergence rates for largemodels. This paper presents a method to accele...... to accelerate computation of aspring-mass system in order to simulate a complex organ such as theheart. This acceleration is achieved by taking advantage of moderngraphics processing units (GPU)....

  1. CAS CERN Accelerator School 5th General Accelerator Physics Course

    Science.gov (United States)

    Turner, S.

    1994-01-01

    The fifth CERN Accelerator School (CAS) basic course on General Accelerator Physics was given at the University of Jyvaeskylae, Finland, from 7 to 18 September 1992. Its syllabus was based on the previous similar courses held at Gif-sur-Yvette in 1984, Aarhus 1986, Salamanca 1988 and Juelich 1990, and whose proceedings were published as CERN Reports 85-19, 87-10, 89-05 and 91-04, respectively. However, certain topics were treated in a different way, improved or extended, while new subjects were introduced. As far as the proceedings of this school are concerned the opportunity was taken not only to include the lectures presented but also to select and revise the most appropriate chapters from the previous similar schools. In this way the present volumes constitute a rather complete introduction to all aspects of the design and construction of particle accelerators, including optics, emittance, luminosity, longitudinal and transverse beam dynamics, insertions, chromaticity, transfer lines, resonances, accelerating structures, tune shifts, coasting beams, lifetime, synchrotron radiation, radiation damping, beam-beam effects, diagnostics, cooling, ion and positron sources, RF and vacuum systems, injection and extraction, conventional, permanent and superconducting magnets, cyclotrons, RF linear accelerators, microtrons, as well as applications of particle accelerators (including therapy) and the history of accelerators. See hints under the relevant topics.

  2. Accelerated thermal and radiative ageing of hydrogenated NBR for DRC

    Energy Technology Data Exchange (ETDEWEB)

    Mares, G. [EUROTEST S.A., Bucharest (Romania). Research, Equipment Testing, Industrial Engineering and Scientific Services; Notingher, P. [Univ. Politehnica, Bucharest (Romania). Faculty of Electrical Engineering

    1996-12-31

    The accelerated thermal and gamma radiation ageing of HNBR carbon black-T80 has been studied by measuring the residual deformation under constant deflection -- DRC, in air, using a relevant equation for the relaxation phenomena. The residual deformation under constant deflection during the process of accelerated ageing is increasing but the structure of polymer answers in the proper manner to the mechanical stress. The degradation equations were obtained, using Alfrey model for the relaxation polymer subject to compression and an Arrhenius dependence for the chemical reaction rate. The inverted relaxation time for the thermal degradation is depending on the chemical reaction rate and the dose rate of gamma radiation.

  3. Numerical Model of the DARHT Accelerating Cell

    CERN Document Server

    Hughes, Thomas P; Genoni, Thomas C; Kang, Mike; Prichard, Benjamin A

    2005-01-01

    The DARHT-2 facility at Los Alamos National Laboratory accelerates a 2 microsecond electron beam using a series of inductive accelerating cells. The cell inductance is provided by large Metglas cores, which are driven by a pulse-forming network. The original cell design was susceptible to electrical breakdown near the outer radius of the cores. We developed a numerical model for the magnetic properties of Metglas over the range of dB/dt (magnetization rate) relevant to DARHT. The model was implemented in a radially-resolved circuit code, and in the LSP* electromagnetic code. LSP simulations showed that the field stress distribution across the outer radius of the cores was highly nonuniform. This was subsequently confirmed in experiments at LBNL. The calculated temporal evolution of the electric field stress inside the cores approximately matches experimental measurements. The cells have been redesigned to greatly reduce the field stresses along the outer radius.

  4. Measuring the Acceleration of a Rigid Body

    Directory of Open Access Journals (Sweden)

    Peter G. Martin

    1998-01-01

    Full Text Available Two methods to measure the six-degree-of-freedom acceleration of a point on a rigid body are presented. The first, referred to as the periphery scheme, makes use of three clusters of accelerometers mounted orthogonal to each other and coincident with the axes of the point. One of the clusters consists of the three accelerometers attached to a cube-shaped triaxial angular rate sensor (ARS. The second method, called the compact cube scheme, uses a single 3-accelerometer/ARS cluster that may be mounted anywhere on the rigid body. During impact tests with an instrumented rigid body, both methods produced measurements that were highly correlated near the time of peak acceleration. Whereas the compact cube scheme was more economical and easier to implement, the periphery scheme produced results that were less disrupted by instrument signal errors and noisy environments.

  5. Ion acceleration from relativistic laser nano-target

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Daniel

    2012-01-06

    Laser-ion acceleration has been of particular interest over the last decade for fundamental as well as applied sciences. Remarkable progress has been made in realizing laser-driven accelerators that are cheap and very compact compared with conventional rf-accelerators. Proton and ion beams have been produced with particle energies of up to 50 MeV and several MeV/u, respectively, with outstanding properties in terms of transverse emittance and current. These beams typically exhibit an exponentially decaying energy distribution, but almost all advanced applications, such as oncology, proton imaging or fast ignition, require quasimonoenergetic beams with a low energy spread. The majority of the experiments investigated ion acceleration in the target normal sheath acceleration (TNSA) regime with comparably thick targets in the {mu}m range. In this thesis ion acceleration is investigated from nm-scaled targets, which are partially produced at the University of Munich with thickness as low as 3 nm. Experiments have been carried out at LANL's Trident high-power and high-contrast laser (80 J, 500 fs, {lambda}=1054 nm), where ion acceleration with these nano-targets occurs during the relativistic transparency of the target, in the so-called Breakout afterburner (BOA) regime. With a novel high resolution and high dispersion Thomson parabola and ion wide angle spectrometer, thickness dependencies of the ions angular distribution, particle number, average and maximum energy have been measured. Carbon C{sup 6+} energies reached 650 MeV and 1 GeV for unheated and heated targets, respectively, and proton energies peaked at 75 MeV and 120 MeV for diamond and CH{sub 2} targets. Experimental data is presented, where the conversion efficiency into carbon C{sup 6+} (protons) is investigated and found to have an up to 10fold (5fold) increase over the TNSA regime. With circularly polarized laser light, quasi-monoenergetic carbon ions have been generated from the same nm-scaled foil

  6. Acceleration of Crystal Growth of Amorphous Griseofulvin by Low-Concentration Poly(ethylene oxide): Aspects of Crystallization Kinetics and Molecular Mobility.

    Science.gov (United States)

    Shi, Qin; Zhang, Chen; Su, Yuan; Zhang, Jie; Zhou, Dongshan; Cai, Ting

    2017-07-03

    This study aims to investigate the crystallization behavior and molecular dynamics of amorphous griseofulvin (GSF) in the presence of low-concentration poly(ethylene oxide) (PEO). We observe that the addition of 3% w/w PEO remarkably increases the crystal growth rate of GSF by two orders of magnitude in both the supercooled liquid and glassy states. The liquid dynamics of amorphous GSF in the presence and absence of PEO are characterized by dielectric spectroscopy. With an increase of the PEO content, the α-relaxation times of the systems decrease, indicating the increase of global molecular mobility. The couplings between molecular mobility and crystallization kinetics of GSF systems show strong time-dependences below Tg. The overlapping of α-relaxation times of GSF in presence and absence of PEO as a function of Tg/T suggest the "plasticization" effect of PEO additives. However, the crystallization kinetics of amorphous GSF containing low-concentration PEO do not overlap with those of pure GSF on a Tg/T scale. The remarkable accelerating effect of crystal growth of amorphous GSF by low-concentration PEO can be partially attributed to the increase of global mobility. The high segmental mobility of PEO is expected to strongly affect the crystal growth rates of GSF. These findings are relevant for understanding and predicting the physical stability of amorphous pharmaceutical solid dispersions.

  7. EDITORIAL: Laser and plasma accelerators Laser and plasma accelerators

    Science.gov (United States)

    Bingham, Robert

    2009-02-01

    This special issue on laser and plasma accelerators illustrates the rapid advancement and diverse applications of laser and plasma accelerators. Plasma is an attractive medium for particle acceleration because of the high electric field it can sustain, with studies of acceleration processes remaining one of the most important areas of research in both laboratory and astrophysical plasmas. The rapid advance in laser and accelerator technology has led to the development of terawatt and petawatt laser systems with ultra-high intensities and short sub-picosecond pulses, which are used to generate wakefields in plasma. Recent successes include the demonstration by several groups in 2004 of quasi-monoenergetic electron beams by wakefields in the bubble regime with the GeV energy barrier being reached in 2006, and the energy doubling of the SLAC high-energy electron beam from 42 to 85 GeV. The electron beams generated by the laser plasma driven wakefields have good spatial quality with energies ranging from MeV to GeV. A unique feature is that they are ultra-short bunches with simulations showing that they can be as short as a few femtoseconds with low-energy spread, making these beams ideal for a variety of applications ranging from novel high-brightness radiation sources for medicine, material science and ultrafast time-resolved radiobiology or chemistry. Laser driven ion acceleration experiments have also made significant advances over the last few years with applications in laser fusion, nuclear physics and medicine. Attention is focused on the possibility of producing quasi-mono-energetic ions with energies ranging from hundreds of MeV to GeV per nucleon. New acceleration mechanisms are being studied, including ion acceleration from ultra-thin foils and direct laser acceleration. The application of wakefields or beat waves in other areas of science such as astrophysics and particle physics is beginning to take off, such as the study of cosmic accelerators considered

  8. Induction Acceleration of a Single RF Bunch in the KEK PS

    CERN Document Server

    Takayama, Ken; Arakida, Yoshio; Horioka, Kazuhiko; Igarashi, Susumu; Iwashita, Taiki; Kawasaki, Atsushi; Kishiro, Junichi; Kono, Tadaaki; Koseki, Kunio; Nakamura, Eiji; Sakuda, Makoto; Sato, Hikaru; Shiho, Makoto; Shimosaki, Yoshito; Shirakata, Masashi; Sueno, Tsuyoshi; Tokuchi, Akira; Torikai, Kota; Toyama, Takeshi; Wake, Masayoshi; Watanabe, Masao; Yamane, Isao

    2005-01-01

    A single bunch trapped in an RF bucket was accelerated by induction devices from 500 MeV to 8GeV beyond transition energy in the KEK-PS. This is the first demonstration of induction acceleration in a high energy circular ring. The acceleration was confirmed by measuring a temporal evolution of the RF phase through an entire acceleration.* Key devices in an induction acceleration system are an induction accelerating cavity capable of generating an induced voltage of 2kV/cell, a pulse modulator to drive the cavity (switching driver), and a DSP system to control gate signals for switching. Their remarkable characteristics are its repetition ratio of about 1MHz and duty factor of 50%. All devices have been newly developed at KEK so as to meet this requirement. The pulse modulator employing MOSFETs as switching elements is connected with the accelerating cavity through a long transmission cable in order to avoid a high-dose irradiation in the accelerator tunnel. The induction system has been running beyond more th...

