WorldWideScience

Sample records for n4 series anomalie

  1. Control rod cluster drop time anomaly Guandong nuclear power station (Daya bay) and Electricite de France nuclear power stations (1450 MWe N4 Series); Anomalie de temps de chute des grappes de controle centrale de guang dong (daya bay) et centrales d`electricite de France (Palier N4-1450 MWE)

    Energy Technology Data Exchange (ETDEWEB)

    Olivera, J.J.; Naury, S.; Tricot, N.; Tran Dai, P.; Gama, J.M.

    1996-12-31

    The anomaly of control rod cluster drop time revealed at Guandong Nuclear Power Station in Daya Bay and in the Chooz B1 pilot unit for the N4 series, led to the replacement of the M1 type control rod cluster guide tubes with 1300 MWe PWR type guide tubes, adapted to the geometry of the Guandong reactors and the 1450 MWe reactors of the N4 series. The comparison of the drop times obtained with the 1300 MWe type control rod cluster guide 1300 MWe type control rod cluster guide tubes gave satisfactory results. These met the safety criterion for N4 series control rod cluster drop times (2.15 under hot shutdown conditions). The drop time tests which will be carried out in middle of and at the end of cycle 1 of Chooz B1 should make it possible to finally validate the solution already successfully implemented at Guandong. However, this anomaly has revealed the limits of representativeness of the experimental test loops with regard to the real reactor configuration. In view of this, it has been deemed necessary to ask Electricite de France to pursue its analysis both on the understanding of the phenomena which led to this anomaly and on the limits of the representativeness of the experimental test loops. (authors).

  2. DEVELOPMENT OF GRAVITY BOUGUER ANOMALIES OF STATE OF OHIO AND THE ISOSTATIC ANOMALIES IN NORTH ATLANTIC IN FOURIER SERIES

    Science.gov (United States)

    Gravity anomalies were developed in Fourier series in two test areas: 2 x 3 deg area in the State of Ohio, and 10 x 35 deg area in the Atlantic...based only on the original anomaly values and the topography, and the mean gravity anomalies were estimated for the same squares as in the Fourier series method...The result is that this second manual method has smaller standard errors than the Fourier series method, and that this kind of extrapolation

  3. Global Horizontal Irradiance Anomalies in Long Term Series Over India

    Science.gov (United States)

    Cony, Marco; Liria, Juan; Weisenberg, Ralf; Serrano, Enrique

    2014-05-01

    India has a high potential for solar energy applications due to its geographic position within the Sun Belt and the large number of cloudless days in many regions of the country. However, certain regions of India, particularly those largely populated, can exhibit large aerosol loading in the atmosphere as a consequence of anthropogenic emissions that could have a negative feedback in the solar resource potential. This effect, named as solar dimming, has already been observed in India, and in some other regions in the world, by some authors using ground data from the last two decades. The recent interest in the promotion of solar energy applications in India highlights the need of extending and improving the knowledge of the solar radiation resources in this country, since most of the long term measurements available correspond to global horizontal radiation (GHI) and most of them are also located big cities or highly populated areas. In addition, accurate knowledge on the aerosol column quantification and on its dynamical behavior with high spatial resolution is particularly important in the case of India, due to their impact on direct normal irradiation. Long term studies of solar irradiation over India can be performed using monthly means of GHI measurements from the Indian Meteorological Department. Ground data are available from 1964 till today through the World Radiation Data Centre that publish these values in the web. This work shows a long term analysis of GHI using anomalies techniques over ten different sites over India. Besides, techniques of linear trends have been applied for to show the evolution over this period. The analysis of anomalies has also found two periods of different behavior. From 1964 till 1988 the anomalies observed were positive and the last 20 years seems to be a period of negative anomalies. The results exhibit a decreasing trend and negative anomalies confirming thus the darkening effect already reported by solar dimming studies

  4. Anomalies.

    Science.gov (United States)

    Online-Offline, 1999

    1999-01-01

    This theme issue on anomalies includes Web sites, CD-ROMs and software, videos, books, and additional resources for elementary and junior high school students. Pertinent activities are suggested, and sidebars discuss UFOs, animal anomalies, and anomalies from nature; and resources covering unexplained phenonmenas like crop circles, Easter Island,…

  5. Detecting Anomaly Regions in Satellite Image Time Series Based on Sesaonal Autocorrelation Analysis

    Science.gov (United States)

    Zhou, Z.-G.; Tang, P.; Zhou, M.

    2016-06-01

    Anomaly regions in satellite images can reflect unexpected changes of land cover caused by flood, fire, landslide, etc. Detecting anomaly regions in satellite image time series is important for studying the dynamic processes of land cover changes as well as for disaster monitoring. Although several methods have been developed to detect land cover changes using satellite image time series, they are generally designed for detecting inter-annual or abrupt land cover changes, but are not focusing on detecting spatial-temporal changes in continuous images. In order to identify spatial-temporal dynamic processes of unexpected changes of land cover, this study proposes a method for detecting anomaly regions in each image of satellite image time series based on seasonal autocorrelation analysis. The method was validated with a case study to detect spatial-temporal processes of a severe flooding using Terra/MODIS image time series. Experiments demonstrated the advantages of the method that (1) it can effectively detect anomaly regions in each of satellite image time series, showing spatial-temporal varying process of anomaly regions, (2) it is flexible to meet some requirement (e.g., z-value or significance level) of detection accuracies with overall accuracy being up to 89% and precision above than 90%, and (3) it does not need time series smoothing and can detect anomaly regions in noisy satellite images with a high reliability.

  6. DETECTING ANOMALY REGIONS IN SATELLITE IMAGE TIME SERIES BASED ON SESAONAL AUTOCORRELATION ANALYSIS

    Directory of Open Access Journals (Sweden)

    Z.-G. Zhou

    2016-06-01

    Full Text Available Anomaly regions in satellite images can reflect unexpected changes of land cover caused by flood, fire, landslide, etc. Detecting anomaly regions in satellite image time series is important for studying the dynamic processes of land cover changes as well as for disaster monitoring. Although several methods have been developed to detect land cover changes using satellite image time series, they are generally designed for detecting inter-annual or abrupt land cover changes, but are not focusing on detecting spatial-temporal changes in continuous images. In order to identify spatial-temporal dynamic processes of unexpected changes of land cover, this study proposes a method for detecting anomaly regions in each image of satellite image time series based on seasonal autocorrelation analysis. The method was validated with a case study to detect spatial-temporal processes of a severe flooding using Terra/MODIS image time series. Experiments demonstrated the advantages of the method that (1 it can effectively detect anomaly regions in each of satellite image time series, showing spatial-temporal varying process of anomaly regions, (2 it is flexible to meet some requirement (e.g., z-value or significance level of detection accuracies with overall accuracy being up to 89% and precision above than 90%, and (3 it does not need time series smoothing and can detect anomaly regions in noisy satellite images with a high reliability.

  7. Diurnal Differences in OLR Climatologies and Anomaly Time Series

    Science.gov (United States)

    Susskind, Joel; Lee, Jae N.; Iredell, Lena; Loeb, Norm

    2015-01-01

    AIRS (Atmospheric Infrared Sounder) Version-6 OLR (Outgoing Long-Wave Radiation) matches CERES (Clouds and the Earth's Radiant Energy System) Edition-2.8 OLR very closely on a 1x1 latitude x longitude scale, both with regard to absolute values, and also with regard to anomalies of OLR. There is a bias of 3.5 watts per meter squared, which is nearly constant both in time and space. Contiguous areas contain large positive or negative OLR difference between AIRS and CERES are where the day-night difference of OLR is large. For AIRS, the larger the diurnal cycle, the more likely that sampling twice a day is inadequate. Lower values of OLRclr (Clear Sky OLR) and LWCRF (Longwave Cloud Radiative Forcing) in AIRS compared to CERES is at least in part a result of AIRS sampling over cold and cloudy cases.

  8. OceanXtremes: Scalable Anomaly Detection in Oceanographic Time-Series

    Science.gov (United States)

    Wilson, B. D.; Armstrong, E. M.; Chin, T. M.; Gill, K. M.; Greguska, F. R., III; Huang, T.; Jacob, J. C.; Quach, N.

    2016-12-01

    The oceanographic community must meet the challenge to rapidly identify features and anomalies in complex and voluminous observations to further science and improve decision support. Given this data-intensive reality, we are developing an anomaly detection system, called OceanXtremes, powered by an intelligent, elastic Cloud-based analytic service backend that enables execution of domain-specific, multi-scale anomaly and feature detection algorithms across the entire archive of 15 to 30-year ocean science datasets.Our parallel analytics engine is extending the NEXUS system and exploits multiple open-source technologies: Apache Cassandra as a distributed spatial "tile" cache, Apache Spark for in-memory parallel computation, and Apache Solr for spatial search and storing pre-computed tile statistics and other metadata. OceanXtremes provides these key capabilities: Parallel generation (Spark on a compute cluster) of 15 to 30-year Ocean Climatologies (e.g. sea surface temperature or SST) in hours or overnight, using simple pixel averages or customizable Gaussian-weighted "smoothing" over latitude, longitude, and time; Parallel pre-computation, tiling, and caching of anomaly fields (daily variables minus a chosen climatology) with pre-computed tile statistics; Parallel detection (over the time-series of tiles) of anomalies or phenomena by regional area-averages exceeding a specified threshold (e.g. high SST in El Nino or SST "blob" regions), or more complex, custom data mining algorithms; Shared discovery and exploration of ocean phenomena and anomalies (facet search using Solr), along with unexpected correlations between key measured variables; Scalable execution for all capabilities on a hybrid Cloud, using our on-premise OpenStack Cloud cluster or at Amazon. The key idea is that the parallel data-mining operations will be run "near" the ocean data archives (a local "network" hop) so that we can efficiently access the thousands of files making up a three decade time-series

  9. Intercomparison of Recent Anomaly Time-Series of OLR as Observed by CERES and Computed Using AIRS Products

    Science.gov (United States)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena; Loeb, Norman G.

    2011-01-01

    This paper compares recent spatial and temporal anomaly time series of OLR as observed by CERES and computed based on AIRS retrieved surface and atmospheric geophysical parameters over the 7 year time period September 2002 through February 2010. This time period is marked by a substantial decrease of OLR, on the order of +/-0.1 W/sq m/yr, averaged over the globe, and very large spatial variations of changes in OLR in the tropics, with local values ranging from -2.8 W/sq m/yr to +3.1 W/sq m/yr. Global and Tropical OLR both began to decrease significantly at the onset of a strong La Ni a in mid-2007. Late 2009 is characterized by a strong El Ni o, with a corresponding change in sign of both Tropical and Global OLR anomalies. The spatial patterns of the 7 year short term changes in AIRS and CERES OLR have a spatial correlation of 0.97 and slopes of the linear least squares fits of anomaly time series averaged over different spatial regions agree on the order of +/-0.01 W/sq m/yr. This essentially perfect agreement of OLR anomaly time series derived from observations by two different instruments, determined in totally independent and different manners, implies that both sets of results must be highly stable. This agreement also validates the anomaly time series of the AIRS derived products used to compute OLR and furthermore indicates that anomaly time series of AIRS derived products can be used to explain the factors contributing to anomaly time series of OLR.

  10. Prediction of altimetric sea level anomalies using time series models based on spatial correlation

    Science.gov (United States)

    Miziński, Bartłomiej; Niedzielski, Tomasz

    2014-05-01

    Sea level anomaly (SLA) times series, which are time-varying gridded data, can be modelled and predicted using time series methods. This approach has been shown to provide accurate forecasts within the Prognocean system, the novel infrastructure for anticipating sea level change designed and built at the University of Wrocław (Poland) which utilizes the real-time SLA data from Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO). The system runs a few models concurrently, and our ocean prediction experiment includes both uni- and multivariate time series methods. The univariate ones are: extrapolation of polynomial-harmonic model (PH), extrapolation of polynomial-harmonic model and autoregressive prediction (PH+AR), extrapolation of polynomial-harmonic model and self-exciting threshold autoregressive prediction (PH+SETAR). The following multivariate methods are used: extrapolation of polynomial-harmonic model and vector autoregressive prediction (PH+VAR), extrapolation of polynomial-harmonic model and generalized space-time autoregressive prediction (PH+GSTAR). As the aforementioned models and the corresponding forecasts are computed in real time, hence independently and in the same computational setting, we are allowed to compare the accuracies offered by the models. The objective of this work is to verify the hypothesis that the multivariate prediction techniques, which make use of cross-correlation and spatial correlation, perform better than the univariate ones. The analysis is based on the daily-fitted and updated time series models predicting the SLA data (lead time of two weeks) over several months when El Niño/Southern Oscillation (ENSO) was in its neutral state.

  11. Feasibility of anomaly occurrence in aerosols time series obtained from MODIS satellite images during hazardous earthquakes

    Science.gov (United States)

    Akhoondzadeh, Mehdi; Jahani Chehrebargh, Fatemeh

    2016-09-01

    Earthquake is one of the most devastating natural disasters that its prediction has not materialized comprehensive. Remote sensing data can be used to access information which is closely related to an earthquake. The unusual variations of lithosphere, atmosphere and ionosphere parameters before the main earthquakes are considered as earthquake precursors. To date the different precursors have been proposed. This paper examines one of the parameters which can be derived from satellite imagery. The mentioned parameter is Aerosol Optical Depth (AOD) that this article reviews its relationship with earthquake. Aerosol parameter can be achieved through various methods such as AERONET ground stations or using satellite images via algorithms such as the DDV (Dark Dense Vegetation), Deep Blue Algorithm and SYNTAM (SYNergy of Terra and Aqua Modis). In this paper, by analyzing AOD's time series (derived from MODIS sensor on the TERRA platform) for 16 major earthquakes, seismic anomalies were observed before and after earthquakes. Before large earthquakes, rate of AOD increases due to the pre-seismic changes before the strong earthquake, which produces gaseous molecules and therefore AOD increases. Also because of aftershocks after the earthquake there is a significant change in AOD due to gaseous molecules and dust. These behaviors suggest that there is a close relationship between earthquakes and the unusual AOD variations. Therefore the unusual AOD variations around the time of earthquakes can be introduced as an earthquake precursor.

  12. PHACE syndrome: MRI of intracerebral vascular anomalies and clinical findings in a series of 12 patients

    Energy Technology Data Exchange (ETDEWEB)

    Bracken, Jennifer; Robinson, Ian; Snow, Aisling; Rea, David; Phelan, Ethna [Our Lady' s Children' s Hospital, Department of Radiology, Dublin (Ireland); Watson, Rosemarie; Irvine, Alan D. [Our Lady' s Children' s Hospital, Department of Dermatology, Dublin (Ireland)

    2011-09-15

    PHACE (posterior fossa defects, haemangioma, arterial anomalies, coarctation of the aorta and cardiac defects, eye abnormalities) syndrome describes a constellation of abnormalities that can occur in association with segmental craniofacial infantile haemangioma. To report the spectrum of clinical and imaging abnormalities seen in a cohort of children. A retrospective review of the clinical and imaging records of all patients diagnosed with PHACE syndrome between 1998 and 2009 was performed. Information sought included patient demographics, craniofacial segments involved, imaging findings and other extracutaneous abnormalities. Twelve patients were diagnosed with PHACE syndrome over 11 years. All patients had a segmental craniofacial haemangioma. Involved facial segments, in order of frequency, were frontotemporal (12), maxillary (8), mandibular (5) and frontonasal (1). The most common extracutaneous abnormalities were neurovascular anomalies (10), with many patients having multiple anomalies. The spectrum of arterial anomalies ranged from hypoplasia (9) to ectasia (3), anomalous origin/course (2) and persistent fetal anastomosis (2). Other anomalies found included cardiac anomalies (3), coarctation of the aorta (2), posterior fossa malformations (1) and sternal region anomalies (1). Intracranial anomalies are the most common extracutaneous feature of PHACE syndrome. The contribution of the radiologist in the recognition of such anomalies is important for the diagnosis of PHACE syndrome. (orig.)

  13. PHACE syndrome: MRI of intracerebral vascular anomalies and clinical findings in a series of 12 patients.

    LENUS (Irish Health Repository)

    Bracken, Jennifer

    2012-02-01

    BACKGROUND: PHACE (posterior fossa defects, haemangioma, arterial anomalies, coarctation of the aorta and cardiac defects, eye abnormalities) syndrome describes a constellation of abnormalities that can occur in association with segmental craniofacial infantile haemangioma. OBJECTIVE: To report the spectrum of clinical and imaging abnormalities seen in a cohort of children. MATERIALS AND METHODS: A retrospective review of the clinical and imaging records of all patients diagnosed with PHACE syndrome between 1998 and 2009 was performed. Information sought included patient demographics, craniofacial segments involved, imaging findings and other extracutaneous abnormalities. RESULTS: Twelve patients were diagnosed with PHACE syndrome over 11 years. All patients had a segmental craniofacial haemangioma. Involved facial segments, in order of frequency, were frontotemporal (12), maxillary (8), mandibular (5) and frontonasal (1). The most common extracutaneous abnormalities were neurovascular anomalies (10), with many patients having multiple anomalies. The spectrum of arterial anomalies ranged from hypoplasia (9) to ectasia (3), anomalous origin\\/course (2) and persistent fetal anastomosis (2). Other anomalies found included cardiac anomalies (3), coarctation of the aorta (2), posterior fossa malformations (1) and sternal region anomalies (1). CONCLUSION: Intracranial anomalies are the most common extracutaneous feature of PHACE syndrome. The contribution of the radiologist in the recognition of such anomalies is important for the diagnosis of PHACE syndrome.

  14. MULTIPLE ASSOCIATED ANOMALIES IN PATIENTS OF DUODENAL ATRESIA: A CASE SERIES

    Directory of Open Access Journals (Sweden)

    Bilal Mirza

    2012-04-01

    Full Text Available Duodenal atresia has been reported in association with various malformations and syndromes common being Down syndrome, malrotation, and annular pancreas. Its association with multiple anomalies is rare and scarcely reported in literature. Herein 3 cases of duodenal atresia associated with multiple congenital anomalies are being reported.

  15. Identification of environmental anomaly hot spots in West Africa from time series of NDVI and rainfall

    Science.gov (United States)

    Boschetti, Mirco; Nutini, Francesco; Brivio, Pietro Alessandro; Bartholomé, Etienne; Stroppiana, Daniela; Hoscilo, Agata

    2013-04-01

    Studies of the impact of human activity on vegetation dynamics of the Sahelian belt of Africa have been recently re-invigorated by new scientific findings that highlighted the primary role of climate in the drought crises of the 1970s-1980s. Time series of satellite observations revealed a re-greening of the Sahelian belt that indicates no noteworthy human effect on vegetation dynamics at sub continental scale from the 1980s to late 1990s. However, several regional/local crises related to natural resources occurred in the last decades despite the re-greening thus underlying that more detailed studies are needed. In this study we used time-series (1998-2010) of SPOT-VGT NDVI and FEWS-RFE rainfall estimates to analyse vegetation - rainfall correlation and to map areas of local environmental anomalies where significant vegetation variations (increase/decrease) are not fully explained by seasonal changes of rainfall. Some of these anomalous zones (hot spots) were further analysed with higher resolution images Landsat TM/ETM+ to evaluate the reliability of the identified anomalous behaviour and to provide an interpretation of some example hot spots. The frequency distribution of the hot spots among the land cover classes of the GlobCover map shows that increase in vegetation greenness is mainly located in the more humid southern part and close to inland water bodies where it is likely to be related to the expansion/intensification of irrigated agricultural activities. On the contrary, a decrease in vegetation greenness occurs mainly in the northern part (12°-15°N) in correspondence with herbaceous vegetation covers where pastoral and cropping practices are often critical due to low and very unpredictable rainfall. The results of this study show that even if a general positive re-greening due to increased rainfall is evident for the entire Sahel, some local anomalous hot spots exist and can be explained by human factors such as population growth whose level reaches the

  16. Interhemispheric Lipoma, Callosal Anomaly, and Malformations of Cortical Development: A Case Series

    OpenAIRE

    Niwa, Tetsu; Linda S de Vries; Manten, GTR; Lequin, Maarten; Cuppen, Inge; Shibasaki, Jun; Aida, Noriko

    2016-01-01

    Intracranial lipomas are rare congenital malformations. The most common type of intracranial lipoma is the interhemispheric lipoma, which is frequently associated with callosal anomalies such as hypogenesis or agenesis of the corpus callosum. In contrast, interhemispheric lipomas are less often accompanied with malformations of cortical development (MCD). We report magnetic resonance imaging findings of three infants with an interhemispheric lipoma, associated with a callosal anomaly, and MCD...

  17. Interhemispheric Lipoma, Callosal Anomaly, and Malformations of Cortical Development: A Case Series.

    Science.gov (United States)

    Niwa, Tetsu; de Vries, Linda S; Manten, Gwendolyn T R; Lequin, Maarten; Cuppen, Inge; Shibasaki, Jun; Aida, Noriko

    2016-04-01

    Intracranial lipomas are rare congenital malformations. The most common type of intracranial lipoma is the interhemispheric lipoma, which is frequently associated with callosal anomalies such as hypogenesis or agenesis of the corpus callosum. In contrast, interhemispheric lipomas are less often accompanied with malformations of cortical development (MCD). We report magnetic resonance imaging findings of three infants with an interhemispheric lipoma, associated with a callosal anomaly, and MCD: two infants with nodular interhemispheric lipoma, agenesis of the corpus callosum, and polymicrogyria, and one infant with interhemispheric curvilinear lipoma, hypoplasia of the corpus callosum, and heterotopias. An association was suggested regarding the occurrence of these malformations.

  18. Interhemispheric Lipoma, Callosal Anomaly, and Malformations of Cortical Development: A Case Series

    NARCIS (Netherlands)

    Niwa, Tetsu; de Vries, Linda S.; Manten, GTR; Lequin, Maarten; Cuppen, Inge; Shibasaki, Jun; Aida, Noriko

    2016-01-01

    Intracranial lipomas are rare congenital malformations. The most common type of intracranial lipoma is the interhemispheric lipoma, which is frequently associated with callosal anomalies such as hypogenesis or agenesis of the corpus callosum. In contrast, interhemispheric lipomas are less often acco

  19. Neural tube defects and associated anomalies in a fetal and perinatal autopsy series

    DEFF Research Database (Denmark)

    Nielsen, Ljudmilla A G; Maroun, Lisa Leth; Broholm, Helle

    2006-01-01

    morphological anomalies, and organ weights. Organ weights were evaluated according to new fetal autopsy standards and grouped as low, normal or high. Ninety-seven NTD cases were found (4.9%): Spina bifida (38 cases), cephalocele (17 cases) and anencephaly (42 cases). 63% of NTD cases had associated morphologic...

  20. Robust and accurate anomaly detection in ECG artifacts using time series motif discovery.

    Science.gov (United States)

    Sivaraks, Haemwaan; Ratanamahatana, Chotirat Ann

    2015-01-01

    Electrocardiogram (ECG) anomaly detection is an important technique for detecting dissimilar heartbeats which helps identify abnormal ECGs before the diagnosis process. Currently available ECG anomaly detection methods, ranging from academic research to commercial ECG machines, still suffer from a high false alarm rate because these methods are not able to differentiate ECG artifacts from real ECG signal, especially, in ECG artifacts that are similar to ECG signals in terms of shape and/or frequency. The problem leads to high vigilance for physicians and misinterpretation risk for nonspecialists. Therefore, this work proposes a novel anomaly detection technique that is highly robust and accurate in the presence of ECG artifacts which can effectively reduce the false alarm rate. Expert knowledge from cardiologists and motif discovery technique is utilized in our design. In addition, every step of the algorithm conforms to the interpretation of cardiologists. Our method can be utilized to both single-lead ECGs and multilead ECGs. Our experiment results on real ECG datasets are interpreted and evaluated by cardiologists. Our proposed algorithm can mostly achieve 100% of accuracy on detection (AoD), sensitivity, specificity, and positive predictive value with 0% false alarm rate. The results demonstrate that our proposed method is highly accurate and robust to artifacts, compared with competitive anomaly detection methods.

  1. The Relationship Between El Nino/La Nina Oscillations and Recent Anomaly Time Series of OLR Determined by CERES and AIRS

    Science.gov (United States)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena; Loeb, Norman G.

    2011-01-01

    This paper compares recent spatial anomaly time series of OLR (Outgoing Longwave Radiation) and OLRCLR (Clear Sky OLR) as determined using CERES and AIRS observations over the time period September 2002 through June 2010. We find excellent agreement in OLR anomaly time series of both data sets in almost every detail, down to the 1 x 1 spatial grid point level. This extremely close agreement of OLR anomaly time series derived from observations by two different instruments implies that both sets of results must be highly stable. This agreement also validates to some extent the anomaly time series of the AIRS derived products used in the computation of the AIRS OLR product. The paper then examines anomaly time series of AIRS derived products over the extended time period September 2002 through April 2011. We show that OLR anomalies during this period are closely in phase with those of an El Nino index, and that the recent global and tropical mean decreases in OLR and OLRCLR are a result of a transition from an El Nino condition at the beginning of the data record to La Nina conditions toward the end of the data period. We show that the relationship between global mean, and especially tropical mean, OLR anomalies to the El Nino index can be explained by temporal changes of the distribution of mid-tropospheric water vapor and cloud cover in two spatial regions that are in direct response to El Nino/La Nina activity which occurs outside these spatial regions.

  2. Research on Healthy Anomaly Detection Model Based on Deep Learning from Multiple Time-Series Physiological Signals

    Directory of Open Access Journals (Sweden)

    Kai Wang

    2016-01-01

    Full Text Available Health is vital to every human being. To further improve its already respectable medical technology, the medical community is transitioning towards a proactive approach which anticipates and mitigates risks before getting ill. This approach requires measuring the physiological signals of human and analyzes these data at regular intervals. In this paper, we present a novel approach to apply deep learning in physiological signals analysis that allows doctor to identify latent risks. However, extracting high level information from physiological time-series data is a hard problem faced by the machine learning communities. Therefore, in this approach, we apply model based on convolutional neural network that can automatically learn features from raw physiological signals in an unsupervised manner and then based on the learned features use multivariate Gauss distribution anomaly detection method to detect anomaly data. Our experiment is shown to have a significant performance in physiological signals anomaly detection. So it is a promising tool for doctor to identify early signs of illness even if the criteria are unknown a priori.

  3. Risk factors, organ weight deviation and associated anomalies in neural tube defects: A prospective fetal and perinatal autopsy series

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    Asaranti Kar

    2015-01-01

    Full Text Available Introduction: Neural tube defects (NTD are a group of serious birth defects occurring due to defective closure of neural tube during embryonic development. It comprises of anencephaly, encephalocele and spina bifida. We conducted this prospective fetal autopsy series to study the rate and distribution of NTD, analyze the reproductive factors and risk factors, note any associated anomalies and evaluate the organ weights and their deviation from normal. Materials and Methods: This was a prospective study done over a period of 6 years from August, 2007 to July, 2013. All cases of NTDs delivered as abortion, still born and live born were included. The reproductive and risk factors like age, parity, multiple births, previous miscarriage, obesity, diabetes mellitus, socioeconomic status and use of folic acid during pregnancy were collected.Autopsy was performed according to Virchow′s technique. Detail external and internal examination were carried out to detect any associated anomalies. Gross and microscopic examination of organs were done. Results: Out of 210 cases of fetal and perinatal autopsy done, 72 (34.28% had NTD constituting 49 cases of anencephaly, 16 spina bifida and 7 cases of encephalocele. The mothers in these cases predominantly were within 25-29 years (P = 0.02 and primy (P = 0.01. Female sex was more commonly affected than males (M:F = 25:47, P = 0.0005 There was no history of folate use in majority of cases. Organ weight deviations were >2 standard deviation low in most of the cases. Most common associated anomalies were adrenal hypoplasia and thymic hyperplasia. Conclusion: The authors have made an attempt to study NTD cases in respect to maternal reproductive and risk factors and their association with NTD along with the organ weight deviation and associated anomalies. This so far in our knowledge is an innovative study which was not found in literature even after extensive search.

  4. Case Series: Fetal Pulmonary Vein A-Wave Reversal: An Early Marker of Left-Sided Cardiac Anomalies?

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    Aldo L. Schenone

    2015-04-01

    Full Text Available Background - Improvements in congenital heart disease (CHD screening are needed based on the lack of sensitivity of current screening methods and the understanding that the early detection of certain CHDs may improve outcomes. Fetal venous circulation has caught medical attention, and two studies demonstrated that it is feasible to register pulmonary vein flow velocity waveforms (FVWs during early gestation. Meanwhile, the latter study proposed pulmonary vein A-wave reversal as a marker of cardiac anomaly. Methods - We report a series of six consecutive fetuses with confirmed cardiac anomalies that underwent first-trimester screening, including pulmonary vein FVWs, at our center during 2013. CHD was confirmed by late pregnancy echocardiography, and in three cases fetal autopsies were performed. Result/Discussion - The ductus venosus (DV and nuchal translucency (NT predicted 50% of CHD cases, whereas the combination of markers identified 66.6% of CHD cases. When adding pulmonary vein assessment, the rate of detection rose to 83.3%. Total five of six cases of CHD had reversal of pulmonary vein A-wave during early pregnancy. The sixth case with CHD and nonreversal of A-wave was described as right ventricle hypoplasia with type 1 tricuspid atresia and persistent ductus arteriosus. Conclusion This is the first series reporting pulmonary vein end-diastolic reversal as a CHD screening add-on during early pregnancy. The addition of pulmonary vein FVW assessment to the current CHD screening bundle could increase the rate detection of cardiac anomalies. This pilot study suggests that pulmonary vein end-diastolic flow reversal favors detection of left-sided CHD over the right-sided ones.

  5. Rare case of congenital anomaly in two different gestational ages: a case series

    Directory of Open Access Journals (Sweden)

    Lopamudra B. John

    2013-04-01

    Full Text Available Acrania is a rare congenital anomaly involving faulty development of membranous flat bones of neurocalvarium. Commonest differential diagnosis is anencephaly. The first case was diagnosed in a second gravida at 13 weeks and terminated by vaginal misoprostol instillation. The second case was diagnosed only by scan at 32 weeks in an unbooked second gravida with previous LSCS. She underwent emergency LSCS for failed induction and a fresh stillborn baby of 1.9 kg was born. [Int J Reprod Contracept Obstet Gynecol 2013; 2(2.000: 240-241

  6. The CACAO Method for Smoothing, Gap Filling, and Characterizing Seasonal Anomalies in Satellite Time Series

    Science.gov (United States)

    Verger, Aleixandre; Baret, F.; Weiss, M.; Kandasamy, S.; Vermote, E.

    2013-01-01

    Consistent, continuous, and long time series of global biophysical variables derived from satellite data are required for global change research. A novel climatology fitting approach called CACAO (Consistent Adjustment of the Climatology to Actual Observations) is proposed to reduce noise and fill gaps in time series by scaling and shifting the seasonal climatological patterns to the actual observations. The shift and scale CACAO parameters adjusted for each season allow quantifying shifts in the timing of seasonal phenology and inter-annual variations in magnitude as compared to the average climatology. CACAO was assessed first over simulated daily Leaf Area Index (LAI) time series with varying fractions of missing data and noise. Then, performances were analyzed over actual satellite LAI products derived from AVHRR Long-Term Data Record for the 1981-2000 period over the BELMANIP2 globally representative sample of sites. Comparison with two widely used temporal filtering methods-the asymmetric Gaussian (AG) model and the Savitzky-Golay (SG) filter as implemented in TIMESAT-revealed that CACAO achieved better performances for smoothing AVHRR time series characterized by high level of noise and frequent missing observations. The resulting smoothed time series captures well the vegetation dynamics and shows no gaps as compared to the 50-60% of still missing data after AG or SG reconstructions. Results of simulation experiments as well as confrontation with actual AVHRR time series indicate that the proposed CACAO method is more robust to noise and missing data than AG and SG methods for phenology extraction.

  7. Surgical Approaches to First Branchial Cleft Anomaly Excision: A Case Series

    Directory of Open Access Journals (Sweden)

    Lourdes Quintanilla-Dieck

    2016-01-01

    Full Text Available Objectives. First branchial cleft anomalies (BCAs constitute a rare entity with variable clinical presentations and anatomic findings. Given the high rate of recurrence with incomplete excision, identification of the entire tract during surgical treatment is of paramount importance. The objectives of this paper were to present five anatomic variations of first BCAs and describe the presentation, evaluation, and surgical approach to each one. Methods. A retrospective case review and literature review were performed. We describe patient characteristics, presentation, evaluation, and surgical approach of five patients with first BCAs. Results. Age at definitive surgical treatment ranged from 8 months to 7 years. Various clinical presentations were encountered, some of which were atypical for first BCAs. All had preoperative imaging demonstrating the tract. Four surgical approaches required a superficial parotidectomy with identification of the facial nerve, one of which revealed an aberrant facial nerve. In one case the tract was found to travel into the angle of the mandible, terminating as a mandibular cyst. This required en bloc excision that included the lateral cortex of the mandible. Conclusions. First BCAs have variable presentations. Complete surgical excision can be challenging. Therefore, careful preoperative planning and the recognition of atypical variants during surgery are essential.

  8. Assessment of Regional Vegetation Response to Climate Anomalies: A Case Study for Australia Using GIMMS NDVI Time Series between 1982 and 2006

    Directory of Open Access Journals (Sweden)

    Wanda De Keersmaecker

    2017-01-01

    Full Text Available Within the context of climate change, it is of utmost importance to quantify the stability of ecosystems with respect to climate anomalies. It is well acknowledged that ecosystem stability may change over time. As these temporal stability changes may provide a warning for increased vulnerability of the system, this study provides a methodology to quantify and assess these temporal changes in vegetation stability. Within this framework, vegetation stability changes were quantified over Australia from 1982 to 2006 using GIMMS NDVI and climate time series (i.e., SPEI (Standardized Precipitation and Evaporation Index. Starting from a stability assessment on the complete time series, we aim to assess: (i the magnitude and direction of stability changes; and (ii the similarity in these changes for different stability metrics, i.e., the standard deviation of the NDVI anomaly (SD, auto-correlation at lag one of the NDVI anomaly (AC and the correlation of NDVI anomaly with SPEI (CS. Results show high variability in magnitude and direction for the different stability metrics. Large areas and types of Australian vegetation showed an increase in variability (SD over time; however, vegetation memory (AC decreased. The association of NDVI anomalies with drought events (CS showed a mixed response: the association increased in the western part, while it decreased in the eastern part. This methodology shows the potential for quantifying vegetation responses to major climate shifts and land use change, but results could be enhanced with higher resolution time series data.

  9. Periodic trends within a series of five-coordinate thiolate-ligated [MII(SMe2N4(tren))]+ (M = Mn, Fe, Co, Ni, Cu, Zn) complexes, including a rare example of a stable CuII-thiolate.

    Science.gov (United States)

    Brines, Lisa M; Shearer, Jason; Fender, Jessica K; Schweitzer, Dirk; Shoner, Steven C; Barnhart, David; Kaminsky, Werner; Lovell, Scott; Kovacs, Julie A

    2007-10-29

    A series of five-coordinate thiolate-ligated complexes [M(II)(tren)N4S(Me2)]+ (M = Mn, Fe, Co, Ni, Cu, Zn; tren = tris(2-aminoethyl)amine) are reported, and their structural, electronic, and magnetic properties are compared. Isolation of dimeric [Ni(II)(SN4(tren)-RS(dang))]2 ("dang"= dangling, uncoordinated thiolate supported by H bonds), using the less bulky [(tren)N4S](1-) ligand, pointed to the need for gem-dimethyls adjacent to the sulfur to sterically prevent dimerization. All of the gem-dimethyl derivatized complexes are monomeric and, with the exception of [Ni(II)(S(Me2)N4(tren)]+, are isostructural and adopt a tetragonally distorted trigonal bipyramidal geometry favored by ligand constraints. The nickel complex uniquely adopts an approximately ideal square pyramidal geometry and resembles the active site of Ni-superoxide dismutase (Ni-SOD). Even in coordinating solvents such as MeCN, only five-coordinate structures are observed. The MII-S thiolate bonds systematically decrease in length across the series (Mn-S > Fe-S > Co-S > Ni-S approximately Cu-S tren)]+, represents a rare example of a stable CuII-thiolate, and models the perturbed "green" copper site of nitrite reductase. In contrast to the intensely colored, low-spin Fe(III)-thiolates, the M(II)-thiolates described herein are colorless to moderately colored and high-spin (in cases where more than one spin-state is possible), reflecting the poorer energy match between the metal d- and sulfur orbitals upon reduction of the metal ion. As the d-orbitals drop in energy proceeding across the across the series M(2+) (M= Mn, Fe, Co, Ni, Cu), the sulfur-to-metal charge-transfer transition moves into the visible region, and the redox potentials cathodically shift. The reduced M(+1) oxidation state is only accessible with copper, and the more oxidized M(+4) oxidation state is only accessible for manganese.

  10. Stratigraphical and biological significance of negative carbon isotopic anomalies in the basal Cambrian series of Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    YANG Ruidong; WANG Shijie; OUYANG Ziyuan; ZHU Lijun; JIANG Lijun; ZHANG Weihua; GAO Hui

    2005-01-01

    The early Early Cambrian strata within the bounds of Guizhou Province are almost predominated by black shale deposition. Recently, however, the authors have found a section consisting of a set of mudstones interbedded with limestones at the basement of the Cambrian at Yingping, Fuquan County, Guizhou Province, which provides favorable conditions for the study of marine geochemical characteristics of the early Early Cambrian. The characteristics of intense negative carbon isotopic anomalies near the Precambrian/Cambrian boundary at Yingping, Fuquan County, Guizhou Province, can be correlated with those of global carbon isotopic anomalies at the same time on a global scale, corresponding to the intense negative carbon isotopic anomalies near the Neoproterozoic/Cambrian boundaries at the bottom of the Xiaowaitoushan Member, Huize, Yunnan Province, at the top of the Tsagaan Oloom Formation of Mongolia and at the top of the Salarmy Gol Formation of Siberia, as well as those observed in southwestern United States, Iran, Amman, Poland, Newfoundland, the Great Britain, Canada, etc. Negative carbon isotopic anomalies can be used as the important basis for the division of the Precambrian/Cambrian boundaries. There have been found 8 m-thick black shales and cherts below the intense negative carbon isotopic anomalies in this profile. In the black shales there have been found large amounts of fossils such as Bradorida, gernus Archotuba, indicating that during the period of sedimentation of black shales under anaerobic conditions there would be large quantities of organic species living in the sea. But in the section of grayish-green mudstones interbedded with limestones with intense negative carbon isotopic anomalies almost no organic fossil has been found. This may imply that the anaerobic event seems to have little bearing on the mass extinction near the Precambrian/Cambrian boundary, whereas the intense negative carbon isotopic anomaly event appears to be more closely

  11. Crystal growth, structure and magnetic properties of Sm3Ni5Al19: A compound in the Sm2n+mNi4n+mAl15n+4m homologous series

    Indian Academy of Sciences (India)

    Udumula Subbarao; Aloke Kumar Ghosh; Sumanta Sarkar; Sebastian C Peter

    2014-09-01

    Sm3Ni5Al19 was obtained as large rod shaped single crystals from reactive aluminium flux. Single crystal X-ray diffraction suggests that Sm3Ni5Al19 crystallizes in the Gd3Ni5Al19 structure type, orthorhombic space group and lattice constants = 4.0974(1) Å, = 16.0172(6)Å and = 27.0774(10) Å. Sm3Ni5Al19 is a member of the Sm2n+mNi4n+mAl15n+4m series with n = 1 and m = 1. The crystal structure of Sm3Ni5Al19 consists of SmNiAl4 and Sm2Al4Al15 slabs intergrown along the -axis. Magnetic susceptibility data on Sm3Ni5Al19 confirms the paramagnetic nature with a complicated magnetic ordering below 18 K. The inverse susceptibility data follows modified Curie-Weiss law above 150 K with effective magnetic moment 1.3 B/Sm atoms suggests trivalent Sm atoms.

  12. AIRS-Observed Interrelationships of Anomaly Time-series of Moist Process-Related Parameters and Inferred Feedback Values on Various Spatial Scales

    Science.gov (United States)

    Molnar, G. I.; Susskind, J.; Iredell, L.

    2011-12-01

    There are some climate feedbacks, especially those associated with moist processes, which are not very well represented in GCMs, the primary tools to predict future climate changes associated with man's ever increasing influences on our planet. Here, we make use of the first 9 years of AIRS observations to evaluate interrelationships/correlations of atmospheric moist parameter anomalies computed from AIRS Version 5 Level-3 products, and demonstrate their usefulness to calculate certain feedback strength values. Note that a rather lively debate has flared up again on the possible usability of shorter-term, satellite-observed climate parameter anomalies for estimating climate sensitivity, i. e., the inferred strength of various (mostly moist processes related) feedbacks. Nevertheless, recent works, in particular analyses by Dessler, have pointed out the usefulness of these shorter term (but reliable) datasets in assessing global water vapor and cloud feedbacks. First we evaluate AIRS-observed interrelationships of anomaly time-series of water vapor, clouds, OLR and temperature on various spatial scales using 1x1 Degree resolution (a common GCM scale) 9-year long (Sept. 2002 through Aug. 2011) monthly anomaly time-series as starting points. We also find significant correlations among the 1x1 Degree average rate of change maps themselves, as well as among the deep tropical anomaly Hovmöller diagrams. We argue that for GCMs to be trusted for predicting longer-term climate variability, e. g., that due to global warming, they should be able to reproduce these observed relationships/metrics as closely as possible. Next, we evaluate the AIRS-observed water vapor feedback on global to regional scales. For cloud feedback, we demonstrate that unlike the global cloud feedback, which may require additional decades of data to compute reliably, regional cloud feedback strengths may already be assessed with sufficient accuracy to provide "benchmarks" for GCMs. The longwave cloud

  13. Anomalies of Pulmonary Circulation as a Cause of Hemoptysis: A Series of Unusual Cases and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Kamini Gupta

    2015-05-01

    Full Text Available The expectoration of blood originating from the lower respiratory tract, called hemoptysis, is a common clinical condition with many potential etiologies. Massive hemoptysis is life threatening and needs urgent intervention. Multidetector computed tomography (MDCT is a useful non-invasive imaging modality for the initial assessment of hemoptysis. Using MDCT with multiplanar reformatted images has improved the diagnosis and management of hemoptysis by providing a more precise depiction of bronchial and non-bronchial systemic arteries than conventional computed tomography (CT. In 95% of hemoptysis cases, the systemic arterial system is the origin of bleeding and pulmonary vascular anomalies are a rare cause. Among these, pulmonary arteriovenous malformation, hereditary hemorrhagic telangiectasia, and Osler-Weber-Rendu disease are well known entities. However, primary anomalies affecting pulmonary vessels in the mediastinum or diseases secondarily affecting the pulmonary vessels are unusual causes. Here we present three cases where patients had pulmonary vascular anomalies causing hemoptysis. These patients had decreased pulmonary arterial pressures leading to bronchial and systemic arterial hypertrophy and development of bronchopulmonary collaterals. Secondary CT signs in the parenchyma and mediastinum (mosaic attenuation, ground glass haze, subpleural interstitial thickening, and hypertrophied bronchial arteries were similar in all patients. Hence, evaluation of the MDCT images for primary abnormality led to the diagnosis.

  14. Spatial Correlations of Anomaly Time Series of AIRS Version-6 Land Surface Skin Temperatures with the Nino-4 Index

    Science.gov (United States)

    Susskind, Joel; Lee, Jae N.; Iredell, Lena

    2013-01-01

    The AIRS Science Team Version-6 data set is a valuable resource for meteorological studies. Quality Controlled earth's surface skin temperatures are produced on a 45 km x 45 km spatial scale under most cloud cover conditions. The same retrieval algorithm is used for all surface types under all conditions. This study used eleven years of AIRS monthly mean surface skin temperature and cloud cover products to show that land surface skin temperatures have decreased significantly in some areas and increased significantly in other areas over the period September 2002 through August 2013. These changes occurred primarily at 1:30 PM but not at 1:30 AM. Cooling land areas contained corresponding increases in cloud cover over this time period, with the reverse being true for warming land areas. The cloud cover anomaly patterns for a given month are affected significantly by El Nino/La Nina activity, and anomalies in cloud cover are a driving force behind anomalies in land surface skin temperature.

  15. Gauged N = 4 matter couplings

    NARCIS (Netherlands)

    Roo, M. de

    1985-01-01

    The N = 4 Yang-Mills multiplet is coupled to N = 4 conformal supergravity. The action has a local U(4)×G symmetry, where G is the Yang-Mills gauge group. The action and supersymmetry transformation rules are presented in the Poincaré gauge, and properties of the scalar potential are discussed.

  16. AIRS-Observed Interrelationships of Anomaly Time-Series of Moist Process-Related Parameters and Inferred Feedback Values on Various Spatial Scales

    Science.gov (United States)

    Molnar, Gyula I.; Susskind, Joel; Iredell, Lena

    2011-01-01

    In the beginning, a good measure of a GMCs performance was their ability to simulate the observed mean seasonal cycle. That is, a reasonable simulation of the means (i.e., small biases) and standard deviations of TODAY?S climate would suffice. Here, we argue that coupled GCM (CG CM for short) simulations of FUTURE climates should be evaluated in much more detail, both spatially and temporally. Arguably, it is not the bias, but rather the reliability of the model-generated anomaly time-series, even down to the [C]GCM grid-scale, which really matter. This statement is underlined by the social need to address potential REGIONAL climate variability, and climate drifts/changes in a manner suitable for policy decisions.

  17. Usefulness of AIRS-Derived OLR, Temperature, Water Vapor and Cloudiness Anomaly Time-series for GCM Validation

    Science.gov (United States)

    Molnar, Gyula; Susskind, Joel; Iredell, Lena

    2010-01-01

    The ROBUST nature (biases are not as important as previous GCM-evaluations suggest) of the AIRS-observations-generated ARC-maps and ATs as well as their interrelations suggest that they could be a useful tool to select CGCMs which may be considered the reliable, i.e., to be trusted even for longer-term climate drift/change predictions (even on the regional scale). Get monthly gridded CGCM time-series of atmospheric variables coinciding with the timeframe of the AIRS analyses for at least 5-6 years and do the actual evaluations of ARC-maps and ATs for the coinciding time periods.

  18. n = 4 supersymmetric FRW model

    Energy Technology Data Exchange (ETDEWEB)

    Rosales, J.J.; Pashnev, A. [Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna, 141980 (Russian Federation); Tkach, V.I. [Instituto de Fisica, Universidad de Guanajuato, 05315-970 Leon, 66318 Guanajuato (Mexico)]. e-mail: juan@ifug3.ugto.mx, pashnev@thsun1.jinr.ru, vladimir@ifug3.ugto.mx

    2003-07-01

    In this work we have constructed the n = 4 extended local conformal time supersymmetry for the Friedmann-Robertson-Walker cosmological models. This is based on the superfield construction of the action, which is invariant under world line local n = 4 supersymmetry with SU(2){sub local} X SU(2){sub global} internal subgroup. It is shown that the supersymmetric action has the form of the localized (or superconformal) version of the action for n = 4 supersymmetric quantum mechanics. This superfield procedure provides a well defined scheme for including super matter. (Author)

  19. All N=4 Conformal Supergravities

    CERN Document Server

    Butter, Daniel; de Wit, Bernard; Sahoo, Bindusar

    2016-01-01

    All N=4 conformal supergravities in four space-time dimensions are constructed. These are the only N=4 supergravity theories whose actions are invariant under off-shell supersymmetry. They are encoded in terms of a holomorphic function that is homogeneous of zeroth degree in scalar fields that parametrize an SU(1,1)/U(1) coset space. When this function equals a constant the Lagrangian is invariant under continuous SU(1,1) transformations.

  20. Analysis of transient deformation and pre-seismic strain anomalies in SW Taiwan by time series of continuous GPS and PS-InSAR

    Science.gov (United States)

    Min-Chien, Tsai

    2017-04-01

    The high precision Global Navigation Satellite System (GNSS) survey technique provides an efficient tool to study active tectonics and geodynamics. The data of more than 400 cGPS stations are processed with the GAMIT/GLOBK 10.6 software. After strictly data control, time series analysis, noise analysis, and common-mode error correction, we can drive a more realistic interseismic ITRF2008 velocity field Taiwan area. This result not only provides high precision GPS data for all of GPS or other users, also can be a basis for the crustal strain rate estimation and analysis of GPS baseline variation. The 2016 Meinong earthquake is the most deadly earthquake occurred in Taiwan after the 1999 Chichi earthquake. This project will focus on characterizing high strain anomalies and transient deformation from time series analysis of cGPS and PS-INSAR to assess the seismic hazards and potential active structures in the SW Taiwan area in terms of the temporal and spatial strain variations.

  1. The Relationship Between Surface Temperature Anomaly Time Series and those of OLR, Water Vapor, and Cloud Cover as Observed Using Nine Years of AIRS Version-5 Level-3 Products

    Science.gov (United States)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena

    2011-01-01

    Outline: (1) Comparison of AIRS and CERES anomaly time series of outgoing longwave radiation (OLR) and OLR(sub CLR), i.e. Clear Sky OLR (2) Explanation of recent decreases in global and tropical mean values of OLR (3) AIRS "Short-term" Longwave Cloud Radiative Feedback -- A new product

  2. Evaluating interannual vegetation anomalies in the Basilicata region using satellite spot vegetation 1999-2011 time series: preliminary results from the Mitra project

    Science.gov (United States)

    Lasaponara, Rosa; Desantis, Fortunato; Aromando, Angelo; Lanorte, Antonio

    2013-04-01

    principal component analysis (PCA) for evaluating interannual vegetation anomalies from SPOT/VEGETATION NDVI temporal series. Ecological Modelling 1 9 4 ( 2 0 0 6 ) 429-434

  3. Clinical, cytogenetic, and molecular outcomes in a series of 66 patients with Pierre Robin sequence and literature review: 22q11.2 deletion is less common than other chromosomal anomalies.

    Science.gov (United States)

    Gomez-Ospina, Natalia; Bernstein, Jonathan A

    2016-04-01

    Pierre Robin sequence (PRS) is an important craniofacial anomaly that can be seen as an isolated finding or manifestation of multiple syndromes. 22q11.2 deletion and Stickler syndrome are cited as the two most common conditions associated with PRS, but their frequencies are debated. We performed a retrospective study of 66 patients with PRS and reviewed their genetic testing, diagnoses, and clinical findings. The case series is complemented by a comprehensive literature review of the nature and frequency of genetic diagnosis in PRS. In our cohort 65% of patients had associated anomalies; of these, a genetic diagnosis was established in 56%. Stickler syndrome was the most common diagnosis, comprising approximately 11% of all cases, followed by Treacher Collins syndrome (9%). The frequency of 22q11.2 deletion was 1.5%. Chromosome arrays, performed for 72% of idiopathic PRS with associated anomalies, revealed two cases of 18q22→qter deletion, a region not previously reported in association with PRS. A review of the cytogenetic anomalies identified in this population supports an association between the 4q33-qter, 17q24.3, 2q33.1, and 11q23 chromosomal loci and PRS. We found a low frequency of 22q11.2 deletion in PRS, suggesting it is less commonly implicated in this malformation. Our data also indicate a higher frequency of cytogenetic anomalies in PRS patients with associated anomalies, and a potential new link with the 18q22→qter locus. The present findings underscore the utility of chromosomal microarrays in cases of PRS with associated anomalies and suggest that delaying testing for apparently isolated cases should be considered.

  4. Dendritic cell algorithm for time series oriented anomaly detection%面向异常检测的时间序列树突状细胞算法

    Institute of Scientific and Technical Information of China (English)

    田玉玲

    2014-01-01

    Aiming at the fact that the high randomness existing in definitions of signals and the antigen results in the lower detection rate used by the Dendritic Cell Algorithm,the Dendritic Cell Algorithm for anomaly detection based on time series is proposed.The underlying methodology is to perform antigen detection via the change point detection and multiple data streams correlation analysis,and the change point data reflecting the mutation status as the candidate solution of the abnormal is selected.Features are extracted based on the subspace tracker algorithm and various input signal subspaces are obtained and classified precisely. A dynamic migration threshold is incorporated into the context evaluation of the algorithm.The accumulation of the antigen assessment in a certain window time decreases the false positive rate effectively.Simulation demonstrates that the algorithm shows a better performance on the detection rate,accuracy rate and stability with less memory space and computing resource.%针对树突状细胞算法中信号及参数的定义存在高度随机性,导致检测率较低的问题,提出了一种时间序列数据的异常检测树突状细胞算法。采用多维数据流相关性分析和变化点检测方法对抗原进行检测,遴选出能够反映突变状态的关键点数据作为异常活动候选解;基于变化点子空间追踪算法提取特征集,准确地获取及分类各种输入信号子空间;在算法的上下文评估中加入动态迁移阈值的概念,累积一定窗口时间内的抗原评估,有效地减少了误判率。通过仿真实验证明该算法能够利用更少的存储空间和计算资源,有效地提高异常检测的检测率与准确率,具有更高的稳定性。

  5. SADM potentiometer anomaly investigations

    Science.gov (United States)

    Wood, Brian; Mussett, David; Cattaldo, Olivier; Rohr, Thomas

    2005-07-01

    During the last 3 years Contraves Space have been developing a Low Power (1-2kW) Solar Array Drive Mechanism (SADM) aimed at small series production. The mechanism was subjected to two test programmes in order to qualify the SADM to acceptable levels. During the two test programmes, anomalies were experienced with the Potentiometers provided by Eurofarad SA and joint investigations were undertaken to resolve why these anomalies had occurred. This paper deals with the lessons learnt from the failure investigation on the two Eurofarad (rotary) Potentiometer anomaly. The Rotary Potentiometers that were used were fully redundant; using two back to back mounted "plastic tracks". It is a pancake configuration mounted directly to the shaft of the Slip Ring Assembly at the extreme in-board end of the SADM. It has no internal bearings. The anomaly initially manifested itself as a loss of performance in terms of linearity, which was first detected during Thermal Vacuum testing. A subsequent anomaly manifested itself by the complete failure of the redundant potentiometer again during thermal vacuum testing. This paper will follow and detail the chain of events following this anomaly and identifies corrective measures to be applied to the potentiometer design and assembly process.

  6. Anomaly holography

    Energy Technology Data Exchange (ETDEWEB)

    Gripaios, Ben [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Rd., Oxford OX1 3NP (United Kingdom); Merton College, Oxford OX1 4JD (United Kingdom)], E-mail: b.gripaios1@physics.ox.ac.uk; West, Stephen M. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Rd., Oxford OX1 3NP (United Kingdom)], E-mail: s.west1@physics.ox.ac.uk

    2008-01-21

    We consider, in the effective field theory context, anomalies of gauge field theories on a slice of a five-dimensional, anti-de Sitter geometry and their four-dimensional, holographic duals. A consistent effective field theory description can always be found, notwithstanding the presence of the anomalies and without modifying the degrees of freedom of the theory. If anomalies do not vanish, the d=4 theory contains additional pseudoscalar states, which are either present in the low-energy theory as physical, light states, or are eaten by (would-be massless) gauge bosons. We show that the pseudoscalars ensure that global anomalies of the four-dimensional dual satisfy the 't Hooft matching condition and comment on the relevance for warped models of electroweak symmetry breaking.

  7. Fetal extracardiac anomalies associated with congenital cardiac diseases

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Bum Ha; Cho, Jung Yeon; Lee, Young Ho; Song, Mi Jin [Samsung Cheil Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2004-06-15

    To evaluate the incidence of associated extracardiac anomalies in fetuses with congenital heart defects on fetal echocardiography, and to estimate the incidence of chromosomal abnormalities according to the extracardiac anomalies. From Jan. 1999 to Dec. 2001, 101 fetuses with prenatally diagnosed extracardiac anomalies and congenital cardiac diseases were selected for study. The mean gestational age at the time of the ultrasound exam was about 25 weeks. Associated extracardiac anomalies were classified into CNS, face and neck, thorax, abdomen, genitourinary system, musculoskeletal, other and multi-systemic anomalies groups. Chromosomal studies including chorionic villi sampling, amniocentesis, cordocentesis, and postnatal exam were correlated. Musculoskeletal anomalies were the most commonly associated extracardiac anomalies (n=28, 27.7%). Abdominal anomaly (n=26, 25.7%), central nervous system anomaly (n=25, 24.8%), genitourinary anomaly(n=12, 11.9%), thoracic anomaly (n=4, 4%), face and neck anomaly (n=3, 3%) were found. Twenty eight fetuses showed other anomalies (n=28, 27.7%). Multi-systemic anomalies were also common (n=20, 19.8%). Fetal anomalies involving two systems were noted in 15 fetuses, and anomalies of more than three systems were not uncommon (5 fetuses). Chromosomal study of 38 fetuses revealed 19 fetuses with abnormal karyotypes (50%). For 19 fetuses with abnormal karyotypes, central nervous system anomalies and musculoskeletal anomalies were the most frequently associated with extracardiac abnormalities (n=9). Multi-systemic anomalies were associated in 9 of the 19 fetuses. In fetuses with cardiac defects, the musculoskeletal, abdomen and CNS anomalies were commonly associated with extracardiac anomalies. Various extracardiac anomalies such as, head and neck anomalies, CNS anomalies, musculoskeletal anomalies, and multi-organ anomalies were highly correlated with chromosomal abnormalities, and so this relationship requires chromosomal study.

  8. Craniofacial anomalies in twins.

    Science.gov (United States)

    Keusch, C F; Mulliken, J B; Kaplan, L C

    1991-01-01

    Studies of twins provide insight into the relative contribution of genetic and environmental factors in the causality of structural anomalies. Thirty-five affected twin pairs were identified from a group of 1114 patients with congenital craniofacial deformities evaluated from 1972 to 1989. Forty-three of these 70 twins exhibited one or more craniofacial anomalies; these were analyzed for dysmorphic characteristics, zygosity, concordance, and family history. The anomalies were categorized into two groups: malformations and deformations. The malformations (n = 36) included hemifacial microsomia (n = 10), cleft lip and palate (n = 8), cleft palate (n = 4), rare facial cleft (n = 2), craniosynostosis (n = 2), Binder syndrome (n = 2), Treacher Collins syndrome (n = 2), craniopagus (n = 2), CHARGE association (n = 1), frontonasal dysplasia (n = 2), and constricted ears (n = 1). The deformations (n = 7) included plagiocephaly (n = 5), hemifacial hypoplasia (n = 1), and micrognathia (n = 1). Twenty-one monozygotic and 14 dizygotic twin pairs were identified. The concordance rate was 33 percent for monozygotic twins and 7 percent for dizygotic twins.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. 基于改进符号化度量方法的机场噪声异常检测%An Anomaly Detection Method of Airport-noise Time Series Based on Improved SAX Measurement

    Institute of Scientific and Technical Information of China (English)

    王伟; 王建东; 张霞

    2014-01-01

    With the expansion of airport transportation scale , the airport noise issue is becoming one of the obstacles for the sustain-able development of the aviation industry .Anomalies in the airport noise are of great significance for the timely improvement of the equipments of aircraft and airports .In this paper , according to the characteristics of airport noise , a time series anomaly detection method for single monitoring point is proposed , which is based on the improved symbolic aggregate approximation similarity measure-ment .This method calculates the measure by applying the improved similarity measure , and finally finds anomalies using the k-nearest neighbor anomaly detection method.The proposed method is applied in practice after the theoretical verification of its feasibility .%机场噪声中的异常情况拥有很大价值,利用它能够及时完善飞机和机场的设备。结合机场噪声数据的特点,对上述问题进行研究并提出一种基于改进的符号化聚集近似( Symbolic Aggregate Approximation ,SAX)相似性度量的单监测点的时间序列异常检测方法。其运用相似性度量方法计算出度量结果,再运用k近邻异常检测方法进行异常发现,最后发现异常时间段。该方法在理论验证可行性之后在某机场的实测数据中进行应用,取得了良好的效果。

  10. Time series analysis of precipitation and vegetation to detect food production anomalies in the Horn of Africa. The case of Lower Shabelle (Somalia

    Directory of Open Access Journals (Sweden)

    M. A. Belenguer-Plomer

    2016-12-01

    Full Text Available The Horn of Africa is one of the most food-insecure locations around the world due to the continuous increase of its population and the practice of the subsistence agriculture. This causes that much of the population cannot take the minimum nutritional needs for a healthy life. Moreover, this situation of food vulnerability may be seriously affected in the coming years due to the effects of climate change. The aim of this work is combine the information about the state of the vegetation that offers the NDVI with rainfall data to detect negative anomalies in food production. This work has been used the monthly products of NDVI MOD13A3 of MODIS and the rainfall estimation product TAMSAT, both during the period 2001-2015. With these products we have calculated the average of the entire time period selected and we have detected the years whose NDVI values were further away from the average, being these 2010, 2011 and 2014. Once detected the years with major anomalies in NDVI, there has been an exclusive monthly analysis of those years, where we have analysed the relationships between the value of NDVI and monthly rainfall, obtaining a direct relationship between the two values. It also has been used crop calendar to focus the analysis in the months of agricultural production and finding that the main cause of anomalies in vegetation is a decrease in the registration of rainfall during the months of agricultural production. This reason explains the origin of the food shortages that occurred in 2010 and 2011 that generated an enormous humanitarian crisis in this area.

  11. On the cusp anomalous dimension in the ladder limit of N=4 SYM

    Energy Technology Data Exchange (ETDEWEB)

    Beccaria, Matteo; Fachechi, Alberto; Macorini, Guido [Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento,Via Arnesano, 73100 Lecce (Italy); INFN,Via Arnesano, 73100 Lecce (Italy)

    2016-06-01

    We analyze the cusp anomalous dimension in the (leading) ladder limit of N=4 SYM and present new results for its higher-order perturbative expansion. We study two different limits with respect to the cusp angle ϕ. The first is the light-like regime where x=e{sup i} {sup ϕ}→0. This limit is characterised by a non-trivial expansion of the cusp anomaly as a sum of powers of log x, where the maximum exponent increases with the loop order. The coefficients of this expansion have remarkable transcendentality features and can be expressed by products of single zeta values. We show that the whole logarithmic expansion is fully captured by a solvable Woods-Saxon like one-dimensional potential. From the exact solution, we extract generating functions for the cusp anomaly as well as for the various specific transcendental structures appearing therein. The second limit that we discuss is the regime of small cusp angle. In this somewhat simpler case, we show how to organise the quantum mechanical perturbation theory in a novel efficient way by means of a suitable all-order Ansatz for the ground state of the associated Schrödinger problem. Our perturbative setup allows to systematically derive higher-order perturbative corrections in powers of the cusp angle as explicit non-perturbative functions of the effective coupling. This series approximation is compared with the numerical solution of the Schrödinger equation to show that we can achieve very good accuracy over the whole range of coupling and cusp angle. Our results have been obtained by relatively simple techniques. Nevertheless, they provide several non-trivial tests useful to check the application of Quantum Spectral Curve methods to the ladder approximation at non zero ϕ, in the two limits we studied.

  12. Anomaly Structure of Supergravity and Anomaly Cancellation

    CERN Document Server

    Butter, Daniel

    2009-01-01

    We display the full anomaly structure of supergravity, including new D-term contributions to the conformal anomaly. This expression has the super-Weyl and chiral U(1)_K transformation properties that are required for implementation of the Green-Schwarz mechanism for anomaly cancellation. We outline the procedure for full anomaly cancellation. Our results have implications for effective supergravity theories from the weakly coupled heterotic string theory.

  13. Peters anomaly: review of the literature.

    Science.gov (United States)

    Bhandari, Ramanath; Ferri, Sara; Whittaker, Beatrice; Liu, Margaret; Lazzaro, Douglas R

    2011-08-01

    Peters anomaly is a rare dramatic finding at birth and can be associated with other systemic malformations. We performed a literature review of multiple case reports and case series to better define the common characteristics and unusual findings associated with Peters anomaly. A representative case is discussed followed by a literature review of multiple case reports and case series. The literature search was conducted for the years 1969 to 2009. Cases and case series were included in the review of published English ophthalmic literature. Cases were excluded if no information was reported on ocular and systemic malformations or if no information was reported on surgical interventions or outcomes. In addition, if cases did not report laterality of the lesion, they were excluded from the review. Fifty-eight cases were found that fit the above criteria, and the relevant cases were reviewed to better characterize the systemic malformations, interventions, and outcomes associated with Peters anomaly reported in the literature. Fifty-eight cases of Peters anomaly were reviewed. Of those cases reporting sex, 56% were men and 44% of cases were women. In terms of laterality, 67.2% of cases were bilateral versus 32.8% of cases that were unilateral. Moreover, bilateral cases of Peters anomaly were associated with a higher rate of systemic malformations (71.8%) versus unilateral Peters anomaly (36.8%). This difference was significant (P anomaly type I (87.5%), as opposed to those patients with Peters anomaly type II (14.2%) (P anomaly are presented. Cornea specialists who care for pediatric patients should be aware of the common and uncommon associations with Peters anomaly. Although bilateral Peters anomaly is much more commonly associated with systemic malformations, we believe that all patients with Peters anomaly should be screened for systemic malformations by both pediatricians and geneticists and undergo chromosomal analysis and molecular genetic testing.

  14. Space weather and space anomalies

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2005-11-01

    Full Text Available A large database of anomalies, registered by 220 satellites in different orbits over the period 1971-1994 has been compiled. For the first time, data from 49 Russian Kosmos satellites have been included in a statistical analysis. The database also contains a large set of daily and hourly space weather parameters. A series of statistical analyses made it possible to quantify, for different satellite orbits, space weather conditions on the days characterized by anomaly occurrences. In particular, very intense fluxes (>1000 pfu at energy >10 MeV of solar protons are linked to anomalies registered by satellites in high-altitude (>15000 km, near-polar (inclination >55° orbits typical for navigation satellites, such as those used in the GPS network, NAVSTAR, etc. (the rate of anomalies increases by a factor ~20, and to a much smaller extent to anomalies in geostationary orbits, (they increase by a factor ~4. Direct and indirect connections between anomaly occurrence and geomagnetic perturbations are also discussed.

  15. Matter coupling in N = 4 supergravity

    NARCIS (Netherlands)

    Roo, M. de

    1985-01-01

    An arbitrary number of abelian vector multiplets is coupled to N = 4 supergravity. The resulting action is invariant under global SO(n,6), where n is the number of vector multiplets, and under local SU(4) × U(1) transformations. The scalar fields of the theory parametrize the manifold [SO(n,6)/SO(n

  16. A R^4 non-renormalisation theorem in N=4 supergravity

    CERN Document Server

    Tourkine, Piotr

    2012-01-01

    We consider the four-graviton amplitudes in CHL constructions providing four-dimensional N=4 models with various numbers of vector multiplets. We show that in these models the two-loop amplitude factorizes a d^2R^4. This implies a non-renormalisation theorem for the R^4 term, which forbids the appearance of a three-loop ultraviolet divergence in four dimensions in the four-graviton amplitude. We connect the special nature of the R^4 term to the U(1) anomaly of pure N=4 supergravity.

  17. N=2 vacua in electrically gauged N=4 supergravities

    Energy Technology Data Exchange (ETDEWEB)

    Horst, Christoph

    2013-06-15

    In this thesis we study N= 2 vacua in gauged N=4 supergravity theories in fourdimensional spacetime. Using the embedding tensor formalism that describes general consistent magnetic gaugings of an ungauged N=4 matter-coupled supergravity theory in a symplectic frame with SO(1,1) x SO(6,n) off-shell symmetry we formulate necessary conditions for partial supersymmetry breaking and find that the Killing spinor equations can be solved for the embedding tensor components. Subsequently, we show that the classification of theories that allow for vacua with partial supersymmetry amounts to solving a system of purely algebraic quadratic equations. Then, we restrict ourselves to the class of purely electric gaugings and explicitly construct a class of consistent super-Higgs mechanisms and study its properties. In particular, we find that the spectrum fills complete N=2 supermultiplets that are either massless or BPS. Furthermore, we demonstrate that (modulo an abelian Lie algebra) arbitrary unbroken gauge Lie algebras can be realized provided that the number of N=4 vector multiplets is sufficiently large. Finally, we compute the relevant terms of the effective action below the scale of partial supersymmetry breaking and argue that the special Kaehler manifold for the scalars of the N=2 vector multiplets has to be in the unique series of special Kaehler product manifolds.

  18. Abelian reductions of deformed N=4 SYM

    Directory of Open Access Journals (Sweden)

    Carlos Cardona

    2015-08-01

    Full Text Available Following the work in [1], where the massive ABJM model in 2+1 dimensions was shown to have an abelian reduction to the relativistic Landau–Ginzburg, and motivated by the implications for condensed matter through AdS/CFT, we show that a FI deformation of N=4 SYM in 3+1 dimensions with a mass term can also be reduced to a relativistic Landau–Ginzburg model, with the possibility of coupling it to a real scalar, whereas the simply mass deformed N=4 SYM reduces only to a massive ϕ4 model (scalar QED coupled to a real scalar. We study the classical solutions of the model, in particular vortex solutions.

  19. Gauging isometries in N=4 supersymmetric mechanics

    CERN Document Server

    Delduc, F

    2008-01-01

    This talk summarizes the study of superfield gaugings of isometries of extended supersymmetric mechanics in hep-th/0605211, hep-th/0611247 and arXiv:0706.0706. The gauging procedure provides a manifestly supersymmetric realization of d=1 automorphic dualities which interrelate various irreducible off-shell multiplets of d=1 extended supersymmetry featuring the same number of physical fermions but different divisions of bosonic fields into the physical and auxiliary subsets. We concentrate on the most interesting N=4 case and demonstrate that, with a suitable choice of the symmetry to be gauged, all such multiplets of N=4 supersymmetric mechanics and their generic superfield actions can be obtained from the "root" multiplet (4,4,0) and the appropriate gauged subclasses of the generic superfield action of the latter by a simple universal recipe.

  20. N = 4 l-conformal Galilei superalgebra

    Science.gov (United States)

    Galajinsky, Anton; Masterov, Ivan

    2017-08-01

    An N = 4 supersymmetric extension of the l-conformal Galilei algebra is constructed. This is achieved by combining generators of spatial symmetries from the l-conformal Galilei algebra and those underlying the most general superconformal group in one dimension D (2 , 1 ; α). The value of the group parameter α is fixed from the requirement that the resulting superalgebra is finite-dimensional. The analysis reveals α = -1/2 thus reducing D (2 , 1 ; α) to OSp (4 | 2).

  1. Chiral anomalies and differential geometry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1983-10-01

    Some properties of chiral anomalies are described from a geometric point of view. Topics include chiral anomalies and differential forms, transformation properties of the anomalies, identification and use of the anomalies, and normalization of the anomalies. 22 references. (WHK)

  2. Counting dyons in N = 4 string theory

    Science.gov (United States)

    Dijkgraaf, Robbert; Verlinde, Erik; Verlinde, Herman

    1997-02-01

    We present a microscopic index formula for the degeneracy of dyons in four-dimensional N = 4 string theory. This counting formula is manifestly symmetric under the duality group, and its asymptotic growth reproduces the macroscopic Bekenstein-Hawking entropy. We give a derivation of this result in terms of the type 11 five-brane compactified on K3, by assuming that its fluctuations are described by a closed string theory on its world-volume. We find that the degeneracies are given in terms of the denominator of a generalized super Kac-Moody algebra. We also discuss the correspondence of this result with the counting of D-brane states.

  3. Counting dyons in N=4 string theory

    CERN Document Server

    Dijkgraaf, R; Verlinde, Herman L

    1997-01-01

    We present a microscopic index formula for the degeneracy of dyons in four-dimensional N=4 string theory. This counting formula is manifestly symmetric under the duality group, and its asymptotic growth reproduces the macroscopic Bekenstein-Hawking entropy. We give a derivation of this result in terms of the type II five-brane compactified on K3, by assuming that its fluctuations are described by a closed string theory on its world-volume. We find that the degeneracies are given in terms of the denominator of a generalized super Kac-Moody algebra. We also discuss the correspondence of this result with the counting of D-brane states.

  4. Minimal N=4 topologically massive supergravity

    Science.gov (United States)

    Kuzenko, Sergei M.; Novak, Joseph; Sachs, Ivo

    2017-03-01

    Using the superconformal framework, we construct a new off-shell model for N=4 topologically massive supergravity which is minimal in the sense that it makes use of a single compensating vector multiplet and involves no free parameter. As such, it provides a counterexample to the common lore that two compensating multiplets are required within the conformal approach to supergravity with eight supercharges in diverse dimensions. This theory is an off-shell N=4 supersymmetric extension of chiral gravity. All of its solutions correspond to non-conformally flat superspaces. Its maximally supersymmetric solutions include the so-called critical (4,0) anti-de Sitter superspace introduced in [25], and well as warped critical (4,0) anti-de Sitter superspaces. We also propose a dual formulation for the theory in which the vector multiplet is replaced with an off-shell hypermultiplet. Upon elimination of the auxiliary fields belonging to the hypermultiplet and imposing certain gauge conditions, the dual action reduces to the one introduced in [20].

  5. Tracheobronchial Branching Anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Min Ji; Kim, Young Tong; Jou, Sung Shick [Soonchunhyang University, Cheonan Hospital, Cheonan (Korea, Republic of); Park, A Young [Soonchunhyang University College of Medicine, Asan (Korea, Republic of)

    2010-04-15

    There are various congenital anomalies with respect to the number, length, diameter, and location of tracheobronchial branching patterns. The tracheobronchial anomalies are classified into two groups. The first one, anomalies of division, includes tracheal bronchus, cardiac bronchus, tracheal diverticulum, pulmonary isomerism, and minor variations. The second one, dysmorphic lung, includes lung agenesis-hypoplasia complex and lobar agenesis-aplasia complex

  6. Counting dyons in N=4 string theory

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, R. [Amsterdam Univ. (Netherlands). Dept. of Mathematics and Computer Science; Verlinde, E. [TH-Division, CERN, CH-1211 Geneva 23 (Switzerland)]|[Institute for Theoretical Physics, Universtity of Utrecht, 3508 TA Utrecht (Netherlands); Verlinde, H. [Institute for Theoretical Physics, University of Amsterdam, 1018 XE Amsterdam (Netherlands)]|[Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States)

    1997-01-27

    We present a microscopic index formula for the degeneracy of dyons in four-dimensional N=4 string theory. This counting formula is manifestly symmetric under the duality group, and its asymptotic growth reproduces the macroscopic Bekenstein-Hawking entropy. We give a derivation of this result in terms of the type II five-brane compactified on K3, by assuming that its fluctuations are described by a closed string theory on its world-volume. We find that the degeneracies are given in terms of the denominator of a generalized super Kac-Moody algebra. We also discuss the correspondence of this result with the counting of D-brane states. (orig.).

  7. Associated congenital anomalies among cases with Down syndrome.

    Science.gov (United States)

    Stoll, Claude; Dott, Beatrice; Alembik, Yves; Roth, Marie-Paule

    2015-12-01

    which associated anomalies are most common in cases with DS with associated anomalies. In this study we observed a higher percentage of associated anomalies than in the other reported series as well as an increase in the incidence of duodenal atresia, urinary system anomalies, musculoskeletal system anomalies, and respiratory system anomalies, and a decrease in the incidence of anal atresia, annular pancreas, and limb reduction defects. In conclusion, we observed a high prevalence of total congenital anomalies and specific patterns of malformations associated with Down syndrome which emphasizes the need to evaluate carefully all cases with Down syndrome for possible associated major congenital anomalies.