  9. The Generalized Optic Acceleration Cancellation Theory of Catching

    Science.gov (United States)

    McLeod, Peter; Reed, Nick; Dienes, Zoltan

    2006-01-01

    The generalized optic acceleration cancellation (GOAC) theory of catching proposes that the path of a fielder running to catch a ball is determined by the attempt to satisfy 2 independent constraints. The 1st is to keep the angle of elevation of gaze to the ball increasing at a decreasing rate. The 2nd is to control the rate of horizontal rotation…

  10. A Novel Guidance Law with Line-of-Sight Acceleration Feedback for Missiles against Maneuvering Targets

    Directory of Open Access Journals (Sweden)

    Kemao Ma

    2014-01-01

    Full Text Available Terminal guidance law design and its implementation are considered for homing missiles against maneuvering targets. The lateral acceleration dynamics are taken into account in the design. In the guidance law design, the line-of-sight acceleration signals are incorporated into the acceleration reference signals to compensate for the targets’ maneuvers. Then the commanded accelerations are designed and the convergent tracking of the lateral accelerations to these signals is proven theoretically. In the guidance implementation, a linear high-gain differentiator is used to estimate the line-of-sight rates and the line-of-sight acceleration signals. To avoid the magnifying effects of higher order differentiation, a practical design of commanded accelerations is given to realize approximate tracking of the lateral accelerations to the given reference signals. Simulation is conducted for both cases with and without measurement noises. The simulation results justify the feasibility of the design and the implementation.

  11. "small ACCELERATORS" 24 May - 2 June 2005

    CERN Multimedia

    2005-01-01

    CERN Accelerator School and Kernfysisch Versneller Instituut (KVI) Groningen, the Netherlands announce a course on "Small Accelerators", Hotel Golden Tulip Drenthe, Zeegse, the Netherlands, 24 May - 2 June 2005. This specialised course is dedicated to the physics and the main applications of small accelerators. The course will review the different accelerator types as well as their specificities in terms of accelerator physics.

  12. Particle acceleration in binaries

    Directory of Open Access Journals (Sweden)

    Sinitsyna V.G.

    2017-01-01

    Full Text Available Cygnus X-3 massive binary system is one of the powerful sources of radio and X-ray emission consisting of an accreting compact object, probably a black hole, with a Wolf-Rayet star companion. Based on the detections of ultra high energy gamma-rays by Kiel and Havera Park, Cygnus X-3 has been proposed to be one of the most powerful sources of charged cosmic ray particles in the Galaxy. The results of long-term observations of the Cyg X-3 binary at energies 800 GeV–85 TeV detected by SHALON in 1995 are presented with images, integral spectra and spectral energy distribution. The identification of source with Cygnus X-3 detected by SHALON was secured by the detection of its 4.8 hour orbital period in TeV gamma-rays. During the whole observation period of Cyg X-3 with SHALON significant flux increases were detected at energies above 0.8 TeV. These TeV flux increases are correlated with flaring activity at a lower energy range of X-ray and/or at observations of Fermi LAT as well as with radio emission from the relativistic jets of Cygnus X-3. The variability of very high-energy gamma-radiation and correlation of radiation activity in the wide energy range can provide essential information on particle mechanism production up to very high energies. Whereas, modulation of very high energy emission connected to the orbital motion of the binary system, provides an understanding of the emission processes, nature and location of particle acceleration.

  13. Particle acceleration in binaries

    Science.gov (United States)

    Sinitsyna, V. G.; Sinitsyna, V. Y.

    2017-06-01

    Cygnus X-3 massive binary system is one of the powerful sources of radio and X-ray emission consisting of an accreting compact object, probably a black hole, with a Wolf-Rayet star companion. Based on the detections of ultra high energy gamma-rays by Kiel and Havera Park, Cygnus X-3 has been proposed to be one of the most powerful sources of charged cosmic ray particles in the Galaxy. The results of long-term observations of the Cyg X-3 binary at energies 800 GeV-85 TeV detected by SHALON in 1995 are presented with images, integral spectra and spectral energy distribution. The identification of source with Cygnus X-3 detected by SHALON was secured by the detection of its 4.8 hour orbital period in TeV gamma-rays. During the whole observation period of Cyg X-3 with SHALON significant flux increases were detected at energies above 0.8 TeV. These TeV flux increases are correlated with flaring activity at a lower energy range of X-ray and/or at observations of Fermi LAT as well as with radio emission from the relativistic jets of Cygnus X-3. The variability of very high-energy gamma-radiation and correlation of radiation activity in the wide energy range can provide essential information on particle mechanism production up to very high energies. Whereas, modulation of very high energy emission connected to the orbital motion of the binary system, provides an understanding of the emission processes, nature and location of particle acceleration.

  14. Physical origins of remarkable thermostabilization by an octuple mutation for the adenosine A2a receptor

    Science.gov (United States)

    Kajiwara, Yuta; Ogino, Takahiro; Yasuda, Satoshi; Takamuku, Yuuki; Murata, Takeshi; Kinoshita, Masahiro

    2016-07-01

    It was experimentally showed that the thermal stability of a membrane protein, the adenosine A2a receptor, was remarkably enhanced by an octuple mutation. Here we theoretically prove that the energy decrease arising from the formation of protein intramolecular hydrogen bonds and the solvent-entropy gain upon protein folding are made substantially larger by the mutation, leading to the remarkable enhancement. The solvent is formed by hydrocarbon groups constituting nonpolar chains of the lipid bilayer within a membrane. The mutation modifies geometric characteristics of the structure so that the solvent crowding can be reduced to a larger extent when the protein folds.

  15. Acceleration of particles in plasmas

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    The accelerating fields in radio-frequency accelerators are limited to roughly 100 MV/m due to material breakdown which occurs on the walls of the structure. In contrast, a plasma, being already ionized, can support electric fields in excess of 100 GV/m. Such high accelerating gradients hold the promise of compact particle accelerators. Plasma acceleration has been an emerging and fast growing field of research in the past two decades. In this series of lectures, we will review the principles of plasma acceleration. We will see how relativistic plasma waves can be excited using an ultra-intense laser or using a particle beam. We will see how these plasma waves can be used to accelerate electrons to high energy in short distances. Throughout the lectures, we will also review recent experimental results. Current laser-plasma experiments throughout the world have shown that monoenergetic electron beams from 100 MeV to 1 GeV can be obtained in distances ranging from the millimetre to the centimetre. Experiments a...

  16. 2014 CERN Accelerator Schools: Beam Loss and Accelerator Protection

    CERN Multimedia

    2014-01-01

    The US-CERN-JAPAN-RUSSIA Joint International Accelerator School is organising a course on Beam Loss and Accelerator Protection to be held in Newport Beach, California, USA from 5-14 November, 2014.    This school is intended for physicists and engineers who are or may be engaged in the design, construction, and/or operation of accelerators with high power photon or particle beams and/or accelerator sub-systems with large stored energy. Application deadlines are 15 August and 4 September. Further information on this Joint School can be found at: http://cas.web.cern.ch/cas/JAS/Newport%20Beach%202014/NPBadvert.html http://indico.cern.ch/event/287647/ http://uspas.fnal.gov/programs/JAS/JAS14.shtml

  17. Superconducting Magnets for Particle Accelerators

    CERN Document Server

    Bottura, Luca; Yamamoto, Akira; Zlobin, Alexander V

    2016-01-01

    In this paper we summarize the evolution and contributions of superconducting magnets to particle accelerators as chronicled over the last 50 years of Particle Accelerator Conferences (PAC, NA-PAC and IPAC). We begin with an historical overview based primarily on PAC Proceedings augmented with references to key milestones in the development of superconducting magnets for particle accelerators. We then provide some illustrative examples of applications that have occurred over the past 50 years, focusing on those that have either been realized in practice or provided technical development for other projects, with discussion of possible future applications.

  18. Diffraction Accelerator Of Charged Particles

    CERN Document Server

    Alekseev, Yu K; Kosarev, A A; Poseryaev, A V; Shvedunov, V I; Vetrov, A A; Zayarniy, D A

    2004-01-01

    We present the results of theoretical and numerical analysis of the physical processes for laser linear accelerator based on two symmetric resonance diffraction gratings with double-sided accelerating field excitation. Structures parameters optimization provides π-mode field amplitude distribution in neighboring diffraction zone. The maximum energy gradient restricted by ablation processes in grating materials is estimated as 1-3 GeV/m. The numerical analyses and analytical approximation of electric and magnetic field structures are done, longitudinal and transverse electron beam dynamics in accelerating systems are considered, wake fields and focusing properties of diffraction gratings are estimated.

  19. Estimation of steady-state culture characteristics during acceleration-stats with yeasts

    NARCIS (Netherlands)

    Sluis, van der C.; Westerink, B.H.; Dijkstal, M.M.; Castelein, S.J.; Boxtel, van A.J.B.; Tramper, J.; Wijffels, R.H.

    2001-01-01

    Steady-state culture characteristics are usually determined in chemostat cultivations, which are very time-consuming. In contrast, acceleration-stat (A-stat) cultivations in which the dilution rate is continuously changed with a constant acceleration rate are not so time-consuming, especially at

  20. SNEAP 80: symposium of Northeastern Accelerator personnel

    Energy Technology Data Exchange (ETDEWEB)

    Billen, J.H. (ed.)

    1980-01-01

    Reports of operations are presented for twenty-seven facilities, along with reports on accelerators in progress, ion sources, insulating gases, charging systems, stripping foils, accelerating tubes, and upgraded accelerator systems. (GHT)

  1. Remarks on the thermopreferendum of palearctic bats in their natural habitats

    NARCIS (Netherlands)

    Gaisler, Jiří

    1970-01-01

    This contribution comprises two remarks of ecological rather than physiological character. Contrary to Herter (1952), Herreid (1967), and Harmata (1969), I did not examine the temperature preference, or thermopreferendum, of bats under experimental conditions but concluded on it only on grounds of

  2. Bernays, Dooyeweerd and Gödel – the remarkable convergence in ...

    African Journals Online (AJOL)

    Bernays, Dooyeweerd and Gödel – the remarkable convergence in their reflections on the foundations of mathematics. ... This is particularly the case in respect of the acknowledgement of the difference between the discrete and the continuous, the foundational position of number and the fact that the idea of continuity is ...