  8. The dynamic Allan Variance IV: characterization of atomic clock anomalies.

    Science.gov (United States)

    Galleani, Lorenzo; Tavella, Patrizia

    2015-05-01

    The number of applications where precise clocks play a key role is steadily increasing, satellite navigation being the main example. Precise clock anomalies are hence critical events, and their characterization is a fundamental problem. When an anomaly occurs, the clock stability changes with time, and this variation can be characterized with the dynamic Allan variance (DAVAR). We obtain the DAVAR for a series of common clock anomalies, namely, a sinusoidal term, a phase jump, a frequency jump, and a sudden change in the clock noise variance. These anomalies are particularly common in space clocks. Our analytic results clarify how the clock stability changes during these anomalies.

  9. Orbital debris hazard insights from spacecraft anomalies studies

    Science.gov (United States)

    McKnight, Darren S.

    2016-09-01

    Since the dawning of the space age space operators have been tallying spacecraft anomalies and failures then using these insights to improve the space systems and operations. As space systems improved and their lifetimes increased, the anomaly and failure modes have multiplied. Primary triggers for space anomalies and failures include design issues, space environmental effects, and satellite operations. Attempts to correlate anomalies to the orbital debris environment have started as early as the mid-1990's. Early attempts showed tens of anomalies correlated well to altitudes where the cataloged debris population was the highest. However, due to the complexity of tracing debris impacts to mission anomalies, these analyses were found to be insufficient to prove causation. After the fragmentation of the Chinese Feng-Yun satellite in 2007, it was hypothesized that the nontrackable fragments causing anomalies in LEO would have increased significantly from this event. As a result, debris-induced anomalies should have gone up measurably in the vicinity of this breakup. Again, the analysis provided some subtle evidence of debris-induced anomalies but it was not convincing. The continued difficulty in linking debris flux to satellite anomalies and failures prompted the creation of a series of spacecraft anomalies and failure workshops to investigate the identified shortfalls. These gatherings have produced insights into why this process is not straightforward. Summaries of these studies and workshops are presented and observations made about how to create solutions for anomaly attribution, especially as it relates to debris-induced spacecraft anomalies and failures.

  10. Minimal $\\cal N=4$ topologically massive supergravity

    CERN Document Server

    Kuzenko, Sergei M; Sachs, Ivo

    2016-01-01

    Using the superconformal framework, we construct a new off-shell model for topologically massive $\\cal N=4$ supergravity which is minimal in the sense that it makes use of a single compensating vector multiplet. Our theory provides a counterexample to the common lore that two compensating multiplets are required within the conformal approach to supergravity with eight supercharges in diverse dimensions. All solutions in this theory correspond to non-conformally flat superspaces. Its maximally supersymmetric solutions include the so-called critical (4,0) anti-de Sitter superspace introduced in arXiv:1205.4622. Other maximally supersymmetric solutions describe warped critical (4,0) anti-de Sitter superspaces. We also propose a dual formulation for the theory in which the vector multiplet is replaced with an off-shell hypermultiplet. Upon elimination of the auxiliary fields belonging to the hypermultiplet and imposing certain gauge conditions, the dual action reduces to the one introduced in arXiv:1605.00103.

  11. Ni-Sn-Ti合金钎料对Si3N4陶瓷的润湿性研究%Study on Wettability of Ni-Sn-Ti Solder Alloy on Si3N4 Ceramics

    Institute of Scientific and Technical Information of China (English)

    苏光; 程芳

    2011-01-01

    Si3N4/Si3N4 is bonded by a series of Ni-20Sn-xTi filler alloys. The results show that Ni-20Sn-10Ti alloy has good wettability on Si3N4 and can improve the bonding strength of welded joint.%采用一系列Ni-20Sn-xTi合金钎料进行了Si3N4/Si3N4真空钎焊连接研究.结果表明:Ni-20Sn-10Ti合金钎料对Si3N4陶瓷具有最好的润湿性,同时能够有效地提高接头的连接强度.

  12. Morphology ofα-Si3N4 in Fe-Si3N4 prepared via flash combustion

    Institute of Scientific and Technical Information of China (English)

    Bin Li; Jun-hong Chen; Jin-dong Su; Ming-wei Yan; Jia-lin Sun; Yong Li

    2015-01-01

    The state and formation mechanism ofα-Si3N4 in Fe–Si3N4 prepared by flash combustion were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results indicate thatα-Si3N4 crystals exist only in the Fe–Si3N4 dense areas. When FeSi75 particles react with N2, which generates substantial heat, a large number of Si solid particles evaporate. The prod-uct between Si gas and N2 is a mixture ofα-Si3N4 andβ-Si3N4. At the later stage of the flash combustion process,α-Si3N4 crystals dissolve and reprecipitate asβ-Si3N4 and theβ-Si3N4 crystals grow outward from the dense areas in the product pool. As the temperature decreases, the α-Si3N4 crystals cool before transforming into β-Si3N4 crystals in the dense areas of Fe–Si3N4. The phase composition of flash-combustion-synthesized Fe–Si3N4 is controllable through manipulation of the gas-phase reaction in the early stage and theα→βtrans-formation in the later stage.

  13. Morphology of α-Si3N4 in Fe-Si3N4 prepared via flash combustion

    Science.gov (United States)

    Li, Bin; Chen, Jun-hong; Su, Jin-dong; Yan, Ming-wei; Sun, Jia-lin; Li, Yong

    2015-12-01

    The state and formation mechanism of α-Si3N4 in Fe-Si3N4 prepared by flash combustion were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results indicate that α-Si3N4 crystals exist only in the Fe-Si3N4 dense areas. When FeSi75 particles react with N2, which generates substantial heat, a large number of Si solid particles evaporate. The product between Si gas and N2 is a mixture of α-Si3N4 and β-Si3N4. At the later stage of the flash combustion process, α-Si3N4 crystals dissolve and reprecipitate as β-Si3N4 and the β-Si3N4 crystals grow outward from the dense areas in the product pool. As the temperature decreases, the α-Si3N4 crystals cool before transforming into β-Si3N4 crystals in the dense areas of Fe-Si3N4. The phase composition of flash-combustion-synthesized Fe-Si3N4 is controllable through manipulation of the gas-phase reaction in the early stage and the α→β transformation in the later stage.

  14. Superconformal Chern-Simons-matter theories in N =4 superspace

    Science.gov (United States)

    Kuzenko, Sergei M.; Samsonov, Igor B.

    2015-11-01

    In three dimensions, every known N =4 supermultiplet has an off-shell completion. However, there is no off-shell N =4 formulation for the known extended superconformal Chern-Simons (CS) theories with eight and more supercharges. To achieve a better understanding of this issue, we provide N =4 superfield realizations for the equations of motion which correspond to various N =4 and N =6 superconformal CS theories, including the Gaiotto-Witten theory and the Aharony-Bergman-Jafferis-Maldacena (ABJM) theory. These superfield realizations demonstrate that the superconformal CS theories with N ≥4 (except for the Gaiotto-Witten theory) require a reducible long N =4 vector multiplet, from which the standard left and right N =4 vector multiplets are obtained by constraining the field strength to be either self-dual or antiself-dual. Such a long multiplet naturally originates upon reduction of any off-shell N >4 vector multiplet to N =4 superspace. For the long N =4 vector multiplet we develop a prepotential formulation. It makes use of two prepotentials being subject to the constraint which defines the so-called hybrid projective multiplets introduced in the framework of N =4 supergravity-matter systems in arXiv:1101.4013. We also couple N =4 superconformal CS theories to N =4 conformal supergravity.

  15. Competing Orders and Anomalies

    Science.gov (United States)

    Moon, Eun-Gook

    2016-08-01

    A conservation law is one of the most fundamental properties in nature, but a certain class of conservation “laws” could be spoiled by intrinsic quantum mechanical effects, so-called quantum anomalies. Profound properties of the anomalies have deepened our understanding in quantum many body systems. Here, we investigate quantum anomaly effects in quantum phase transitions between competing orders and striking consequences of their presence. We explicitly calculate topological nature of anomalies of non-linear sigma models (NLSMs) with the Wess-Zumino-Witten (WZW) terms. The non-perturbative nature is directly related with the ’t Hooft anomaly matching condition: anomalies are conserved in renormalization group flow. By applying the matching condition, we show massless excitations are enforced by the anomalies in a whole phase diagram in sharp contrast to the case of the Landau-Ginzburg-Wilson theory which only has massive excitations in symmetric phases. Furthermore, we find non-perturbative criteria to characterize quantum phase transitions between competing orders. For example, in 4D, we show the two competing order parameter theories, CP(1) and the NLSM with WZW, describe different universality class. Physical realizations and experimental implication of the anomalies are also discussed.

  16. Anomaly-induced baryogenesis

    CERN Document Server

    Kobakhidze, A

    2004-01-01

    We propose a new mechanism for dynamical generation of the observed baryon asymmetry within the minimal Standard model extended by massive Majorana neutrinos and non-vanishing electroweak Chern-Simons term. We show that electroweak Chern-Simons number is produced in the expanding universe due to the conformal anomaly and subsequently converted into baryon number through the triangle anomaly.

  17. Competing Orders and Anomalies.

    Science.gov (United States)

    Moon, Eun-Gook

    2016-08-08

    A conservation law is one of the most fundamental properties in nature, but a certain class of conservation "laws" could be spoiled by intrinsic quantum mechanical effects, so-called quantum anomalies. Profound properties of the anomalies have deepened our understanding in quantum many body systems. Here, we investigate quantum anomaly effects in quantum phase transitions between competing orders and striking consequences of their presence. We explicitly calculate topological nature of anomalies of non-linear sigma models (NLSMs) with the Wess-Zumino-Witten (WZW) terms. The non-perturbative nature is directly related with the 't Hooft anomaly matching condition: anomalies are conserved in renormalization group flow. By applying the matching condition, we show massless excitations are enforced by the anomalies in a whole phase diagram in sharp contrast to the case of the Landau-Ginzburg-Wilson theory which only has massive excitations in symmetric phases. Furthermore, we find non-perturbative criteria to characterize quantum phase transitions between competing orders. For example, in 4D, we show the two competing order parameter theories, CP(1) and the NLSM with WZW, describe different universality class. Physical realizations and experimental implication of the anomalies are also discussed.

  18. Synthesis and phase transition studies on non-symmetric liquid crystal dimers: N-(4-(n-(4-(benzothiazol-2-yl)phenoxy)alkyloxy)-benzylidene)-4-chloroanilines

    Science.gov (United States)

    Yeap, Guan-Yeow; Al-Taifi, Elham A.; Ong, Chin-Hin; Kamil Mahmood, Wan Ahmad; Takeuchi, Daisuke; Ito, Masato M.

    2012-06-01

    A new series of non-symmetric liquid crystal dimers N-(4-(n-(4-(benzothiazol-2-yl)phenoxy)alkyloxy)benzylidene)-4-chloroaniline containing benzothiazole and benzylideneimine units connected by a flexible alkyl spacer, -(CH2) n -, with n ranging from 4 to 12 in even parity have been prepared. All five members of this homologous series exhibit an enantiotropic nematic phase. The compounds with greater n of 8-12 exhibit both nematic and smectic phases upon cooling. A notable feature among this series is that for the member with n = 10, the smectic-nematic transition is also present. The nematic-isotropic transition temperatures and associated entropy changes with respect to all compounds in this series exhibit a dramatic dependence on the length of the flexible spacer. A comparison of the transitional properties of this series with those of α-(4-benzylidenechloroaniline-4‧-oxy)-ω-[4-(thiophene-2-carboxyl)benzylideneaniline-4‧-oxy]alkanes reveals that replacing benzothiazole moiety at one side of the flexible alkyl spacer reduces the nematic-isotropic transition temperature.

  19. Gas-Pressure Sintering of β-Si3N4 and α-Si3N4 with β-Si3N4 Addition%β-Si3N4及添加β-Si3N4的α-Si3N4的气氛加压烧结

    Institute of Scientific and Technical Information of China (English)

    张宝林; 庄汉锐; 罗新宇; 李文兰

    1999-01-01

    介绍了β-Si3N4及添加β-Si3N4的α-Si3N4的气氛加压烧结,β-Si3N4在GPS中具有不低于α-Si3N4的烧结活性,而且陶瓷显微结构更容易调节.由GPS β-Si3N4制备的陶瓷材料晶粒比较均匀,具有较高的力学性能,尤其是高的韦泊模数.添加于α-Si3N4中的β-Si3N4对陶瓷材料显微结构具有明显的调控作用.

  20. Novel N4 Bacteriophages Prevail in the Cold Biosphere

    Science.gov (United States)

    Zhan, Yuanchao; Buchan, Alison

    2015-01-01

    Coliphage N4 is a lytic bacteriophage discovered nearly half a century ago, and it was considered to be a “genetic orphan” until very recently, when several additional N4-like phages were discovered to infect nonenteric bacterial hosts. Interest in this genus of phages is stimulated by their unique genetic features and propagation strategies. To better understand the ecology of N4-like phages, we investigated the diversity and geographic patterns of N4-like phages by examining 56 Chesapeake Bay viral communities, using a PCR-clone library approach targeting a diagnostic N4-like DNA polymerase gene. Many new lineages of N4-like phages were found in the bay, and their genotypes shift from the lower to the upper bay. Interestingly, signature sequences of N4-like phages were recovered only from winter month samples, when water temperatures were below 4°C. An analysis of existing metagenomic libraries from various aquatic environments supports the hypothesis that N4-like phages are most prolific in colder waters. In particular, a high number of N4-like phages were detected in Organic Lake, Antarctica, a cold and hypersaline system. The prevalence of N4-like phages in the cold biosphere suggests these viruses possess yet-to-be-determined mechanisms that facilitate lytic infections under cold conditions. PMID:26025897

  1. Novel N4 Bacteriophages Prevail in the Cold Biosphere.

    Science.gov (United States)

    Zhan, Yuanchao; Buchan, Alison; Chen, Feng

    2015-08-01

    Coliphage N4 is a lytic bacteriophage discovered nearly half a century ago, and it was considered to be a "genetic orphan" until very recently, when several additional N4-like phages were discovered to infect nonenteric bacterial hosts. Interest in this genus of phages is stimulated by their unique genetic features and propagation strategies. To better understand the ecology of N4-like phages, we investigated the diversity and geographic patterns of N4-like phages by examining 56 Chesapeake Bay viral communities, using a PCR-clone library approach targeting a diagnostic N4-like DNA polymerase gene. Many new lineages of N4-like phages were found in the bay, and their genotypes shift from the lower to the upper bay. Interestingly, signature sequences of N4-like phages were recovered only from winter month samples, when water temperatures were below 4°C. An analysis of existing metagenomic libraries from various aquatic environments supports the hypothesis that N4-like phages are most prolific in colder waters. In particular, a high number of N4-like phages were detected in Organic Lake, Antarctica, a cold and hypersaline system. The prevalence of N4-like phages in the cold biosphere suggests these viruses possess yet-to-be-determined mechanisms that facilitate lytic infections under cold conditions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Anomalies on orbifolds

    Energy Technology Data Exchange (ETDEWEB)

    Arkani-Hamed, Nima; Cohen, Andrew G.; Georgi, Howard

    2001-03-16

    We discuss the form of the chiral anomaly on an S1/Z2 orbifold with chiral boundary conditions. We find that the 4-divergence of the higher-dimensional current evaluated at a given point in the extra dimension is proportional to the probability of finding the chiral zero mode there. Nevertheless the anomaly, appropriately defined as the five dimensional divergence of the current, lives entirely on the orbifold fixed planes and is independent of the shape of the zero mode. Therefore long distance four dimensional anomaly cancellation ensures the consistency of the higher dimensional orbifold theory.

  3. Normal-state magnetic properties and their correlation with Tc suppression and the resistivity anomalies in the (La1-xPrx)1.85Sr0.15CuO4 series

    Science.gov (United States)

    Musa, J. E.; García, S.; Rothier de Amaral, M.; Salim de Amorim, H.; Giordanengo, B.; Baggio-Saitovitch, E. M.; Pagliuso, P. J. G.; Rettori, C.; Yelon, W. B.; Malik, S. K.

    1999-04-01

    We have investigated the normal-state anomalies observed in the magnetic and transport properties of the (La1-xPrx)1.85Sr0.15CuO4 system with 0⩽x⩽0.5. The resistivity curves showed an increasing deviation from linearity below ˜100 K. This behavior is properly accounted by a logarithmic term, whose coefficient C linearly increases with x. The normal-state magnetic susceptibility measurements evidenced a departure from the Pr3+ Curie-Weiss dependence in the same temperature range for which the resistivity anomaly occurs. A comprehensive picture of the conduction mechanism is presented in terms of a Kondo-like scattering of the mobile holes by the spin fluctuations.

  4. Theoretically Optimal Distributed Anomaly Detection

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel general framework for distributed anomaly detection with theoretical performance guarantees is proposed. Our algorithmic approach combines existing anomaly...

  5. Theoretical Hardness of Zr3N4 Films

    Institute of Scientific and Technical Information of China (English)

    GAO Fa-Ming

    2011-01-01

    The structures,energetics and properties for orthohombic Zr3N4 and cubic Zr3N4 are calculated by first-principles calculations.The agreement between the predicted properties with available experimental data is excellent.The cubic phase has a smaller volume (by 11.2%) and a slightly higher total energy (by 0.3eV/pair),in comparison to the orthohombic phase.We elucidate the effects of stress on hardness of Zr3N4 films.The results show that the hardness of c-Zr3N4 increases up to 23% as the stress increases to 15 GPa.

  6. Anomaly Detection in Sequences

    Data.gov (United States)

    National Aeronautics and Space Administration — We present a set of novel algorithms which we call sequenceMiner, that detect and characterize anomalies in large sets of high-dimensional symbol sequences that...

  7. Neutrino anomalies without oscillations

    Indian Academy of Sciences (India)

    Sandip Pakvasa

    2000-01-01

    I review explanations for the three neutrino anomalies (solar, atmospheric and LSND) which go beyond the `conventional' neutrino oscillations induced by mass-mixing. Several of these require non-zero neutrino masses as well.

  8. Scattering anomaly in optics

    CERN Document Server

    Silveirinha, Mario G

    2016-01-01

    In time-reversal invariant electronic systems the scattering matrix is anti-symmetric. This property enables an effect, designated here as "scattering anomaly", such that the electron transport does not suffer from back reflections, independent of the specific geometry of the propagation path or the presence of time-reversal invariant defects. In contrast, for a generic time-reversal invariant photonic system the scattering matrix is symmetric and there is no similar anomaly. Here, it is theoretically proven that despite these fundamental differences there is a wide class of photonic platforms - in some cases formed only by time-reversal invariant media - in which the scattering anomaly can occur. It is shown that an optical system invariant under the action of the composition of the time-reversal, parity and duality operators is characterized by an anti-symmetric scattering matrix. Specific examples of photonic platforms wherein the scattering anomaly occurs are given, and it is demonstrated with full wave n...

  9. The Pioneer Anomaly

    CERN Document Server

    de Diego, Jose A

    2008-01-01

    Analysis of the radio-metric data from Pioneer 10 and 11 spacecrafts has indicated the presence of an unmodeled acceleration starting at 20 AU, which has become known as the Pioneer anomaly. The nature of this acceleration is uncertain. In this paper we give a description of the effect and review some relevant mechanisms proposed to explain the observed anomaly. We also discuss on some future projects to investigate this phenomenon.

  10. DREDed Anomaly Mediation

    CERN Document Server

    Boyda, E; Pierce, A T; Boyda, Ed; Murayama, Hitoshi; Pierce, Aaron

    2002-01-01

    We offer a guide to dimensional reduction (DRED) in theories with anomaly mediated supersymmetry breaking. Evanescent operators proportional to epsilon arise in the bare Lagrangian when it is reduced from d=4 to d= (4-2 epsilon) dimensions. In the course of a detailed diagrammatic calculation, we show that inclusion of these operators is crucial. The evanescent operators conspire to drive the supersymmetry-breaking parameters along anomaly-mediation trajectories across heavy particle thresholds, guaranteeing the ultraviolet insensitivity.

  11. Anomalies and gravity

    CERN Document Server

    Mielke, E W

    2006-01-01

    Anomalies in Yang-Mills type gauge theories of gravity are reviewed. Particular attention is paid to the relation between the Dirac spin, the axial current j_5 and the non-covariant gauge spin C. Using diagrammatic techniques, we show that only generalizations of the U(1)- Pontrjagin four--form F^ F= dC arise in the chiral anomaly, even when coupled to gravity. Implications for Ashtekar's canonical approach to quantum gravity are discussed.

  12. High-Energy Dijets in N=4 SYM

    CERN Document Server

    Chachamics, Grigorios; Vera, Agustín Sabio

    2011-01-01

    Ratios of azimuthal angle correlations for Mueller-Navelet jets are compared in QCD and N = 4 SYM. Such observables are well suited to study the effects of Moebius invariance in the Regge limit. The role of the renormalization prescription and the size of conformal contributions is addressed, showing that the BLM procedure best reproduces the N = 4 SYM results.

  13. Characterization of Si3N4 powders in aqueous dispersions

    Directory of Open Access Journals (Sweden)

    Castanho S. Mello

    1998-01-01

    Full Text Available alpha- Si3N4 can easily oxidize when exposed in air atmosphere or other oxidizing environment. The chemistry of Si3N4 particle surfaces can change by different synthesis routes and also by subsequent processing steps. To avoid this oxidation is a challenge when Si3N4 powder is shaped by slip casting process from aqueous suspension. This study shows the variations on Si3N4 powder surface after slip casting process using x-ray photoelectron spectroscopy (XPS and high resolution transmission electron microscopy (HTEM on the green compacts. The results show that the dispersant used during the preparation of the slurry can reduce the level of oxidation of the Si3N4 particles when processing in aqueous solutions.

  14. Microstructure of Si3 N4/Si3 N4 joint brazed using Cu-Pd-Ti alloy filler

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jie(张杰); N. Massaki; ZHOU Yu(周玉)

    2004-01-01

    Microstructure of the Si3 N4/Si3 N4 joint brazed using an active filler of Cu-Pd-Ti alloy was analyzed by means of EPMA and XRD. The results indicate that a perfect Si3 N4/Si3 N4 joint is obtained by using an active filler of Cu76.5Pd8.5Ti15 alloy with brazing temperature, pressure and holding time of 1 373 - 1 473 K, 2× 10-3 MPa and 1.8 ks, respectively. The filler alloy in the joint is a Cu-Pd solution containing reactant of TiN, PdTiSi and Pd2Si.The interface between the filler alloy and Si3 N4 ceramic is composed of TiN reactant.

  15. Congenital anomalies surveillance in Canada.

    Science.gov (United States)

    Lowry, R Brian

    2008-01-01

    Congenital anomalies (CA) are present in approximately 3% of all newborn babies and account for about 12% of paediatric hospital admissions. They represent an important public health problem. Surveillance is especially important so that preventive measures such as folic acid fortification can be properly assessed without resorting to a series of ad hoc studies. Canada's surveillance of CAs is weak, with only Alberta and British Columbia having established sytems. Most provinces have perinatal systems but their CA data are incomplete and they do not capture terminations of pregnancy. The same is true of the Public Health Agency of Canada's system. A new system, the Fetal Alert Network, has been proposed for Ontario, which represents a start but will require additional sources of ascertainment if it is to be a truly population-based system for Ontario.

  16. Synthesis and characterization of C3N4 hard films

    Institute of Scientific and Technical Information of China (English)

    顾有松; 张永平; 常香荣; 田中卓; 陈难先; 时东霞; 张秀芳; 袁磊

    2000-01-01

    C3N4 films have been synthesized on both Si and R substrates by microwave plasma chemical vapor deposition (MPCVD) method. X-ray spectra were calculated for single phase α-C3N4 and p-C3N4 respectively. The experimental X-ray spectra of films deposited on both Si and R substrates showed all the strong peaks of α-C3N4 and β-C3N4 so the films are mixtures of α-C3N4 and β-C3N4. The N/C atomic ratio is in the range of 1.0-2.0. X-ray photoelectron spectroscopy (XPS) analysis indicated that the binding energy of C 1s and N 1s are 286.2 eV and 399.5 eV respectively, corresponding to polarized C-N bond. Fourier transform infrared absorption (FT-IR) and Raman spectra support the existence of C-N covalent bond in the films. Nano-indentation hardness tests showed that the bulk modulus of a film deposited on R is up to 349 GPa.

  17. CO observation of the Galactic bubble N4

    CERN Document Server

    Li, Junyu; Liu, Yao; Wang, Yuan

    2013-01-01

    We presented a study on the Galactic bubble N4 using the 13.7 m millimeter telescope of Purple Mountain Observatory at the Qinghai Station. N4 is one of the science demonstration regions for the Milky Way Imaging Scroll Painting (WMISP). Simultaneous observations of $^{12}$CO (J = 1$-$0), $^{13}$CO (J = 1$-$0) and C$^{18}$O (J = 1$-$0) line emission towards N4 were carried out. We analyzed the spectral profile and the distribution of the molecular gas. Morphologically, the CO emissions correlate well with Spitzer IRAC 8.0 $\\mu$m emission. The channel map and velocity-position diagram shows that N4 is more likely an inclined expanding ring than a spherical bubble. We calculated the physical parameters of N4 including the mass, size, column density and optical depth. Some massive star candidates were discovered in the region of N4 using (J, J$-$H) color-magnitude diagram. We found an energy source candidate for the expansion of N4, a massive star with a mass of ${\\sim} 15\\,M_{\\odot}$ and an age of $\\sim$ 1 Myr....

  18. Anomalies without Massless Particles

    CERN Document Server

    Gurlanik, Z

    1994-01-01

    Baryon and lepton number in the standard model are violated by anomalies, even though the fermions are massive. This problem is studied in the context of a two dimensional model. In a uniform background field, fermion production arise from non-adiabatic behavior that compensates for the absence of massless modes. On the other hand, for localized instanton-like configurations, there is an adiabatic limit. In this case, the anomaly is produced by bound states which travel across the mass gap. The sphaleron corresponds to a bound state at the halfway point.

  19. Classical Trace Anomaly

    OpenAIRE

    Farhoudi, M.

    1995-01-01

    We seek an analogy of the mathematical form of the alternative form of Einstein's field equations for Lovelock's field equations. We find that the price for this analogy is to accept the existence of the trace anomaly of the energy-momentum tensor even in classical treatments. As an example, we take this analogy to any generic second order Lagrangian and exactly derive the trace anomaly relation suggested by Duff. This indicates that an intrinsic reason for the existence of such a relation sh...

  20. Congenital laryngeal anomalies,

    Directory of Open Access Journals (Sweden)

    Michael J. Rutter

    2014-12-01

    Full Text Available Introduction: It is essential for clinicians to understand issues relevant to the airway management of infants and to be cognizant of the fact that infants with congenital laryngeal anomalies are at particular risk for an unstable airway. Objectives: To familiarize clinicians with issues relevant to the airway management of infants and to present a succinct description of the diagnosis and management of an array of congenital laryngeal anomalies. Methods: Revision article, in which the main aspects concerning airway management of infants will be analyzed. Conclusions: It is critical for clinicians to understand issues relevant to the airway management of infants.

  1. N = (4,4 Supersymmetry and T-Duality

    Directory of Open Access Journals (Sweden)

    Malin Göteman

    2012-10-01

    Full Text Available A sigma model with four-dimensional target space parametrized by chiral and twisted chiral N =(2,2 superfields can be extended to N =(4,4 supersymmetry off-shell, but this is not true for a model of semichiral fields, where the N = (4,4 supersymmetry can only be realized on-shell. The two models can be related to each other by T-duality. In this paper we perform a duality transformation from a chiral and twisted chiral model with off-shell N = (4,4 supersymmetry to a semichiral model. We find that additional non-linear terms must be added to the original transformations to obtain a semichiral model with N =(4,4 supersymmetry, and that the algebra closes on-shell as a direct consequence of the T-duality.

  2. Thermal expansion of spinel-type Si3N4

    DEFF Research Database (Denmark)

    Paszkowics, W.; Minkikayev, R.; Piszora, P.

    2004-01-01

    The lattice parameter and thermal expansion coefficient (TEC) for the spinel-type Si3N4 phase prepared under high-pressure and high-temperature conditions are determined for 14 K......The lattice parameter and thermal expansion coefficient (TEC) for the spinel-type Si3N4 phase prepared under high-pressure and high-temperature conditions are determined for 14 K...

  3. The reactor antineutrino anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Haser, Julia; Buck, Christian; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2016-07-01

    Major discoveries were made in the past few years in the field of neutrino flavour oscillation. Nuclear reactors produce a clean and intense flux of electron antineutrinos and are thus an essential neutrino source for the determination of oscillation parameters. Most currently the reactor antineutrino experiments Double Chooz, Daya Bay and RENO have accomplished to measure θ{sub 13}, the smallest of the three-flavour mixing angles. In the course of these experiments two anomalies emerged: (1) the reanalysis of the reactor predictions revealed a deficit in experimentally observed antineutrino flux, known as the ''reactor antineutrino anomaly''. (2) The high precision of the latest generation of neutrino experiments resolved a spectral shape distortion relative to the expected energy spectra. Both puzzles are yet to be solved and triggered new experimental as well as theoretical studies, with the search for light sterile neutrinos as most popular explanation for the flux anomaly. This talk outlines the two reactor antineutrino anomalies. Discussing possible explanations for their occurrence, recent and upcoming efforts to solve the reactor puzzles are highlighted.

  4. Bolivian Bouguer Anomaly Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 1 kilometer Bouguer anomaly grid for the country of Bolivia.Number of columns is 550 and number of rows is 900. The order of the data is from the lower left to the...

  5. Minnesota Bouguer Anomaly Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 1.5 kilometer Bouguer anomaly grid for the state of Minnesota. Number of columns is 404 and number of rows is 463. The order of the data is from the lower left to...

  6. Astrometric solar system anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, Michael Martin [Los Alamos National Laboratory; Anderson, John D [PROPULSION LABORATORY

    2009-01-01

    There are at least four unexplained anomalies connected with astrometric data. perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. next, a secular change in the astronomical unit AU is definitely a concern. It is increasing by about 15 cm yr{sup -1}. The other two anomalies are perhaps less disturbing because of known sources of nongravitational acceleration. The first is an apparent slowing of the two Pioneer spacecraft as they exit the solar system in opposite directions. Some astronomers and physicists are convinced this effect is of concern, but many others are convinced it is produced by a nearly identical thermal emission from both spacecraft, in a direction away from the Sun, thereby producing acceleration toward the Sun. The fourth anomaly is a measured increase in the eccentricity of the Moon's orbit. Here again, an increase is expected from tidal friction in both the Earth and Moon. However, there is a reported unexplained increase that is significant at the three-sigma level. It is produent to suspect that all four anomalies have mundane explanations, or that one or more anomalies are a result of systematic error. Yet they might eventually be explained by new physics. For example, a slightly modified theory of gravitation is not ruled out, perhaps analogous to Einstein's 1916 explanation for the excess precession of Mercury's perihelion.

  7. The Pioneer Anomaly

    Directory of Open Access Journals (Sweden)

    Viktor T. Toth

    2010-09-01

    Full Text Available Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20-70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ~6 × 10–9 Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of aP = (8.74 ± 1.33 × 10–10 m/s2. This apparent violation of the Newton's gravitational inverse square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the anomaly and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. As the new study is yet to report its findings, this review provides the necessary background for the new results to appear in the near future. In particular, we provide a significant amount of information on the design, operations and behavior of the two Pioneers during their entire missions, including descriptions of various data formats and techniques used for their navigation and radio-science data analysis. As most of this information was recovered relatively recently, it was not used in the previous studies of the Pioneer anomaly, but it is critical for the new investigation.

  8. XYY chromosome anomaly and schizophrenia.

    Science.gov (United States)

    Rajagopalan, M; MacBeth, R; Varma, S L

    1998-02-07

    Sex chromosome anomalies have been associated with psychoses, and most of the evidence is linked to the presence of an additional X chromosome. We report a patient with XYY chromosome anomaly who developed schizophrenia.

  9. Discrete R Symmetries and Anomalies

    OpenAIRE

    Michael Dine(Santa Cruz Institute for Particle Physics and Department of Physics, Santa Cruz CA 95064, U.S.A.); Angelo Monteux(Santa Cruz Institute for Particle Physics, University of California Santa Cruz, 1156 High Street, Santa Cruz, U.S.A.)

    2012-01-01

    We comment on aspects of discrete anomaly conditions focussing particularly on $R$ symmetries. We review the Green-Schwarz cancellation of discrete anomalies, providing a heuristic explanation why, in the heterotic string, only the "model-independent dilaton" transforms non-linearly under discrete symmetries; this argument suggests that, in other theories, multiple fields might play a role in anomaly cancellations, further weakening any anomaly constraints at low energies. We provide examples...

  10. Anomaly-safe discrete groups

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mu-Chun, E-mail: muchunc@uci.edu [Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575 (United States); Fallbacher, Maximilian, E-mail: m.fallbacher@tum.de [Physik–Department T30, Technische Universität München, James–Franck–Straße 1, 85748 Garching (Germany); Ratz, Michael, E-mail: michael.ratz@tum.de [Physik–Department T30, Technische Universität München, James–Franck–Straße 1, 85748 Garching (Germany); Trautner, Andreas, E-mail: andreas.trautner@tum.de [Physik–Department T30, Technische Universität München, James–Franck–Straße 1, 85748 Garching (Germany); Excellence Cluster Universe, Boltzmannstraße 2, 85748 Garching (Germany); Vaudrevange, Patrick K.S., E-mail: patrick.vaudrevange@tum.de [Excellence Cluster Universe, Boltzmannstraße 2, 85748 Garching (Germany); TUM Institute for Advanced Study, Lichtenbergstraße 2a, 85748 Garching (Germany); Arnold Sommerfeld Center for Theoretical Physics, Ludwig–Maximilians–Universität München, Theresienstraße 37, 80333 München (Germany)

    2015-07-30

    We show that there is a class of finite groups, the so-called perfect groups, which cannot exhibit anomalies. This implies that all non-Abelian finite simple groups are anomaly-free. On the other hand, non-perfect groups generically suffer from anomalies. We present two different ways that allow one to understand these statements.

  11. Anomaly-safe discrete groups

    Directory of Open Access Journals (Sweden)

    Mu-Chun Chen

    2015-07-01

    Full Text Available We show that there is a class of finite groups, the so-called perfect groups, which cannot exhibit anomalies. This implies that all non-Abelian finite simple groups are anomaly-free. On the other hand, non-perfect groups generically suffer from anomalies. We present two different ways that allow one to understand these statements.

  12. Discovering System Health Anomalies Using Data Mining Techniques

    Science.gov (United States)

    Sriastava, Ashok, N.

    2005-01-01

    We present a data mining framework for the analysis and discovery of anomalies in high-dimensional time series of sensor measurements that would be found in an Integrated System Health Monitoring system. We specifically treat the problem of discovering anomalous features in the time series that may be indicative of a system anomaly, or in the case of a manned system, an anomaly due to the human. Identification of these anomalies is crucial to building stable, reusable, and cost-efficient systems. The framework consists of an analysis platform and new algorithms that can scale to thousands of sensor streams to discovers temporal anomalies. We discuss the mathematical framework that underlies the system and also describe in detail how this framework is general enough to encompass both discrete and continuous sensor measurements. We also describe a new set of data mining algorithms based on kernel methods and hidden Markov models that allow for the rapid assimilation, analysis, and discovery of system anomalies. We then describe the performance of the system on a real-world problem in the aircraft domain where we analyze the cockpit data from aircraft as well as data from the aircraft propulsion, control, and guidance systems. These data are discrete and continuous sensor measurements and are dealt with seamlessly in order to discover anomalous flights. We conclude with recommendations that describe the tradeoffs in building an integrated scalable platform for robust anomaly detection in ISHM applications.

  13. On the cusp anomalous dimension in the ladder limit of $\\mathcal N=4$ SYM

    CERN Document Server

    Beccaria, Matteo; Macorini, Guido

    2016-01-01

    We analyze the cusp anomalous dimension in the (leading) ladder limit of $\\mathcal N=4$ SYM and present new results for its higher-order perturbative expansion. We study two different limits with respect to the cusp angle $\\phi$. The first is the light-like regime where $x = e^{i\\,\\phi}\\to 0$. This limit is characterised by a non-trivial expansion of the cusp anomaly as a sum of powers of $\\log x$, where the maximum exponent increases with the loop order. The coefficients of this expansion have remarkable transcendentality features and can be expressed by products of single zeta values. We show that the whole logarithmic expansion is fully captured by a solvable Woods-Saxon like one-dimensional potential. From the exact solution, we extract generating functions for the cusp anomaly as well as for the various specific transcendental structures appearing therein. The second limit that we discuss is the regime of small cusp angle. In this somewhat simpler case, we show how to organise the quantum mechanical pert...

  14. Spectral Methods for Magnetic Anomalies

    Science.gov (United States)

    Parker, R. L.; Gee, J. S.

    2013-12-01

    Spectral methods, that is, those based in the Fourier transform, have long been employed in the analysis of magnetic anomalies. For example, Schouten and MaCamy's Earth filter is used extensively to map patterns to the pole, and Parker's Fourier transform series facilitates forward modeling and provides an efficient algorithm for inversion of profiles and surveys. From a different, and perhaps less familiar perspective, magnetic anomalies can be represented as the realization of a stationary stochastic process and then statistical theory can be brought to bear. It is vital to incorporate the full 2-D power spectrum, even when discussing profile data. For example, early analysis of long profiles failed to discover the small-wavenumber peak in the power spectrum predicted by one-dimensional theory. The long-wavelength excess is the result of spatial aliasing, when energy leaks into the along-track spectrum from the cross-track components of the 2-D spectrum. Spectral techniques may be used to improve interpolation and downward continuation of survey data. They can also evaluate the reliability of sub-track magnetization models both across and and along strike. Along-strike profiles turn out to be surprisingly good indicators of the magnetization directly under them; there is high coherence between the magnetic anomaly and the magnetization over a wide band. In contrast, coherence is weak at long wavelengths on across-strike lines, which is naturally the favored orientation for most studies. When vector (or multiple level) measurements are available, cross-spectral analysis can reveal the wavenumber interval where the geophysical signal resides, and where noise dominates. One powerful diagnostic is that the phase spectrum between the vertical and along-path components of the field must be constant 90 degrees. To illustrate, it was found that on some very long Project Magnetic lines, only the lowest 10% of the wavenumber band contain useful geophysical signal. In this

  15. All Next-to-Maximally-Helicity-Violating One-Loop Gluon Amplitudes in N=4 Super-Yang-Mills Theory

    CERN Document Server

    Bern, Z; Kosower, D A; Bern, Zvi; Dixon, Lance J.; Kosower, David A.