  3. The Public University in South Africa: Philosophical Remarks on the Notion of "Elitist Knowledge" Production

    Science.gov (United States)

    Waghid, Yusef

    2009-01-01

    In my remarks about elitist knowledge production, I firstly try to adjust the perspective from which the university could be analysed; I specifically explore the functions of the university in relation to Habermas's categorisation of knowledge. Secondly, with reference to Derrida's reflections on the university, I reformulate a conception of the…

  4. A Brief History of the Most Remarkable Numbers "e," "i" and "?" in Mathematical Sciences with Applications

    Science.gov (United States)

    Debnath, Lokenath

    2015-01-01

    This paper deals with a brief history of the most remarkable Euler numbers "e,"?"i"?and?"?" in mathematical sciences. Included are many properties of the constants "e,"?"i"?and?"?" and their applications in algebra, geometry, physics, chemistry, ecology, business and industry. Special…

  5. a new record of zoraptera (insecta) from kenya, with remarks on their

    African Journals Online (AJOL)

    Journal of East African Natural History 105(2): 213–222 (2016). A NEW RECORD OF ZORAPTERA (INSECTA) FROM KENYA,. WITH REMARKS ON THEIR ..... A new Zorotypus from Peru, with notes on related Neotropical species. (Zoraptera: Zorotypidae). Journal of the Kansas Entomological Society 73: 11–20. Engel ...

  6. Diffusion-Weighted MRI in Recurrent Wernicke's Encephalopathy: a Remarkable Cerebellar Lesion.

    Science.gov (United States)

    Kim, Jung Eun; Kim, Tae Hyung; Yu, In Kyu; Lee, Bo Ram; Lee, Soo Joo; Oh, Gun Sei

    2006-06-01

    We report unusual MRI findings (including those from diffusion-weighted imaging (DWI)) in a patient with recurrent Wernicke's encephalopathy with a remarkable cerebellar lesion. DWI showed high signal intensities in the superior portion of the cerebellar hemisphere and vermis area. After thiamine administration, clinical symptoms improved and the lesions with high signal intensities disappeared on follow-up DWI.

  7. [Use of tissue adhesives and collagen membranes in clinical cases. Critical remarks].

    Science.gov (United States)

    Smolarek, F

    1977-01-01

    On the base of his own 7 years clinical experience the author discusses with some critical remarks the possibilities and indications for applying tissue adhesive and adhesives together with collagen membranes in the treatment of injuries to the chest, abdomen and blood vessels.

  8. Remarks on the Distribution and Migration of Whales, based on Observations from Netherlands Ships

    NARCIS (Netherlands)

    Slijper, E.J.; Utrecht, van W.L.; Naaktgeboren, C.

    1964-01-01

    A. GENERAL REMARKS During three years 4500 reports of whales sighted from Netherlands ships were collected, bearing on approximately 11.000 individual animals. Most of the observations were made in the Atlantic and Indian Ocean. It was supposed that the species could be determined with a fairly high

  9. George E. Pake Prize Lecture: Crystalline Silicon Photovoltaics: Accelerating to Grid Parity

    Science.gov (United States)

    Pinto, Mark

    2013-03-01

    Lost in recent headlines about solar company failures, reduced government support and depressed stock valuations is the fact that photovoltaic (PV) systems continue to be installed at an extremely healthy rate - a ten-fold increase between 2007 and 2012, to a cumulative 100GWp of installations worldwide. The primary factor behind this remarkable growth has been cost reduction at the installed system level afforded by manufacturing and technology improvements to the crystalline silicon (c-Si) PV cell. In fact in the past 2 years, c-Si module cost learning curves have accelerated over their historical norms as a function of both volume and time, and as a result c-Si PV has reached parity with conventional forms of electricity in 20 + countries worldwide. In this presentation future c-Si technology paths will be reviewed along with market implications, leading to the projection that between 2015 and 2020, c-Si based PV electricity will be cost-effectively delivered to >95% of the world's population.

  10. Carbon nanotubes accelerate methane production in pure cultures of methanogens and in a syntrophic coculture.

    Science.gov (United States)

    Salvador, Andreia F; Martins, Gilberto; Melle-Franco, Manuel; Serpa, Ricardo; Stams, Alfons J M; Cavaleiro, Ana J; Pereira, M Alcina; Alves, M Madalena

    2017-07-01

    Carbon materials have been reported to facilitate direct interspecies electron transfer (DIET) between bacteria and methanogens improving methane production in anaerobic processes. In this work, the effect of increasing concentrations of carbon nanotubes (CNT) on the activity of pure cultures of methanogens and on typical fatty acid-degrading syntrophic methanogenic coculture was evaluated. CNT affected methane production by methanogenic cultures, although acceleration was higher for hydrogenotrophic methanogens than for acetoclastic methanogens or syntrophic coculture. Interestingly, the initial methane production rate (IMPR) by Methanobacterium formicicum cultures increased 17 times with 5 g·L-1 CNT. Butyrate conversion to methane by Syntrophomonas wolfei and Methanospirillum hungatei was enhanced (∼1.5 times) in the presence of CNT (5 g·L-1 ), but indications of DIET were not obtained. Increasing CNT concentrations resulted in more negative redox potentials in the anaerobic microcosms. Remarkably, without a reducing agent but in the presence of CNT, the IMPR was higher than in incubations with reducing agent. No growth was observed without reducing agent and without CNT. This finding is important to re-frame discussions and re-interpret data on the role of conductive materials as mediators of DIET in anaerobic communities. It also opens new challenges to improve methane production in engineered methanogenic processes. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. High temperature superconductor accelerator magnets

    NARCIS (Netherlands)

    van Nugteren, J.

    2016-01-01

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding 20T. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and

  12. Advanced Superconducting Test Accelerator (ASTA)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Superconducting Test Accelerator (ASTA) facility will be based on upgrades to the existing NML pulsed SRF facility. ASTA is envisioned to contain 3 to 6...

  13. Extinction Events Can Accelerate Evolution

    DEFF Research Database (Denmark)

    Lehman, Joel; Miikkulainen, Risto

    2015-01-01

    Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate...

  14. Particle accelerator; the Universe machine

    CERN Multimedia

    Yurkewicz, Katie

    2008-01-01

    "In summer 2008, scientists will switch on one of the largest machines in the world to search for the smallest of particle. CERN's Large Hadron Collider particle accelerator has the potential to chagne our understanding of the Universe."

  15. Remarkable spatial variation in the seroprevalence of Coxiella burnetii after a large Q fever epidemic

    Directory of Open Access Journals (Sweden)

    Roan Pijnacker

    2017-11-01

    Full Text Available Abstract Background Prior to the 2007–2010 Q fever epidemic in the Netherlands, the seroprevalence of antibodies against Coxiella burnetii in the general population was 1.5%, which is low compared to other countries. We aimed to determine the seroprevalence after the Q fever epidemic among people living in the affected area, compare the seroprevalence with the incidence of Q fever notifications during the 2007–2010 Q fever epidemic, and to identify farm exposures associated with having antibodies against C. burnetii. Methods During the period March 2014–February 2015, residents aged 18–70 years from two provinces were invited by general practitioners to complete a questionnaire on their symptoms and personal characteristics and to submit a blood sample. We used the mandatory provincial database of livestock licences to calculate distance to farms/farm animals for each participant. To compare ELISA-positive participants for C. burnetii antibodies with those who were negative, we calculated prevalence ratios (PR using binominal regression. We compared the C. burnetii seroprevalence in the period March 2014–February 2015 with the incidence of Q fever notifications during the 2007–2010 Q fever epidemic at municipal level by calculating the Spearman correlation coefficient. Results Of the 2296 participants (response rate: 34%, 6.1% (n = 139, 95% CI 5.1–7.1% had C. burnetii antibodies (range in municipalities: 1.7–14.1%. C. burnetii seroprevalence was higher in individuals living within 1000 m of goat farms (PR 3.0; 95% CI 1.4–6.4 or within 1000 m of > 50 goats (PR 1.9; 95% CI 1.2–3.0. Seroprevalence increased with decreasing distance to the closest goat farm that was infected during the epidemic years ( 2000 reference group. There was no significant correlation between C. burnetii seroprevalence and Q fever incidence during the 2007–2010 epidemic (r s  = 0.42, p = 0.156. Conclusions Results showed a remarkable

  16. Accelerators for Discovery Science and Security applications

    Energy Technology Data Exchange (ETDEWEB)

    Todd, A.M.M., E-mail: alan_todd@mail.aesys.net; Bluem, H.P.; Jarvis, J.D.; Park, J.H.; Rathke, J.W.; Schultheiss, T.J.

    2015-05-01

    Several Advanced Energy Systems (AES) accelerator projects that span applications in Discovery Science and Security are described. The design and performance of the IR and THz free electron laser (FEL) at the Fritz-Haber-Institut der Max-Planck-Gesellschaft in Berlin that is now an operating user facility for physical chemistry research in molecular and cluster spectroscopy as well as surface science, is highlighted. The device was designed to meet challenging specifications, including a final energy adjustable in the range of 15–50 MeV, low longitudinal emittance (<50 keV-psec) and transverse emittance (<20 π mm-mrad), at more than 200 pC bunch charge with a micropulse repetition rate of 1 GHz and a macropulse length of up to 15 μs. Secondly, we will describe an ongoing effort to develop an ultrafast electron diffraction (UED) source that is scheduled for completion in 2015 with prototype testing taking place at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF). This tabletop X-band system will find application in time-resolved chemical imaging and as a resource for drug–cell interaction analysis. A third active area at AES is accelerators for security applications where we will cover some top-level aspects of THz and X-ray systems that are under development and in testing for stand-off and portal detection.

  17. Adaptive and accelerated tracking-learning-detection

    Science.gov (United States)

    Guo, Pengyu; Li, Xin; Ding, Shaowen; Tian, Zunhua; Zhang, Xiaohu

    2013-08-01

    An improved online long-term visual tracking algorithm, named adaptive and accelerated TLD (AA-TLD) based on Tracking-Learning-Detection (TLD) which is a novel tracking framework has been introduced in this paper. The improvement focuses on two aspects, one is adaption, which makes the algorithm not dependent on the pre-defined scanning grids by online generating scale space, and the other is efficiency, which uses not only algorithm-level acceleration like scale prediction that employs auto-regression and moving average (ARMA) model to learn the object motion to lessen the detector's searching range and the fixed number of positive and negative samples that ensures a constant retrieving time, but also CPU and GPU parallel technology to achieve hardware acceleration. In addition, in order to obtain a better effect, some TLD's details are redesigned, which uses a weight including both normalized correlation coefficient and scale size to integrate results, and adjusts distance metric thresholds online. A contrastive experiment on success rate, center location error and execution time, is carried out to show a performance and efficiency upgrade over state-of-the-art TLD with partial TLD datasets and Shenzhou IX return capsule image sequences. The algorithm can be used in the field of video surveillance to meet the need of real-time video tracking.

  18. 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.

  19. Hamiltonian mechanics of stochastic acceleration.

    Science.gov (United States)

    Burby, J W; Zhmoginov, A I; Qin, H

    2013-11-08

    We show how to find the physical Langevin equation describing the trajectories of particles undergoing collisionless stochastic acceleration. These stochastic differential equations retain not only one-, but two-particle statistics, and inherit the Hamiltonian nature of the underlying microscopic equations. This opens the door to using stochastic variational integrators to perform simulations of stochastic interactions such as Fermi acceleration. We illustrate the theory by applying it to two example problems.

  20. Design acceleration in chemical engineering

    OpenAIRE

    Cortes Robles, Guillermo; Negny, Stéphane; Le Lann, Jean-Marc

    2008-01-01

    Nowadays, Chemical Engineering has to face a new industrial context with for example: the gradually falling of hydrocarbon reserves after 2020-2030, relocation, emerging of new domains of application (nano-micro technologies) which necessitate new solutions and knowledges… All this tendencies and demands accelerate the need of tool for design and innovation (technically, technologically). In this context, this paper presents a tool to accelerate innovative preliminary design. This model is ba...

  1. High temperature superconductor accelerator magnets

    OpenAIRE

    van Nugteren, J.

    2016-01-01

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding 20T. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and development before they can be applied in a practical accelerator magnet. In order to study HTS in detail, a five tesla demonstrator magnet named Feather-M2 is designed and constructed. The magnet is ...

  2. High Temperature Superconductor Accelerator Magnets

    OpenAIRE

    Van Nugteren, Jeroen; ten Kate, Herman; de Rijk, Gijs; Dhalle, Marc

    2016-01-01

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding $20T$. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and development before they can be applied in a practical accelerator magnet. In order to study HTS in detail, a five tesla demonstrator magnet named Feather-M2 is designed and constructed. The magnet ...

  3. How anomalous resistivity accelerates magnetic reconnection

    Science.gov (United States)

    Che, H.

    2017-08-01

    Whether turbulence induced anomalous resistivity (AR) can facilitate a fast magnetic reconnection in collisionless plasma is a subject of active debate for decades. Recent space observations suggest that the reconnection rate can be higher than the Hall-reconnection rate and turbulent dissipation is required. In this paper, using particle-in-cell simulations, we present a case study of how AR produced by Buneman instability accelerates magnetic reconnection. We first show that the AR/drag produced by Buneman instability in a thin electron current layer (1) can dissipate magnetic energy stored in the current layer through dissipation of the kinetic energy of electron beams; (2) the inhomogeneous drag caused by wave couplings spontaneously breaks the magnetic field lines and causes impulsive fast non-Hall magnetic reconnection on electron-scales with a mean rate reaching of 0.6 VA. We then show that a Buneman instability driven by intense electron beams around the x-point in a 3D magnetic reconnection significantly enhances the dissipation of the magnetic energy. Electron-scale magnetic reconnections driven by the inhomogeneous drag around the x-line enhance the reconnection electric field and the in-plane perpendicular magnetic field. About 40% of the released magnetic energy is converted into electron thermal energy by AR while 50% is converted into kinetic energy of the electron beams through the acceleration by the reconnection electric field. The enhanced magnetic energy dissipation is balanced by a net Poynting flux in-flow. About 10% of the released magnetic energy is brought out by an enhanced Poynting flux out-flow. These results suggest that AR with sufficient intensity and electron-scale inhomogeneity can significantly accelerate magnetic reconnection.

  4. Detection of laser-accelerated protons

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Sabine

    2012-08-08

    Real-time (Online) detection of laser-accelerated protons is a challenge for any electronic detector system due to the peculiar time structure ({<=} ns) and high intensity ({>=}10{sup 7} p/cm{sup 2}) of the generated ion pulses. Besides considerable saturation effects, problems are expected by an electromagnetic interference pulse (EMP), generated during laser-plasma interaction. In the scope of this work, different detection systems were built-up with regard to specific demands of laser-ion-acceleration at the MPQ ATLAS laser, which allow the quantitative analysis of the generated proton beam. A cell irradiation experiment at the ATLAS laser was accomplished to demonstrate the usability of laser-accelerated protons for radiation therapy. Cells were irradiated with a single shot dose of few Gy for a proton energy of 5 MeV. The following cell analysis required the spatially resolved measurement of the dose distribution. Only radiation-sensitive films were applicable because of the small proton range, although they show significant quenching effects for the used proton energy. This was extensively studied in the 3-200 MeV energy range. A film-based dosimetry protocol for low-energy proton irradiations was developed, making the absolute dose determination in the cell experiment possible. The non-electronic detectors (nuclear track detectors, radiation-sensitive films) are still state of the art in laser-accelerated ion diagnostics, although these detectors only allow a delayed in time (offline) detection. A non-electronic system, based on image plates, was thoroughly characterized and calibrated for ongoing experiments at the ATLAS laser, for the first time. Main objective of this work, though, was the set-up of a real-time detection system, which is urgently required, owing to increasing repetition rate of the laser accelerator (>Hz), to advance the parameter optimisation of the laser-acceleration in an efficient way. Systems based on silicon pixel detectors are

  5. High-Intensity Proton Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2011-12-27

    Analysis is presented for an eight-cavity proton cyclotron accelerator that could have advantages as compared with other accelerators because of its potentially high acceleration gradient. The high gradient is possible since protons orbit in a sequence of TE111 rotating mode cavities of equally diminishing frequencies with path lengths during acceleration that greatly exceed the cavity lengths. As the cavities operate at sequential harmonics of a basic repetition frequency, phase synchronism can be maintained over a relatively wide injection phase window without undue beam emittance growth. It is shown that use of radial vanes can allow cavity designs with significantly smaller radii, as compared with simple cylindrical cavities. Preliminary beam transport studies show that acceptable extraction and focusing of a proton beam after cyclic motion in this accelerator should be possible. Progress is also reported on design and tests of a four-cavity electron counterpart accelerator for experiments to study effects on beam quality arising from variations injection phase window width. This device is powered by four 500-MW pulsed amplifiers at 1500, 1800, 2100, and 2400 MHz that provide phase synchronous outputs, since they are driven from a with harmonics derived from a phase-locked 300 MHz source.

  6. Electrodynamics in accelerated frames revisited

    Energy Technology Data Exchange (ETDEWEB)

    Maluf, J.W. [Instituto de Fisica, Universidade de Brasilia (Brazil); Ulhoa, S.C. [Instituto de Ciencia e Tecnologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, UFVJM, Diamantina, MG (Brazil)

    2010-10-15

    Maxwell's equations are formulated in arbitrary moving frames by means of tetrad fields, which are interpreted as reference frames adapted to observers in space-time. We assume the existence of a general distribution of charges and currents in an inertial frame. Tetrad fields are used to project the electromagnetic fields and sources on accelerated frames. The purpose is to study several configurations of fields and observers that in the literature are understood as paradoxes. For instance, are the two situations, (i) an accelerated charge in an inertial frame, and (ii) a charge at rest in an inertial frame described from the perspective of an accelerated frame, physically equivalent? Is the electromagnetic radiation the same in both frames? Normally in the analysis of these paradoxes the electromagnetic fields are transformed to (uniformly) accelerated frames by means of a coordinate transformation of the Faraday tensor. In the present approach coordinate and frame transformations are disentangled, and the electromagnetic field in the accelerated frame is obtained through a frame (local Lorentz) transformation. Consequently the fields in the inertial and accelerated frames are described in the same coordinate system. This feature allows the investigation of paradoxes such as the one mentioned above. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  7. Tutorial on Superconducting Accelerator Magnets

    Science.gov (United States)

    Ball, M. J. Penny; Goodzeit, Carl L.

    1997-05-01

    A multimedia CD-ROM tutorial on the physics and engineering concepts of superconducting magnets for particle accelerators is being developed under a U.S. Dept. of Energy SBIR grant. The tutorial, scheduled for distribution this summer, is targeted to undergraduate junior or senior level science students. However, its unified presentation of the broad range of issues involved in the design of superconducting magnets for accelerators and the extensive detail about the construction process (including animations and video clips) will also be of value to staff of research institutes and industrial concerns with an interest in applied superconductivity or magnet development. The source material, which is based on the world-wide R and D programs to develop superconducting accelerator magnets, is organized in five units with the following themes: Introduction to magnets and accelerators; (2) Superconductors for accelerator magnets; (3) Magnetic design methods for accelerator magnets; (4) Electrical, mechanical, and cryogenic considerations for the final magnet package; (5) Performance characteristics and measurement methods. A detailed outline and examples will be shown.

  8. Stellar winds, fast rotators, and magnetic acceleration

    Science.gov (United States)

    Nerney, S.

    1980-01-01

    The assumption that observed mass outflow from a star is due to a magnetically driven wind implies an upper bound on the surface magnetic field strength from regions where the wind originates. Evidence is reported that corroborates Rosendhal's observation of an abrupt change in the velocity-gradient-luminosity relationship for B8 and later supergiants. The smallest upper bounds correspond to later spectral types, for which radiation would be a relatively inefficient mechanism for driving wind; these winds may in fact be magnetically driven. Be stars are prime candidates for magnetically accelerated winds due to large rotation rates and small mass loss rates. Observed flows can be driven by 0.1-10 gauss surface fields. Intense field in fast rotators can lead to dramatic mass loss rates and large terminal velocities; sigma Ori E may be such an object. Finally, the effect of magnetic acceleration on the dispersal of solar nebula is considered. The increased velocities allow the wind to disperse a mass of 90 times the initial outflowing mass in the wind.