    2004-01-01

    We compute the next-to-MHV one-loop n-gluon amplitudes in N=4 super-Yang-Mills theory. These amplitudes contain three negative-helicity gluons and an arbitrary number of positive-helicity gluons, and are the first infinite series of amplitudes beyond the simplest, MHV, amplitudes. We also discuss some aspects of their twistor-space structure.

  16. Theoretical Analysis of Structures of Ga4N4 Clusters

    Institute of Scientific and Technical Information of China (English)

    宋斌; 曹培林

    2003-01-01

    The structures and energies of a Ga4N4 cluster have been calculated using a full-potential linear-muffin-tin-orbital molecular-dynamics (FP-LMTO MD) method. We obtained twenty-four structures for a Ga4N4 cluster. The most stable structure we obtained is a Cs three-dimensional structure, the energy of which is lower than that of the C2v symmetry structure proposed by Kandalam et al. [J. Phys. Chem. B 106 (2002) 1945] The calculated results show that the isomer with an N3 subunit is preferred, supporting the previous result made by Kandalam et al.We found that the most stable structure of Ga4N4 clusters presented semiconductor-like properties through the calculation of the density of states.

  17. A New Methodology for Early Anomaly Detection of BWR Instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, K. N.

    2005-11-27

    The objective of the performed research is to develop an early anomaly detection methodology so as to enhance safety, availability, and operational flexibility of Boiling Water Reactor (BWR) nuclear power plants. The technical approach relies on suppression of potential power oscillations in BWRs by detecting small anomalies at an early stage and taking appropriate prognostic actions based on an anticipated operation schedule. The research utilizes a model of coupled (two-phase) thermal-hydraulic and neutron flux dynamics, which is used as a generator of time series data for anomaly detection at an early stage. The model captures critical nonlinear features of coupled thermal-hydraulic and nuclear reactor dynamics and (slow time-scale) evolution of the anomalies as non-stationary parameters. The time series data derived from this nonlinear non-stationary model serves as the source of information for generating the symbolic dynamics for characterization of model parameter changes that quantitatively represent small anomalies. The major focus of the presented research activity was on developing and qualifying algorithms of pattern recognition for power instability based on anomaly detection from time series data, which later can be used to formulate real-time decision and control algorithms for suppression of power oscillations for a variety of anticipated operating conditions. The research being performed in the framework of this project is essential to make significant improvement in the capability of thermal instability analyses for enhancing safety, availability, and operational flexibility of currently operating and next generation BWRs.

  18. A New Methodology for Early Anomaly Detection of BWR Instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, K. N.

    2005-11-27

    The objective of the performed research is to develop an early anomaly detection methodology so as to enhance safety, availability, and operational flexibility of Boiling Water Reactor (BWR) nuclear power plants. The technical approach relies on suppression of potential power oscillations in BWRs by detecting small anomalies at an early stage and taking appropriate prognostic actions based on an anticipated operation schedule. The research utilizes a model of coupled (two-phase) thermal-hydraulic and neutron flux dynamics, which is used as a generator of time series data for anomaly detection at an early stage. The model captures critical nonlinear features of coupled thermal-hydraulic and nuclear reactor dynamics and (slow time-scale) evolution of the anomalies as non-stationary parameters. The time series data derived from this nonlinear non-stationary model serves as the source of information for generating the symbolic dynamics for characterization of model parameter changes that quantitatively represent small anomalies. The major focus of the presented research activity was on developing and qualifying algorithms of pattern recognition for power instability based on anomaly detection from time series data, which later can be used to formulate real-time decision and control algorithms for suppression of power oscillations for a variety of anticipated operating conditions. The research being performed in the framework of this project is essential to make significant improvement in the capability of thermal instability analyses for enhancing safety, availability, and operational flexibility of currently operating and next generation BWRs.

  19. N= 4 Supersymmetric Quantum Mechanical Model: Novel Symmetries

    CERN Document Server

    Krishna, S

    2016-01-01

    We discuss a set of novel discrete symmetry transformations of the N = 4 supersymmetric quantum mechanical model of a charged particle moving on a sphere in the background of Dirac magnetic monopole. The usual five continuous symmetries (and their conserved Noether charges) and two discrete symmetries together provide the physical realizations of the de Rham cohomological operators of differential geometry. We have also exploited the supervariable approach to derive the nilpotent N = 4 SUSY transformations and provided the geometrical interpretation in the language of translational generators along the Grassmannian directions onto (1, 4)-dimensional supermanifold.

  20. Hardness of dense beta-Si3N4

    Science.gov (United States)

    Greskovich, C.; Yeh, H. C.

    1983-01-01

    The effects of small changes in the concentration of an oxygen content densification aid on the room temperature microhardness of hot isostatically pressed and sintered beta-Si3N4 ceramics are studied. The compositions studied were Si3N4 containing 7 wt. pct BeSiN2, a fixed nonoxide densification aid, and 1.9-3.7 wt. pct oxygen as a second, variable densification aid. A proportional relationship between high density and high oxygen content, regardless of heat treatment type, is noted.

  1. Statistical Anomaly Detection for Monitoring of Human Dynamics

    Science.gov (United States)

    Kamiya, K.; Fuse, T.

    2015-05-01

    Understanding of human dynamics has drawn attention to various areas. Due to the wide spread of positioning technologies that use GPS or public Wi-Fi, location information can be obtained with high spatial-temporal resolution as well as at low cost. By collecting set of individual location information in real time, monitoring of human dynamics is recently considered possible and is expected to lead to dynamic traffic control in the future. Although this monitoring focuses on detecting anomalous states of human dynamics, anomaly detection methods are developed ad hoc and not fully systematized. This research aims to define an anomaly detection problem of the human dynamics monitoring with gridded population data and develop an anomaly detection method based on the definition. According to the result of a review we have comprehensively conducted, we discussed the characteristics of the anomaly detection of human dynamics monitoring and categorized our problem to a semi-supervised anomaly detection problem that detects contextual anomalies behind time-series data. We developed an anomaly detection method based on a sticky HDP-HMM, which is able to estimate the number of hidden states according to input data. Results of the experiment with synthetic data showed that our proposed method has good fundamental performance with respect to the detection rate. Through the experiment with real gridded population data, an anomaly was detected when and where an actual social event had occurred.

  2. Ethyl anomaly in the nucleophilic substitution at a series of β-methylated alkyl RCH2Z and carbonyl RCOZ carbon centers for R = Me, Et, i-Pr, t-Bu, and Z = LG.

    Science.gov (United States)

    Sung, Dae Dong; Lee, Ikchoon

    2011-04-21

    We have carried out DFT studies to explore the cause of anomalously fast reaction rates of ethyl group (R = Et) in the gas-phase S(N)2 reactions of RCH(2)Cl+Cl(-) and RCH(CN)Cl+Cl(-), and also for those in the cationic forms of RCH(2)(+) and RCH(CN)(+) with R = Me, Et, i-Pr, and t-Bu. The TS stabilization by hyperconjugative donor-acceptor vicinal charge transfers (CTs) from R to the major NBOs at the reaction center carbon in the S(N)2 TSs were estimated using natural bond orbital (NBO) analyses. In all cases the hyperconjugative CT stabilization increases in the order R = t-Bu < i-Pr < Me < Et in agreement with the experimental as well as theoretical rate orders, exhibiting an ethyl anomaly. We have also determined the reorganization energies and hyperconjugative CTs from R to the two major NBOs, C-O(-) and C-N(+), in the tetrahedral intermediate formed with five water molecules, T(5w), by transformation of sp(2) to sp(3) centers in the reactions of RC(═O)OC(6)H(5) with NH(3). The reorganization energy is the lowest and CT stabilization is the strongest with R = Et in line with the fastest experimental rate. We conclude that C-H is a better donor than C-C bond orbital and hyperconjugative vicinal σ chain extension leads to a stronger CT stabilization in the TS. The stronger CT stabilization for R = Et rather than Me is achieved by enhanced hyperconjugative CT to the reaction center in the TS as a result of narrower energy gap and greater overlap brought about by long-range orbital mixing as the C-H σ-chain is extended from n = 2 for Me to n = 3 for Et. We find that CT properties of the all-trans vicinal hyprconjugative C-H σ-chains are closely analogous to the corresponding conjugative polyene π-chains although skeletal patterns of bridge bonds are different and the stabilization energy gained by extension of the σ-chain is much weaker than that gained by the π-chain.

  3. Phase structure of lattice N=4 super Yang-Mills

    DEFF Research Database (Denmark)

    Catterall, Simon; Damgaard, Poul H.; DeGrand, Thomas;

    2012-01-01

    We make a first study of the phase diagram of four-dimensional N = 4 super Yang-Mills theory regulated on a space-time lattice. The lattice formulation we employ is both gauge invariant and retains at all lattice spacings one exactly preserved supersymmetry charge. Our numerical results are consi...

  4. S-duality in N=4 Yang-Mills theories

    CERN Document Server

    Girardello, L; Porrati, Massimo; Zaffaroni, A

    1995-01-01

    Evidence in favor of SL(2,Z) S-duality in N=4 supersymmetric Yang-Mills theories in four dimensions and with general compact, simple gauge groups is presented. (Contribution to the Proceedings of the Strings '95 conference, March 13-18, 1995, USC, and the Proceedings of the Trieste Conference on S-Duality and Mirror Symmetry June 5-9, 1995.)

  5. Dijet Production in QCD and N=4 SYM

    CERN Document Server

    Chachamis, Grigorios; Vera, Agustín Sabio

    2012-01-01

    We investigate dijet production at large rapidity separation in QCD and N = 4 SYM, showing that both theories give similar predictions for observables only sensitive to conformal properties of the scattering such as ratios of azimuthal angle correlations. Renormalization prescriptions are important in this comparison.

  6. Eigenvalue spectrum of lattice N=4 super Yang-Mills

    Science.gov (United States)

    Weir, D.; Catterall, S.; Mehta, D. B.

    We present preliminary results for the eigenvalue spectrum of four-dimensional ${\\cal N}=4$ super Yang-Mills theory on the lattice. In particular, by studying the the spectral density a measurement of the anomalous dimension is made and found to be consistent with zero.

  7. The hybridization of Ag2CO3 rods with g-C3N4 sheets with improved photocatalytic activity

    Directory of Open Access Journals (Sweden)

    Konglin Wu

    2015-09-01

    Full Text Available A series of graphitic carbon nitride/silver carbonate (g-C3N4/Ag2CO3 rod-like composites with different weight contents of g-C3N4 have been prepared by a facile precipitation method. The g-C3N4/Ag2CO3 rod-like composites exhibited higher photocatalytic activity than pure Ag2CO3 toward degradation of rhodamine B (RhB and methylene blue (MB under visible-light irradiation. The photocatalytic reaction follows a pseudo-first-order reaction and the rate constants for the degradation of RhB and MB by 3.5% g-C3N4/Ag2CO3 are about 2 times and 1.7 times that of pure Ag2CO3, respectively. A possible photocatalytic mechanism was proposed based on the photoluminescence (PL spectra and a series of radical trapping experimental analyses. The remarkably improved photocatalytic performance should be ascribed to the heterostructure between Ag2CO3 and g-C3N4, which greatly promoted the photoinduced charge transfer and inhibited the recombination of electrons and holes.

  8. Syntheses of DNA Duplexes That Contain a N4C-alkyl-N4C Interstrand Cross-Link

    Science.gov (United States)

    Miller, Paul S.

    2011-01-01

    A simple procedure is described for preparing short DNA duplexes that contain a single N4C-alkyl-N4C interstrand cross-link. The synthesis is carried out on an automated DNA synthesizer using standard phosphoramidite chemistry. The cross-link is introduced during the synthesis of the duplex. The method can be used to prepare mg quantities of cross-linked duplexes suitable for physical studies and for the preparation of larger DNA molecules that can be used as substrates to study DNA repair in whole cell extracts and in living cells in culture. PMID:21400705

  9. Detecting Patterns of Anomalies

    Science.gov (United States)

    2009-03-01

    detect anomalies in the dataset is used in [Leung and Leckie, 2005] and [Eskin et al., 2002]. One-class SVMs [Li et al., 2003, Heller et al., 2003] and...IEE Proceedings F, 140(2): 107–113, 1993. J.D.F. Habbema, J. Hermans , and K. Vandenbroek. A stepwise discriminant analysis pro- gram using density...Technometrics, 29(4):409–412, 1987. K.A. Heller , K.M. Svore, A. Keromytis, and S.J. Stolfo. One class support vector machines for detecting anomalous

  10. Chiral supergravity and anomalies

    CERN Document Server

    Mielke, E W; Macias, Alfredo; Mielke, Eckehard W.

    1999-01-01

    Similarily as in the Ashtekar approach, the translational Chern-Simons term is, as a generating function, instrumental for a chiral reformulation of simple (N=1) supergravity. After applying the algebraic Cartan relation between spin and torsion, the resulting canonical transformation induces not only decomposition of the gravitational fields into selfdual and antiselfdual modes, but also a splitting of the Rarita-Schwinger fields into their chiral parts in a natural way. In some detail, we also analyze the consequences for axial and chiral anomalies.

  11. Low Risk Anomalies?

    DEFF Research Database (Denmark)

    Schneider, Paul; Wagner, Christian; Zechner, Josef

    This paper shows theoretically and empirically that beta- and volatility-based low risk anomalies are driven by return skewness. The empirical patterns concisely match the predictions of our model that endogenizes the role of skewness for stock returns through default risk. With increasing downside...... of betting against beta/volatility among low skew firms compared to high skew firms is economically large. Our results suggest that the returns to betting against beta or volatility do not necessarily pose asset pricing puzzles but rather that such strategies collect premia that compensate for skew risk...

  12. Detecting Biosphere anomalies hotspots

    Science.gov (United States)

    Guanche-Garcia, Yanira; Mahecha, Miguel; Flach, Milan; Denzler, Joachim

    2017-04-01

    The current amount of satellite remote sensing measurements available allow for applying data-driven methods to investigate environmental processes. The detection of anomalies or abnormal events is crucial to monitor the Earth system and to analyze their impacts on ecosystems and society. By means of a combination of statistical methods, this study proposes an intuitive and efficient methodology to detect those areas that present hotspots of anomalies, i.e. higher levels of abnormal or extreme events or more severe phases during our historical records. Biosphere variables from a preliminary version of the Earth System Data Cube developed within the CAB-LAB project (http://earthsystemdatacube.net/) have been used in this study. This database comprises several atmosphere and biosphere variables expanding 11 years (2001-2011) with 8-day of temporal resolution and 0.25° of global spatial resolution. In this study, we have used 10 variables that measure the biosphere. The methodology applied to detect abnormal events follows the intuitive idea that anomalies are assumed to be time steps that are not well represented by a previously estimated statistical model [1].We combine the use of Autoregressive Moving Average (ARMA) models with a distance metric like Mahalanobis distance to detect abnormal events in multiple biosphere variables. In a first step we pre-treat the variables by removing the seasonality and normalizing them locally (μ=0,σ=1). Additionally we have regionalized the area of study into subregions of similar climate conditions, by using the Köppen climate classification. For each climate region and variable we have selected the best ARMA parameters by means of a Bayesian Criteria. Then we have obtained the residuals by comparing the fitted models with the original data. To detect the extreme residuals from the 10 variables, we have computed the Mahalanobis distance to the data's mean (Hotelling's T^2), which considers the covariance matrix of the joint

  13. When do anomalies begin?

    Science.gov (United States)

    Lightman, Alan; Gingerich, Owen

    1992-02-01

    The present historical and methodological consideration of scientific anomalies notes that some of these are recognized as such, after long neglect, only after the emergence of compelling explanations for their presence in the given theory in view of an alternative conceptual framework. These cases of 'retrorecognition' are indicative not merely of a significant characteristic of the process of conceptual development and scientific discovery, but of the bases for such process in human psychology. Attention is given to the illustrative cases of the 'flatness problem' in big bang theory, the perigee-opposition problem in Ptolemaic astronomy, the continental-fit problem in geology, and the equality of inertial and gravitational mass.

  14. The diphoton anomaly

    Science.gov (United States)

    Nardecchia, M.

    2017-07-01

    In December 2015, the ATLAS and CMS Collaborations presented results from data taken at the LHC with pp collisions at the center-of-mass energy of √{s} = 13{ TeV} . In the search for resonances decaying into two photons, both experiments observed a tantalising excess of events at an invariant mass of the photon pair of 750GeV. In this contribution, I will summarise some of the main phenomenological and theoretical aspects of this anomaly in terms of New Physics.

  15. Urinary System anomalies at birth

    Directory of Open Access Journals (Sweden)

    Sharada B. Menasinkai

    2015-06-01

    Full Text Available Background: Congenital anomalies of urinary system are common and are found in 3-4% of population, and lethal urinary anomalies account for 10% of termination of pregnancy. Methods: A study was done to know the incidence of congenital anomalies at birth for the period of 4 months from May 99 - Sept 99 at Cheluvamba hospital attached to Mysore medical college. Congenital anomalies in the still births, live births and aborted fetuses >20 weeks were studied along with the case history and ultrasound reports. Aborted fetuses and still born babies were collected for autopsy after the consent of parents. These babies were fixed in 10% formalin and autopsy was done after fixing, and anomalies were noted. Results: Total births during study period were 3000. There were 61 babies with congenital anomalies and 6 babies had anomalies of urinary system. Among the urinary system anomalies 1 baby had bilateral renal agenesis, 1 baby had unilateral renal agenesis with anophthalmia (Fraser syndrome, 2 babies had Multicystic dysplastic kidney disease (MCDK and 1 live baby had hydronephrosis due to obstruction at pelvi ureteric junction, and 1 live female baby had polycystic kidneys. Conclusion: Incidence of urinary system anomalies in the present study was 2 per 1000 births. U/S detection of urinary anomalies varies with period of gestation, amniotic fluid volume and visualisation of urinary bladder. Autopsy helps to detect renal agenesis. [Int J Res Med Sci 2015; 3(3.000: 743-748

  16. Deep learning on temporal-spectral data for anomaly detection

    Science.gov (United States)

    Ma, King; Leung, Henry; Jalilian, Ehsan; Huang, Daniel

    2017-05-01

    Detecting anomalies is important for continuous monitoring of sensor systems. One significant challenge is to use sensor data and autonomously detect changes that cause different conditions to occur. Using deep learning methods, we are able to monitor and detect changes as a result of some disturbance in the system. We utilize deep neural networks for sequence analysis of time series. We use a multi-step method for anomaly detection. We train the network to learn spectral and temporal features from the acoustic time series. We test our method using fiber-optic acoustic data from a pipeline.

  17. State-selective electron-capture measurements for N4+-H and N4+-H-2 collisions

    NARCIS (Netherlands)

    Bliek, FW; Woestenenk, GR; Hoekstra, R; Morgenstern, R

    1998-01-01

    State-selective electron-capture cross-section measurements in the energy range between 1 and 4 keV/amu are reported for collisions between N4+ ions and atomic and molecular hydrogen. The cross sections are measured in a crossed-beam experiment by means of photon emission spectroscopy. The singlet a

  18. Data Mining for Anomaly Detection

    Science.gov (United States)

    Biswas, Gautam; Mack, Daniel; Mylaraswamy, Dinkar; Bharadwaj, Raj

    2013-01-01

    The Vehicle Integrated Prognostics Reasoner (VIPR) program describes methods for enhanced diagnostics as well as a prognostic extension to current state of art Aircraft Diagnostic and Maintenance System (ADMS). VIPR introduced a new anomaly detection function for discovering previously undetected and undocumented situations, where there are clear deviations from nominal behavior. Once a baseline (nominal model of operations) is established, the detection and analysis is split between on-aircraft outlier generation and off-aircraft expert analysis to characterize and classify events that may not have been anticipated by individual system providers. Offline expert analysis is supported by data curation and data mining algorithms that can be applied in the contexts of supervised learning methods and unsupervised learning. In this report, we discuss efficient methods to implement the Kolmogorov complexity measure using compression algorithms, and run a systematic empirical analysis to determine the best compression measure. Our experiments established that the combination of the DZIP compression algorithm and CiDM distance measure provides the best results for capturing relevant properties of time series data encountered in aircraft operations. This combination was used as the basis for developing an unsupervised learning algorithm to define "nominal" flight segments using historical flight segments.

  19. Coulomb branches for rank 2 gauge groups in 3d N=4 gauge theories

    CERN Document Server

    Hanany, Amihay

    2016-01-01

    The Coulomb branch of 3-dimensional N=4 gauge theories is the space of bare and dressed BPS monopole operators. We utilise the conformal dimension to define a fan which, upon intersection with the weight lattice of a GNO-dual group, gives rise to a collection of semi-groups. It turns out that the unique Hilbert bases of these semi-groups are a sufficient, finite set of monopole operators which generate the entire chiral ring. Moreover, the knowledge of the properties of the minimal generators is enough to compute the Hilbert series explicitly. The techniques of this paper allow an efficient evaluation of the Hilbert series for general rank gauge groups. As an application, we provide various examples for all rank two gauge groups to demonstrate the novel interpretation.

  20. Coulomb branches for rank 2 gauge groups in 3dN=4 gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Hanany, Amihay [Theoretical Physics Group, Imperial College London,Prince Consort Road, London, SW7 2AZ (United Kingdom); Sperling, Marcus [Institut für Theoretische Physik, Leibniz Universität Hannover,Appelstraße 2, 30167 Hannover (Germany)

    2016-08-02

    The Coulomb branch of 3-dimensional N=4 gauge theories is the space of bare and dressed BPS monopole operators. We utilise the conformal dimension to define a fan which, upon intersection with the weight lattice of a GNO-dual group, gives rise to a collection of semi-groups. It turns out that the unique Hilbert bases of these semi-groups are a sufficient, finite set of monopole operators which generate the entire chiral ring. Moreover, the knowledge of the properties of the minimal generators is enough to compute the Hilbert series explicitly. The techniques of this paper allow an efficient evaluation of the Hilbert series for general rank gauge groups. As an application, we provide various examples for all rank two gauge groups to demonstrate the novel interpretation.

  1. Preface: Graphene and C3N4-based photocatalysts

    Science.gov (United States)

    Yu, Jiaguo; Jaroniec, Mietek

    2015-12-01

    In recent years, 2D layered materials including graphene and g-C3N4 have attracted more and more attention in the field of photocatalysis and have become the research hotspots due to their broad applications in energy and environment-related areas. A critical appraisal of recent developments related to these important materials was the main theme of the 1st International Workshop on Graphene and C3N4-based Photocatalysts (IWGCP) held at the Wuhan University of Technology, Wuhan, China on June 5-8, 2015. This workshop was jointly organized by Wuhan University of Technology, Jianghan University and Changsha University, China. More than 140 scientists from four continents (Asia, America, Australia and Europe) participated in this workshop, the agenda of which included 8 plenary lectures, 17 keynote lectures, 11 invited lectures, 6 oral presentations and 61 posters.

  2. Integrability of Smooth Wilson Loops in N=4 Superspace

    CERN Document Server

    Beisert, Niklas; Plefka, Jan; Vergu, Cristian

    2015-01-01

    We perform a detailed study of the Yangian symmetry of smooth supersymmetric Maldacena-Wilson loops in planar N=4 super Yang-Mills theory. This hidden symmetry extends the global superconformal symmetry present for these observables. A gauge-covariant action of the Yangian generators on the Wilson line is established that generalizes previous constructions built upon path variations. Employing these generators the Yangian symmetry is proven for general paths in non-chiral N=4 superspace at the first perturbative order. The bi-local piece of the level-one generators requires the use of a regulator due to divergences in the coincidence limit. We perform regularization by point splitting in detail, thereby constructing additional local and boundary contributions as regularization for all level-one Yangian generators. Moreover, the Yangian algebra at level one is checked and compatibility with local kappa-symmetry is established. Finally, the consistency of the Yangian symmetry is shown to depend on two propertie...

  3. Drag force in a charged N = 4 SYM plasma

    Energy Technology Data Exchange (ETDEWEB)

    Caceres, Elena [Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima (Mexico); Gueijosa, Alberto [Departamento de Fisica de Altas Energias, Instituto de Ciencias Nucleares, Universidad Autonoma de Mexico, Apdo. Postal 70-543, D.F. 04510 (Mexico)

    2006-11-15

    Following recent developments, we employ the AdS/CFT correspondence to determine the drag force exerted on an external quark that moves through an N = 4 super-Yang-Mills plasma with a non-zero R-charge density (or, equivalently, a non-zero chemical potential). We find that the drag force is larger than in the case where the plasma is neutral, but the dependence on the charge is non-monotonic.

  4. Quark-anti-quark potential in N = 4 SYM

    Science.gov (United States)

    Gromov, Nikolay; Levkovich-Maslyuk, Fedor

    2016-12-01

    We construct a closed system of equations describing the quark-anti-quark potential at any coupling in planar N = 4 supersymmetric Yang-Mills theory. It is based on the Quantum Spectral Curve method supplemented with a novel type of asymptotics. We present a high precision numerical solution reproducing the classical and one-loop string predictions very accurately. We also analytically compute the first 7 nontrivial orders of the weak coupling expansion.

  5. N >= 4 Supergravity Amplitudes from Gauge Theory at One Loop

    CERN Document Server

    Bern, Z; Johansson, H

    2011-01-01

    We expose simple and practical relations between the integrated four- and five-point one-loop amplitudes of N >= 4 supergravity and the corresponding (super-)Yang-Mills amplitudes. The link between the amplitudes is simply understood using the recently uncovered duality between color and kinematics that leads to a double-copy structure for gravity. These examples provide additional direct confirmations of the duality and double-copy properties at loop level for a sample of different theories.

  6. Higher-Loop Integrability in N=4 Gauge Theory

    CERN Document Server

    Beisert, N

    2004-01-01

    The dilatation operator measures scaling dimensions of local operator in a conformal field theory. Algebraic methods of constructing the dilatation operator in four-dimensional N=4 gauge theory are reviewed. These led to the discovery of novel integrable spin chain models in the planar limit. Making use of Bethe ansaetze, a superficial discrepancy in the AdS/CFT correspondence was found, we discuss this issue and give a possible resolution.

  7. N=4 superconformal Ward identities for correlation functions

    Directory of Open Access Journals (Sweden)

    A.V. Belitsky

    2016-03-01

    Full Text Available In this paper we study the four-point correlation function of the energy–momentum supermultiplet in theories with N=4 superconformal symmetry in four dimensions. We present a compact form of all component correlators as an invariant of a particular abelian subalgebra of the N=4 superconformal algebra. This invariant is unique up to a single function of the conformal cross-ratios which is fixed by comparison with the correlation function of the lowest half-BPS scalar operators. Our analysis is independent of the dynamics of a specific theory, in particular it is valid in N=4 super Yang–Mills theory for any value of the coupling constant. We discuss in great detail a subclass of component correlators, which is a crucial ingredient for the recent study of charge-flow correlations in conformal field theories. We compute the latter explicitly and elucidate the origin of the interesting relations among different types of flow correlations previously observed in arXiv:1309.1424.

  8. New Results on N=4 SuperYang-Mills Theory

    CERN Document Server

    Baulieu, L; Baulieu, Laurent; Bossard, Guillaume

    2005-01-01

    The N=4 SuperYang--Mills theory is covariantly determined by a U(1) \\times SU(2) \\subset SL(2,R) \\times SU(2) internal symmetry and two scalar and one vector BRST topological symmetry operators. This determines an off-shell closed sector of N=4 SuperYang-Mills, with 6 generators, which is big enough to fully determine the theory, in a Lorentz covariant way. This reduced algebra derives from horizontality conditions in four dimensions. The horizontality conditions only depend on the geometry of the Yang-Mills fields. They also descend from a genuine horizontality condition in eight dimensions. In fact, the SL(2,R) symmetry is induced by a dimensional reduction from eight to seven dimensions, which establishes a ghost-antighost symmetry, while the SU(2) symmetry occurs by dimensional reduction from seven to four dimensions. When the four dimensional manifold is hyperKahler, one can perform a twist operation that defines the N=4 supersymmetry and its SL(2,H)\\sim SU(4) R-symmetry in flat space. (For defining a TQ...

  9. Quivers via anomaly chains

    Energy Technology Data Exchange (ETDEWEB)

    Casero, Roberto [Dipartimento di Fisica, Universita di Milano-Bicocca, Piazza della Scienza, 3, 20126 Milan (Italy)]. E-mail: roberto.casero@mib.infn.it; Trincherini, Enrico [Dipartimento di Fisica, Universita di Milano-Bicocca, Piazza della Scienza, 3, 20126 Milan (Italy)

    2003-09-01

    We study quivers in the context of matrix models. We introduce chains of generalized Konishi anomalies to write the quadratic and cubic equations that constrain the resolvents of general affine A-circumflex{sub n-1} and non-affine A{sub n} quiver gauge theories, and give a procedure to calculate all higher-order relations. For these theories we also evaluate, as functions of the resolvents, VEV's of chiral operators with two and four bi-fundamental insertions. As an example of the general procedure we explicitly consider the two simplest quivers A{sub 2} and A-circumflex{sub 1}, obtaining in the first case a cubic algebraic curve, and for the affine theory the same equation as that of U(N) theories with adjoint matter, successfully reproducing the RG cascade result. (author)

  10. Quivers via anomaly chains

    CERN Document Server

    Casero, R; Casero, Roberto; Trincherini, Enrico

    2003-01-01

    We study quivers in the context of matrix models. We introduce chains of generalized Konishi anomalies to write the quadratic and cubic equations that constrain the resolvents of general affine and non-affine quiver gauge theories, and give a procedure to calculate all higher-order relations. For these theories we also evaluate, as functions of the resolvents, VEV's of chiral operators with two and four bifundamental insertions. As an example of the general procedure we explicitly consider the two simplest quivers A2 and A1(affine), obtaining in the first case a cubic algebraic curve, and for the affine theory the same equation as that of U(N) theories with adjoint matter, successfully reproducing the RG cascade result.

  11. Low Risk Anomalies?

    DEFF Research Database (Denmark)

    Schneider, Paul; Wagner, Christian; Zechner, Josef

    risk, the standard capital asset pricing model (CAPM) increasingly overestimates expected equity returns relative to firms' true (skew-adjusted) market risk. Empirically, the profitability of betting against beta/volatility increases with firms' downside risk, and the risk-adjusted return differential...... of betting against beta/volatility among low skew firms compared to high skew firms is economically large. Our results suggest that the returns to betting against beta or volatility do not necessarily pose asset pricing puzzles but rather that such strategies collect premia that compensate for skew risk......This paper shows theoretically and empirically that beta- and volatility-based low risk anomalies are driven by return skewness. The empirical patterns concisely match the predictions of our model that endogenizes the role of skewness for stock returns through default risk. With increasing downside...

  12. Cubic anomalies in WMAP

    CERN Document Server

    Land, K; Land, Kate; Magueijo, Joao

    2004-01-01

    We perform a frequentist analysis of the bispectrum of WMAP first year data. We find clear signal domination up to l=200, with overall consistency with Gaussianity except for the following features. There is a flat patch (i.e. a low chi-squared region) in the same-l components of the bispectrum spanning the range l=32-62; this may be interpreted as ruling out Gaussianity at the 99.6% confidence level. There is also an asymmetry between the North and South inter-l bispectrum components at the 99% confidence level. The preferred asymmetry axis correlates well with the (l,b)=(57,10) direction quoted in the literature for asymmetries in the power spectrum and three-point correlation function. However our analysis of the quadrupole (its bispectrum and principal axes) fail to make contact with previously claimed anomalies.

  13. Synthesis and Screening of Some New N-Substituted Derivatives of N-(4-Methylpyridin-2-ylbenzenesulfonamides as Potential Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Aziz-ur-Rehman

    2014-03-01

    Full Text Available The two step synthesis of a series of N-substituted derivatives of N-(4-Methylpyridin-2-ylbenzenesulfonamide with potential antibacterial activity, has been reported. First step includes the synthesis of N-(4-Methylpyridin-2-ylbenzenesulfonamide (3 by reaction of 2-Amino-4-methylpyridine (1 and Benzenesulfonyl chloride (2 in a slightly basic aqueous medium. The molecule 3 was converted to N-Alkyl/aralkyl-N-(4-methylpyridin-2-ylbenzenesulfonamide derivatives, 5a-f, on treatment with alkyl/aralkyl halides, 4a-f, using lithium hydride as activator in N,N-dimethylformamide. The synthesized molecules were well corroborated by 1H-NMR, IR and EI-MS spectral data and evaluated for antibacterial activity against four gram-negative and two gram-positive bacteria. The evaluation results rendered these compounds as moderately good inhibitors and may be employed as therapeutic agent for certain inflammatory ailments.

  14. Algebraic study of chiral anomalies

    Indian Academy of Sciences (India)

    Juan Mañes; Raymond Stora; Bruno Zumino

    2012-06-01

    The algebraic structure of chiral anomalies is made globally valid on non-trivial bundles by the introduction of a fixed background connection. Some of the techniques used in the study of the anomaly are improved or generalized, including a systematic way of generating towers of ‘descent equations’.

  15. Anomaly mediation deformed by axion

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Kazunori, E-mail: kazunori@hep-th.phys.s.u-tokyo.ac.jp [Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa 277-8583 (Japan); Yanagida, Tsutomu T. [Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa 277-8583 (Japan)

    2013-05-13

    We show that in supersymmetric axion models the axion supermultiplet obtains a sizable F-term due to a non-supersymmetric dynamics and it generally gives the gaugino masses comparable to the anomaly mediation contribution. Thus the gaugino mass relation predicted by the anomaly mediation effect can be significantly modified in the presence of axion to solve the strong CP problem.

  16. What is a Timing Anomaly?

    DEFF Research Database (Denmark)

    Cassez, Franck; Hansen, Rene Rydhof; Olesen, Mads Chr.

    2012-01-01

    Timing anomalies make worst-case execution time analysis much harder, because the analysis will have to consider all local choices. It has been widely recognised that certain hardware features are timing anomalous, while others are not. However, defining formally what a timing anomaly is, has bee...

  17. Seismic data fusion anomaly detection

    Science.gov (United States)

    Harrity, Kyle; Blasch, Erik; Alford, Mark; Ezekiel, Soundararajan; Ferris, David

    2014-06-01

    Detecting anomalies in non-stationary signals has valuable applications in many fields including medicine and meteorology. These include uses such as identifying possible heart conditions from an Electrocardiography (ECG) signals or predicting earthquakes via seismographic data. Over the many choices of anomaly detection algorithms, it is important to compare possible methods. In this paper, we examine and compare two approaches to anomaly detection and see how data fusion methods may improve performance. The first approach involves using an artificial neural network (ANN) to detect anomalies in a wavelet de-noised signal. The other method uses a perspective neural network (PNN) to analyze an arbitrary number of "perspectives" or transformations of the observed signal for anomalies. Possible perspectives may include wavelet de-noising, Fourier transform, peak-filtering, etc.. In order to evaluate these techniques via signal fusion metrics, we must apply signal preprocessing techniques such as de-noising methods to the original signal and then use a neural network to find anomalies in the generated signal. From this secondary result it is possible to use data fusion techniques that can be evaluated via existing data fusion metrics for single and multiple perspectives. The result will show which anomaly detection method, according to the metrics, is better suited overall for anomaly detection applications. The method used in this study could be applied to compare other signal processing algorithms.

  18. Radiological evaluation congenital gastrointestinal tract anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Hee; Kim, Ock [Hanil Hospital, Seoul (Korea, Republic of); Jang, Jung Wha [Seoul Nationl Hospital, Seoul (Korea, Republic of)

    1983-06-15

    With the improvements, during recent years, in the control of the infections and nutritional diseases the subject of congenital malformation becomes of increasing importance. The radiologic signs are crucial for prompt diagnosis of anomalies of alimentary tract and with early identification of resulting complication, surgical therapy is usually life-saving. 30 cases of congenital anomalies of alimentary tract in infants were reviewed in respect of age, sex, incidence and radiological findings. The results are summarized as follows; 1, The most common lesion was hypertrophic pyloric stenosis, followed by congenital megacolon and anorectal anomaly, tracheoesophageal fistula, intestinal atresia. 2. Male outnumbered female in most congenital anomalies of alimentary tract. 25 cases were under the age of 1 month. 3. Common symptoms of upper gastrointestinal tract obstruction are vomiting and abdominal distension. In the obstruction of lower gastrointestinal tract, abdominal distension and failure of meconium passage were noted. 4. Roentgenologic findings were as follows, a. Chest A-P and lateral view: In tracheoesophageal fistula, saccular dilatation of upper esophagus and displacement of trachea anterolaterally were the most common finding. b. Simple abdomen: Obstructive pattern of proximal portion of duodenum shows in 11 cases, of distal bowel shows in 16 cases. Duodenal atresia showed 'double bubble' sign, hypertrophic pyloric stenosis showed marked gastric distension, paucity of air in small bowel and increases gastric peristalsis were the most common findings. Hirschsprung's disease showed absenced of rectal gas almostly. The variable length between blind hindgut to anus was seen in anorectal anomalies. c. Esophagogram: Blind sac of upper esophagus was seen at the 4th thoracic spinal level and displacement of trachea anterolaterally. 1 case of tracheoesophageal fistula had an intact esophageal lumen. d. Upper G-I series: In hypertrophic pyloric

  19. Integrability in N=4 super Yang-Mills theory

    Energy Technology Data Exchange (ETDEWEB)

    Eden, B. [ITF and Spinoza Institute, University of Utrecht, Minnaertgebouw, Leuvenlaan 4, 3584 CE Utrecht (Netherlands)

    2008-10-15

    We use the Bethe ansatz to calculate the cusp anomalous dimension in planar N=4 super Yang-Mills theory as an exact function of the coupling constant. The calculation allows us to fix the remaining ambiguities in the integrable system describing the spectrum of operators/string energy levels in the AdS/CFT correspondence. The cusp anomalous dimension is not affected by finite size effects, which in general remain ill-understood. We suggest a method for computing the lowest example of an anomalous dimension modified by such corrections.