  9. Characteristics of Three Decomposer Accelerators on Maize Straw Decomposition

    Directory of Open Access Journals (Sweden)

    KUANG En-jun

    2014-10-01

    Full Text Available In order to make sure the effect of straw decomposer accelerators on the maize straws in Northeast of China, mesh bag method was used to determine the decomposition characteristics of maize straw biomass amount and nutrition release regularity in one year. The results showed that after 100 days, decomposition rates of maize straws biomass amount were between 57.1%-64.1%. The highest decomposition rate of 64.1% was the treatment with the 3rd decomposer accelerator. The nutrition release rates of N, P and K were 35.1%-57.2%, 44.2%-59.6%,and 77.4%-89.7% at the end of period, respectively. And the 3rd decomposer accelerator treatment had a better effect on the release rate of P and K. All treatments had the same trend of organic C mineralization rate which increased with the time extending, at last the organic C min-eralization rate was between 65.3% and 69.1%. The results showed the 3rd decomposition accelerator had better effect than others.

  10. Accelerated Near-Threshold Fatigue Crack Growth Behavior of an Aluminum Powder Metallurgy Alloy

    Science.gov (United States)

    Piascik, Robert S.; Newman, John A.

    2002-01-01

    Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low DK, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = Kmin/Kmax). The near threshold accelerated FCG rates are exacerbated by increased levels of Kmax (Kmax less than 0.4 KIC). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and Kmax influenced accelerated crack growth is time and temperature dependent.

  11. Plasma wave undulator for laser-accelerated electrons

    CERN Document Server

    Corde, S; 10.1063/1.3569827

    2011-01-01

    Laser-plasma accelerators have become compact sources of ultrashort electron bunches at energies up to the gigaelectronvolt range thanks to the remarkable progress made over the past decade. A direct application of these electron bunches is the production of short pulse x-ray radiation sources. In this letter, we study a fully optically driven x-ray source based on the combination of a laser-plasma accelerator and a plasma wave undulator. The longitudinal electric field of a laser-generated plasma wave is used to wiggle electrons transversally. The period of this plasma undulator being equal to the plasma wavelength, tunable photon energies in the 10 keV range can be achieved with electron energies in the 100-200 MeV range. Considering a 10s TW class femtosecond laser system, undulators with a strength parameter K~0.5 and with about ten periods can be combined with a laser-plasma accelerator, resulting in several 10^-2 emitted x-ray photons per electron.

  12. Steady state quantum discord for circularly accelerated atoms

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jiawei, E-mail: hujiawei@nbu.edu.cn [Center for Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang 315211 (China); Yu, Hongwei, E-mail: hwyu@hunnu.edu.cn [Center for Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang 315211 (China); Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, Hunan 410081 (China)

    2015-12-15

    We study, in the framework of open quantum systems, the dynamics of quantum entanglement and quantum discord of two mutually independent circularly accelerated two-level atoms in interaction with a bath of fluctuating massless scalar fields in the Minkowski vacuum. We assume that the two atoms rotate synchronically with their separation perpendicular to the rotating plane. The time evolution of the quantum entanglement and quantum discord of the two-atom system is investigated. For a maximally entangled initial state, the entanglement measured by concurrence diminishes to zero within a finite time, while the quantum discord can either decrease monotonically to an asymptotic value or diminish to zero at first and then followed by a revival depending on whether the initial state is antisymmetric or symmetric. When both of the two atoms are initially excited, the generation of quantum entanglement shows a delayed feature, while quantum discord is created immediately. Remarkably, the quantum discord for such a circularly accelerated two-atom system takes a nonvanishing value in the steady state, and this is distinct from what happens in both the linear acceleration case and the case of static atoms immersed in a thermal bath.

  13. Ocular responses and visual performance after emergent acceleration stress.

    Science.gov (United States)

    Tsai, Ming-Ling; Horng, Chi-Ting; Liu, Chun-Cheng; Shieh, Pochuen; Hung, Chun-Ling; Lu, Da-Wen; Chiang, Shang-Yi; Wu, Yi-Cheng; Chiou, Wen-Yaw

    2011-11-07

    To evaluate visual function after emergent acceleration stress. Sixteen subjects were enrolled in this study. Human ejection seat trainer was used to induce six times gravitational force in the head-to-toe (z-axis) direction (+6 Gz). Visual performance was evaluated using the visual chart and contrast sensitivity (CS) at indicated times. Ocular reactions were assessed with biomicroscopy and topographic mapping. Temporary visual acuity reduction (0.02 ± 0.05 vs. 0.18 ± 0.08 logMAR visual acuity [VA]; P spatial frequencies immediately after ejection. However, CS returned to the initial range at high spatial frequency by 30 minutes. Emergent acceleration force induces significant ocular responses and visual fluctuation. Prolonged ACD deepening (>15 minutes) and PD (>30 minutes) were noted, but cornea and refraction remain stable. CS at all spatial frequencies revealed remarkable reduction immediately after ejection, and recovered to baseline levels within 30 minutes only at high spatial frequency. Neuroretinal function may involve visual fluctuation after acceleration stress, because visual fluctuation corresponds with the characters of neuroretinal function. However, further studies are necessary.

  14. Accelerator and electrodynamics capability review

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Kevin W [Los Alamos National Laboratory

    2010-01-01

    Los Alamos National Laboratory (LANL) uses capability reviews to assess the science, technology and engineering (STE) quality and institutional integration and to advise Laboratory Management on the current and future health of the STE. Capability reviews address the STE integration that LANL uses to meet mission requirements. The Capability Review Committees serve a dual role of providing assessment of the Laboratory's technical contributions and integration towards its missions and providing advice to Laboratory Management. The assessments and advice are documented in reports prepared by the Capability Review Committees that are delivered to the Director and to the Principal Associate Director for Science, Technology and Engineering (PADSTE). Laboratory Management will use this report for STE assessment and planning. LANL has defined fifteen STE capabilities. Electrodynamics and Accelerators is one of the seven STE capabilities that LANL Management (Director, PADSTE, technical Associate Directors) has identified for review in Fiscal Year (FY) 2010. Accelerators and electrodynamics at LANL comprise a blend of large-scale facilities and innovative small-scale research with a growing focus on national security applications. This review is organized into five topical areas: (1) Free Electron Lasers; (2) Linear Accelerator Science and Technology; (3) Advanced Electromagnetics; (4) Next Generation Accelerator Concepts; and (5) National Security Accelerator Applications. The focus is on innovative technology with an emphasis on applications relevant to Laboratory mission. The role of Laboratory Directed Research and Development (LDRD) in support of accelerators/electrodynamics will be discussed. The review provides an opportunity for interaction with early career staff. Program sponsors and customers will provide their input on the value of the accelerator and electrodynamics capability to the Laboratory mission.

  15. Fundamental challenges in mechanistic enzymology: progress toward understanding the rate enhancements of enzymes.

    Science.gov (United States)

    Herschlag, Daniel; Natarajan, Aditya

    2013-03-26

    Enzymes are remarkable catalysts that lie at the heart of biology, accelerating chemical reactions to an astounding extent with extraordinary specificity. Enormous progress in understanding the chemical basis of enzymatic transformations and the basic mechanisms underlying rate enhancements over the past decades is apparent. Nevertheless, it has been difficult to achieve a quantitative understanding of how the underlying mechanisms account for the energetics of catalysis, because of the complexity of enzyme systems and the absence of underlying energetic additivity. We review case studies from our own work that illustrate the power of precisely defined and clearly articulated questions when dealing with such complex and multifaceted systems, and we also use this approach to evaluate our current ability to design enzymes. We close by highlighting a series of questions that help frame some of what remains to be understood, and we encourage the reader to define additional questions and directions that will deepen and broaden our understanding of enzymes and their catalysis.

  16. CAS Accelerator Physics (RF for Accelerators) in Denmark

    CERN Multimedia

    Barbara Strasser

    2010-01-01

    The CERN Accelerator School (CAS) and Aarhus University jointly organised a specialised course on RF for Accelerators, at the Ebeltoft Strand Hotel, Denmark from 8 to 17 June 2010.   Caption The challenging programme focused on the introduction of the underlying theory, the study and the performance of the different components involved in RF systems, the RF gymnastics and RF measurements and diagnostics. This academic part was supplemented with three afternoons dedicated to practical hands-on exercises. The school was very successful, with 100 participants representing 25 nationalities. Feedback from the participants was extremely positive, praising the expertise and enthusiasm of the lecturers, as well as the high standard and excellent quality of their lectures. In addition to the academic programme, the participants were able to visit a small industrial exhibition organised by Aarhus University and take part in a one-day excursion consisting of a visit of the accelerators operated ...

  17. Some remarks on in-situ studies using TEM-heavy-ion accelerator link from the stand point of extracting radiation damage caused by fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Ishino, Shiori, E-mail: ishino@k9.dion.ne.jp [University of Tokyo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Sekimura, Naoto [Department of Nuclear Engineering and Management, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Murakami, Kenta [Nuclear Professional School, University of Tokyo, Tokai-mura, Naka-gun, Ibaraki, 319-1194 (Japan); Abe, Hiroaki [Institute of Materials Research, Tohoku University, Aoba-ku, Sendai, 980-8577 (Japan)

    2016-04-01

    Radiation damage of materials for fission and fusion reactors has been scaled in terms of the number of displacements per atoms (dpa). The method of evaluating the dpa has been established and standardized. However, it has become obvious that more detailed analyses are required, particularly for the nature and spatial distribution of the introduced point defects and their clusters. Such detailed nature of the defects introduced is thought to be governed by the primary knock-on atom (PKA) spectrum, A number of trials to elucidate the PKA dependent radiation effects by choosing the mass and energy of the incident ions have been explored. In some cases, defect formation by a single impinging ion has been observed. However, it has also been recognized that there are a number of artefacts arising from energy deposition distributions, existence of surface sinks together with radiation induced surface modifications and so on. In this paper, discussion will be made on how to establish irradiation correlation between neutron and heavy ion irradiations in a cascade damage formation regime. For the past fifty years, the correlation between neutron and ion irradiations from the view point of simulating the neutron radiation damage by ion irradiations has been discussed many times. However, the correlation itself has not been fully discussed separately. This is the major objective of this paper.

  18. DARHT II Scaled Accelerator Tests on the ETA II Accelerator*

    Energy Technology Data Exchange (ETDEWEB)

    Weir, J T; Anaya Jr, E M; Caporaso, G J; Chambers, F W; Chen, Y; Falabella, S; Lee, B S; Paul, A C; Raymond, B A; Richardson, R A; Watson, J A; Chan, D; Davis, H A; Day, L A; Scarpetti, R D; Schultze, M E; Hughes, T P

    2005-05-26

    The DARHT II accelerator at LANL is preparing a series of preliminary tests at the reduced voltage of 7.8 MeV. The transport hardware between the end of the accelerator and the final target magnet was shipped to LLNL and installed on ETA II. Using the ETA II beam at 5.2 MeV we completed a set of experiments designed reduce start up time on the DARHT II experiments and run the equipment in a configuration adapted to the reduced energy. Results of the beam transport using a reduced energy beam, including the kicker and kicker pulser system will be presented.

  19. Accelerator Technology Division annual report, FY 1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-06-01

    This paper discusses: accelerator physics and special projects; experiments and injectors; magnetic optics and beam diagnostics; accelerator design and engineering; radio-frequency technology; accelerator theory and simulation; free-electron laser technology; accelerator controls and automation; and high power microwave sources and effects.

  20. Superconducting linear accelerator system for NSC

    Indian Academy of Sciences (India)

    This paper reports the construction of a superconducting linear accelerator as a booster to the 15 UD Pelletron accelerator at Nuclear Science Centre, New Delhi. The LINAC will use superconducting niobium quarter wave resonators as the accelerating element. Construction of the linear accelerator has progressed ...

  1. Remarks on the Radiative Transfer Approach to Scattering of Electromagnetic Waves in Layered Random Media

    Science.gov (United States)

    2010-03-01

    AFRL-RY-HS-TR-2010-0029 REMARKS ON THE RADIATIVE TRANSFER APPROACH TO SCATTERING OF ELECTROMAGNETIC WAVES IN LAYERED RANDOM MEDIA...TRANSFER APPROACH TO SCATTERING OF ELECTROMAGNETIC WAVES IN LAYERED RANDOM MEDIA 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT NUMBER 5c. PROGRAM...Beckmann and A. Spizzichino. The Scattering of Electromagnetic Waves from Rough Surfaces. Artech House, Norwood, Massachusetts, 1987. [3] G. S. Brown. A

  2. Some remarks on theological thought of María Zambrano

    Directory of Open Access Journals (Sweden)

    Juana Sánchez-Gey Venegas

    2018-01-01

    Full Text Available Maria Zambrano reflects upon some of the problems she has been always interested in: Christianity and Mysticism with especial emphasis on the divine processions, the Incarnation of Christ, the Virgin Mary, the liturgy among other personal experiences. In these letters the pursuit for the Holy Spirit as the foundation of knowledge is remarkably noticeable, so that it could be argued that this experience contributes and gives rise to the rejection both of rationalism and of materialism of the philosophy.

  3. A REMARKABLE CLADONIACEAE FLORA AT SUBANDEAN REGION IN CHÁMEZA (CASANARE, COLOMBIA

    Directory of Open Access Journals (Sweden)

    LADY JOHANNA HERRERA VARGAS

    2014-12-01

    Full Text Available A remarkable Cladoniaceae flora was discovered in the subandean region of Chámeza, ( Casanare, Colombia at 1200 meters above sea level. Four species of the genus Cladonia (Cladoniaceae, Lichenized Fungi are new records for Colombia : Cladonia macilentoides, C. scabriuscula, C. sipmanii and C. subdelicatula. This shows the importance of increasing diversity studies at mid elevations where suitable habitats for species of Cladonia occur.

  4. Remarks on Heavy-Light Mesons from AdS/CFT

    CERN Document Server

    Herzog, Christopher P; Vuorinen, Aleksi

    2008-01-01

    We use the AdS/CFT correspondence to compute the energy spectrum of heavy-light mesons in a N=2 SU(N) super Yang-Mills theory with two massive hypermultiplets. In the heavy quark limit, similar to QCD, we find that the excitation energies are independent of the heavy quark mass. We also make some remarks about related AdS/CFT models of flavor with less supersymmetry.

  5. The Diamond Light Source and the challenges ahead for structural biology: some informal remarks.

    Science.gov (United States)

    Ramakrishnan, V

    2015-03-06

    The remarkable advances in structural biology in the past three decades have led to the determination of increasingly complex structures that lie at the heart of many important biological processes. Many of these advances have been made possible by the use of X-ray crystallography using synchrotron radiation. In this short article, some of the challenges and prospects that lie ahead will be summarized. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  6. Hyperbaric hyperoxia accelerates fracture healing in mice.

    Directory of Open Access Journals (Sweden)

    Shigeo Kawada

    Full Text Available Increased oxygen tension influences bone metabolism. This study comprised two main experiments: one aimed to determine the bone mineral apposition and bone formation rates in vivo under hyperbaric hyperoxia (HBO, and the other aimed to evaluate the effects of exposure to HBO on fracture healing. In experiment 1, male mice were exposed to HBO [90 min/day at 90% O₂ at 2 atmospheres absolute (ATA for 5 days]. In experiment 2, an open femur fracture model was created in mice, followed by exposure to HBO 5 times/week (90 min/day at 90% O₂ at 2 ATA for 6 weeks after surgery. In experiment 1, HBO treatment significantly increased the mineral apposition and bone formation rates in the lumbar vertebra and femur and type 1 collagen alpha 1 and alkaline phosphatase mRNA expression in the lumbar vertebra. In experiment 2, at 2 weeks after fracture, the fracture callus was significantly larger in the HBO group than in the non-HBO group. Furthermore, at 4 and 6 weeks after fracture, radiographic findings showed accelerated fracture healing in the HBO group. At 6 weeks after fracture, femur stiffness and maximum load were significantly higher in the HBO group than in the non-HBO group. Urinary 8-hydroxy-2'-deoxyguanosine and plasma calcium concentrations were not significantly different between groups. These results suggest that exposure to HBO enhances bone anabolism and accelerates fracture healing without causing oxidative DNA damage or disruption of plasma calcium homeostasis.

  7. Regional warming of hot extremes accelerated by surface energy fluxes

    Science.gov (United States)

    Donat, M. G.; Pitman, A. J.; Seneviratne, S. I.

    2017-07-01

    Strong regional differences exist in how hot temperature extremes increase under global warming. Using an ensemble of coupled climate models, we examine the regional warming rates of hot extremes relative to annual average warming rates in the same regions. We identify hot spots of accelerated warming of model-simulated hot extremes in Europe, North America, South America, and Southeast China. These hot spots indicate where the warm tail of a distribution of temperatures increases faster than the average and are robust across most Coupled Model Intercomparison Project Phase 5 models. Exploring the conditions on the specific day when the hot extreme occurs demonstrates that the hot spots are explained by changes in the surface energy fluxes consistent with drying soils. However, the model-simulated accelerated warming of hot extremes appears inconsistent with observations, except over Europe. The simulated acceleration of hot extremes may therefore be unreliable, a result that necessitates a reevaluation of how climate models resolve the relevant terrestrial processes.

  8. A reference accelerator scheme for ADS applications

    Science.gov (United States)

    Biarrotte, Jean-Luc; Bousson, Sébastien; Junquera, Tomas; Mueller, Alex C.; Olivier, Aurélia

    2006-06-01

    Accelerator Driven Systems (ADS) for transmutation of nuclear waste typically require 350 MeV-1 GeV accelerators delivering proton fluxes of 5-10 mA for demonstrators, and 20-50 mA for large industrial systems. Thus, such machines belong to the category of the so-called HPPA (High-Power Proton Accelerators), with multi-megawatt beam power. HPPA are presently developed and constructed at great pace for their broad utility in fundamental or applied science. Compared to other HPPA, many features and requirements are similar for the ADS driver. However, there is a need for exceptional reliability: because of the induced thermal stress to the sub-critical core, the number of unwanted "beam-trips" should not exceed a few per year, a requirement that is several orders of magnitude above usual performance. Consecutive to the work of the European Technical Working Group (ETWG) on ADS, the Preliminary Design Study of an Experimental ADS (PDS-XADS) was launched in 2001 as a 5th Framework Program EC project. A special Working Package (WP3) was dedicated to the accelerator design, taking especially into account that the issue of "beam-trips" could be a potential "show-stopper" for ADS technology in general. A reference solution, based on a linear superconducting accelerator with its associated doubly achromatic beam line, has been worked out to some detail. For high reliability, the proposed design is intrinsically fault tolerant, relying on highly modular "de-rated" components associated to a fast digital feedback system. The proposed solution also appears to be robust concerning operational aspects like maintenance and radioprotection. A roadmap for construction as well as the required consolidated budget was elaborated. A program for the remaining R&D, focused on experimental reliability demonstration of prototypical components has been elaborated. This R&D will be performed in the 6th Framework Program EC project EUROTRANS, which presently is just starting. EC Contract No

  9. Superconducting Magnets for Particle Accelerators

    CERN Document Server

    Rossi, L

    2012-01-01

    Superconductivity has been the most influential technology in the field of accelerators in the last 30 years. Since the commissioning of the Tevatron, which demonstrated the use and operability of superconductivity on a large scale, superconducting magnets and rf cavities have been at the heart of all new large accelerators. Superconducting magnets have been the invariable choice for large colliders, as well as cyclotrons and large synchrotrons. In spite of the long history of success, superconductivity remains a difficult technology, requires adequate R&D and suitable preparation, and has a relatively high cost. Hence, it is not surprising that the development has also been marked by a few setbacks. This article is a review of the main superconducting accelerator magnet projects; it highlights the main characteristics and main achievements, and gives a perspective on the development of superconducting magnets for the future generation of very high energy colliders.

  10. Niobium LEP 2 accelerating cavities

    CERN Multimedia

    An accelerating cavity from LEP. This could be cut open to show the layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities were used in an upgrade of the LEP accelerator to double the energy of the particle beams.

  11. A Multibunch Plasma Wakefield Accelerator

    CERN Document Server

    Kallos, Efthymios; Ben-Zvi, Ilan; Katsouleas, Thomas C; Kimura, Wayne D; Kusche, Karl; Muggli, Patric; Pavlishin, Igor; Pogorelsky, Igor; Yakimenko, Vitaly; Zhou, Feng

    2005-01-01

    We investigate a plasma wakefield acceleration scheme where a train of electron microbunches feeds into a high density plasma. When the microbunch train enters such a plasma that has a corresponding plasma wavelength equal to the microbunch separation distance, a strong wakefield is expected to be resonantly driven to an amplitude that is at least one order of magnitude higher than that using an unbunched beam. PIC simulations have been performed using the beamline parameters of the Brookhaven National Laboratory Accelerator Test Facility operating in the configuration of the STELLA inverse free electron laser (IFEL) experiment. A 65 MeV electron beam is modulated by a 10.6 um CO2 laser beam via an IFEL interaction. This produces a train of ~90 microbunches separated by the laser wavelength. In this paper, we present both a simple theoretical treatment and simulation results that demonstrate promising results for the multibunch technique as a plasma-based accelerator.