  20. An N/4 fixed-point duality quantum search algorithm

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Here a fixed-point duality quantum search algorithm is proposed.This algorithm uses iteratively non-unitary operations and measurements to search an unsorted database.Once the marked item is found,the algorithm stops automatically.This algorithm uses a constant non-unitary operator,and requires N/4 steps on average(N is the number of data from the database) to locate the marked state.The implementation of this algorithm in a usual quantum computer is also demonstrated.

  1. Non-unimodular reductions and N=4 gauged supergravities

    Energy Technology Data Exchange (ETDEWEB)

    Petropoulos, P.M. [Centre de Physique Theorique, Ecole Polytechnique, Palaiseau (France)

    2008-08-05

    We analyze the class of four-dimensional N=4 supergravities obtained by gauging the axionic shift and axionic rescaling symmetries. These theories are formulated with the machinery of embedding tensors and shown to be deducible from higher dimensions using a Scherk-Schwarz reduction with a twist by a non-compact symmetry. This allows to evade the usual unimodularity requirement and completes the dictionary between heterotic gaugings and fluxes, at least for the ''geometric sector''. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  2. A Curious Truncation of N=4 Yang-Mills

    CERN Document Server

    Basu, A; Sethi, S; Basu, Anirban; Sethi, Savdeep

    2004-01-01

    The coupling constant dependence of correlation functions of BPS operators in N=4 Yang-Mills can be expressed in terms of integrated correlation functions. We approximate these integrated correlators by using a truncated OPE expansion. This leads to differential equations for the coupling dependence. When applied to a particular sixteen point correlator, the coupling dependence we find agrees with the corresponding amplitude computed via the AdS/CFT correspondence. We conjecture that this truncation becomes exact in the large N and large 't Hooft coupling limit.

  3. A Note on Dual MHV Diagrams in N=4 SYM

    CERN Document Server

    Brandhuber, Andreas; Travaglini, Gabriele; Yang, Gang

    2010-01-01

    Recently a reformulation of the MHV diagram method in N=4 supersymmetric Yang-Mills theory in momentum twistor space was presented and was shown to be equivalent to the perturbative expansion of the expectation value of a supersymmetric Wilson loop in momentum twistor space. In this note we present related explicit Feynman rules in dual momentum space, which should have the interpretation of Wilson loop diagrams in dual momentum space. We show that these novel rules are completely equivalent to ordinary spacetime MHV rules and can be naturally viewed as their graph dual representation.

  4. N=4 Multi-Particle Mechanics, WDVV Equation and Roots

    Directory of Open Access Journals (Sweden)

    Olaf Lechtenfeld

    2011-03-01

    Full Text Available We review the relation of N=4 superconformal multi-particle models on the real line to the WDVV equation and an associated linear equation for two prepotentials, F and U. The superspace treatment gives another variant of the integrability problem, which we also reformulate as a search for closed flat Yang-Mills connections. Three- and four-particle solutions are presented. The covector ansatz turns the WDVV equation into an algebraic condition, for which we give a formulation in terms of partial isometries. Three ideas for classifying WDVV solutions are developed: ortho-polytopes, hypergraphs, and matroids. Various examples and counterexamples are displayed.

  5. Excited hexagon Wilson loops for strongly coupled N=4 SYM

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, J.; Kotanski, J. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Schomerus, V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics and Astronomy

    2010-10-15

    This work is devoted to the six-gluon scattering amplitude in strongly coupled N=4 supersymmetric Yang-Mills theory. At weak coupling, an appropriate high energy limit of the so-called remainder function, i.e. of the deviation from the BDS formula, may be understood in terms of the lowest eigenvalue of the BFKL hamiltonian. According to Alday et al., amplitudes in the strongly coupled theory can be constructed through an auxiliary 1-dimensional quantum system. We argue that certain excitations of this quantum system determine the Regge limit of the remainder function at strong coupling and we compute its precise value. (orig.)

  6. The Algebraic Curve of 1-loop Planar N=4 SYM

    CERN Document Server

    Schafer-Nameki, S

    2004-01-01

    The algebraic curve for the psu (2,2|4) quantum spin chain is determined from the thermodynamic limit of the algebraic Bethe ansatz. The Hamiltonian of this spin chain has been identified with the planar 1-loop dilatation operator of N=4 SYM. In the dual AdS_5 x S^5 string theory, various properties of the data defining the curve for the gauge theory are compared to the ones obtained from semiclassical spinning-string configurations, in particular for the case of strings on AdS_5 x S^1 and the su(2,2) spin chain agreement of the curves is shown.

  7. Aspects of lattice N=4 supersymmetric Yang--Mills

    CERN Document Server

    Schaich, David

    2015-01-01

    Non-perturbative investigations of $\\mathcal N = 4$ supersymmetric Yang--Mills theory formulated on a space-time lattice have advanced rapidly in recent years. Large-scale numerical calculations are currently being carried out based on a construction that exactly preserves a single supersymmetry at non-zero lattice spacing. A recent development is the creation of an improved lattice action through a new procedure to regulate flat directions in a manner compatible with this supersymmetry, by modifying the moduli equations. In this proceedings I briefly summarize this new procedure and discuss the parameter space of the resulting improved action that is now being employed in numerical calculations.

  8. Latest results from lattice N=4 supersymmetric Yang--Mills

    CERN Document Server

    Schaich, David; Damgaard, Poul H; Giedt, Joel

    2016-01-01

    We present some of the latest results from our numerical investigations of N=4 supersymmetric Yang--Mills theory formulated on a space-time lattice. Based on a construction that exactly preserves a single supersymmetry at non-zero lattice spacing, we recently developed an improved lattice action that is now being employed in large-scale calculations. Here we update our studies of the static potential using this new action, also applying tree-level lattice perturbation theory to improve the analysis of the potential itself. Considering relatively weak couplings, we obtain results for the Coulomb coefficient that are consistent with continuum perturbation theory.

  9. Anomaly Mediation and Cosmology

    CERN Document Server

    Basboll, A; Jones, D R T

    2011-01-01

    We consider an extension of the MSSM wherein anomaly mediation is the source of supersymmetry-breaking, and the tachyonic slepton problem is solved by a Fayet-Iliopoulos (FI) $D$-term associated with an additional $U(1)$ symmetry, which also facilitates the see-saw mechanism for neutrino masses and a natural source for the Higgs $\\mu$-term. We explore the cosmological consequences of the model, showing that the model naturally produces a period of hybrid inflation, terminating in the production of cosmic strings. In spite of the presence of a $U(1)$ with an FI term, inflation is effected by the $F$-term, with a $D$-flat tree potential (the FI term being cancelled by non-zero squark and slepton fields). Calculating the 1-loop corrections to the inflaton potential, we estimate the constraints on the parameters of the model from Cosmic Microwave Background data. We briefly discuss the mechanisms for baryogenesis via conventional leptogenesis, the out-of-equilibrium production of neutrinos from the cosmic strings...

  10. Smooth Wilson loops in N=4 non-chiral superspace

    Science.gov (United States)

    Beisert, Niklas; Müller, Dennis; Plefka, Jan; Vergu, Cristian

    2015-12-01

    We consider a supersymmetric Wilson loop operator for 4d N = 4 super Yang-Mills theory which is the natural object dual to the AdS 5 × S 5 superstring in the AdS/CFT correspondence. It generalizes the traditional bosonic 1 /2 BPS Maldacena-Wilson loop operator and completes recent constructions in the literature to smooth (non-light-like) loops in the full N=4 non-chiral superspace. This Wilson loop operator enjoys global super-conformal and local kappa-symmetry of which a detailed discussion is given. Moreover, the finiteness of its vacuum expectation value is proven at leading order in perturbation theory. We determine the leading vacuum expectation value for general paths both at the component field level up to quartic order in anti-commuting coordinates and in the full non-chiral superspace in suitable gauges. Finally, we discuss loops built from quadric splines joined in such a way that the path derivatives are continuous at the intersection.

  11. Integrability of smooth Wilson loops in N=4 superspace

    Science.gov (United States)

    Beisert, Niklas; Müller, Dennis; Plefka, Jan; Vergu, Cristian

    2015-12-01

    We perform a detailed study of the Yangian symmetry of smooth supersymmetric Maldacena-Wilson loops in planar N=4 super Yang-Mills theory. This hidden symmetry extends the global superconformal symmetry present for these observables. A gauge-covariant action of the Yangian generators on the Wilson line is established that generalizes previous constructions built upon path variations. Employing these generators the Yangian symmetry is proven for general paths in non-chiral N=4 superspace at the first perturbative order. The bi-local piece of the level-one generators requires the use of a regulator due to divergences in the coincidence limit. We perform regularization by point splitting in detail, thereby constructing additional local and boundary contributions as regularization for all level-one Yangian generators. Moreover, the Yangian algebra at level one is checked and compatibility with local kappa-symmetry is established. Finally, the consistency of the Yangian symmetry is shown to depend on two properties: the vanishing of the dual Coxeter number of the underlying superconformal algebra and the existence of a novel superspace "G-identity" for the gauge field theory. This tightly constrains the conformal gauge theories to which integrability can possibly apply.

  12. Smooth Wilson Loops in N=4 Non-Chiral Superspace

    CERN Document Server

    Beisert, Niklas; Plefka, Jan; Vergu, Cristian

    2015-01-01

    We consider a supersymmetric Wilson loop operator for 4d N=4 super Yang-Mills theory which is the natural object dual to the AdS_5 x S^5 superstring in the AdS/CFT correspondence. It generalizes the traditional bosonic 1/2 BPS Maldacena-Wilson loop operator and completes recent constructions in the literature to smooth (non-light-like) loops in the full N=4 non-chiral superspace. This Wilson loop operator enjoys global superconformal and local kappa-symmetry of which a detailed discussion is given. Moreover, the finiteness of its vacuum expectation value is proven at leading order in perturbation theory. We determine the leading vacuum expectation value for general paths both at the component field level up to quartic order in anti-commuting coordinates and in the full non-chiral superspace in suitable gauges. Finally, we discuss loops built from quadric splines joined in such a way that the path derivatives are continuous at the intersection.

  13. Impact of maternal body mass index on the antenatal detection of congenital anomalies.

    Science.gov (United States)

    Best, K E; Tennant, P W G; Bell, R; Rankin, J

    2012-11-01

    To investigate the association between maternal body mass index (BMI) and antenatal ultrasound detection of congenital anomalies. Population-based register study. North of England (UK). All pregnancies (n = 3096) associated with a congenital anomaly notified to the Northern Congenital Abnormality Survey (NorCAS) during 2006-2009. Cases with chromosomal and teratogenic anomalies (n = 611) or without information on antenatal scanning (n = 4) were excluded. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for antenatal detection according to maternal BMI categories were estimated using logistic regression. For all anomalies combined, cases were defined as 'detected' if any congenital anomaly was suspected antenatally. Organ system-specific anomalies were defined as detected if an anomaly of the correct system was suspected. Antenatal detection of any anomaly occurred in 1146 of 2483 (46.2%) cases with normal karyotype. The odds of detection were significantly decreased in obese (BMI ≥ 30 kg/m(2)) women compared with women of recommended BMI (18.5-24.9 kg/m(2); aOR, 0.77; 95% CI, 0.60-0.99; P = 0.046). Cardiovascular system anomalies were suspected antenatally in 109 of 945 (11.5%) cases. The odds of detecting a cardiovascular anomaly were significantly greater in underweight women (BMI BMI (aOR, 2.95; 95% CI, 1.13-7.70; P = 0.027). There was no association between BMI and detection in any other organ system or between BMI and termination of pregnancy for fetal anomaly. Antenatal ultrasound detection of a congenital anomaly is decreased in obese pregnant women. This has implications for the scanning and counselling of obese women. © 2012 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2012 RCOG.

  14. First branchial cleft anomalies: presentation, variability and safe surgical management.

    Science.gov (United States)

    Magdy, Emad A; Ashram, Yasmine A

    2013-05-01

    First branchial cleft (FBC) anomalies are uncommon. The aim of this retrospective clinical study is to describe our experience in dealing with these sporadically reported lesions. Eighteen cases presenting with various FBC anomalies managed surgically during an 8-year period at a tertiary referral medical institution were included. Ten were males (56 %) and eight females (44 %) with age range 3-18 years. Anomaly was right-sided in 12 cases (67 %). None were bilateral. Nine patients (50 %) had prior abscess incision and drainage procedures ranging from 1 to 9 times. Two also had previous unsuccessful surgical excisions. Clinical presentations included discharging tract openings in external auditory canal/conchal bowl (n = 9), periauricular (n = 6), or upper neck (n = 4); cystic postauricular, parotid or upper neck swellings (n = 5); and eczematous scars (n = 9). Three distinct anatomical types were encountered: sinuses (n = 7), fistulas (n = 6), and cysts (n = 5). Complete surgical excision required superficial parotidectomy in 11 patients (61 %). Anomaly was deep to facial nerve (FN) in three cases (17 %), in-between its branches in two (11 %) and superficial (but sometimes adherent to the nerve) in remaining cases (72 %). Continuous intraoperative electrophysiological FN monitoring was used in all cases. Two cases had postoperative temporary lower FN paresis that recovered within 2 months. No further anomaly manifestation was observed after 49.8 months' mean postoperative follow-up (range 10-107 months). This study has shown that awareness of different presentations and readiness to identify and protect FN during surgery is essential for successful management of FBC anomalies. Intraoperative electrophysiological FN monitoring can help in that respect.

  15. The effect of scale on the interpretation of geochemical anomalies

    Science.gov (United States)

    Theobald, P.K.; Eppinger, R.G.; Turner, R.L.; Shiquan, S.

    1991-01-01

    The purpose of geochemical surveys changes with scale. Regional surveys identify areas where mineral deposits are most likely to occur, whereas intermediate surveys identify and prioritize specific targets. At detailed scales specific deposit models may be applied and deposits delineated. The interpretation of regional geochemical surveys must take into account scale-dependent difference in the nature and objectives of this type of survey. Overinterpretation of regional data should be resisted, as should recommendations to restrict intermediate or detailed follow-up surveys to the search for specific deposit types or to a too limited suite of elements. Regional surveys identify metallogenic provinces within which a variety of deposit types and metals are most likely to be found. At intermediate scale, these regional provinces often dissipate into discrete clusters of anomalous areas. At detailed scale, individual anomalous areas reflect local conditions of mineralization and may seem unrelated to each other. Four examples from arid environments illustrate the dramatic change in patterns of anomalies between regional and more detailed surveys. On the Arabian Shield, a broad regional anomaly reflects the distribution of highly differentiated anorogenic granites. A particularly prominent part of the regional anomaly includes, in addition to the usual elements related to the granites, the assemblage of Mo, W and Sn. Initial interpretation suggested potential for granite-related, stockwork Mo deposits. Detailed work identified three separate sources for the anomaly: a metal-rich granite, a silicified and stockwork-veined area with scheelite and molybdenite, and scheelite/powellite concentrations in skarn deposits adjacent to a ring-dike complex. Regional geochemical, geophysical and remote-sensing data in the Sonoran Desert, Mexico, define a series of linear features interpreted to reflect fundamental, northeast-trending fractures in the crust that served as the prime

  16. Spatial Correlations of Anomalies of Tropospheric Temperature and Water Vapor, Cloud Cover, and OLR with the El Nino Index

    Science.gov (United States)

    Susskind, Joel; Iredell, Lena; Lee, Jae N.

    2014-01-01

    In this presentation, we will show AIRS Version-6 area weighted anomaly time series over the time period September 2002 through August 2014 of atmospheric temperature and water vapor profiles as a function of height. These anomaly time series show very different behaviors in the stratosphere and in the troposphere. Tropical mean stratospheric temperature anomaly time series are very strongly influenced by the Quasi-Biennial Oscillation (QBO) with large anomalies that propagate downward from 1 mb to 100 mb with a period of about two years. AIRS stratospheric temperature anomalies are in good agreement with those obtained by MLS over a common period. Tropical mean tropospheric temperature profile anomalies appear to be totally disconnected from those of the stratosphere and closely follow El Nino La Nina activity.

  17. Carbon isotope anomalies in carbonates of the Karelian series

    Science.gov (United States)

    Iudovich, Ia. E.; Makarikhin, V. V.; Medvedev, P. V.; Sukhanov, N. V.

    1990-07-01

    Results are presented on carbon isotope distributions in carbonates of the Karelian complex. A highly anomalous isotopic composition was found in carbonate rocks aged from 2.6 to 1.9 b.y. In the stromatolitic carbonates of the Onega water table, delta-(C-13) reaches a value of +18 percent, while the shungite layer of the Zaonega horizon is characterized by a wide dispersion (from +7.9 to -11.8 percent). These data are in good agreement with the known geochemical boundary (about 2.2 b.y. ago) in the history of the earth.

  18. Anomaly Characterization in Flow-Based Traffic Time Series

    NARCIS (Netherlands)

    Sperotto, A.; Sadre, R.; Pras, A.

    2008-01-01

    The increasing number of network attacks causes growing problems for network operators and users. Not only do these attacks pose direct security threats to our infrastructure, but they may also lead to service degradation, due to the massive traffic volume variations that are possible during such at

  19. Effect of Auxiliary Gases on Combustion Synthesis of Si3N4

    Institute of Scientific and Technical Information of China (English)

    Weiping SHEN; Fei WANG; Zhuohui WU; Changchun GE

    2005-01-01

    This paper presents results of combustion synthesis (Self-Propagating High Temperature Synt hesis, SHS) of Si3N4under nitrogen with argon, hydrogen or ammonia. Higher percentages of α-Si3N4 content were obtained in large size cakes in SHS with hydrogen and ammonia than those with argon. Effect of the auxiliary gases for combustion synthesis of Si3N4 on α phase content, on phase transformation of α-Si3N4 toβ-Si3N4 in SHS Si3N4 and on oxygen content in SHS Si3N4 were investigated.

  20. N=4 superconformal n-particle mechanics via superspace

    CERN Document Server

    Krivonos, Sergey; Polovnikov, Kirill

    2008-01-01

    We revisit the (untwisted) superfield approach to one-dimensional multi-particle systems with N=4 superconformal invariance. The requirement of a standard (flat) bosonic kinetic energy implies the existence of inertial (super-)coordinates, which is nontrivial beyond three particles. We formulate the corresponding integrability conditions, whose solution directly yields the superpotential, the two prepotentials and the bosonic potential. The structure equations for the two prepotentials, including the WDVV equation, follow automatically. The general solution for translation-invariant three-particle models is presented and illustrated with examples. For the four-particle case, we take advantage of known WDVV solutions to construct a D_3 and a B_3 model, thus overcoming a previously-found barrier regarding the bosonic potential. The general solution and classification remain a challenge.

  1. On Form Factors in N=4 SYM Theory and Polytopes

    CERN Document Server

    Bork, L V

    2014-01-01

    In this paper we discuss different recursion relations (BCFW and all-line shift) for the form factors of the operators from the $\\mathcal{N}=4$ SYM stress-tensor current supermultiplet $T^{AB}$ in momentum twistor space. We show that cancelations of spurious poles and equivalence between different types of recursion relations can be naturally understood using geometrical interpretation of the form factors as special limit of the volumes of polytopes in $\\mathbb{C}\\mathbb{P}^4$ in close analogy with the amplitude case. We also show how different relations for the IR pole coefficients can be easily derived using momentum twistor representation. This opens an intriguing question - which of powerful on-shell methods and ideas can survive off-shell ?

  2. Tessellating cushions: four-point functions in N=4 SYM

    CERN Document Server

    Eden, Burkhard

    2016-01-01

    We consider a class of planar tree-level four-point functions in N=4 SYM in a special kinematic regime: one BMN operator with two scalar excitations and three half-BPS operators are put onto a line in configuration space; additionally, for the half-BPS operators a co-moving frame is chosen in flavour space. In configuration space, the four-punctured sphere is naturally triangulated by tree-level planar diagrams. We demonstrate on a number of examples that each tile can be associated with a modified hexagon form-factor in such a way as to efficiently reproduce the tree-level four-point function. Our tessellation is not of the OPE type, fostering the hope of finding an independent, integrability-based approach to the computation of planar four-point functions.

  3. The Coulomb Branch of 3d N= 4 Theories

    Science.gov (United States)

    Bullimore, Mathew; Dimofte, Tudor; Gaiotto, Davide

    2017-09-01

    We propose a construction for the quantum-corrected Coulomb branch of a general 3d gauge theory with N=4 supersymmetry, in terms of local coordinates associated with an abelianized theory. In a fixed complex structure, the holomorphic functions on the Coulomb branch are given by expectation values of chiral monopole operators. We construct the chiral ring of such operators, using equivariant integration over BPS moduli spaces. We also quantize the chiral ring, which corresponds to placing the 3d theory in a 2d Omega background. Then, by unifying all complex structures in a twistor space, we encode the full hyperkähler metric on the Coulomb branch. We verify our proposals in a multitude of examples, including SQCD and linear quiver gauge theories, whose Coulomb branches have alternative descriptions as solutions to Bogomolnyi and/or Nahm equations.

  4. Compositional effects on Si3N4 fracture surfaces

    Science.gov (United States)

    Hench, L. L.; Ohuchi, F.; Vaidyanathan, P. N.; Dutta, S.

    1983-01-01

    Surface analysis techniques (X-ray, infrared reflection spectroscopy, Auger electron spectroscopy) applied to the same samples reveal that fracture surfaces of Si3N4 with Y2O3 densification aids possess a higher concentration of oxygen than the bulk. The oxide densification aids thus concentrate in the grain boundaries, and even low-temperature fracture is seen as occurring preferentially within the oxygen-enriched grain boundaries. It is found that increasing the concentrations of Y2O3 and Al2O3 increases the oxygen content of the fracture surface. A range of 13-15 percent Y2O3 + 6 percent Al2O3 gives an amorphous grain-boundary phase that is resistant to devitrification. Fracture occurs through the amorphous phase, and heat treatment at 1000 C has little effect on the amorphous phase.

  5. The exact Schur index of $\\mathcal{N}=4$ SYM

    CERN Document Server

    Bourdier, Jun; Felix, Jan

    2015-01-01

    The Witten index counts the difference in the number of bosonic and fermionic states of a quantum mechanical system. The Schur index, which can be defined for theories with at least $\\mathcal{N}=2$ supersymmetry in four dimensions is a particular refinement of the index, dependent on one parameter $q$ serving as the fugacity for a particular set of charges which commute with the hamiltonian and some supersymmetry generators. This index has a known expression for all Lagrangian and some non-Lagrangian theories as a finite dimensional integral or a complicated infinite sum. In the case of $\\mathcal{N}=4$ SYM with gauge group $U(N)$ we rewrite this as the partition function of a gas of $N$ non interacting and translationally invariant fermions on a circle. This allows us to perform the integrals and write down explicit expressions for fixed $N$ as well as the exact all orders large $N$ expansion.

  6. BPS domain walls in N=4 supergravity and dual flows

    CERN Document Server

    Cassani, Davide; Faedo, Anton F

    2012-01-01

    We establish the conditions for supersymmetric domain wall solutions to N=4 gauged supergravity in five dimensions. These read as BPS first-order equations for the warp factor and the scalar fields, driven by a superpotential and supplemented by a set of constraints that we specify in detail. Then we apply our results to certain consistent truncations of IIB supergravity, thus exploring their dual field theory renormalization group flows. We find a universal flow deforming superconformal theories on D3-branes at Calabi-Yau cones. Moreover, we obtain a superpotential for the solution corresponding to the baryonic branch of the Klebanov-Strassler theory, as well as the superpotential for the flow describing D3 and wrapped D5-branes on the resolved conifold.

  7. N >= 4 Supergravity Amplitudes from Gauge Theory at Two Loops

    Energy Technology Data Exchange (ETDEWEB)

    Boucher-Veronneau, C.; Dixon, L.J.; /SLAC

    2012-02-15

    We present the full two-loop four-graviton amplitudes in N = 4, 5, 6 supergravity. These results were obtained using the double-copy structure of gravity, which follows from the recently conjectured color-kinematics duality in gauge theory. The two-loop four-gluon scattering amplitudes in N = 0, 1, 2 supersymmetric gauge theory are a second essential ingredient. The gravity amplitudes have the expected infrared behavior: the two-loop divergences are given in terms of the squares of the corresponding one-loop amplitudes. The finite remainders are presented in a compact form. The finite remainder for N = 8 supergravity is also presented, in a form that utilizes a pure function with a very simple symbol.

  8. Interior Alaska Bouguer Gravity Anomaly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 1 kilometer Complete Bouguer Anomaly gravity grid of interior Alaska. Only those grid cells within 10 kilometers of a gravity data point have gravity values....

  9. Interior Alaska Bouguer Gravity Anomaly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 1 kilometer Complete Bouguer Anomaly gravity grid of interior Alaska. All grid cells within the rectangular data area (from 61 to 66 degrees North latitude and...

  10. ALP hints from cooling anomalies

    CERN Document Server

    Giannotti, Maurizio

    2015-01-01

    We review the current status of the anomalies in stellar cooling and argue that, among the new physics candidates, an axion-like particle would represent the best option to account for the hinted additional cooling.

  11. Notes on Anomaly Induced Transport

    CERN Document Server

    Landsteiner, Karl

    2016-01-01

    Chiral anomalies give rise to dissipationless transport phenomena such as the chiral magnetic and vortical effects. In these notes I review the theory from a quantum field theoretic, hydrodynamic and holographic perspective. A physical interpretation of the otherwise somewhat obscure concepts of consistent and covariant anomalies will be given. Vanishing of the CME in strict equilibrium will be connected to the boundary conditions in momentum space imposed by the regularization. The role of the gravitational anomaly will be explained. That it contributes to transport in an unexpectedly low order in the derivative expansion can be easiest understood via holography. Anomalous transport is supposed to play also a key role in understanding the electronics of advanced materials, the Dirac- and Weyl (semi)metals. Anomaly related phenomena such as negative magnetoresistivity, anomalous Hall effect, thermal anomalous Hall effect and Fermi arcs can be understood via anomalous transport. Finally I briefly review a holo...

  12. INTERACTIONS OF THE INFRARED BUBBLE N4 WITH ITS SURROUNDINGS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hong-Li; Li, Jin-Zeng; Yuan, Jing-Hua; Huang, Maohai; Huang, Ya-Fang; Zhang, Si-Ju [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Wu, Yuefang [Department of Astronomy, Peking University, 100871 Beijing (China); Liu, Tie [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Dubner, G.; Paron, S.; Ortega, M. E. [1Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Molinari, Sergio [Istituto di Astrofisica e Planetologia Spaziali—IAPS, Istituto Nazionale di Astrofisica—INAF, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Zavagno, Annie; Samal, Manash R., E-mail: hlliu@nao.cas.cn [Aix Marseille Universit, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France)

    2016-02-10

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with H ii regions have been considered to be good samples for investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the H ii region G11.898+0.747, analyzing its interaction with its surroundings and star formation histories therein, with the aim of determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 × 10{sup 22} cm{sup −2}, mean volume density of about 4.4 × 10{sup 4} cm{sup −3}, and a mean mass of 320 M{sub ⊙}. In addition, from PAH emission seen at 8 μm, free–free emission detected at 20 cm, and a probability density function in special regions, we could identify clear signatures of the influence of the H ii region on the surroundings. There are hints of star formation, though further investigation is required to demonstrate that N4 is the triggering source.

  13. Novel anomaly detection approach for telecommunication network proactive performance monitoring

    Institute of Scientific and Technical Information of China (English)

    Yanhua YU; Jun WANG; Xiaosu ZHAN; Junde SONG

    2009-01-01

    The mode of telecommunication network management is changing from "network oriented" to "subscriber oriented". Aimed at enhancing subscribers'feeling, proactive performance monitoring (PPM) can enable a fast fault correction by detecting anomalies designating performance degradation. In this paper, a novel anomaly detection approach is the proposed taking advantage of time series prediction and the associated confidence interval based on multiplicative autoregressive integrated moving average (ARIMA). Furthermore, under the assumption that the training residual is a white noise process following a normal distribution, the associated confidence interval of prediction can be figured out under any given confidence degree 1-α by constructing random variables satisfying t distribution. Experimental results verify the method's effectiveness.

  14. α-Si3N4与γ-Si3N4、α-Si3N4混合粉体超高压烧结的比较研究%Compare Research on Ultra-high Pressure Sintering of α-Si3N4 with Mixed Powder of γ-Si3N4 and α-Si3N4

    Institute of Scientific and Technical Information of China (English)

    姚怀; 徐巧玉; 苌清华; 唐敬友

    2008-01-01

    以Y2O3-Al2O3-La2O3体系作烧结助剂,在5.4~5.7GPa、1620~1770K的高温高压条件下进行了α-Si3N4与γ-Si3N4、α-Si3N4粉体的烧结研究,并探讨了烧结温度及压力对烧结体性能的影响.实验结果表明:α-Si3N4、γ-Si3N4完全相变为βSi3N4;在相同的烧结条件下,α-Si3N4比γ-Si3N4、α-Si3N4混合粉体烧结试样的相对密度、维氏硬度高.α-Si3N4与γ-Si3N4、α-Si3N4混合粉体烧结试样的最高相对密度与维氏硬度分别为98.78%、21.87GPa和98.71%、21.76GPa.烧结体由相互交错的长柱状β-Si3N4晶粒组成,显微结构均匀.

  15. Renormalization group flows and anomalies

    CERN Document Server

    Komargodski, Zohar

    2015-01-01

    This chapter reviews various aspects of renormalization group flows and anomalies. The chapter considers specific Euclidean two-dimensional theories. Namely, the theories are invariant under translations and rotations in the two space directions. Here the chapter studies theories where, if possible, certain equations hold in fact also at coincident points. In other words, the chapter looks at theories where there is no local gravitational anomaly.

  16. Situs anomalies on prenatal MRI.

    Science.gov (United States)

    Nemec, Stefan F; Brugger, Peter C; Nemec, Ursula; Bettelheim, Dieter; Kasprian, Gregor; Amann, Gabriele; Rimoin, David L; Graham, John M; Prayer, Daniela

    2012-04-01

    Situs anomalies refer to an abnormal organ arrangement, which may be associated with severe errors of development. Due regard being given to prenatal magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US), this study sought to demonstrate the in utero visualization of situs anomalies on MRI, compared to US. This retrospective study included 12 fetuses with situs anomalies depicted on fetal MRI using prenatal US as a comparison modality. With an MRI standard protocol, the whole fetus was assessed for anomalies, with regard to the position and morphology of the following structures: heart; venous drainage and aorta; stomach and intestines; liver and gallbladder; and the presence and number of spleens. Situs inversus totalis was found in 3/12 fetuses; situs inversus with levocardia in 1/12 fetuses; situs inversus abdominis in 2/12 fetuses; situs ambiguous with polysplenia in 3/12 fetuses, and with asplenia in 2/12 fetuses; and isolated dextrocardia in 1/12 fetuses. Congenital heart defects (CHDs), vascular anomalies, and intestinal malrotations were the most frequent associated malformations. In 5/12 cases, the US and MRI diagnoses were concordant. Compared to US, in 7/12 cases, additional MRI findings specified the situs anomaly, but CHDs were only partially visualized in six cases. Our initial MRI results demonstrate the visualization of situs anomalies and associated malformations in utero, which may provide important information for perinatal management. Using a standard protocol, MRI may identify additional findings, compared to US, which confirm and specify the situs anomaly, but, with limited MRI visualization of fetal CHDs. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Anomaly detection on cup anemometers

    Science.gov (United States)

    Vega, Enrique; Pindado, Santiago; Martínez, Alejandro; Meseguer, Encarnación; García, Luis

    2014-12-01

    The performances of two rotor-damaged commercial anemometers (Vector Instruments A100 LK) were studied. The calibration results (i.e. the transfer function) were very linear, the aerodynamic behavior being more efficient than the one shown by both anemometers equipped with undamaged rotors. No detection of the anomaly (the rotors’ damage) was possible based on the calibration results. However, the Fourier analysis clearly revealed this anomaly.

  18. Compare Research on Ultra-High Pressure Sintering of α-Si3N4 with Mixed Powder of γ-Si3N4and α-Si3N4%α-Si3 N4与γ-Si3 N4、α-Si3N4混合粉体超高压烧结的比较研究

    Institute of Scientific and Technical Information of China (English)

    姚怀; 徐巧玉; 苌清华; 刘海洋

    2008-01-01

    以Y2O3-Al2O3-La2O3体系作烧结助剂,在5.4~5.7GPa、1620K~1770K的高温高压条件下进行了α-Si3N2与γ-Si3N4、α-Si3N4粉体的烧结研究.探讨了烧结温度及压力对烧结体性能的影响.实验测试结果表明:α-Si3N4、γ-Si3N4完全相变为β-Si3N4,相同的烧结条件下,α-Si3N4比γ-Si3N4、α-Si3N4混合粉体烧结试样的相对密度、维氏硬度高.α-Si3N4与γ-Si3N4、α-Si3N4混合粉体烧结试样的最高相对密度与维氏硬度分别为98.78%、21.87GPa和98.71%、21.76GPa.烧结体由相互交错的长柱状β-Si3N4晶粒组成,显微结构均匀.

  19. Coronary Artery Anomalies in Animals

    Directory of Open Access Journals (Sweden)

    Brian A. Scansen

    2017-04-01

    Full Text Available Coronary artery anomalies represent a disease spectrum from incidental to life-threatening. Anomalies of coronary artery origin and course are well-recognized in human medicine, but have received limited attention in veterinary medicine. Coronary artery anomalies are best described in the dog, hamster, and cow though reports also exist in the horse and pig. The most well-known anomaly in veterinary medicine is anomalous coronary artery origin with a prepulmonary course in dogs, which limits treatment of pulmonary valve stenosis. A categorization scheme for coronary artery anomalies in animals is suggested, dividing these anomalies into those of major or minor clinical significance. A review of coronary artery development, anatomy, and reported anomalies in domesticated species is provided and four novel canine examples of anomalous coronary artery origin are described: an English bulldog with single left coronary ostium and a retroaortic right coronary artery; an English bulldog with single right coronary ostium and transseptal left coronary artery; an English bulldog with single right coronary ostium and absent left coronary artery with a prepulmonary paraconal interventricular branch and an interarterial circumflex branch; and a mixed-breed dog with tetralogy of Fallot and anomalous origin of all coronary branches from the brachiocephalic trunk. Coronary arterial fistulae are also described including a coronary cameral fistula in a llama cria and an English bulldog with coronary artery aneurysm and anomalous shunting vessels from the right coronary artery to the pulmonary trunk. These examples are provided with the intent to raise awareness and improve understanding of such defects.

  20. Si3N4陶瓷球加工工艺的研究%Study on processing technology of Si3N4 ceramics ball

    Institute of Scientific and Technical Information of China (English)

    王泉; 刘秀莲; 葛华伟

    2012-01-01

      According to the Si3N4 material performance, its certain characteristics are favorable for manufacturing rolling element, by researching Si3N4 ceramic ball test processing, the Si3N4 ceramic ball machining process was determined, ceramic ball meeting the G5 level requirements was developed.%  根据Si3N4的材料性能可知其某些特性对制造滚动体是有利的,通过对Si3N4陶瓷球试验加工工艺的研究,确定Si3N4陶瓷球加工工艺,研制出符合G5级要求的陶瓷球。

  1. Interactions of the Infrared bubble N4 with the surroundings

    CERN Document Server

    Liu, Hong-Li; Wu, Yuefang; Yuan, Jing-Hua; Liu, Tie; Dubner, G; Paron, S; Ortega, M E; Molinari, Sergio; Huang, Maohai; Zavagno, Annie; Samal, Manash R; Huang, Ya-Fang; Zhang, Si-Ju

    2016-01-01

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with HII regions have been considered to be a good sample to investigate triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the HII region G11.898+0.747, analyzing its interaction with the surroundings and star formation histories therein, aiming at determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 $\\times10^{22}$ cm$^{-2}$, mean volume density of about 4.4 $\\times10^{4}$ cm$^{-3}$, and a mean mass of 320 $M_{\\odot}$. In addition, from PAH emission seen at 8 $\\mu$m, ...

  2. Null Zig-Zag Wilson Loops in N=4 SYM

    CERN Document Server

    Xie, Zhifeng

    2009-01-01

    In planar ${\\cal N}=4$ supersymmetric Yang-Mills theory we have studied supersymmetric Wilson loops composed of a large number of light-like segments, i.e., null zig-zags. These contours oscillate around smooth underlying spacelike paths. At one-loop in perturbation theory we have compared the finite part of the expectation value of null zig-zags to the finite part of the expectation value of non-scalar-coupled Wilson loops whose contours are the underlying smooth spacelike paths. In arXiv:0710.1060 [hep-th] it was argued that these quantities are equal for the case of a rectangular Wilson loop. Here we present a modest extension of this result to zig-zags of circular shape and zig-zags following non-parallel, disconnected line segments and show analytically that the one-loop finite part is indeed that given by the smooth spacelike Wilson loop without coupling to scalars which the zig-zag contour approximates. We make some comments regarding the generalization to arbitrary shapes.

  3. Null Zig-Zag Wilson Loops in {N}=4 Sym

    Science.gov (United States)

    Xie, Zhifeng

    In planar {N}=4 supersymmetric Yang-Mills theory we have studied one kind of (locally) BPS Wilson loops composed of a large number of light-like segments, i.e. null zig-zags. These contours oscillate around smooth underlying spacelike paths. At one-loop in perturbation theory, we have compared the finite part of the expectation value of null zig-zags to the finite part of the expectation value of non-scalar-coupled Wilson loops whose contours are the underlying smooth spacelike paths. In arXiv:0710.1060 [hep-th] it was argued that these quantities are equal for the case of a rectangular Wilson loop. Here we present a modest extension of this result to zig-zags of circular shape and zig-zags following non-parallel, disconnected line segments and show analytically that the one-loop finite part is indeed that given by the smooth spacelike Wilson loop without coupling to scalars which the zig-zag contour approximates. We make some comments regarding the generalization to arbitrary shapes.

  4. Analytic two-loop form factors in N=4 SYM

    CERN Document Server

    Brandhuber, Andreas; Yang, Gang

    2012-01-01

    We derive a compact expression for the three-point MHV form factors of half-BPS operators in N=4super Yang-Mills at two loops. The main tools of our calculation are generalised unitarity applied at the form factor level, and the compact expressions for supersymmetric tree-level form factors and amplitudes entering the cuts. We confirm that infrared divergences exponentiate as expected, and that collinear factorisation is entirely captured by an ABDK/BDS ansatz. Next, we construct the two-loop remainder function obtained by subtracting this ansatz from the full two-loop form factor and compute it numerically. Using symbology, combined with various physical constraints and symmetries, we find a unique solution for its symbol. With this input we construct a remarkably compact analytic expression for the remainder function, which contains only classical polylogarithms, and compare it to our numerical results. Furthermore, we make the surprising observation that our remainder is equal to the maximally transcendent...

  5. Chiral 2D "Strange Metals" from N = 4 SYM

    CERN Document Server

    Berkooz, Micha; Zait, Amir

    2014-01-01

    Familiar field theories may contain closed subsectors made out of only fermions, which can be used to explore new and unusual phases of matter in lower dimensions. We focus on the fermionic su(1,1) sector in N=4 SYM and on its ground states, which are Fermi surface states/operators. By computing their spectrum to order $(g_{YM}^2 N)^2$, we argue that fluctuations around this fermi surface, within the sector and in the limit $k_F\\rightarrow\\infty$, are governed by a chiral 1+1 dimensional sector of the "strange metal" coset $SU(N)_N \\otimes SU(N)_N/SU(N)_{2N}$. On the gravity side, the conjectured dual configuration is an $S=0$ degeneration of a rotating black hole. On general grounds we expect that the near horizon excitations of $(S=0,\\Omega=1,J\\rightarrow\\infty)$ degenerations of black holes will be governed by a chiral sector of a 1+1 CFT.

  6. Resummation and S-duality in N=4 SYM

    CERN Document Server

    Beem, Christopher; Sen, Ashoke; van Rees, Balt C

    2013-01-01

    We consider the problem of resumming the perturbative expansions for anomalous dimensions of low twist, non-BPS operators in four dimensional N=4 supersymmetric Yang-Mills theories. The requirement of S-duality invariance imposes considerable restrictions on any such resummation. We introduce several prescriptions that produce interpolating functions on the upper half plane that are compatible with a subgroup of the full duality group. These lead to predictions for the anomalous dimensions at all points in the fundamental domain of the complex gauge coupling, and in particular at the duality-invariant values \\tau=i and \\tau=exp(i\\pi/3). For low-rank gauge groups, the predictions are compatible with the bounds derived by conformal bootstrap methods for these anomalous dimensions; within numerical errors, they are in good agreement with the conjecture that said bounds are saturated at a duality-invariant point. We also find that the anomalous dimensions of the lowest twist operators lie within an extremely narr...

  7. Bootstrap equations for $\\mathcal{N}=4$ SYM with defects

    CERN Document Server

    Liendo, Pedro

    2016-01-01

    This paper focuses on the analysis of $4d$ $\\mathcal{N}=4$ superconformal theories in the presence of a defect from the point of view of the conformal bootstrap. We will concentrate first on the case of codimension one, where the defect is a boundary that preserves half of the supersymmetry. After studying the constraints imposed by supersymmetry, we will write the Ward identities associated to two-point functions of $\\tfrac{1}{2}$-BPS operators and write their solution as a superconformal block expansion. Due to a surprising connection between spacetime and R-symmetry conformal blocks, our results not only apply to $4d$ $\\Nm=4$ superconformal theories with a boundary, but also to three more systems that have the same symmetry algebra: $4d$ $\\Nm=4$ superconformal theories with a line defect, $3d$ $\\Nm=4$ superconformal theories with no defect, and $OSP(4^*|4)$ superconformal quantum mechanics. The superconformal algebra implies that all these systems possess a closed subsector of operators in which the bootst...

  8. Fourier series

    CERN Document Server

    Tolstov, Georgi P

    1962-01-01

    Richard A. Silverman's series of translations of outstanding Russian textbooks and monographs is well-known to people in the fields of mathematics, physics, and engineering. The present book is another excellent text from this series, a valuable addition to the English-language literature on Fourier series.This edition is organized into nine well-defined chapters: Trigonometric Fourier Series, Orthogonal Systems, Convergence of Trigonometric Fourier Series, Trigonometric Series with Decreasing Coefficients, Operations on Fourier Series, Summation of Trigonometric Fourier Series, Double Fourie

  9. Highly Enhanced Photoreductive Degradation of Polybromodiphenyl Ethers with g-C3N4/TiO2 under Visible Light Irradiation

    Directory of Open Access Journals (Sweden)

    Weidong Ye

    2017-04-01

    Full Text Available A series of high activity photocatalysts g-C3N4-TiO2 were synthesized by simple one-pot thermal transformation method and characterized by transmission electron microscopy (TEM, scanning electron microscopy (SEM, X-ray diffraction (XRD, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller (BET surface area, and ultraviolet–visible diffuse reflectance spectroscopy (UV-Vis-DRS. The g-C3N4-TiO2 samples show highly improved photoreductive capability for the degradation of polybromodiphenyl ethers compared with g-C3N4 under visible light irradiation. Among all the hybrids, 0.02-C3N4-TiO2 with 2 wt % g-C3N4 loaded shows the highest reaction rate, which is 15 times as high as that in bare g-C3N4. The well-matched band gaps in heterojunction g-C3N4-TiO2 not only strengthen the absorption intensity, but also show more effective charge carrier separation, which results in the highly enhanced photoreductive performance under visible light irradiation. The trapping experiments show that holetrapping agents largely affect the reaction rate. The rate of electron accumulation in the conductive band is the rate-determining step in the degradation reaction. A possible photoreductive mechanism has been proposed.

  10. Evaluation of the Properties of Si3N4/Si3N4 Joint Brazed Using a Filler Alloy Containing Pd

    Institute of Scientific and Technical Information of China (English)

    M. Naka; Jie ZHANG; Yu ZHOU

    2003-01-01

    Si3N4 ceramic was jointed to itself using a filler alloy of Cu76.5Pd8.5Ti15, and the mechanical properties of the jointwere measured and analyzed. By using a filler alloy of Cu76.5Pd8.5Ti15, the SisN4/SisN4 joints were obtained bybrazing at 1373~1473 K f

  11. Hybridized and isosteric analogues of N1-acetyl-N4-dimethyl-piperazinium iodide (ADMP) and N1-phenyl-N4-dimethyl-piperazinium iodide (DMPP) with central nicotinic action.

    Science.gov (United States)

    Manetti, D; Bartolini, A; Borea, P A; Bellucci, C; Dei, S; Ghelardini, C; Gualtieri, F; Romanelli, M N; Scapecchi, S; Teodori, E; Varani, K

    1999-03-01

    A series of piperazine derivatives, obtained by hybridization of N1-acetyl-N4-dimethyl-piperazinium iodide (1, ADMP) and N1-phenyl-N4-dimethyl-piperazinium iodide (3, DMPP) or of the corresponding tertiary bases (2, 4) with arecoline (5) and arecolone (6) or by isosteric substitution of the phenyl ring of DMPP, has been synthesized. Hybridization afforded compounds that, both as tertiary bases and as iodomethylates, have no affinity for the nicotinic receptor. On the contrary, isosteric substitution gave compounds that maintain affinity for the receptor; among them, two tertiary bases (37, 38), show affinity in the nanomolar range for the nicotinic receptor. The pharmacological profile of these isomeric compounds is quite interesting as they present differences in their peripheral and central effects, suggesting that they interact with different subtypes of the nicotinic receptor.

  12. Si3N4陶瓷与Si3N4陶瓷及金属连接的研究进展%Progression of the Joining of Si3N4 Ceramic to Si3N4 Ceramic and to Metal

    Institute of Scientific and Technical Information of China (English)

    曹优明; 郑仕远

    2002-01-01

    对Si3N4陶瓷与Si3N4陶瓷、Si3N4陶瓷与金属的连接工艺进展进行了系统的介绍,重点评述了Si3N4直接钎焊法、Si3N4间接钎焊法、Si3N4陶瓷玻璃焊法的研究进展,并提出了今后研究的重点.

  13. On the Constant Metric Dimension of Generalized Petersen Graphs P (n, 4)

    Institute of Scientific and Technical Information of China (English)

    Saba NAZ; Muhammad SALMAN; Usman ALI; Imran JAVAID; Syed Ahtsham-ul-Haq; BOKHARY

    2014-01-01

    In this paper, we consider the family of generalized Petersen graphs P (n, 4). We prove that the metric dimension of P (n, 4) is 3 when n≡0 (mod 4), and is 4 when n=4k+3 (k is even). For n ≡ 1, 2 (mod 4) and n = 4k+3 (k is odd), we prove that the metric dimension of P (n, 4) is bounded above by 4. This shows that each graph of the family of generalized Petersen graphs P (n, 4) has constant metric dimension.

  14. Si3N4薄膜的成分与结构研究%Study on composition and structure of Si3N4 film

    Institute of Scientific and Technical Information of China (English)

    赵毅红; 陈荣发; 刘伯实

    2004-01-01

    通过PECVD方法,在Si基体表面制备了Si3N4薄膜,给出了XRD、TEM、AES、DPS的分析结果,表明Si3N4是非晶态结构,薄膜的主要成分是Si3N4,SEM分析结果显示Si3N4薄膜与基体材料的结合强度高,薄膜致密性好.

  15. Detection of data taking anomalies for the ATLAS experiment

    CERN Document Server

    De Castro Vargas Fernandes, Julio; The ATLAS collaboration; Lehmann Miotto, Giovanna

    2015-01-01

    The physics signals produced by the ATLAS detector at the Large Hadron Collider (LHC) at CERN are acquired and selected by a distributed Trigger and Data AcQuistition (TDAQ) system, comprising a large number of hardware devices and software components. In this work, we focus on the problem of online detection of anomalies along the data taking period. Anomalies, in this context, are defined as an unexpected behaviour of the TDAQ system that result in a loss of data taking efficiency: the causes for those anomalies may come from the TDAQ itself or from external sources. While the TDAQ system operates, it publishes several useful information (trigger rates, dead times, memory usage…). Such information over time creates a set of time series that can be monitored in order to detect (and react to) problems (or anomalies). Here, we approach TDAQ operation monitoring through a data quality perspective, i.e, an anomaly is seen as a loss of quality (an outlier) and it is reported: this information can be used to rea...

  16. Network traffic anomaly prediction using Artificial Neural Network

    Science.gov (United States)

    Ciptaningtyas, Hening Titi; Fatichah, Chastine; Sabila, Altea

    2017-03-01

    As the excessive increase of internet usage, the malicious software (malware) has also increase significantly. Malware is software developed by hacker for illegal purpose(s), such as stealing data and identity, causing computer damage, or denying service to other user[1]. Malware which attack computer or server often triggers network traffic anomaly phenomena. Based on Sophos's report[2], Indonesia is the riskiest country of malware attack and it also has high network traffic anomaly. This research uses Artificial Neural Network (ANN) to predict network traffic anomaly based on malware attack in Indonesia which is recorded by Id-SIRTII/CC (Indonesia Security Incident Response Team on Internet Infrastructure/Coordination Center). The case study is the highest malware attack (SQL injection) which has happened in three consecutive years: 2012, 2013, and 2014[4]. The data series is preprocessed first, then the network traffic anomaly is predicted using Artificial Neural Network and using two weight update algorithms: Gradient Descent and Momentum. Error of prediction is calculated using Mean Squared Error (MSE) [7]. The experimental result shows that MSE for SQL Injection is 0.03856. So, this approach can be used to predict network traffic anomaly.

  17. Resurgent Transseries and the Holomorphic Anomaly

    CERN Document Server

    Santamaría, Ricardo Couso; Schiappa, Ricardo; Vonk, Marcel

    2013-01-01

    The gauge theoretic large N expansion yields an asymptotic series which requires a nonperturbative completion in order to be well defined. Recently, within the context of random matrix models, it was shown how to build resurgent transseries solutions encoding the full nonperturbative information beyond the 't Hooft genus expansion. On the other hand, via large N duality, random matrix models may be holographically described by B-model closed topological strings in local Calabi-Yau geometries. This raises the question of constructing the corresponding holographically dual resurgent transseries, tantamount to nonperturbative topological string theory. This paper addresses this point by showing how to construct resurgent transseries solutions to the holomorphic anomaly equations. These solutions are built upon (generalized) multi-instanton sectors, where the instanton actions are holomorphic. The asymptotic expansions around the multi-instanton sectors have both holomorphic and anti-holomorphic dependence, may a...

  18. Shortening Anomalies in Supersymmetric Theories

    CERN Document Server

    Gomis, Jaume; Ooguri, Hirosi; Seiberg, Nathan; Wang, Yifan

    2016-01-01

    We present new anomalies in two-dimensional ${\\mathcal N} =(2, 2)$ superconformal theories. They obstruct the shortening conditions of chiral and twisted chiral multiplets at coincident points. This implies that marginal couplings cannot be promoted to background super-fields in short representations. Therefore, standard results that follow from ${\\mathcal N} =(2, 2)$ spurion analysis are invalidated. These anomalies appear only if supersymmetry is enhanced beyond ${\\mathcal N} =(2, 2)$. These anomalies explain why the conformal manifolds of the K3 and $T^4$ sigma models are not K\\"ahler and do not factorize into chiral and twisted chiral moduli spaces and why there are no ${\\mathcal N} =(2, 2)$ gauged linear sigma models that cover these conformal manifolds. We also present these results from the point of view of the Riemann curvature of conformal manifolds.

  19. Boundary terms of conformal anomaly

    Directory of Open Access Journals (Sweden)

    Sergey N. Solodukhin

    2016-01-01

    Full Text Available We analyze the structure of the boundary terms in the conformal anomaly integrated over a manifold with boundaries. We suggest that the anomalies of type B, polynomial in the Weyl tensor, are accompanied with the respective boundary terms of the Gibbons–Hawking type. Their form is dictated by the requirement that they produce a variation which compensates the normal derivatives of the metric variation on the boundary in order to have a well-defined variational procedure. This suggestion agrees with recent findings in four dimensions for free fields of various spins. We generalize this consideration to six dimensions and derive explicitly the respective boundary terms. We point out that the integrated conformal anomaly in odd dimensions is non-vanishing due to the boundary terms. These terms are specified in three and five dimensions.

  20. Multiple Visceral and Peritoneal Anomalies

    Directory of Open Access Journals (Sweden)

    Gayathri Prabhu S

    2016-07-01

    Full Text Available Visceral and peritoneal anomalies are frequently encountered during cadaveric dissections and surgical procedures of abdomen. A thorough knowledge of the same is required for the success of diagnostic, surgical and radiological procedures of abdomen. We report multiple peritoneal and visceral anomalies noted during dissection classes for medical undergraduates. The anomalies were found in an adult male cadaver aged approximately 70 years. The right iliac fossa was empty due to the sub-hepatic position of caecum and appendix. The sigmoid colon formed an inverted “U” shaped loop above the sacral promontory in the median position. It entered the pelvis from the right side and descended along the lateral wall of the pelvis. The sigmoid mesocolon was attached obliquely to the posterior abdominal wall, just above the sacral promontory. Further there was a cysto-colic fold of peritoneum extending from the right colic flexure. We discuss the clinical significance of the variations.

  1. Electromagnetic Duality and Entanglement Anomalies

    CERN Document Server

    Donnelly, William; Wall, Aron

    2016-01-01

    Duality is an indispensable tool for describing the strong-coupling dynamics of gauge theories. However, its actual realization is often quite subtle: quantities such as the partition function can transform covariantly, with degrees of freedom rearranged in a nonlocal fashion. We study this phenomenon in the context of the electromagnetic duality of abelian $p$-forms. A careful calculation of the duality anomaly on an arbitrary $D$-dimensional manifold shows that the effective actions agree exactly in odd $D$, while in even $D$ they differ by a term proportional to the Euler number. Despite this anomaly, the trace of the stress tensor agrees between the dual theories. We also compute the change in the vacuum entanglement entropy under duality, relating this entanglement anomaly to the duality of an "edge mode" theory in two fewer dimensions. Previous work on this subject has led to conflicting results; we explain and resolve these discrepancies.

  2. Conformal Anomalies and Gravitational Waves

    CERN Document Server

    Meissner, Krzysztof A

    2016-01-01

    We argue that the presence of conformal anomalies in gravitational theories can lead to observable modifications to Einstein's equations via the induced anomalous effective actions, whose non-localities can overwhelm the smallness of the Planck scale. The fact that no such effects have been seen in recent cosmological or gravitational wave observations therefore imposes strong restrictions on the field content of possible extensions of Einstein's theory: all viable theories should have vanishing conformal anomalies. We then show that, among presently known theories, a complete cancellation of conformal anomalies in $D=4$ for both the $C^2$ invariant and the Euler (Gauss-Bonnet) invariant $E_4$ can only be achieved for $N$-extended supergravities with $N\\geq 5$, as well as for M theory compactified to four dimensions.

  3. Boundary terms of conformal anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Solodukhin, Sergey N., E-mail: Sergey.Solodukhin@lmpt.univ-tours.fr

    2016-01-10

    We analyze the structure of the boundary terms in the conformal anomaly integrated over a manifold with boundaries. We suggest that the anomalies of type B, polynomial in the Weyl tensor, are accompanied with the respective boundary terms of the Gibbons–Hawking type. Their form is dictated by the requirement that they produce a variation which compensates the normal derivatives of the metric variation on the boundary in order to have a well-defined variational procedure. This suggestion agrees with recent findings in four dimensions for free fields of various spins. We generalize this consideration to six dimensions and derive explicitly the respective boundary terms. We point out that the integrated conformal anomaly in odd dimensions is non-vanishing due to the boundary terms. These terms are specified in three and five dimensions.

  4. The N4 CAD chain: Another electricite de France breakthrough in nuclear engineering

    Energy Technology Data Exchange (ETDEWEB)

    Cornon, P.; Durey, P. [Electricite de France, Clamart (France)

    1996-12-31

    With the previous pressurized water reactor (PWR) series (1300 MW), Electricite de France (EdF) has experienced the first chain of computer-aided design (CAD) tools from programming drawings to instrumentation and control microprocessor memories. The Engineering and Construction Division of EdF decided to integrate the CAD tools in the design and construction process of its new N4 series (1400-MW PWR). At that time, EdF determined four safety and data quality principles for the human/machine interface of the CAD: 1. Unique data capture: A common alphanumeric database shares all the information used by more than one application, so this information is typed only once and can be verified independently. 2. Intrinsic consistency: Added to the previous principle, data consistency is also ensured by every application that provides ways to enter only allowed data when it is possible. This is completed by some checking facilities. 3. Ergonomy: Making extensive use of windows, buttons, pictures, and wysiwyg facilities, the CAD section develops applications speaking the real language of every designer who is able to understand and verify her/his work. 4. On-line help: For any question, prompted by any application, some on-line help has been written giving the list of allowed answers with explanations and/or examples.

  5. Boundary Anomalies and Correlation Functions

    CERN Document Server

    Huang, Kuo-Wei

    2016-01-01

    It was shown recently that boundary terms of conformal anomalies recover the universal contribution to the entanglement entropy and also play an important role in the boundary monotonicity theorem of odd-dimensional quantum field theories. Motivated by these results, we investigate relationships between boundary anomalies and the stress tensor correlation functions in conformal field theories. In particular, we focus on how the conformal Ward identity and the renormalization group equation are modified by boundary central charges. Renormalized stress tensors induced by boundary Weyl invariants are also discussed, with examples in spherical and cylindrical geometries.

  6. Influences of Irradiation on the C–V and G/ ω –V Characteristics of Si3N4 MIS Capacitors

    OpenAIRE

    Kaya, Ş.; Yılmaz, E.; Çetinkaya, A. O.

    2015-01-01

    The effects of gamma-ray exposures on the electrical characteristics of Silicon Nitride (Si3N4) metal–insulator–semiconductor (MIS) structures have been investigated at room temperature. The MIS structures were irradiated with the GAMMACELL 220 Co-60 radioactive source. The distributions of interface states and series resistance were determined from the C–V and G/ω-V characteristics by taking into account the irradiation-dependent the barrier height. Both the values of series resistance, inte...

  7. Electronic structure, charge distribution, and charge transfer in α- and β-Si3N4 and at the Si(111)/Si3N4(001) interface

    Science.gov (United States)

    Zhao, G. L.; Bachlechner, M. E.

    1997-02-01

    The electronic structure, charge distribution, and charge transfer in α- and β- Si3N4 and at the Si(111)/Si3N4(001) interface have been studied using a self-consistent first-principles LCAO method. The calculated charge transfer suggests that both in α- and β-phases, the ionic formula may be written as Si3+1.24N4-0.93. For the Si(111)/Si3N4(001) interface, the silicon atoms from the Si(111) side give some electrons to the N atoms of Si3N4 forming the Si-N bonds at the interface. One Si-N bond is associated with a charge transfer of about 0.31 electrons.

  8. Global gravitational anomalies and transport

    Science.gov (United States)

    Chowdhury, Subham Dutta; David, Justin R.

    2016-12-01

    We investigate the constraints imposed by global gravitational anomalies on parity odd induced transport coefficients in even dimensions for theories with chiral fermions, gravitinos and self dual tensors. The η-invariant for the large diffeomorphism corresponding to the T transformation on a torus constraints the coefficients in the thermal effective action up to mod 2. We show that the result obtained for the parity odd transport for gravitinos using global anomaly matching is consistent with the direct perturbative calculation. In d = 6 we see that the second Pontryagin class in the anomaly polynomial does not contribute to the η-invariant which provides a topological explanation of this observation in the `replacement rule'. We then perform a direct perturbative calculation for the contribution of the self dual tensor in d = 6 to the parity odd transport coefficient using the Feynman rules proposed by Gaumé and Witten. The result for the transport coefficient agrees with that obtained using matching of global anomalies.

  9. Anomalies and noncommutative index theory

    CERN Document Server

    Perrot, D

    2006-01-01

    These are the notes of a lecture given during the summer school "Geometric and Topological Methods for Quantum Field Theory", Villa de Leyva, Colombia, july 11 - 29, 2005. We review basic facts concerning gauge anomalies and discuss the link with the Connes-Moscovici index formula in noncommutative geometry.

  10. Bony anomaly of Meckel's cave.

    Science.gov (United States)

    Tubbs, R Shane; Salter, E George; Oakes, W Jerry

    2006-01-01

    This study describes the seemingly rare occurrence of bone formation within the proximal superior aspect of Meckel's cave thus forming a bony foramen for the proximal trigeminal nerve to traverse. The anatomy of Meckel's cave is reviewed and the clinical potential for nerve compression from this bony anomaly discussed.

  11. Conformal anomalies and gravitational waves

    Science.gov (United States)

    Meissner, Krzysztof A.; Nicolai, Hermann

    2017-09-01

    We argue that the presence of conformal anomalies in gravitational theories can lead to observable modifications to Einstein's equations via the induced anomalous effective actions, whose non-localities can overwhelm the smallness of the Planck scale. The fact that no such effects have been seen in recent cosmological or gravitational wave observations therefore imposes strong restrictions on the field content of possible extensions of Einstein's theory: all viable theories should have vanishing conformal anomalies. We then show that a complete cancellation of conformal anomalies in D = 4 for both the C2 invariant and the Euler (Gauss-Bonnet) invariant E4 can only be achieved for N-extended supergravity multiplets with N ⩾ 5, as well as for M theory compactified to four dimensions. Although there remain open questions, in particular concerning the true significance of conformal anomalies in non-conformal theories, as well as their possible gauge dependence for spin s ⩾3/2, these cancellations suggest a hidden conformal structure of unknown type in these theories.

  12. Connecting Stratospheric and Ionospheric Anomalies

    Science.gov (United States)

    Spraggs, M. E.; Goncharenko, L. P.; Zhang, S.; Coster, A. J.; Benkevitch, L. V.

    2014-12-01

    This study investigates any relationship between lunar phases and ionospheric anomalies that appear at low latitudes concurrently with sudden stratospheric warmings (SSWs). The study utilizes World-wide GPS Receiver Network Total Electron Content (TEC) data spanning 13 years (2001-2014) and focuses on the changes in the equatorial ionization anomaly the Western hemisphere. TEC is highly variable due to the influences of solar flux, geomagnetic activity, and seasonal variation and these influences are removed by the use of model. This empirical TEC model is a combination of linear dependencies of solar flux (F10.7) and geomagnetic activity (Ap3) with a third degree polynomial dependency for day-of-year (DOY). With such dependencies removed, the remaining TEC variation could be resolved and attributed to an appropriate mechanism. Lunar phase and apside was investigated in particular, especially the new and full moon phases during perigees when tidal forcing would be most powerful. Lunar tidal forcing on planetary waves is also examined as being physically responsible for setting up conditions that may give rise to SSWs and ionospheric anomalies. Preliminary results suggest that such anomalies may be enhanced in intensity during the full or new moon and even more so during perigee by different amounts depending on whether the SSW is a major (40-60%) or minor (20-45%) event.

  13. Thermal anomalies in stressed Teflon.

    Science.gov (United States)

    Lee, S. H.; Wulff, C. A.

    1972-01-01

    In the course of testing polytetrafluoroethylene (Teflon) as a calorimetric gasketing material, serendipity revealed a thermal anomaly in stressed film that occurs concomitantly with the well-documented 25 C transition. The magnitude of the excess energy absorption - about 35 cal/g - is suggested to be related to the restricted thermal expansion of the film.

  14. ANALISA ANOMALI GAYABERAT TERHADAP KONDISI TATANAN TEKTONIK ZONA SUBDUKSI SUNDA MEGATHRUST DI SEBELAH BARAT PULAU SUMATERA

    Directory of Open Access Journals (Sweden)

    Anita Thea Saraswati

    2015-02-01

    Full Text Available Aktivitas tektonik yang terjadi di bumi merupakan hal yang masih terus diteliti sampai sekarang. Sumatera yang terletak pada area Sunda Megathrust, yang merupakan zona subduksi Lempeng Indo-Australia dan Lempeng Eurasia, mengakibatkan daerah ini rentan dengan aktivitas seismogenic. Salah satu akibat dari adanya pergerakan kedua lempeng ini adalah terbentuknya tatanan tektonik di wilayah Sumatera. GOCE (Gravity field and steady-state Ocean Circulation Explorer menawarkan metode yang cepat dengan cakupan global untuk mendapatkan data gayaberat bumi. Dengan memanfaatkan hitungan dari spherical harmonic coeffisien (SHC serta dilengkapi dengan data Digital Elevation Model (DEM, dapat diketahui nilai anomali gayaberat pada suatu wilayah. Distribusi anomali gayaberat mampu mencerminkan kondisi tektonik di suatu area. Variasi spasial dari anomali gayaberat menunjukkan bahwa pada palung yang terbentuk akibat subduksi kedua lempeng memiliki nilai anomali gayaberat negatif dengan nilai rata-rata sebesar -42.8729 mgal. Forearc ridge yang terbentuk akibat konvergensi lempeng memiliki nilai anomali gayaberat positif, sedangkan forearc basin yang merupakan cekungan diantara backarc dan forearc ridge, memiliki nilai anomali gayaberat negatif yang lebih kuat daripada yang terdapat pada Sunda Megathrust. Variasi temporal yang teramati menunjukkan bahwa distribusi anomali gayaberat positif yang terdapat pada prisma akresi di kedua tepian palung bergerak semakin mendekati Sunda Megathrust pada tiap seri pengamatannya, sedangkan distribusi anomali gayaberat negatif pada palung laut dan forearc basin membentuk suatu  pola distribusi yang semakin menyempit sehingga menyebabkan semakin curamnya gradient anomali gayaberat pada area di sekitarnya.

  15. Order 1/N2 test of the Maldacena conjecture : cancellation of the one-loop Weyl anomaly.

    OpenAIRE

    Mansfield, Paul; Nolland, David

    2000-01-01

    We test the Maldacena conjecture for type IIB String Theory/ N=4 Yang-Mills by calculating the one-loop corrections in the bulk theory to the Weyl anomaly of the boundary CFT when the latter is coupled to a Ricci-flat metric. The contributions cancel within each supermultiplet, in agreement with the conjecture.

  16. A Study of the Method for the Recognition of Anomalies in Geochemical Hydrocarbon Exploration

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The greatest difficulties in recognizing geochemical hydrocarbon anomalies are: (1) how to objectively and accurately separate anomalies from background; (2) how to distinguish hydrocarbon-pool-related apical anomalies from lateral anomalies controlled by faults; and (3) how to eliminate interferences. These uncertainties are serious obstacles for the wide acceptance and use of geochemical techniques in hydrocarbon exploration. In this paper, the features of hydrocarbon anomalies were analyzed based on the micro-migration mechanisms. In most cases, there are two anomalous populations or point groups, which are produced by two distinct mechanisms: (1) a population that directly reflects oil and gas fields, and (2) one that is related to structures such as faults. Statistical studies show that background anomalous populations and the boundaries between them can be described by the population means, prior probabilities, which are the proportions of population sizes, and covariance matrices, when background and anomalous populations have normal distributions. When this normality condition is met, a series of formulas can be derived. The method is designed on the basis of these allows: (1) univariate anomaly recognition, (2) elimination of interferences, (3) multivariate anomaly recognition, and (4) multivariate anomaly combination which depicts a more representative picture of morphology of the anomalous target than individual anomalies. The univariate and multivariate anomaly recognition can not only separate anomalies from background objectively, but also simultaneously distinguish the two types of anomalies objectively. This method was applied to the hydrocarbon data in Yangshuiwu region, Hebei Province. The interferences from regional variation of background were eliminated, and the interpretation uncertainty was reduced greatly as the anomalous populations were separated. The method was also used in Daxing region within the confines of Beijing City, and Aershan

  17. Impact behavior of a SiC fiber-reinforced reaction bonded Si3N4 composite

    Science.gov (United States)

    Grady, J.; Bhatt, R.; Klima, S.

    1989-01-01

    Impact tests were performed on a series of ceramic plate specimens. Monolithic (unreinforced) and composite specimens with various fiber layups were tested to determine the effect that the fiber reinforcement has on impact damage initiation and dynamic response of the ceramic materials. Results show that a porous surface layer of Si3N4 on the composite specimens can enhance the energy absorbing capability of the composite specimens. The addition of SiC fiber reinforcement to the RBSN matrix material is also shown to significantly change the mode of failure and reduce the extent of damage due to impact.

  18. Improvement of g-C3N4 photocatalytic properties using the Hummers method.

    Science.gov (United States)

    Feng, Jing; Chen, Tingting; Liu, Shenna; Zhou, Qihang; Ren, Yueming; Lv, Yanzhuo; Fan, Zhuangjun

    2016-10-01

    In this study, graphitic C3N4 (g-C3N4) with high photocatalytic properties to methylene blue (MB) was synthesized by treating the bulk g-C3N4 using the Hummers method. The bulk g-C3N4 was obtained by calcining dicyandiamide. The g-C3N4 treated by the Hummers method (E-g-C3N4) was characterized and utilized for the photocatalytic removal of MB. The results showed that the Hummers treatment exfoliated the nanosheets bulk g-C3N4 into nanorods and improved the dispersion of E-g-C3N4 in an aqueous solution. It also distinctly enhanced the photocatalytic activity of g-C3N4 to MB, i.e., the removal efficiency increased from 38.45% for the bulk g-C3N4 to 96.61% for the E-g-C3N4.

  19. Anomalies, counterterms and the ${\\cal N} =0$ Polchinski-Strassler solutions

    CERN Document Server

    Taylor-Robinson, M M

    2001-01-01

    The singularity structure of many IIB supergravity solutions asymptotic to $AdS_5 \\times S^5$ becomes clearer when one considers the full ten dimensional solution rather than the dimensionally reduced solution of gauged supergravity. It has been shown that all divergences in the gravitational action of the dimensionally reduced spacetime can be removed by the addition of local counterterms on the boundary. Here we attempt to formulate the counterterm action directly in ten dimensions for a particular class of solutions, the ${\\cal N} = 0$ Polchinski-Strassler solutions, which are dual to an ${\\cal N} =4$ SYM theory perturbed by mass terms for all scalars and spinors. This involves constructing the solution perturbatively near the boundary. There is a contribution to the Weyl anomaly from the mass terms (which break the classical conformal invariance of the action). The coefficient of this anomaly is reproduced by a free field calculation indicating a non-renormalisation theorem inherited from the ${\\cal N} =4...

  20. Effect of bonding parameters on microstructure and properties of Si3N4/Si3N4 joint brazed by Cu-Zn-Ti filler alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jie; Naka Massaki; ZHOU Yu

    2005-01-01

    Si3N4 ceramic was jointed to Si3N4 ceramic using a filler alloy of Cu-Zn-Ti at 1 123-1 323 K for 0.3 -2.7 ks. Ti content in the Cu-Zn-Ti filler alloy was 15% (molar fraction). The effect of bonding parameters on the microstructure and mechanical properties of the Si3N4/Si3N4 joint were investigated. The results indicate that with increasing brazing temperature from 1 123K to 1 323 K and brazing time from 0.3 ks to 2.7 ks, the thickness of the interfacial reaction layer between the filler alloy and the Si3 N4 ceramic and the size and amount of the reactant products in the filler alloy increase, leading to an increase in shear strength of the joint from 163 MPa to 276 MPa. It is also found that the fracture behavior of the Si3 N4/Si3 N4 joint greatly depends on the microstructure of the joint.

  1. Anomaly detection in online social networks

    CERN Document Server

    Savage, David; Yu, Xinghuo; Chou, Pauline; Wang, Qingmai

    2016-01-01

    Anomalies in online social networks can signify irregular, and often illegal behaviour. Anomalies in online social networks can signify irregular, and often illegal behaviour. Detection of such anomalies has been used to identify malicious individuals, including spammers, sexual predators, and online fraudsters. In this paper we survey existing computational techniques for detecting anomalies in online social networks. We characterise anomalies as being either static or dynamic, and as being labelled or unlabelled, and survey methods for detecting these different types of anomalies. We suggest that the detection of anomalies in online social networks is composed of two sub-processes; the selection and calculation of network features, and the classification of observations from this feature space. In addition, this paper provides an overview of the types of problems that anomaly detection can address and identifies key areas of future research.

  2. Focal skin defect, limb anomalies and microphthalmia.

    NARCIS (Netherlands)

    Jackson, K.E.; Andersson, H.C.

    2004-01-01

    We describe two unrelated female patients with congenital single focal skin defects, unilateral microphthalmia and limb anomalies. Growth and psychomotor development were normal and no brain malformation was detected. Although eye and limb anomalies are commonly associated, clinical anophthalmia and

  3. Development of -N4-NIM for Molecular Imaging of Tumor Hypoxia

    Directory of Open Access Journals (Sweden)

    Mohammad S. Ali

    2012-01-01

    Full Text Available The nitro group of 2-nitroimidazole (NIM enters the tumor cells and is bioreductively activated and fixed in the hypoxia cells. 1,4,8,11-tetraazacyclotetradecane (N4 has shown to be a stable chelator for 99mTc. The present study was aimed to develop 99mTc-cyclam-2-nitroimidazole (99mTc-N4-NIM for tumor hypoxia imaging. N4-NIM precursor was synthesized by reacting N4-oxalate and 1,3-dibromopropane-NIM, yielded 14% (total synthesis. Cell uptake of 99mTc-N4-NIM and 99mTc-N4 was obtained in 13762 rat mammary tumor cells and mesothelioma cells in 6-well plates. Tissue distribution of 99mTc-N4-NIM was evaluated in breast-tumor-bearing rats at 0.5–4 hrs. Tumor oxygen tension was measured using an oxygen probe. Planar imaging was performed in the tumor-bearing rat and rabbit models. Radiochemical purity of 99mTc-N4-NIM was >96% by HPLC. Cell uptake of 99mTc-N4-NIM was higher than 99mTc-N4 in both cell lines. Biodistribution of 99mTc-N4-NIM showed increased tumor-to-blood and tumor-to-muscle count density ratios as a function of time. Oxygen tension in tumor tissue was 6–10 mmHg compared to 40–50 mmHg in normal muscle tissue. Planar imaging studies confirmed that the tumors could be visualized clearly with 99mTc-N4-NIM in animal models. Efficient synthesis of N4-NIM was achieved. 99mTc-N4-NIM is a novel hypoxic probe and may be useful in evaluating cancer therapy.

  4. Si3N4-SiC材料的氧化性能研究%Study on Oxidation Performance of Si3N4-SiC

    Institute of Scientific and Technical Information of China (English)

    李杰

    2009-01-01

    通过对不同Si3N4含量、不同温度下Si3N4-SiC材料的氧化实验,分析氧化后的氧化增重率,得出Si3N4含量越高,材料氧化越严重;氧化温度越高,材料氧化越严重;且氧化增重率与氧化时间呈直线-抛物线规律.

  5. Prevalence of dental anomalies in orthodontic patients.

    Science.gov (United States)

    Thongudomporn, U; Freer, T J

    1998-12-01

    The prevalence of dental anomalies including agenesis, crown shape, tooth position, root shape, and invagination were examined in 111 orthodontic patients; 74.77 per cent of the patients exhibited at least one dental anomaly. Invagination was found to be the most prevalent anomaly, whereas supernumerary teeth and root dilaceration were the least frequent anomalies. Dental invagination and short or blunt roots were significantly more prevalent in females than in males. Implications for orthodontic treatment planning are discussed.

  6. [Ectopia cordis and cardiac anomalies].