  12. Symposium on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

  13. Accelerator science in medical physics.

    Science.gov (United States)

    Peach, K; Wilson, P; Jones, B

    2011-12-01

    The use of cyclotrons and synchrotrons to accelerate charged particles in hospital settings for the purpose of cancer therapy is increasing. Consequently, there is a growing demand from medical physicists, radiographers, physicians and oncologists for articles that explain the basic physical concepts of these technologies. There are unique advantages and disadvantages to all methods of acceleration. Several promising alternative methods of accelerating particles also have to be considered since they will become increasingly available with time; however, there are still many technical problems with these that require solving. This article serves as an introduction to this complex area of physics, and will be of benefit to those engaged in cancer therapy, or who intend to acquire such technologies in the future.

  14. Accelerated evolution of Fetuin-A (FETUA, also AHSG) is driven by positive Darwinian selection, not GC-biased gene conversion.

    Science.gov (United States)

    Döring, Yvonne; Zechner, Ulrich; Roos, Christian; Rosenkranz, David; Zischler, Hans; Herlyn, Holger

    2010-09-01

    Human Fetuin-A (FETUA, also termed AHSG) is a serum protein composed of two cystatin-like domains D1 and D2 of together 235 amino acids (aa) and an unrelated domain D3 of 114 aa. Though the protein plays a role in diverse physiological and pathological processes, comparably little is known about sequence evolution of FETUA. We therefore analyzed its molecular evolution on the basis of coding sequences of 16 primate species. Ratios of non-synonymous to synonymous substitution rates (d(n)/d(s)=omega) suggest that a previously reported acceleration of sequence evolution of exon 7, which encodes domain D3, is driven by positive selection instead of neutral evolution. Irrespective of the maximum likelihood model used, a remarkable 40% of codon sites is estimated to be positively selected in domain D3, with an average omega of 4.3. Analyses of GC/AT- and AT/GC-substitutions reveal that GC-biased gene conversion (gBGC) cannot explain the observed pattern. We thus reject the extended null model of molecular evolution (neutral evolution and gBGC) and conclude that positive Darwinian selection contributes to the sequence evolution of FETUA domain D3. Remarkably, domain D3 of human FETUA is characterized by a significant accumulation of proteolytic cleavage sites. Though speculative at present, the accelerated evolution of domain D3 might be due to the evolution of differential cleavage site patterns across primates reflecting different paths to achieve one goal, the decomposition of FETUA under pathological conditions. Present analyses use a PERL-script ("Substitution Bias Indicator", SBI) for the extraction of the numbers of GC/AT- and AT/GC-substitutions from supplemental results files of PAML analyses. The script is available upon request and the presented approach of testing the extended null hypothesis of molecular evolution can be transferred to every other protein coding locus. Copyright 2010 Elsevier B.V. All rights reserved.

  15. Thermal Hydraulic Design of PWT Accelerating Structures

    CERN Document Server

    Yu, David; Chen Ping; Lundquist, Martin; Luo, Yan

    2005-01-01

    Microwave power losses on the surfaces of accelerating structures will transform to heat which will deform the structures if it is not removed in time. Thermal hydraulic design of the disk and cooling rods of a Plane Wave Transformer (PWT) structure is presented. Experiments to measure the hydraulic (pressure vs flow rate) and cooling (heat removed vs flow rate) properties of the PWT disk are performed, and results compared with simulations using Mathcad models and the COSMOSM code. Both experimental and simulation results showed that the heat deposited on the structure could be removed effectively using specially designed water-cooling circuits and the temperature of the structure could be controlled within the range required.

  16. Vessels under Body Accelerations: A Comparative Study

    Directory of Open Access Journals (Sweden)

    D. S. Sankar

    2012-01-01

    Full Text Available Pulsatile flow of blood in constricted narrow arteries under periodic body acceleration is analyzed, modeling blood as non-Newtonian fluid models with yield stress such as (i Herschel-Bulkley fluid model and (ii Casson fluid model. The expressions for various flow quantities obtained by Sankar and Ismail (2010 for Herschel-Bulkley fluid model and Nagarani and Sarojamma (2008, in an improved form, for Casson fluid model are used to compute the data for comparing these fluid models. It is found that the plug core radius and wall shear stress are lower for H-B fluid model than those of the Casson fluid model. It is also noted that the plug flow velocity and flow rate are considerably higher for H-B fluid than those of the Casson fluid model. The estimates of the mean velocity and mean flow rate are considerably higher for H-B fluid model than those of the Casson fluid model.

  17. Acceleration parameters for fluid physics with accelerating bodies

    CSIR Research Space (South Africa)

    Gledhill, Irvy MA

    2016-06-01

    Full Text Available accelerating bodies, and reference must be made, above all, to the Mach number for transonic effects. Other parameters from the literature on impulsive start-up in wind tunnels are also shown to be useful in delimiting regimes of flow, such as the Freymuth...

  18. State of accelerator for therapy

    CERN Document Server

    Maruhashi, A

    2002-01-01

    21 facilities carry out particle radiotherapy in the world and 6 facilities will start in the next year. They are shown in the table. 6 facilities of them exist in Japan. Small accelerator for proton therapy is developed. The area of them becomes smaller than 100 m sup 2. 5 makers, form, kinds of accelerator, length of track, beam energy of them are shown. States of particle radiotherapy in 4 facilities in Japan are explained by the kinds of particle, energy, beam intensity, time structure and radiation room. The important problems are reconsideration of building and compact rotating gantry. The problems of radiotherapy are explained. (S.Y.)

  19. OpenMP for Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, J C; Stotzer, E J; Hart, A; de Supinski, B R

    2011-03-15

    OpenMP [13] is the dominant programming model for shared-memory parallelism in C, C++ and Fortran due to its easy-to-use directive-based style, portability and broad support by compiler vendors. Similar characteristics are needed for a programming model for devices such as GPUs and DSPs that are gaining popularity to accelerate compute-intensive application regions. This paper presents extensions to OpenMP that provide that programming model. Our results demonstrate that a high-level programming model can provide accelerated performance comparable to hand-coded implementations in CUDA.

  20. Electron Cloud Effects in Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Furman, M.A.

    2012-11-30

    Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

  1. Seismic response of linear accelerators

    CERN Document Server

    Collette, C; Guinchard, M; Hauviller, C

    2010-01-01

    This paper is divided into two parts. The first part presents recent measurements of ground motion in the LHC tunnel at CERN. From these measurements, an update of the ground motion model currently used in accelerator simulations is presented. It contains new features like a model of the lateral motion and the technical noise. In the second part, it is shown how this model can be used to evaluate the seismic response of a linear accelerator in the frequency domain. Then, the approach is validated numerically on a regular lattice, taking the dynamic behavior of the machine alignment stage and the mechanical stabilization of the quadrupoles into account.

  2. Seismic response of linear accelerators

    Directory of Open Access Journals (Sweden)

    C. Collette

    2010-07-01

    Full Text Available This paper is divided into two parts. The first part presents recent measurements of ground motion in the LHC tunnel at CERN. From these measurements, an update of the ground motion model currently used in accelerator simulations is presented. It contains new features like a model of the lateral motion and the technical noise. In the second part, it is shown how this model can be used to evaluate the seismic response of a linear accelerator in the frequency domain. Then, the approach is validated numerically on a regular lattice, taking the dynamic behavior of the machine alignment stage and the mechanical stabilization of the quadrupoles into account.

  3. Thermodynamics of Accelerating Black Holes.

    Science.gov (United States)

    Appels, Michael; Gregory, Ruth; Kubizňák, David

    2016-09-23

    We address a long-standing problem of describing the thermodynamics of an accelerating black hole. We derive a standard first law of black hole thermodynamics, with the usual identification of entropy proportional to the area of the event horizon-even though the event horizon contains a conical singularity. This result not only extends the applicability of black hole thermodynamics to realms previously not anticipated, it also opens a possibility for studying novel properties of an important class of exact radiative solutions of Einstein equations describing accelerated objects. We discuss the thermodynamic volume, stability, and phase structure of these black holes.

  4. Accelerated hypertension: Treatable yet underdiagnosed

    Directory of Open Access Journals (Sweden)

    Pranav Ish

    2017-01-01

    Full Text Available Patients who present in young age with accelerated hypertension (HTN should always be evaluated for secondary causes of hypertension. Renal parenchyma and vascular diseases constitute the majority of the etiology. Other causes include endocrine diseases such as pheochromocytoma, pregnancy-related HTN, and sleep apnea. We report a 23-year-old female who presented with palpitations and headache under treatment for anxiety from a tertiary care hospital. She was found to have accelerated HTN and was thoroughly worked up for etiology and treatment.

  5. Einstein, Nobel Prize, and Accelerators

    CERN Document Server

    Jarlskog, C

    2005-01-01

    We are celebrating the year of physics thanks to Einstein’s monumental contributions a hundred years ago. Indeed, the current field of accelerator physics is also deeply indebted to him. Why did it take more than a decade and a half for him to be "crowned" in Stockholm by the Nobel Prize? Did he get the Prize for the "wrong" thing? Based on original material from the archives of the Swedish Academy of Sciences, I will discuss how Einstein got the Nobel Prize and will give a short summary of his everlasting impact on the field of accelerator physics.

  6. Hamiltonian theory of stochastic acceleration.

    Science.gov (United States)

    Makhnovskii, Yurii A; Pollak, Eli

    2006-04-01

    Stochastic acceleration, defined in terms of a stochastic equation of motion for the acceleration, is derived from a Hamiltonian model. A free particle is coupled bilinearly to a harmonic bath through the particle's momentum and coordinate. Under appropriate conditions, momentum coupling induces velocity diffusion which is not destroyed by the spatial coupling. Spatial-momentum coupling may induce spatial subdiffusion. The thermodynamic equilibrium theory presented in this paper does not violate the second law of thermodynamics, although the average velocity squared of the particle may increase in time without bound.

  7. Repetitive nanosecond electron accelerators type URT-1 for radiation technology

    Science.gov (United States)

    Sokovnin, S. Yu.; Balezin, M. E.