    Science.gov (United States)

    Cabrera, Alberto; Rodrigo, David; Luis, María Teresa; Pastor, Esteban; Galdeano, José Miguel; Esteban, Susana

    2002-11-01

    Ectopia cordis is a rare disease that occurs in 5.5 to 7.9 per million live births. Only 267 cases had been reported as of 2001, most (95%) associated with other cardiac anomalies. We studied the cardiac malformations associated in 6 patients with ectopia cordis. Depending on where the defect was located, the cases of ectopia were classified into four groups: cervical, thoracic, thoraco-abdominal, and abdominal. All 6 patients died before the third day of life, 4 during delivery. Three of the patients were included in the thoracic group, whereas the other 3 belonged to the thoraco-abdominal group. All the patients had associated ventricular septal defects, 3 double-outlet right ventricle (50%) and the rest (50%) tetralogy of Fallot-pulmonary atresia. Two patients with double-outlet right ventricle presented mitral-valve pathology, a parachute valve and an atresic mitral valve. None of these cardiac anomalies have been reported to date.

  7. On Anomaly Mediated SUSY Breaking

    CERN Document Server

    de Alwis, S P

    2008-01-01

    A discrepancy between the Anomaly Mediated Supersymmetry Breaking (AMSB) gaugino mass calculated from the work of Kaplunovsky and Louis (hep-th/9402005) (KL) and other calculations in the literature is explained, and it is argued that the KL expression is the correct one relevant to the Wilsonian action. Furthermore it is argued that the AMSB contribution to the squark and slepton masses should be replaced by the contribution pointed out by Dine and Seiberg (DS) which has nothing to do with Weyl anomalies. This is not in general equivalent to the AMSB expression, and it is shown that there are models in which the usual AMSB expression would vanish but the DS one is non-zero. In fact the latter has aspects of both AMSB and gauge mediated SUSY breaking. In particular like the latter, it gives positive squared masses for sleptons.

  8. Survey of Anomaly Detection Methods

    Energy Technology Data Exchange (ETDEWEB)

    Ng, B

    2006-10-12

    This survey defines the problem of anomaly detection and provides an overview of existing methods. The methods are categorized into two general classes: generative and discriminative. A generative approach involves building a model that represents the joint distribution of the input features and the output labels of system behavior (e.g., normal or anomalous) then applies the model to formulate a decision rule for detecting anomalies. On the other hand, a discriminative approach aims directly to find the decision rule, with the smallest error rate, that distinguishes between normal and anomalous behavior. For each approach, we will give an overview of popular techniques and provide references to state-of-the-art applications.

  9. Leptoquark patterns unifying neutrino masses, flavor anomalies, and the diphoton excess

    Science.gov (United States)

    Deppisch, F. F.; Kulkarni, S.; Päs, H.; Schumacher, E.

    2016-07-01

    Vector leptoquarks provide an elegant solution to a series of anomalies and at the same time generate naturally light neutrino masses through their mixing with the standard model Higgs boson. We present a simple Froggatt-Nielsen model to accommodate the B physics anomalies RK and RD , neutrino masses, and the 750 GeV diphoton excess in one cohesive framework adding only two vector leptoquarks and two singlet scalar fields to the standard model field content.

  10. Leptoquark patterns unifying neutrino masses, flavor anomalies and the diphoton excess

    CERN Document Server

    Deppisch, F F; Päs, H; Schumacher, E

    2016-01-01

    Vector leptoquarks provide an elegant solution to a series of anomalies and at the same time generate naturally light neutrino masses through their mixing with the standard model Higgs boson. We present a simple Froggatt-Nielsen model to accommodate the B physics anomalies $R_K$ and $R_D$, neutrino masses, and the $750\\,$GeV diphoton excess in one cohesive framework adding only two vector leptoquarks and two singlet scalar fields to the standard model field content.

  11. Theory of Geological Anomaly in Remote Sensing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Geological anomaly is geological body or complex body with obviously different compositions, structures or orders of genesis as compared with those in the surrounding areas. Geological anomaly, restrained by the geological factors closely associated with ore-forming process, is an important clue to ore deposits. The geological anomaly serves as a geological sign to locate ore deposits. Therefore, it is very important to study how to define the characteristics of geological anomaly and further to locate the changes in these characteristics. In this paper, the authors propose the geological anomaly based on the remote-sensing images and data, and expound systematically such image features as scale, size, boundary, morphology and genesis of geological anomalies. Then the authors introduce the categorization of the geological anomalies according to their geneses. The image characteristics of some types of geological anomalies, such as the underground geological anomaly, are also explained in detail. Based on the remote-sensing interpretation of these geological anomalies, the authors conclude that the forecasting and exploration of ore deposits should be focused on the following three aspects: (1) the analysis of geological setting and geological anomaly; (2) the analysis of circular geological anomaly, and (3) the comprehensive forecasting of ore deposits and the research into multi-source information.

  12. Fetal renal anomalies : diagnosis, management, and outcome

    NARCIS (Netherlands)

    Damen-Elias, Henrica Antonia Maria

    2004-01-01

    In two to three percent of fetuses structural anomalies can be found with prenatal ultrasound investigation. Anomalies of the urinary tract account for 15 to 20% of these anomalies with a detection rate of approximately of 90%. In Chapter 2, 3 and 4 we present reference curves for size and growth of

  13. Fetal renal anomalies : diagnosis, management, and outcome

    NARCIS (Netherlands)

    Damen-Elias, Henrica Antonia Maria

    2004-01-01

    In two to three percent of fetuses structural anomalies can be found with prenatal ultrasound investigation. Anomalies of the urinary tract account for 15 to 20% of these anomalies with a detection rate of approximately of 90%. In Chapter 2, 3 and 4 we present reference curves for size and growth

  14. Bifid rib: A rare anomaly

    Directory of Open Access Journals (Sweden)

    Mythili Krishnan Rathinasabapathi

    2015-01-01

    Full Text Available A case of the bifid rib was found during routine bone study. The distal part of the osseous rib bifurcated into two divisions with an angle of 60°. Both divisions had their own costal cartilage. Bifid rib is a congenital abnormality of the rib cage and usually asymptomatic, often discovered incidentally on chest X-ray. Effects of this neuroskeletal anomaly can include respiratory difficulties and neurological limitations.

  15. Sharing AIS Related Anomalies (SARA)

    Science.gov (United States)

    2016-03-01

    misconfiguration and intentional misuse. These unintended behaviours generate an abundance of anomalies that the security community has an interest in monitoring...Lastly, the feedback loop formed with clients is essential to SARA’s advancement. The more SARA is exposed, the better and faster it can be adapted...to end-user needs and thus be adopted by them. This section is organised as follows : • Section 2.1 describes the strategy used to identify potential

  16. Causes and Consequences of the Late 1960s Great Salinity Anomaly

    OpenAIRE

    Dima, Mihai; Lohmann, Gerrit

    2011-01-01

    The second half of the 20th century showed a series of decadal-scale anomalies of salinity, temperature and sea ice cover in the northern North Atlantic. One pronounced event, the 'great salinity anomaly' (GSA) is observed in the late 1060s and the early 1970s (Dickson et al., 1988). This anomaly can be linked to the sea ice volume out of the Arctic through Fram Strait, which represents a major source of freshwater (Aagaard & Carmack, 1989; Schmith & Hansen, 2003). Increased se...

  17. Anomaly mediation in superstring theory

    Energy Technology Data Exchange (ETDEWEB)

    Conlon, J.P. [Rudolf Peierls Center for Theoretical Physics, 1 Keble Road, Oxford, OX1 3NP (United Kingdom); Balliol College, Oxford, OX1 3BJ (United Kingdom); Kavli Institute of Theoretical Physics, Kohn Hall, University of California, Santa Barbara CA 93106-4030 (United States); Goodsell, M. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22603 Hamburg (Germany); Palti, E. [Centre de Physique Theorique, Ecole Polytechnique, CNRS, 91128 Palaiseau (France)

    2011-01-15

    We study anomaly mediated supersymmetry breaking in type IIB string theory and use our results to test the supergravity formula for anomaly mediated gaugino masses. We compute 1-loop gaugino masses for models of D3-branes on orbifold singularities with 3-form fluxes by calculating the annulus correlator of 3-form flux and two gauginos in the zero momentum limit. Consistent with supergravity expectations we find both anomalous and running contributions to 1-loop gaugino masses. For background Neveu-Schwarz H-flux we find an exact match with the supergravity formula. For Ramond-Ramond flux there is an off-shell ambiguity that precludes a full matching. The anomaly mediated gaugino masses, while determined by the infrared spectrum, arise from an explicit sum over UV open string winding modes. We also calculate brane-to-brane tree-level gravity mediated gaugino masses and show that there are two contributions coming from the dilaton and from the twisted modes, which are suppressed by the full T{sup 6} volume and the untwisted T{sup 2} volume respectively. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Anomaly mediation in superstring theory

    Energy Technology Data Exchange (ETDEWEB)

    Conlon, Joseph P. [Rudolf Peierls Center for Theoretical Physics, Oxford (United Kingdom); Balliol College, Oxford (United Kingdom); Goodsell, Mark [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Palti, Eran [Centre de Physique Theoretique, Ecole Polytechnique, CNRS, Palaiseau (France)

    2010-08-15

    We study anomaly mediated supersymmetry breaking in type IIB string theory and use our results to test the supergravity formula for anomaly mediated gaugino masses. We compute 1-loop gaugino masses for models of D3-branes on orbifold singularities with 3-form fluxes by calculating the annulus correlator of 3-form flux and two gauginos in the zero momentum limit. Consistent with supergravity expectations we find both anomalous and running contributions to 1-loop gaugino masses. For background Neveu-Schwarz H-flux we find an exact match with the supergravity formula. For Ramond-Ramond flux there is an off-shell ambiguity that precludes a full matching. The anomaly mediated gaugino masses, while determined by the infrared spectrum, arise from an explicit sum over UV open string winding modes. We also calculate brane-to-brane tree-level gravity mediated gaugino masses and show that there are two contributions coming from the dilaton and from the twisted modes, which are suppressed by the full T{sup 6} volume and the untwisted T{sup 2} volume respectively. (orig.)

  19. Columbus Payloads Flow Rate Anomalies

    Science.gov (United States)

    Quaranta, Albino; Bufano, Gaetana; DePalo, Savino; Holt, James M.; Szigetvari, Zoltan; Palumberi, Sergio; Hinderer, S.

    2011-01-01

    The Columbus Active Thermal Control System (ATCS) is the main thermal bus for the pressurized racks working inside the European laboratory. One of the ATCS goals is to provide proper water flow rate to each payload (P/L) by controlling actively the pressure drop across the common plenum distribution piping. Overall flow measurement performed by the Water Pump Assembly (WPA) is the only flow rate monitor available at system level and is not part of the feedback control system. At rack activation the flow rate provided by the system is derived on ground by computing the WPA flow increase. With this approach, several anomalies were raised during these 3 years on-orbit, with the indication of low flow rate conditions on the European racks FSL, BioLab, EDR and EPM. This paper reviews the system and P/Ls calibration approach, the anomalies occurred, the engineering evaluation on the measurement approach and the accuracy improvements proposed, the on-orbit test under evaluation with NASA and finally discusses possible short and long term solutions in case of anomaly confirmation.

  20. Trace anomalies from quantum mechanics

    CERN Document Server

    Bastianelli, F; Bastianelli, Fiorenzo; Nieuwenhuizen, Peter van

    1993-01-01

    The 1-loop anomalies of a d-dimensional quantum field theory can be computed by evaluating the trace of the regulated path integral jacobian matrix, as shown by Fujikawa. In 1983, Alvarez-Gaum\\'e and Witten observed that one can simplify this evaluation by replacing the operators which appear in the regulator and in the jacobian by quantum mechanical operators with the same (anti)commutation relations. By rewriting this quantum mechanical trace as a path integral with periodic boundary conditions for a one-dimensional supersymmetric nonlinear sigma model, they obtained the chiral anomalies for spin 1/2 and 3/2 fields and selfdual antisymmetric tensors in d dimensions. In this article, we treat the case of trace anomalies for spin 0, 1/2 and 1 fields in a gravitational and Yang-Mills background. We do not introduce a supersymmetric sigma model, but keep the original Dirac matrices $\\g^\\m$ and internal symmetry generators $T^a$ in the path integral. As a result, we get a matrix-valued action. Gauge covariance o...

  1. Astrometric Solar-System Anomalies

    CERN Document Server

    Anderson, John D

    2009-01-01

    There are at least four unexplained anomalies connected with astrometric data. Perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. Next, a secular change in the astronomical unit AU is definitely a concern. It is increasing by about 15 cm yr$^{-1}$. The other two anomalies are perhaps less disturbing because of known sources of nongravitational acceleration. The first is an apparent slowing of the two Pioneer spacecraft as they exit the solar system in opposite directions. Some astronomers and physicists are convinced this effect is of concern, but many others are convinced it is produced by a nearly identical thermal emission from both spacecraft, in a direction away from the Sun, thereby producing acceleration toward the Sun. The fourth anomaly is a measured increase in the eccentricity of the Moon's orbit. Here again, an increase is expected from tidal friction ...

  2. Characteristic Comparison of α-Si3N4 and γ-Si3N4 Sintered under Ultra-high Pressure%α-Si3N4与γ-Si3N4超高压烧结体的性能对比

    Institute of Scientific and Technical Information of China (English)

    姚怀; 徐巧玉; 唐敬友; 苌清华

    2009-01-01

    以Y2O3-Al2O3-La2O3体系作烧结助剂,在5.4~5.7 GPa、1 620~1 770 K的高温高压条件下进行了α-Si3N4与γ-Si3N4粉体的烧结,研究了烧结体的相对密度、韦氏硬度和物相组成.结果表明:α-Si3N4、γ-Si3N4在烧结后完全转变为β-Si3N4;在相同烧结条件下,γ-Si3N4烧结体的相对密度、维氏硬度比α-Si3N4的高γ-Si3N4与α-Si3N4烧结体的最高相对密度与维氏硬度分别为99.20%,23.42 GPa和98.78%,21.87 GPa;烧结体由相互交错的长柱状β-Si3N4晶粒组成,显微结构均匀.

  3. Electronic structure and charge transfer in α- and β-Si3N4 and at the Si(111)/Si3N4(001) interface

    Science.gov (United States)

    Zhao, G. L.; Bachlechner, M. E.

    1998-07-01

    Using a self-consistent linear combination of atomic orbitals method based on density-functional theory in a local-density approximation, the electronic structure in the high-temperature ceramics α-Si3N4 and β-Si3N4 and at the Si(111)/Si3N4(001) interface have been calculated. The resulting charge transfer suggests that the ionic formula can be written as Si+1.243N-0.934. For the Si(111)/Si3N4(001) interface, the silicon atoms from the silicon side lose some electrons to the nitrogen atoms of the silicon nitride side forming Si-N bonds at the interface. The calculated electronic density of states spectrum of Si 2p core levels for this interface is in good agreement with x-ray photoemission spectroscopy experiments.

  4. Research on Nano-Si3N4 Dispersion Technology%纳米Si3N4粉末分散工艺研究

    Institute of Scientific and Technical Information of China (English)

    田春艳; 刘宁

    2006-01-01

    研究了纳米Si3N4粉末的分散性能,得到了优化的分散工艺参数.实验结果表明,将纳米Si3N4进行超声分散,可以改善其分散状况;加入适量的表面活性剂能改善Si3N4的分散效果,阳离子型表面活性剂的分散效果优于非离子型表面活性剂;分散体系的pH值也影响纳米Si3N4粉的分散效果.

  5. Nqrs Data for C6H16I2N4O8 [C6H14N4O2·2(HIO3)] (Subst. No. 0932)

    Science.gov (United States)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for C6H16I2N4O8 [C6H14N4O2·2(HIO3)] (Subst. No. 0932)

  6. ANOMALY DETECTION AND ATTRIBUTION USING AUTO FORECAST AND DIRECTED GRAPHS

    Directory of Open Access Journals (Sweden)

    Vivek Sankar

    2016-03-01

    Full Text Available In the business world, decision makers rely heavily on data to back their decisions. With the quantum of data increasing rapidly, traditional methods used to generate insights from reports and dashboards will soon become intractable. This creates a need for efficient systems which can substitute human intelligence and reduce time latency in decision making. This paper describes an approach to process time series data with multiple dimensions such as geographies, verticals, products, efficiently, and to detect anomalies in the data and further, to explain potential reasons for the occurrence of the anomalies. The algorithm implements auto selection of forecast models to make reliable forecasts and detect such anomalies. Depth First Search (DFS is applied to analyse each of these anomalies and find its root causes. The algorithm filters the redundant causes and reports the insights to the stakeholders. Apart from being a hair-trigger KPI tracking mechanism, this algorithm can also be customized for problems lke A/B testing, campaign tracking and product evaluations.

  7. Bathymetry Prediction Based on the Admittance Theory of Gravity Anomalies

    Directory of Open Access Journals (Sweden)

    OUYANG Mingda

    2015-10-01

    Full Text Available Based on the admittance theory of gravity anomalies, the method of bathymetry prediction was studied in detail in this paper. In frequency domains, the correlation between gravity anomalies and bathymetry was analyzed, which suggests that the wavelength band correlated strongly was in a range of 20—300 km, this band was appropriated to inverse bathymetry by gravity anomalies. Took the Emperor Chain as an example, the uncompensated admittance model and flexural isostatic admittance model were used for researching, respectively, the included parameter of crust thickness and effective elastic thickness were calculated by the isostatic response function. As the down continuation factor was unstable, a high-cut filter was proposed in the inversion procedure to ensure convergence of series. The results showed that, the admittance theory of gravity anomalies can be used effectively in the bathymetry prediction, the predicted result was real and reliable, the relative precision was approximately 6%, which was equal to ETOPO1 model, and the detailed feature of sea floor which was not showed in ETOPO1 model can also be depicted; the precisions were not so well in areas of ocean mountains intensively distributed because of the complexion of the sea floor.

  8. Diffusivity anomaly in modified Stillinger-Weber liquids

    Science.gov (United States)

    Sengupta, Shiladitya; Vasisht, Vishwas V.; Sastry, Srikanth

    2014-01-01

    By modifying the tetrahedrality (the strength of the three body interactions) in the well-known Stillinger-Weber model for silicon, we study the diffusivity of a series of model liquids as a function of tetrahedrality and temperature at fixed pressure. Previous work has shown that at constant temperature, the diffusivity exhibits a maximum as a function of tetrahedrality, which we refer to as the diffusivity anomaly, in analogy with the well-known anomaly in water upon variation of pressure at constant temperature. We explore to what extent the structural and thermodynamic changes accompanying changes in the interaction potential can help rationalize the diffusivity anomaly, by employing the Rosenfeld relation between diffusivity and the excess entropy (over the ideal gas reference value), and the pair correlation entropy, which provides an approximation to the excess entropy in terms of the pair correlation function. We find that in the modified Stillinger-Weber liquids, the Rosenfeld relation works well above the melting temperatures but exhibits deviations below, with the deviations becoming smaller for smaller tetrahedrality. Further we find that both the excess entropy and the pair correlation entropy at constant temperature go through maxima as a function of the tetrahedrality, thus demonstrating the close relationship between structural, thermodynamic, and dynamical anomalies in the modified Stillinger-Weber liquids.

  9. Diffusivity anomaly in modified Stillinger-Weber liquids

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Shiladitya [TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Narsingi, Hyderabad 500089 (India); Vasisht, Vishwas V. [Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur Campus, Bangalore 560064 (India); Sastry, Srikanth [TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Narsingi, Hyderabad 500089 (India); Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur Campus, Bangalore 560064 (India)

    2014-01-28

    By modifying the tetrahedrality (the strength of the three body interactions) in the well-known Stillinger-Weber model for silicon, we study the diffusivity of a series of model liquids as a function of tetrahedrality and temperature at fixed pressure. Previous work has shown that at constant temperature, the diffusivity exhibits a maximum as a function of tetrahedrality, which we refer to as the diffusivity anomaly, in analogy with the well-known anomaly in water upon variation of pressure at constant temperature. We explore to what extent the structural and thermodynamic changes accompanying changes in the interaction potential can help rationalize the diffusivity anomaly, by employing the Rosenfeld relation between diffusivity and the excess entropy (over the ideal gas reference value), and the pair correlation entropy, which provides an approximation to the excess entropy in terms of the pair correlation function. We find that in the modified Stillinger-Weber liquids, the Rosenfeld relation works well above the melting temperatures but exhibits deviations below, with the deviations becoming smaller for smaller tetrahedrality. Further we find that both the excess entropy and the pair correlation entropy at constant temperature go through maxima as a function of the tetrahedrality, thus demonstrating the close relationship between structural, thermodynamic, and dynamical anomalies in the modified Stillinger-Weber liquids.

  10. Cation-Cation Interactions in [(UO2)2(OH)n](4-n) Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Odoh, Samuel O.; Govind, Niranjan; Schreckenbach, Georg; De Jong, Wibe A.

    2013-10-07

    The structures and bonding of gas-phase [(UO2)2(OH)n]4-n (n=2-6) complexes have been studied using density functional theory (DFT), MP2 and CCSD(T) methods with particular emphasis on ground state structures featuring cation-cation interactions (CCIs) between the uranyl groups. An interesting trend is observed in the stabilities of members of this series of complexes. The structures of [(UO2)2(OH)2]2+, [(UO2)2(OH)4] and [(UO2)2(OH)6]2- featuring CCIs are found at higher energies (by 3-20 kcal/mol) in comparison to their conventional μ2-dihydroxo structures. In contrast, the CCI structures of [(UO2)2(OH)3]+ and [(UO2)2(OH)5]- are respectively almost degenerate with and lower in energy than the structures with the μ2-dihydroxo format. The origin of this trend lies in the ‘symmetry’-based need to balance the coordination numbers and effective atomic charges of each uranium center. The calculated IR vibrational frequencies provide signature probes that can be used in differentiating the lowenergy structures and in experimentally confirming the existence of the structures featuring CCIs. Analysis of the bonding in the structures of [(UO2)2(OH)3]+ and [(UO2)2(OH)5]- shows that the CCIs and bridging hydroxo between the dioxo-uranium units are mainly electrostatic in nature.

  11. Selective serotonin reuptake inhibitor antidepressant use in first trimester pregnancy and risk of congenital anomalies

    DEFF Research Database (Denmark)

    Wemakor, A.; Casson, K.; Garne, E.

    2015-01-01

    Objective / Background The Selective Serotonin Reuptake Inhibitor (SSRI) antidepressants are widely prescribed in pregnancy, but there is evidence that they may cause congenital anomalies, particularly congenital heart defects (CHD). Objective: To determine the specificity of association between...... first trimester pregnancy exposure to individual SSRI and specific congenital anomalies (CAs). Methods Population-based case-malformed control study covering 3.3 million births from 12 EUROCAT registries 1995-2009. CAs included non-syndromic live births, fetal deaths and terminations of pregnancy...... % CI 1.67-6.75, n=9), and Ebstein's anomaly (OR 8.23, 95 % CI 2.91-23.28, n=4) were detected. Statistically significant associations between SSRI and four of the 15 non- CHDsignals (anorectal atresia and stenosis, gastroschisis, renal dysplasia, clubfoot) were found. In all the statistically...

  12. Development and Congenital Anomalies of the Pancreas

    Directory of Open Access Journals (Sweden)

    Hiroyuki Tadokoro

    2011-01-01

    Full Text Available Understanding how the pancreas develops is essential to understand the pathogenesis of congenital pancreatic anomalies. Recent studies have shown the advantages of investigating the development of frogs, mice, and chickens for understanding early embryonic development of the pancreas and congenital anomalies, such as choledochal cysts, anomalous pancreaticobiliary junction, annular pancreas, and pancreas divisum. These anomalies arise from failure of complete rotation and fusion during embryogenesis. There are many theories in the etiology of congenital anomalies of the pancreas. We review pancreas development in humans and other vertebrates. In addition, we attempt to clarify how developmental failure is related to congenital pancreatic anomalies.

  13. Global Anomalies and Effective Field Theory

    CERN Document Server

    Golkar, Siavash

    2015-01-01

    We show that matching anomalies under large gauge transformations and large diffeomorphisms can explain the appearance and non-renormalization of couplings in effective field theory. We focus on %thermal partition functions and thermal effective field theory where we argue that the appearance of certain unusual Chern-Simons couplings is a consequence of global anomalies. As an example, we show that a mixed global anomaly in four dimensions fixes the chiral vortical effect coefficient. This is an experimentally measurable prediction from a global anomaly. For certain situations, we propose a simpler method for calculating global anomalies which uses correlation functions rather than eta invariants.

  14. Fabrication of Si3N4 Nanocrystals and Nanowires Using PECVD

    Directory of Open Access Journals (Sweden)

    Jingwei Song

    2010-01-01

    Full Text Available Si3N4 nanowires and nanocrystals were prepared on Si substrates with or without Fe catalyst using silane (SiH4 and nitrogen (N2 as reactive gases through plasma-enhanced chemical vapor deposition (PECVD technology. With Fe catalyst, Si3N4 nanowires were developed, indicating that Fe catalyst played a role for Si3N4 molecules directionally depositing into strings. The density of the nanowires is closely related to the density of Fe catalyst. When the density of Fe ions on the substrate was decreased remarkably, a smooth superlong Si3N4 nanowire with 12 μm in length was fabricated. Having analyzed the growth mechanism, a growth model for Si3N4 nanowires was developed. The growth of Si3N4 nanocrystallines was attributed to be a vapor-solid (V-S deposition process.

  15. Contribution to the safety assessment of instrumentation and control software for nuclear power plants: Application to SPIN N4

    Energy Technology Data Exchange (ETDEWEB)

    Soubies, B.; Henry, J.Y.; Le Meur, M. [and others

    1995-04-01

    1300 MWe pressurised water reactors (PWRs), like the 1400 MWe reactors, operate with microprocessor-based safety systems. This is particularly the case for the Digital Integrated Protection System (SPIN), which trips the reactor in an emergency and sets in action the safeguard functions. The softwares used in these systems must therefore be highly dependable in the execution of their functions. In the case of SPIN, three players are working at different levels to achieve this goal: the protection system manufacturer, Merlin Gerin; the designer of the nuclear steam supply system, Framatome; the operator of the nuclear power plants, Electricite de France (EDF), which is also responsible for the safety of its installations. Regulatory licenses are issued by the French safety authority, the Nuclear Installations Safety Directorate (French abbreviation DSIN), subsequent to a successful examination of the technical provisions adopted by the operator. This examination is carried out by the IPSN and the standing group on nuclear reactors. This communication sets out: the methods used by the manufacturer to develop SPIN software for the 1400 MWe PWRs (N4 series); the approach adopted by the IPSN to evaluate the safety software of the protection system for the N4 series of reactors.

  16. Algorithms for Anomaly Detection - Lecture 2

    CERN Document Server

    CERN. Geneva

    2017-01-01

    The concept of statistical anomalies, or outliers, has fascinated experimentalists since the earliest attempts to interpret data. We want to know why some data points don’t seem to belong with the others: perhaps we want to eliminate spurious or unrepresentative data from our model. Or, the anomalies themselves may be what we are interested in: an outlier could represent the symptom of a disease, an attack on a computer network, a scientific discovery, or even an unfaithful partner. We start with some general considerations, such as the relationship between clustering and anomaly detection, the choice between supervised and unsupervised methods, and the difference between global and local anomalies. Then we will survey the most representative anomaly detection algorithms, highlighting what kind of data each approach is best suited to, and discussing their limitations. We will finish with a discussion of the difficulties of anomaly detection in high-dimensional data and some new directions for anomaly detec...

  17. Algorithms for Anomaly Detection - Lecture 1

    CERN Document Server

    CERN. Geneva

    2017-01-01

    The concept of statistical anomalies, or outliers, has fascinated experimentalists since the earliest attempts to interpret data. We want to know why some data points don’t seem to belong with the others: perhaps we want to eliminate spurious or unrepresentative data from our model. Or, the anomalies themselves may be what we are interested in: an outlier could represent the symptom of a disease, an attack on a computer network, a scientific discovery, or even an unfaithful partner. We start with some general considerations, such as the relationship between clustering and anomaly detection, the choice between supervised and unsupervised methods, and the difference between global and local anomalies. Then we will survey the most representative anomaly detection algorithms, highlighting what kind of data each approach is best suited to, and discussing their limitations. We will finish with a discussion of the difficulties of anomaly detection in high-dimensional data and some new directions for anomaly detec...

  18. Major congenital anomalies in a Danish region

    DEFF Research Database (Denmark)

    Garne, Ester; Hansen, Anne Vinkel; Birkelund, Anne Sofie

    2014-01-01

    congenital anomaly, 13.9% had a chromosomal anomaly and 7.7% were multiple congenital anomalies. The combined foetal and infant mortality in the study area was 11.6 per 1,000 births. 19% (2.2 per 1,000) of these deaths were foetuses and infants with major congenital anomalies. Combined foetal and infant......INTRODUCTION: This study describes the prevalence of congenital anomalies and changes over time in birth outcome, mortality and chronic maternal diseases. MATERIAL AND METHODS: This study was based on population data from the EUROCAT registry covering the Funen County, Denmark, 1995......-2008. The registry covers live births, foetal deaths with a gestational age (GA) of 20 weeks or more, and terminations of pregnancy due to congenital anomalies (TOPFA). RESULTS: The overall prevalence of congenital anomalies was 2.70% (95% confidence interval: 2.58-2.80). The majority of cases had an isolated...

  19. Time Series

    OpenAIRE

    Gil-Alana, L.A.; Moreno, A; Pérez-de-Gracia, F. (Fernando)

    2011-01-01

    The last 20 years have witnessed a considerable increase in the use of time series techniques in econometrics. The articles in this important set have been chosen to illustrate the main themes in time series work as it relates to econometrics. The editor has written a new concise introduction to accompany the articles. Sections covered include: Ad Hoc Forecasting Procedures, ARIMA Modelling, Structural Time Series Models, Unit Roots, Detrending and Non-stationarity, Seasonality, Seasonal Adju...

  20. INVESTIGATION OF MULTIPHASE-REINFORCED Si3N4 COMPOSITE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    曾鸣; 丁博; 郭梦熊

    1995-01-01

    By means of whisker reinforce and paricle dispersion, the routes of property improvement on Si3N4 ceramic material have been studied. The mecihaniacl properties of Siw/Si3N4 and Siw/Si3N4TiC material was compared, which proved that multiphase reinforce had overlap effect. Microstructure of the material was investigated by means of SEM and the mechanisms of SiCw and TiCP reinforces had been disussed.

  1. Terahertz generation from Si3N4 covered photoconductive dipole antenna

    Institute of Scientific and Technical Information of China (English)

    Wei Shi(施卫); Jingzhou Xu; X.-C.Zhang

    2003-01-01

    We observe enhanced terahertz (THz) radiation generated from a Si3N4 film-coated GaAs photoconductivedipole antenna. Compared to an uncoated antenna with identical electrode geometry and optical excitationpower, the Si3N4 film-coated antenna has a higher effective DC resistance and larger breakdown voltage.As a result, the peak amplitude of generated THz radiation is significantly enhanced due to the Si3N4film-coated layer.

  2. Two Novel C3N4 Phases: Structural, Mechanical and Electronic Properties

    Directory of Open Access Journals (Sweden)

    Qingyang Fan

    2016-05-01

    Full Text Available We systematically studied the physical properties of a novel superhard (t-C3N4 and a novel hard (m-C3N4 C3N4 allotrope. Detailed theoretical studies of the structural properties, elastic properties, density of states, and mechanical properties of these two C3N4 phases were carried out using first-principles calculations. The calculated elastic constants and the hardness revealed that t-C3N4 is ultra-incompressible and superhard, with a high bulk modulus of 375 GPa and a high hardness of 80 GPa. m-C3N4 and t-C3N4 both exhibit large anisotropy with respect to Poisson’s ratio, shear modulus, and Young’s modulus. Moreover, m-C3N4 is a quasi-direct-bandgap semiconductor, with a band gap of 4.522 eV, and t-C3N4 is also a quasi-direct-band-gap semiconductor, with a band gap of 4.210 eV, with the HSE06 functional.

  3. Preparation and Properties of Sintering Additives Coated Si3N4 from Heterogeneous Nucleation Processing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The sintering additives such as Al2O3 and/or Y2O3 were coated on the surfaces of Si3N4 particles via heterogeneousnucleation processing using a buffered pH solution as the precipitation reagent. They nucleated and grew only onthe surfaces of Si3N4 and did not form sol particles in solution by TEM observation. The isoelectric point (IEP) ofcoated Si3N4 was different from that of as-received Si3N4. The IEP of Al(OH)3-coated Si3N4 occurred at pH8.4,which is close to that of alumina. When Al(OH)3-coated Si3N4 particles were coated with Y(OH)3, the IEP of coatedSi3N4 powder shifted from pH8.4 to pH9.2, similar to that of yttria. In addition, the rheological data showed thatAl2O3 and/or Y2O3 coated Si3N4 suspension is nearly Newtonian and that added Si3N4 suspension shows a shearrate thinning behavior.

  4. Pyrolysis Synthesized g-C3N4 for Photocatalytic Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Gang Xin

    2013-01-01

    Full Text Available Graphitic carbon nitride (g-C3N4 was synthesized at 520°C by the pyrolysis of cyanamide, dicyandiamide, and melamine. The samples were characterized by X–ray diffraction (XRD, UV-visible diffuse reflectance spectra, Fourier transform infrared spectroscopy (FT-IR, and elemental analyzer. The photocatalytic activity of g-C3N4 was evaluated by the photodegrading experiments of methylene blue (MB. The results indicated that g-C3N4. A photocatalytic mechanism presumed the MB photodegradation over the C3N4 photocatalyst is attributed to photogenerated electron impelled multistep reduction of O2.

  5. Preparation of Si3N4 Monolithic and Si3N4/BN Multilayer Materials with Tape Casting Method%流延法在Si3N4块体及Si3N4/BN层状材料制备中的应用

    Institute of Scientific and Technical Information of China (English)

    昝青峰; 黄勇; 汪长安; 余志勇; 崔学民

    2001-01-01

    本文采用流延法制备了Si3N4块体及Si3N4/BN层状材料.流延法已经在陶瓷的制备工艺中得到了广泛的应用,但是很少用于Si3N4体系,尤其是水基流延法.用流延法制备Si3N4/BN层状材料时,可以较为容易地控制坯片的厚度,得到性能稳定的层状材料.

  6. The Impact of Si3N4 Content on the Si3N4-SiC Materials Corrosion%Si3N4含量对Si3N4-SiC材料腐蚀性能的影响

    Institute of Scientific and Technical Information of China (English)

    李杰

    2009-01-01

    利用Si3N4-SiC材料在冰晶石静态融盐电解质中的腐蚀实验研究材料的腐蚀性能,对腐蚀增重率进行记录分析,Si3N4的含量是影响材料腐蚀性能的重要因素,根据实验测定得出Si3N4的含量越高,Si3N4-SiC材料腐蚀程度越严重.

  7. On superconformal Chern-Simons-matter theories in N=4 superspace

    CERN Document Server

    Kuzenko, Sergei M

    2015-01-01

    In three dimensions, every known N=4 supermultiplet has an off-shell completion. However, there is no off-shell N=4 formulation for the known extended superconformal Chern-Simons (CS) theories with eight and more supercharges. To achieve a better understanding of this issue, we provide N=4 superfield realisations for the equations of motion which correspond to various N=4 and N=6 superconformal CS theories, including the Gaiotto-Witten theory and the ABJM theory. These superfield realisations demonstrate that the superconformal CS theories with N>3 (except for the Gaiotto-Witten theory) require a reducible long N=4 vector multiplet, from which the standard left and right N=4 vector multiplets are obtained by constraining the field strength to be either self-dual or anti self-dual. Such a long multiplet naturally originates upon reduction of any off-shell N>4 vector multiplet to N=4 superspace. For the long N=4 vector multiplet we develop a prepotential formulation. It makes use of two prepotentials being subj...

  8. Congenital anomalies in Primorsky region.

    Science.gov (United States)

    Kiku, P; Voronin, S; Golokhvast, K

    2015-01-01

    According to WHO hereditary diseases and congenital malformations contribute significantly to the health of population. Thus, the problems of epidemiology, clinical presentation, diagnosis and treatment of congenital abnormalities are of interest for many researchers [2]. In addition, the dynamic accounting for the incidence of congenital malformations and hereditary diseases allows the researchers to assess the ecological situation in the region [1]. The occurrence of congenital anomalies in the world varies; it depends heavily on how carefully the data is collected [4]. Multifactorial or polygenic diseases develop under the influence of environmental factors in the presence of defective genes. They can constitute up to 90% of all chronic pathology [2-5]. To determine the incidence of congenital anomalies under the influence of environmental factors. The study used the methodology of system evaluation of congenital anomalies incidence in Primorsky region, depending on bio-climatic and environmental conditions. The authors used health statistics for the period from 2000 to 2014, F.12 class for congenital abnormalities in adolescents and children that were compared in geographical and temporal aspects with environmental factors of 33 settlements in Primorsky region. The environment is represented by nature and climate (6 factor modules) and sanitation (7 factor modules) blocks of factors. When formalizing the information database of the environment a specially developed 10-point assessment scale was used. Statistical processing of the information was carried out using Pearson's chi-squared test and multiple regression method from SSPS application program package. The study found that over the 15-year period the level of congenital abnormalities in children increased by 27.5% and in adolescents - by 35.1%, and in 2014 it amounted to 1687.6 and 839.3 per 100 000 people, respectively. The predictive model shows a steady further growth of this pathology. The incidence

  9. Chiral Anomaly in Contorted Spacetimes

    CERN Document Server

    Mielke, E W

    1999-01-01

    The Dirac equation in Riemann-Cartan spacetimes with torsion is reconsidered. As is well-known, only the axial covector torsion $A$, a one-form, couples to massive Dirac fields. Using diagrammatic techniques, we show that besides the familiar Riemannian term only the Pontrjagin type four-form $dA\\wedge dA$ does arise additionally in the chiral anomaly, but not the Nieh-Yan term $d ^* A$, as has been claimed recently. Implications for cosmic strings in Einstein-Cartan theory as well as for Ashtekar's canonical approach to quantum gravity are discussed.