    2018-03-01

    The electron accelerator URT-1М-300 for mobile installation was created for radiation disinfecting to correct drawbacks that were found the URT-1M electron accelerator operation (the accelerating voltage up to 1 МV, repetition rate up to 300 pps, electron beam size 400 × 100 mm, the pulse width about 100 ns). Accelerator configuration was changed that allowed to reduce significantly by 20% tank volume with oil where is placed the system of formation high-voltage pulses, thus the average power of the accelerator is increased by 6 times at the expense of increase in pulses repetition rate. Was created the system of the computerized monitoring parameters (output parameters and thermal mode) and remote control of the accelerator (charge voltage, pulse repetition rate), its elements and auxiliary systems (heat of the thyratron, vacuum system), the remote control panel is connected to the installation by the fiber-optical channel, what lightens the work for service personnel. For generating an electron beam up to 400 mm wide there are used metal- ceramic] and metal-dielectric cold cathodes of several emission elements (plates) with a non-uniform distribution of the electron beam current density on the output foil ± 15%. It was found that emission drop of both type of cathodes, during the operation at the high repetition rate (100 pps) is substantial at the beginning of the process, and then proceeds rather slowly that allows for continuous operation up to 40 h. Experiments showed that linear dependence of the voltage and a signal from the pin-diode remains within the range of the charge voltage 45-65 kV. Thus, voltage increases from 690 to 950 kV, and the signal from the pin-diode - from (2,8-4,6)*104 Gy/s. It allows to select electron energy quite precisely with consideration of the radiation technology requirements.

  8. A new lithium alkoxide accelerated diastereoselective cyanation of ketones.

    Science.gov (United States)

    Wilkinson, H S; Grover, P T; Vandenbossche, C P; Bakale, R P; Bhongle, N N; Wald, S A; Senanayake, C H

    2001-02-22

    [reaction: see text] A remarkably general lithium heteroatom assisted TMSCN or TBSCN addition to aldehydes and ketones has been discovered. The process provides excellent selectivities and high rates. Conformationally constrained ketones such as camphor, fenchone, and nopinone give excellent diastereoselectivities with TMSCN. Reduction of 2 provided diastereopure amino alcohol 3 in good yield. alpha- and beta-Methyl cyclohexanones with TBSCN-LiOR afford high diastereoselectivities and yields.

  9. Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures

    Energy Technology Data Exchange (ETDEWEB)

    Byer, Robert L. [Stanford Univ., CA (United States). Edward L. Ginzton Lab.

    2013-11-07

    The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

  10. Accelerated ripening of Kashar cheese with encapsulated protease ...

    African Journals Online (AJOL)

    The study demonstrated that sodium alginate, gellan and Κ-carrageenan could successfully be used as protease carrier systems to accelerate the protein breakdown process during the ripening of Kashar cheese. Those samples treated with Κ-carrageenan capsules showed the highest rate of proteolysis compared to those ...

  11. Accelerated apoptosis of neutrophils in familial Mediterranean fever

    DEFF Research Database (Denmark)

    Manukyan, Gayane; Aminov, Rustam; Hakobyan, Gagik

    2015-01-01

    not revealed any conventional mechanisms contributing to the enhanced apoptotic rate of neutrophils in FMF. Although the exact molecular mechanisms of accelerated neutrophil apoptosis in FMF remain unknown, it may provide a protection against excessive inflammation and tissue damage due to a massive...

  12. The Inhibiting or Accelerating Effect of Different Surfactants on ...

    African Journals Online (AJOL)

    NICO

    surfactants had a varying effect on the kinetics of electroreduction of Zn2+ ions. Simple relationships were presented ... drastic influence on the rate of an electrode reaction, either in a decelerating or an accelerating sense. ... surfactant concentrations were lower than their critical micellar point (CMC). 2. Experimental. 2.1.

  13. Extraordinary Tools for Extraordinary Science: The Impact ofSciDAC on Accelerator Science&Technology

    Energy Technology Data Exchange (ETDEWEB)

    Ryne, Robert D.

    2006-08-10

    Particle accelerators are among the most complex and versatile instruments of scientific exploration. They have enabled remarkable scientific discoveries and important technological advances that span all programs within the DOE Office of Science (DOE/SC). The importance of accelerators to the DOE/SC mission is evident from an examination of the DOE document, ''Facilities for the Future of Science: A Twenty-Year Outlook''. Of the 28 facilities listed, 13 involve accelerators. Thanks to SciDAC, a powerful suite of parallel simulation tools has been developed that represent a paradigm shift in computational accelerator science. Simulations that used to take weeks or more now take hours, and simulations that were once thought impossible are now performed routinely. These codes have been applied to many important projects of DOE/SC including existing facilities (the Tevatron complex, the Relativistic Heavy Ion Collider), facilities under construction (the Large Hadron Collider, the Spallation Neutron Source, the Linac Coherent Light Source), and to future facilities (the International Linear Collider, the Rare Isotope Accelerator). The new codes have also been used to explore innovative approaches to charged particle acceleration. These approaches, based on the extremely intense fields that can be present in lasers and plasmas, may one day provide a path to the outermost reaches of the energy frontier. Furthermore, they could lead to compact, high-gradient accelerators that would have huge consequences for US science and technology, industry, and medicine. In this talk I will describe the new accelerator modeling capabilities developed under SciDAC, the essential role of multi-disciplinary collaboration with applied mathematicians, computer scientists, and other IT experts in developing these capabilities, and provide examples of how the codes have been used to support DOE/SC accelerator projects.

  14. Towards the final BSA modeling for the accelerator-driven BNCT facility at INFN LNL

    Energy Technology Data Exchange (ETDEWEB)

    Ceballos, C. [Centro de Aplicaciones Tecnlogicas y Desarrollo Nuclear, 5ta y30, Miramar, Playa, Ciudad Habana (Cuba); Esposito, J., E-mail: juan.esposito@lnl.infn.it [INFN, Laboratori Nazionali di Legnaro (LNL), via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Agosteo, S. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Colautti, P.; Conte, V.; Moro, D. [INFN, Laboratori Nazionali di Legnaro (LNL), via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Pola, A. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2011-12-15

    Some remarkable advances have been made in the last years on the SPES-BNCT project of the Istituto Nazionale di Fisica Nucleare (INFN) towards the development of the accelerator-driven thermal neutron beam facility at the Legnaro National Laboratories (LNL), aimed at the BNCT experimental treatment of extended skin melanoma. The compact neutron source will be produced via the {sup 9}Be(p,xn) reactions using the 5 MeV, 30 mA beam driven by the RFQ accelerator, whose modules construction has been recently completed, into a thick beryllium target prototype already available. The Beam Shaping Assembly (BSA) final modeling, using both neutron converter and the new, detailed, Be(p,xn) neutron yield spectra at 5 MeV energy recently measured at the CN Van de Graaff accelerator at LNL, is summarized here.

  15. Ion Accelerator Merges Several Beams

    Science.gov (United States)

    Aston, G.

    1984-01-01

    Intense ion beam formed by merging multiple ion beamlets into one concentrated beam. Beamlet holes in graphite screen and focusing grids arranged in hexagonal pattern. Merged beam passes through single hole in each of aluminum accelerator and decelerator grids. Ion extraction efficiency, beam intensity, and focusing improved.

  16. 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.

  17. High-current electron accelerator

    Science.gov (United States)

    Alekseyev, B. V.; Gorelikov, I. M.; Kazurov, V. I.; Mashkov, L. V.; Greshko, A. G.; Soklakov, G. I.; Fedorenko, A. I.; Yurekevich, K. B.

    1986-02-01

    A high current electron accelerator was developed and built on the basis of computer aided design calculations and electrolytic trough simulation. A 15 stage Arkadyev/Marx pulse voltage generator serves as the primary energy storing device. Each stage consists of two IK-100-0.4 capacitors connected in parallel and all immersed in transformer oil inside a metal container on electrically insulating posts. Each stage is shielded on both the positive and negative potential side. The shields, made of copper foil, not only smooth the electric field in the clearances but also constitute part of the commutating circuit and contribute to reduction of the overall generator size. The pulse voltage generator is triggered by a synchronizer through the conventional firing circuit of a TGI1-350/16 thyratron. To operate the accelerator in the nanosecond mode, the generator discharges into a diode through a twin shaping line. In this mode the accelerator can produce 0.8 MeV to 240 kA electron beams of 0.8 ns duration. To operate in the microsecond mode, the shaping line acts as storing capacitor, and the discharge gaps must be charged with polarity reversal in each stage. In this mode the accelerator can produce 0.5 MeV to 10 kA electron beams of 1 microsecond duration.

  18. CLIC Drive Beam Accelerating Structures

    CERN Document Server

    Wegner, Rolf

    2012-01-01

    Travelling structures for accelerating the high-current (4.2 A) CLIC Drive Beam to an energy of 2.37 GeV are presented. The structures are optimised for efficiency (full beam loading operation) and a desired filling time. Higher order modes are studied and are reduced by detuning along the structure and by damping with silicon carbide loads.

  19. CERNois wins prestigious accelerator award

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    During the 2nd International Particle Accelerator Conference, CERN’s Rogelio Tomás García became the first Spaniard to receive the Frank Sacherer Prize for his work in particle beam optics.   Rogelio Tomás García at the 2nd International Particle Accelerator Conference. The Frank Sacherer Prize is awarded to physicists who have made a “significant, original contribution to the accelerator field" early on in their career. This year the prize was given to Rogelio Tomás García who, at only 35 years of age, has made important contributions to the optics design, optics measurement, and correction techniques applied at both the LHC and Brookhaven’s RHIC. “Tomás has had a vital impact on CERN’s beam optics studies and has made very impressive achievements in the field of beam optics,” says Oliver Brüning, Head of the Accelerators and Beam Physics...

  20. Thomas Jefferson National Accelerator Facility

    Energy Technology Data Exchange (ETDEWEB)

    Grames, Joseph; Higinbotham, Douglas; Montgomery, Hugh

    2010-09-08

    The Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, Virginia, USA, is one of ten national laboratories under the aegis of the Office of Science of the U.S. Department of Energy (DOE). It is managed and operated by Jefferson Science Associates, LLC. The primary facility at Jefferson Lab is the Continuous Electron Beam Accelerator Facility (CEBAF) as shown in an aerial photograph in Figure 1. Jefferson Lab was created in 1984 as CEBAF and started operations for physics in 1995. The accelerator uses superconducting radio-frequency (srf) techniques to generate high-quality beams of electrons with high-intensity, well-controlled polarization. The technology has enabled ancillary facilities to be created. The CEBAF facility is used by an international user community of more than 1200 physicists for a program of exploration and study of nuclear, hadronic matter, the strong interaction and quantum chromodynamics. Additionally, the exceptional quality of the beams facilitates studies of the fundamental symmetries of nature, which complement those of atomic physics on the one hand and of high-energy particle physics on the other. The facility is in the midst of a project to double the energy of the facility and to enhance and expand its experimental facilities. Studies are also pursued with a Free-Electron Laser produced by an energy-recovering linear accelerator.