  10. Endocrine disruptors and congenital anomalies

    Directory of Open Access Journals (Sweden)

    Mônica Rittler

    2002-04-01

    Full Text Available The specialized literature was reviewed concerning the suspected increasing secular trends in the frequency of female births, male genital congenital anomalies, abnormal sperm counts, and testicular cancer. Although no risk factors could be identified yet, the observed sex ratio decline during the last decades has been considered to be an effect of certain pollutants on normal hormone activity, and human reproductive development. Reported increasing trends in the frequencies of hypospadias and cryptorchidism are very difficult to be interpreted due to the large variability in the registered frequency of these malformations due to operational as well as biological reasons.

  11. Recognising serious umbilical cord anomalies.

    Science.gov (United States)

    Marshall, Andrew S J; Jayapal, Sathiya S K; Whitburn, Jessica A S; Akinbiyi, Bolutito A; Willetts, Ian E

    2013-11-27

    Umbilical vessel catheterisation is a common intervention in neonatal care. Many complications are recognised, some of which are life-threatening. We report the case of a term neonate who was compromised at birth following antepartum haemorrhage with evidence of multiorgan ischaemic injury. Following resuscitation and umbilical vessel catheterisation, she developed pneumoperitoneum. At laparotomy, a patent vitellointestinal duct was identified and resected. Intestinal perforation was found in the duct wall, most plausibly explained by the unintentional catheterisation of the duct via the umbilicus. Learning to recognise umbilical cord anomalies, such as patent vitellointestinal duct, can be simple and could prevent potentially serious complications.

  12. Hot Flow Anomalies at Venus

    Science.gov (United States)

    Collinson, G. A.; Sibeck, David Gary; Boardsen, Scott A.; Moore, Tom; Barabash, S.; Masters, A.; Shane, N.; Slavin, J.A.; Coates, A.J.; Zhang, T. L.; Sarantos, M.

    2012-01-01

    We present a multi-instrument study of a hot flow anomaly (HFA) observed by the Venus Express spacecraft in the Venusian foreshock, on 22 March 2008, incorporating both Venus Express Magnetometer and Analyzer of Space Plasmas and Energetic Atoms (ASPERA) plasma observations. Centered on an interplanetary magnetic field discontinuity with inward convective motional electric fields on both sides, with a decreased core field strength, ion observations consistent with a flow deflection, and bounded by compressive heated edges, the properties of this event are consistent with those of HFAs observed at other planets within the solar system.

  13. Data mining in time series databases

    CERN Document Server

    Kandel, Abraham; Bunke, Horst

    2004-01-01

    Adding the time dimension to real-world databases produces Time SeriesDatabases (TSDB) and introduces new aspects and difficulties to datamining and knowledge discovery. This book covers the state-of-the-artmethodology for mining time series databases. The novel data miningmethods presented in the book include techniques for efficientsegmentation, indexing, and classification of noisy and dynamic timeseries. A graph-based method for anomaly detection in time series isdescribed and the book also studies the implications of a novel andpotentially useful representation of time series as strings. Theproblem of detecting changes in data mining models that are inducedfrom temporal databases is additionally discussed.

  14. Preparation and EDM Performance of Si3N4-TiC and Si3N4-TiN Composite Conductive Ceramics%Si3N4-TiC和Si3N4-TiN复相导电陶瓷的制备及电加工性能研究

    Institute of Scientific and Technical Information of China (English)

    古尚贤; 郭伟明; 伍尚华; 游洋; 蒋强国; 高棱

    2015-01-01

    以TiC和TiN粉为导电相,利用热压烧结制备了Si3N4-TiC和Si3N4-TiN复相导电陶瓷.比较了TiC和TiN对Si3N4陶瓷相组成、致密度、显微结构、力学性能、导电性能及电火花加工性能的影响.结果表明:高温下TiN与Si3N4具有良好稳定性,烧结后获得Si3N4-TiN复相导电陶瓷,然而高温下TiC却与Si3N4反应形成了TiC0.5N0.5和SiC,烧结后获得Si3 N4-TiC0.5N0.5-SiC复相导电陶瓷.虽然TiN和TiC的引入对Si3N4的硬度和断裂韧性的影响没有明显差别,然而TiC的引入可以更好的改善Si3N4的致密化、导电性能及电火花加工性能;与以TiN为导电相所制备的Si3N4基导电陶瓷相比,以TiC为导电相所制备的Si3N4基复相导电陶瓷电火花加工后表面的粗糙度值和材料去除率更低.

  15. Anomaly detection based on sensor data in petroleum industry applications.

    Science.gov (United States)

    Martí, Luis; Sanchez-Pi, Nayat; Molina, José Manuel; Garcia, Ana Cristina Bicharra

    2015-01-27

    Anomaly detection is the problem of finding patterns in data that do not conform to an a priori expected behavior. This is related to the problem in which some samples are distant, in terms of a given metric, from the rest of the dataset, where these anomalous samples are indicated as outliers. Anomaly detection has recently attracted the attention of the research community, because of its relevance in real-world applications, like intrusion detection, fraud detection, fault detection and system health monitoring, among many others. Anomalies themselves can have a positive or negative nature, depending on their context and interpretation. However, in either case, it is important for decision makers to be able to detect them in order to take appropriate actions. The petroleum industry is one of the application contexts where these problems are present. The correct detection of such types of unusual information empowers the decision maker with the capacity to act on the system in order to correctly avoid, correct or react to the situations associated with them. In that application context, heavy extraction machines for pumping and generation operations, like turbomachines, are intensively monitored by hundreds of sensors each that send measurements with a high frequency for damage prevention. In this paper, we propose a combination of yet another segmentation algorithm (YASA), a novel fast and high quality segmentation algorithm, with a one-class support vector machine approach for efficient anomaly detection in turbomachines. The proposal is meant for dealing with the aforementioned task and to cope with the lack of labeled training data. As a result, we perform a series of empirical studies comparing our approach to other methods applied to benchmark problems and a real-life application related to oil platform turbomachinery anomaly detection.

  16. Anomaly Detection Based on Sensor Data in Petroleum Industry Applications

    Directory of Open Access Journals (Sweden)

    Luis Martí

    2015-01-01

    Full Text Available Anomaly detection is the problem of finding patterns in data that do not conform to an a priori expected behavior. This is related to the problem in which some samples are distant, in terms of a given metric, from the rest of the dataset, where these anomalous samples are indicated as outliers. Anomaly detection has recently attracted the attention of the research community, because of its relevance in real-world applications, like intrusion detection, fraud detection, fault detection and system health monitoring, among many others. Anomalies themselves can have a positive or negative nature, depending on their context and interpretation. However, in either case, it is important for decision makers to be able to detect them in order to take appropriate actions. The petroleum industry is one of the application contexts where these problems are present. The correct detection of such types of unusual information empowers the decision maker with the capacity to act on the system in order to correctly avoid, correct or react to the situations associated with them. In that application context, heavy extraction machines for pumping and generation operations, like turbomachines, are intensively monitored by hundreds of sensors each that send measurements with a high frequency for damage prevention. In this paper, we propose a combination of yet another segmentation algorithm (YASA, a novel fast and high quality segmentation algorithm, with a one-class support vector machine approach for efficient anomaly detection in turbomachines. The proposal is meant for dealing with the aforementioned task and to cope with the lack of labeled training data. As a result, we perform a series of empirical studies comparing our approach to other methods applied to benchmark problems and a real-life application related to oil platform turbomachinery anomaly detection.

  17. TECHNICAL AND FUNDAMENTAL ANOMALIES. PARADOXES OF MODERN STOCK EXCHANGE MARKETS

    Directory of Open Access Journals (Sweden)

    BAKO Elena Dana

    2013-07-01

    Full Text Available This paper continues the series of researches about the paradoxes of modern stock exchange markets and their impact on the real economy, addressing this time the most important technical anomalies but also fundamental anomalies, which can be observed on the financial markets. As we mentioned in several previous articles, the paradoxes of stock exchanges are related to potential contradictions that arise in relation to a generally accepted truth. A lot of researches in the field of stock market investment focused on finding the answer to the question whether historical prices can be used to predict future prices for listed securities. Complex forecasting methods were created to clarify this aspect. Thus, technical analysis is a method of forecasting the price movements and trends of the market in the future, by studying the market graphs (including here both, the price of the listed instruments and the volume of transactions. The fundamental anomalies refer to the anomalies in trading financial instruments, and to the elements of fundamental analysis. The basic principle of fundamental analysis refers to the fact that the market price of any financial instrument is the result of supply and demand for that instrument. Both the supply and demand that finally determine the price of a financial instrument, are under the influence of various factors. Market’s analysts monitor various economic indicators and examine the market reports, to detect changes that may occur in the economy. The fundamental analysis attempts to predict prices and the overall market development by analyzing some economic indicators, political or social factors which are likely to influence the stock exchange prices. Both technical and fundamental anomalies have a major impact on price formation for financial instruments which are traded on stock exchanges, and are able to offer to warned investors higher earnings.

  18. Anomaly Detection Based on Sensor Data in Petroleum Industry Applications

    Science.gov (United States)

    Martí, Luis; Sanchez-Pi, Nayat; Molina, José Manuel; Garcia, Ana Cristina Bicharra

    2015-01-01

    Anomaly detection is the problem of finding patterns in data that do not conform to an a priori expected behavior. This is related to the problem in which some samples are distant, in terms of a given metric, from the rest of the dataset, where these anomalous samples are indicated as outliers. Anomaly detection has recently attracted the attention of the research community, because of its relevance in real-world applications, like intrusion detection, fraud detection, fault detection and system health monitoring, among many others. Anomalies themselves can have a positive or negative nature, depending on their context and interpretation. However, in either case, it is important for decision makers to be able to detect them in order to take appropriate actions. The petroleum industry is one of the application contexts where these problems are present. The correct detection of such types of unusual information empowers the decision maker with the capacity to act on the system in order to correctly avoid, correct or react to the situations associated with them. In that application context, heavy extraction machines for pumping and generation operations, like turbomachines, are intensively monitored by hundreds of sensors each that send measurements with a high frequency for damage prevention. In this paper, we propose a combination of yet another segmentation algorithm (YASA), a novel fast and high quality segmentation algorithm, with a one-class support vector machine approach for efficient anomaly detection in turbomachines. The proposal is meant for dealing with the aforementioned task and to cope with the lack of labeled training data. As a result, we perform a series of empirical studies comparing our approach to other methods applied to benchmark problems and a real-life application related to oil platform turbomachinery anomaly detection. PMID:25633599

  19. Comparative genomics defines the core genome of the growing N4-like phage genus and identifies N4-like Roseophage specific genes

    Directory of Open Access Journals (Sweden)

    Jacqueline Zoe-Munn Chan

    2014-10-01

    Full Text Available Two bacteriophages, RPP1 and RLP1, infecting members of the marine Roseobacter clade were isolated from seawater. Their linear genomes are 74.7 and 74.6 kb and encode 91 and 92 coding DNA sequences, respectively. Around 30% of these are homologous to genes found in Enterobacter phage N4. Comparative genomics of these two new Roseobacter phages and twenty-three other sequenced N4-like phages (three infecting members of the Roseobacter lineage and twenty infecting other Gammaproteobacteria revealed that N4-like phages share a core genome of 14 genes responsible for control of gene expression, replication and virion proteins. Phylogenetic analysis of these genes placed the five N4-like roseophages (RN4 into a distinct subclade. Analysis of the RN4 phage genomes revealed they share a further 19 genes of which nine are found exclusively in RN4 phages and four appear to have been acquired from their bacterial hosts. Proteomic analysis of the RPP1 and RLP1 virions identified a second structural module present in the RN4 phages similar to that found in the Pseudomonas N4-like phage LIT1. Searches of various metagenomic databases, included the GOS database, using CDS sequences from RPP1 suggests these phages are widely distributed in marine environments in particular in the open ocean environment.

  20. Graphitic-C(3)N(4)-hybridized TiO(2) nanosheets with reactive {001} facets to enhance the UV- and visible-light photocatalytic activity.

    Science.gov (United States)

    Gu, Liuan; Wang, Jingyu; Zou, Zhijuan; Han, Xijiang

    2014-03-15

    AnataseTiO(2)nanosheets with dominant {001} facets were hybridized with graphitic carbon nitride (g-C(3)N(4)) using a facile solvent evaporation method. On top of the superior photocatalytic performance of highly reactive {001} facets, the hybridization with g-C(3)N(4) is confirmed to further improve the reactivity through degrading a series of organic molecules under both UV- and visible-light irradiation. It is proposed that an effective charge separation between g-C(3)N(4) and TiO2 exists in the photocatalytic process, i.e., the transferring of photogenerated holes from the valence band (VB) of TiO(2) to the highest occupied molecular orbital (HOMO) of g-C(3)N(4), and the injecting of electrons from the lowest unoccupied molecular orbital (LUMO) of g-C(3)N(4) to the conduction band (CB) of TiO(2). Due to this synergistic effect, the enhancement of UV- and visible-light photoactivity over the hybrid is achieved. Furthermore, it has been revealed that holes were the main factor for the improved photoactivity under UV-light, while the OH radicals gained the predominance for degrading organic molecules under visible-light. Overall, this work would be significant for fabricating efficient UV-/visible-photocatalysts and providing deeper insight into the enhanced mechanisms of π-conjugated molecules hybridized semiconductors. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Relationship between monthly temperature anomalies and drought frequency

    Science.gov (United States)

    Maeda, E.; Naumann, G.

    2012-04-01

    Meteorological droughts are extreme climate events characterized by a period, of months or years, with below-normal precipitation. The economical and ecological impacts of such events can be catastrophic, having profound effects for agricultural production, water resources, biodiversity, tourism and many other aspects. It is recognized that the cause of meteorological droughts are largely associated with fluctuations on sea surface temperature and atmospheric dynamic processes. Nevertheless, the influence of surface air temperature on the frequency of meteorological droughts is still unclear. The objective of this study was to assess the relationship between temperature anomalies and drought frequency. Records from 50 stations from the Global Historical Climatology Network (GHCN) were analyzed at monthly time scale. The criterion used to select the stations was solely the length of the time series recorded in the stations. Namely, only stations with more than 100 years records, for both precipitation and temperature, were used in this study. In general, the selected stations were distributed along Australia, European countries, Unites States and Canada. Standardized temperature anomalies were calculated taking as baseline the entire dataset recorded at the station. The precipitation anomalies for each month were assessed through the Standardized Precipitation Index (SPI) according to the empirical cumulative distribution at each location. Therefore, both temperature anomalies and precipitation deficits were normalized, allowing a direct comparison of the entire dataset in each station, independent of the season of the year. Next, the monthly SPI were associated with the respective monthly temperatures anomalies. The SPI values were binned based on the temperature anomaly values. The used bin width was 0.5 degC. Finally, for each temperature anomaly bin, the average SPI and the frequency of months with SPI lower than -1 (moderated drought) were calculated. In order

  2. Luminescent nitridophosphates CaP2 N4 :Eu(2+) , SrP2 N4 :Eu(2+) , BaP2 N4 :Eu(2+) , and BaSr2 P6 N12 :Eu(2.).

    Science.gov (United States)

    Pucher, Florian J; Marchuk, Alexey; Schmidt, Peter J; Wiechert, Detlef; Schnick, Wolfgang

    2015-04-20

    Nitridophosphates MP2 N4 :Eu(2+) (M=Ca, Sr, Ba) and BaSr2 P6 N12 :Eu(2+) have been synthesized at elevated pressures and 1100-1300 °C starting from the corresponding azides and P3 N5 with EuCl2 as dopant. Addition of NH4 Cl as mineralizer allowed for the growth of single crystals. This led to the successful structure elucidation of a highly condensed nitridophosphate from single-crystal X-ray diffraction data (CaP2 N4 :Eu(2+) (P63 , no. 173), a=16.847(2), c=7.8592(16) Å, V=1931.7(6) Å(3) , Z=24, 2033 observed reflections, 176 refined parameters, wR2 =0.096). Upon excitation by UV light, luminescence due to parity-allowed 4f(6) ((7) F)5d(1) →4f(7) ((8) S7/2 ) transition was observed in the orange (CaP2 N4 :Eu(2+) , λmax =575 nm), green (SrP2 N4 :Eu(2+) , λmax =529 nm), and blue regions of the visible spectrum (BaSr2 P6 N12 :Eu(2+) and BaP2 N4 :Eu(2+) , λmax =450 and 460 nm, respectively). Thus, the emission wavelength decreases with increasing ionic radius of the alkaline-earth ions. The corresponding full width at half maximum values (2240-2460 cm(-1) ) are comparable to those of other known Eu(2+) -doped (oxo)nitrides emitting in the same region of the visible spectrum. Following recently described quaternary Ba3 P5 N10 Br:Eu(2+) , this investigation represents the first report on the luminescence of Eu(2+) -doped ternary nitridophosphates. Similarly to nitridosilicates and related oxonitrides, Eu(2+) -doped nitridophosphates may have the potential to be further developed into efficient light-emitting diode phosphors.

  3. A study of dental anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Sook; Kim, Jae Duck [Dept. of Oral Radiology, College of Dentistry, Chosun University, Kwangju (Korea, Republic of)

    1993-08-15

    The purpose of this study was to find out the prevalence of dental anomalies in 600 normal persons (male:363, female:237) at age 14 to 39 years, through history taking, oral examination, and radiographic observations of subjects. The obtained results were as follows: 1. The prevalence of individual dental anomalies were as follows; Congenitally missing teeth 7%; supernumerary teeth 1.33%; ectopic eruption 8.50%; transposition 0.33%; rotation 23.67%; microdontia 11.16% (peg lateral is 5.33%; third molar 5.83%); prolonged retention of deciduous teeth 1.33%; crowding 49.83%; and spacing 15.17%. 2. Alterations in numbers of teeth : The most frequently missing teeth were mandibular lateral incisors, followed by mandibular second premolars and maxillary second premolars. In numbers of congenitally missing teeth per person, 52.38% had one missing tooth and 30.95% had two missing teeth. In supernumerary teeth, there was higher rate in male than in female. Most supernumerary teeth were mesiodens of median area in maxilla and the eruption pattern of that teeth generally was unerupted state. 3. In transposition, exchange of position of teeth involved the canine and first premolar. 4. Congenital missing rate of permanent successors in prolonged retention of deciduous teeth was 69.23%. 5. Crowding and spacing had respectively higher rate in mandible and in maxilla.

  4. Multimodality imaging of vascular anomalies.

    Science.gov (United States)

    Restrepo, Ricardo

    2013-03-01

    Vascular malformations and hemangiomas are common in children but remain a source of confusion during diagnosis, in part because of the lack of a uniform terminology. With the existing treatments for hemangiomas and vascular malformations, it is important to make the correct diagnosis initially to prevent adverse physical and emotional sequelae in not only the child but also the family. The diagnosis of vascular malformations is made primarily by the clinician and based on the physical exam. Imaging is carried out using predominantly ultrasound (US) and magnetic resonance imaging (MRI), which are complementary modalities. In most cases of vascular anomalies, US is the first line of imaging as it is readily available, less expensive, lacks ionizing radiation and does not require sedation. MRI is also of great help for further characterizing the lesions. Conventional arteriography is reserved for cases that require therapeutic intervention, more commonly for arteriovenous malformations. Radiographs usually play no role in diagnosing vascular anomalies in children. In this article, the author describes the terminology and types of hemangiomas and vascular malformations and their clinical, histological features, as well as the imaging approach and appearance.

  5. Microstructure and mechanical properties of Ni-P-Si3N4 nanowire electroless composite coatings

    Science.gov (United States)

    Wang, Shilong; Huang, Xuefei; Gong, Mengxiao; Huang, Weigang

    2015-12-01

    In this paper, a new Ni-P-Si3N4 nanowire composite coating has been successfully prepared on AZ31 Mg substrate through electroless deposition technique. The effect of Si3N4 nanowire concentration in the plating bath on the surface morphology, hardness and wear behavior of the composite coatings have been investigated. The results show that when the concentrations of Si3N4 nanowire is 1.5 g/L, the morphology of composite coating appears the fine nodular structure. Moreover, the Si3N4 nanowire is uniformly dispersed in the coating at the 1.5 g/L concentrations of Si3N4 nanowire. But when the concentrations of Si3N4 nanowire in bath over 1.5 g/L, the coatings surface morphology become roughness and some pores appear on the coating surface because of the agglomeration of Si3N4 nanowire. As seen from the experiments results, the microhardness of the composite coating were significantly increased to about 790HV200 as plating, the friction coefficient and wear weight loss of the composite coating is both decreased to the 1/6 of conventional Ni-P electroless coating. These improvements have been attributed to the dispersion strengthening effect of Si3N4 nanowire.

  6. Process control & monitoring for laser micromaching of Si3N4 ceramics

    CSIR Research Space (South Africa)

    Tshabalala, L

    2012-09-01

    Full Text Available Laser machining which is a non-contact process that offers the advantage of machining advanced ceramics. In laser machining Si3N4, surface temperature is increased and controlled to evaporate the YSiAlON glassy phase of the Si3N4. However...

  7. Enhancement of photocatalytic and photoelectrocatalytic activity of Ag modified Mpg-C3N4 composites

    Science.gov (United States)

    He, Qiuchen; Zhou, Feng; Zhan, Su; Yang, Yifan; Liu, Yujun; Tian, Yu; Huang, Naibao

    2017-01-01

    In this study, mpg-C3N4/Ag composites of surface plasmon resonance structures were fabricated to improve the photocatalytic and photoelectrocatalytic activities of g-C3N4 via photo-assisted reduction method, which were characterized by XRD, EDS, XPS, FT-IR, FE-SEM, TEM, DRS and BET. The photocatalytic and photoelectrocatalytic activities were evaluated by the degradation of methylene blue (MB) and the oxygen reduction experiment under visible light. The results showed the photocatalytic and photoelectrocatalytic activities were dependent on the weight ratio of Ag and the optimum photocatalytic activity of mpg-C3N4/Ag at a weight ratio of 3% is almost 3 times as high as that of mpg-C3N4. Additionally, mpg-C3N4/Ag exhibited a significantly enhanced oxygen reduction performance under visible light. The limit current density was increased about 2 times by the modification of Ag nanoparticles, compared with that of pristine mpg-C3N4. Finally, based on the first principle, the enhancement mechanism of the photocatalytic and photoelectrocatalytic activities was discussed by the calculation on the band structure and density of states in the mpg-C3N4/Ag composites. The appropriate amount of Ag modification would cause the surface plasmon resonance effect, which improved the photocatalytic, photoelectrocatalytic, and oxygen reduction activities of mpg-C3N4.

  8. Sintering and properties of Si3N4 with and without additives by HIP treatment

    Science.gov (United States)

    Kuratani, S.; Shimada, M.; Koizumi, M.

    1986-01-01

    Hot Isostatic Pressing (HIP) of Si3N4 powders with and without additives was performed using a glass container, and various kinds of pressureless-sintered Si3N4 were HIP'ed without a container. The effects of HIP treatment on density, microstructure, flexural strength, microhardness, and fracture toughness on Si3N4 ceramics were studied. Using a glass container it was difficult to reach theoretical density. The microhardness of HIP'ed Si3N4 without additives was low, and the fracture toughness of HIP'ed Si3N4 with and without additives was 22 to 25 W/m-K, and it decreased with increasing the amount of additives. The density and flexural strength, and hardness of pressureless-sintered Si3N4 which contained Al2O and Y2O3 as oxide additives were remarkably improved by HIP treatment using nitrogen as a pressure transmitting gas. It is very important to select the sintering conditions for fabricating the presintered body of Si3N4 in order to improve the mechanical properties of Si3N4 by HIP treatment.

  9. High confinement, high yield Si3N4 waveguides for nonlinear optical applications

    NARCIS (Netherlands)

    Epping, J.P.; Hoekman, M.; Mateman, R.; Leinse, A.; Heideman, R.G.; Rees, van A.; Slot, van der P.J.M.; Lee, C.J.; Boller, K-J.

    2015-01-01

    In this paper we present a novel fabrication technique for silicon nitride (Si3N4) waveguides with a thickness of up to 900 nm, which are suitable for nonlinear optical applications. The fabrication method is based on etching trenches in thermally oxidized silicon and filling the trenches with Si3N4

  10. Space Telescope Fine Guidance Sensor Bearing Anomaly

    Science.gov (United States)

    Loewenthal, S.; Esper, J.; Pan, J.; Decker, J.

    1996-01-01

    Early in 1993, a servo motor within one of three Fine Guidance Sensors (FGS) aboard the Hubble Space Telescope (HST) reached stall torque levels on several occasions. Little time was left to plan replacement during the first servicing mission, scheduled at the end of '93. Accelerated bearing life tests confirmed that a small angle rocking motion, known as Coarse Track (CT), accelerated bearing degradation. Saturation torque levels were reached after approximately 20 million test cycles, similar to the flight bearings. Reduction in CT operation, implemented in flight software, extended FGS life well beyond the first servicing mission. However in recent years, bearing torques have resumed upward trends and together with a second, recent bearing torque anomaly has necessitated a scheduled FGS replacement during the upcoming second servicing mission in '97. The results from two series of life tests to quantify FGS bearing remaining life, discussion of bearing on-orbit performance, and future plans to service the FGS servos are presented in this paper.

  11. Developmental venous anomaly in the newborn brain

    Energy Technology Data Exchange (ETDEWEB)

    Horsch, S. [Erasmus MC-Sophia Children' s Hospital, Department of Neonatology, Rotterdam (Netherlands); Helios Klinikum Berlin-Buch, Department of Neonatology, Berlin (Germany); Govaert, P. [Erasmus MC-Sophia Children' s Hospital, Department of Neonatology, Rotterdam (Netherlands); Cowan, F.M. [Hammersmith Hospital, Department of Paediatrics, Imperial College Healthcare NHS Trust, London (United Kingdom); Benders, M.J.N.L.; Groenendaal, F.; Vries, L.S. de [University Medical Centre Utrecht, Wilhelmina Children' s Hospital, Department of Neonatology, Utrecht (Netherlands); Lequin, M.H. [Erasmus MC/Sophia Children' s Hospital, Department of Paediatric Radiology, Rotterdam (Netherlands); Saliou, G. [University Hospital, Department of Neuroradiology, Le Kremlin-Bicetre (France)

    2014-07-15

    Cerebral developmental venous anomaly (DVA) is considered a benign anatomical variant of parenchymal venous drainage; it is the most common vascular malformation seen in the adult brain. Despite its assumed congenital origin, little is known about DVA in the neonatal brain. We report here the first cohort study of 14 neonates with DVA. Fourteen infants (seven preterm) with DVA diagnosed neonatally using cranial ultrasound (cUS) and magnetic resonance imaging (MRI) from three tertiary neonatal units over 14 years are reviewed. DVA was first detected on cUS in 6 and on MRI in 8 of the 14 infants. The cUS appearances of DVA showed a focal fairly uniform area of increased echogenicity, often (86 %) adjacent to the lateral ventricle and located in the frontal lobe (58 %). Blood flow in the dilated collector vein detected by Doppler ultrasound (US) varied between cases (venous flow pattern in ten and arterialized in four). The appearance on conventional MRI was similar to findings in adults. Serial imaging showed a fairly constant appearance to the DVAs in some cases while others varied considerably regarding anatomical extent and flow velocity. This case series underlines that a neonatal diagnosis of DVA is possible with carefully performed cUS and MRI and that DVA tends to be an incidental finding with a diverse spectrum of imaging appearances. Serial imaging suggests that some DVAs undergo dynamic changes during the neonatal period and early infancy; this may contribute to why diagnosis is rare at this age. (orig.)

  12. Effect of β-Si3N4 Content on Y2O3 -MgO-α-Si3N4 Properties%β-Si3N4含量对Y2O3-MgO-α-Si3N4陶瓷性能的影响

    Institute of Scientific and Technical Information of China (English)

    李荐; 李淳伟; 周宏明; 黄祖琼; 刘凡; 李艳芬; 杨俊; 杨亮

    2011-01-01

    利用扫描电子显微分析等手段,研究了棒状β-Si3N4含量对Y2O3-MgO-α-Si3N4陶瓷致密度、力学性能和显微结构的影响,确定了β-Si3N4和α-Si3N4的适宜配比.结果显示:随着β-Si3N4含量的增加,Y2O3-MgO-α-Si3N4陶瓷材料致密度和力学性能均先增加后降低,当β-Si3N4含量达到40%时,陶瓷致密度和力学性能同时达到最大,此时致密度为93%,横向断裂强度为583.4 MPa,断裂韧性为5.42 MPa·m1/2.%The influence of bar-shaped (3-Si3N4 content on the density, mechanical property and microstructure of Y2O3-MgO-a-Si3N4 was researched by using SME and other methods, and the most appropriate proportion of JJ-Si3N4 to ct-Si3N4 was determined. The results showed that with the increasing of the content of p-Si3N4 both of the density and mechanical property of Y2O3-MgO-a-Si3N4 ceramic material first increased, then decreased. When p-Si3N4 content achieved 40% , the density and mechanical property both reached to the maximum, with a density of 93% , transverse rupture strength of 583.4 Mpa and fracture toughness of 5.42 Mpa ? M1/2.

  13. Effects of talc and clay addition on pressureless sintering of porous Si3N4 ceramics

    Indian Academy of Sciences (India)

    Yu Fangli; Yang Jianfeng; Xue Yaohui; Du Jun; Lu Yuan; Gao Jiqiang

    2009-04-01

    Porous Si3N4 ceramics were successfully synthesized using cheaper talc and clay as sintering additives by pressureless sintering technology and the microstructure and mechanical properties of the ceramics were also investigated. The results indicated that the ceramics consisted of elongated -Si3N4 and small Si2N2O grains. Fibrous -Si3N4 grains developed in the porous microstructure, and the grain morphology and size were affected by different sintering conditions. Adding 20% talc and clay sintered at 1700°C for 2 h, the porous Si3N4 ceramics were obtained with excellent properties. The final mechanical properties of the Si3N4 ceramics were as follows: porosity, 0 = 45.39%; density, ρ = 1.663.g.cm-3; flexural strength, b (average) = 131.59 MPa; Weibull modulus, = 16.20.

  14. Effect of electrodeposition conditions on the properties of Cu-Si3N4 composite coatings

    Science.gov (United States)

    Eslami, Maryam; Saghafian, Hassan; Golestani-fard, Farhad; Robin, Alain

    2014-05-01

    Cu-Si3N4 composite coatings were obtained by co-electrodeposition under DC conditions from a copper sulphate bath containing suspended Si3N4 particles. The effect of some electroplating parameters such as surfactant (SDS) concentration, stirring rate, and particle concentration on microstructural and mechanical properties of the coatings was investigated. The incorporation of Si3N4 particles into the copper matrix resulted in the production of coatings with finer copper grains. The incorporation of Si3N4 particles also led to a change of the preferred growth orientation of copper grains from (2 0 0) to (2 2 0) crystal face. Cu-Si3N4 composite coatings presented lower friction coefficient and wear loss than pure copper deposit due to the increased hardness related to grain refinement strengthening and dispersion strengthening.

  15. Effect of Rare Earths on Mechanical Properties and Microstructures of Si3N4-based Ceramics

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effects of Y2O3, La2O3 and Nd2O3 on the mechanical properties and microstructures of Si3N4-based ceramics were studied. It shows that a significant improvement in mechanical properties can be obtained by adding rare earths oxides in Si3N4. The fracture toughness and the flexural strength of Si3N4 added with both Y2O3 and La2O3 are 7.8 MPa.m1/2 and 962 MPa, respectively. The main reason is that adding rare earths in Si3N4 can improve the microstructure of the material and increase the aspect ratio of β-Si3N4 grain.

  16. Oxidation Behaviour of Si3N4 Materials in Air and Nitrogen Atmosphere

    Institute of Scientific and Technical Information of China (English)

    ZHANGQitu; LINGZhida

    1999-01-01

    Si3N4 powder and hot-pressed Si3N4 ceramics added with Al2O3 are used for investigate their oxidation behvior in air and nitrogen atmosphere(with oxygen partial pressure PO2=1-10Pa),The oxidation products of Si3N4 are examined by chemical analysi,X-ray diffraction (XRD) and XPS method,Also, thermodynamic calculation is made to analyze oxidation behavior of Si3N4.The results show that only passive oxidation will occur when Si3N4 is oxidized in air at high temperature,whereas in N2 at high temperature,the active oxidation is dominant in spite of the existence of a little passive oxidation.

  17. Highly Corrosion Resistant and Sandwich-like Si3N4/Cr-CrNx/Si3N4 Coatings Used for Solar Selective Absorbing Applications.

    Science.gov (United States)

    Zhang, Ke; Du, Miao; Haoa, Lei; Meng, Jianping; Wang, Jining; Mi, Jing; Liu, Xiaopeng

    2016-12-14

    Highly corrosion resistant, layer-by-layer nanostructured Si3N4/Cr-CrNx/Si3N4 coatings were deposited on aluminum substrate by DC/RF magnetron sputtering. Corrosion resistance experiments were performed in 0.5, 1.0, 3.0, and 5.0 wt % NaCl salt spray at 35 °C for 168 h. Properties of the coatings were comprehensively investigated in terms of optical property, surface morphology, microstructure, elemental valence state, element distribution, and potentiodynamic polarization. UV-vis-near-IR spectrophotometer and FTIR measurements show that the change process in optical properties of Si3N4/Cr-CrNx/Si3N4/Al coatings can be divided into three stages: a rapid active degradation stage, a steady passivation stage, and a transpassivation degradation stage. With the increase in the concentration of NaCl salt spray, solar absorptance and thermal emittance experienced a slight degradation. SEM images reveal that there is an increase in surface defects, such as microcracks and holes and -cracks. XRD and TEM measurements indicate that the phase structure changed partially and the content of CrOx and Al2O3 has increased. Auger electron spectroscopy shows that the elements of Cr, N, and O have undergone a minor diffusion. Electrochemical polarization curves show that the as-deposited Si3N4/Cr-CrNx/Si3N4/Al coatings have excellent corrosion resistance of 3633.858 kΩ, while after corroding in 5.0 wt % NaCl salt spray for 168 h the corrosion resistance dropped to 13.759 kΩ. However, these coatings still have an outstanding performance of high solar absorptance of 0.924 and low thermal emittance of 0.090 after corroding in 3.0 wt % NaCl salt spray for 120 h. Thus, the Si3N4/Cr-CrNx/Si3N4/Al coating is a good choice for solar absorber coatings applied in the high-saline environment.

  18. The Si/Si_3N4 Interface and Si/Si_3N4 Submicron Mesa: A Multi-million Atom Molecular Dynamics Study

    Science.gov (United States)

    Bachlechner, Martina E.; Omeltchenko, Andrey; Nakano, Aiichiro; Kalia, Rajiv K.; Vashishta, Priya; Ebbsjö, Ingvar; Madhukar, Anupam

    1998-03-01

    Using molecular dynamics simulations on parallel computers, the interface structure, stress distribution, crack propagation and fracture in a Si_3N4 film on Si substrate are studied. Bulk Si is described by Stillinger-Weber potential and Si_3N4 is represented by a combination of two- and three-body covalent interactions. At the interface, the charge transfer is taken from LCAO electronic structure calculations (G.-L. Zhao and M.E. Bachlechner, Europhys. Lett. 36, 287 (1997)). Results for structural correlations at the interface and 3D stress distribution for the submicron mesa are presented.

  19. Correlation Analysis for Total Electron Content Anomalies on 11th March, 2011

    CERN Document Server

    Iwata, Takuya

    2016-01-01

    We can observe the changes of Total Electron Content, TEC, in ionosphere by analyzing the data from GNSS satellites. There are many reports about TEC anomalies after earthquakes, i.e. large earthquakes often disturb the ionosphere. Up to now, preseismic TEC anomalies have been reported in several papers. However, they are not so clear as coseismic TEC anomalies, and their analysis methods have some problems for practical earthquake prediction. One factor making it difficult to detect TEC anomalies is large noises in TEC data. Non-negligible TEC disturbances are caused by many natural mechanisms. To overcome this difficulty, we propose correlation analyses between one GNSS station and GNSS stations surrounding it. First, we model TEC time series over a few hours using polynomial functions of time. Second, we calculate prediction errors as the departure of the TEC time series from the models over time scale of a few minutes, and define it as the TEC anomaly. Third, we calculate the correlation between anomaly o...

  20. Correlation analysis for preseismic total electron content anomalies around the 2011 Tohoku-Oki earthquake

    Science.gov (United States)

    Iwata, Takuya; Umeno, Ken

    2016-09-01

    We can observe the changes of Total Electron Content, TEC, in ionosphere by analyzing the data from Global Navigation Satellite Systems (GNSS) satellites. Up to now, preseismic TEC anomalies have been reported in several papers. However, they are not so clear as coseismic TEC anomalies, and their analysis methods have some problems for practical earthquake prediction. One factor making it difficult to detect TEC anomalies is large noises in TEC data. Nonnegligible TEC disturbances are caused by many natural mechanisms. To overcome this difficulty, we propose correlation analyses between one GNSS station and GNSS stations surrounding it. First, we model TEC time series over a few hours using polynomial functions of time. Second, we calculate prediction errors as the departure of the TEC time series from the models over time scale of a few minutes and define it as the TEC anomaly. Third, we calculate the correlation between anomaly of one GNSS station and those at the surrounding stations. Although such a correlation method has long been used for radio communications, in particular for spread spectrum communications and very long baseline interferometry to increase signal-to-noise ratio, it has not been widely applied for TEC analysis. As a result of our method, we demonstrate that the correlation analysis can detect preseismic anomalies about 1 h before the 2011 Tohoku-Oki earthquake on 11 March (Mw 9.0), 20 min before the foreshock on 9 March and 40 min before the aftershock on 7 April (Mw 7.3).

  1. The effect of nano-Si3N4 on the sintering of Si3N4 r eaction bonded SiC material%纳米Si3N4对反应烧结Si3N4结合SiC材料的影响

    Institute of Scientific and Technical Information of China (English)

    何钢; 石磊; 吕珺; 郑治祥

    2001-01-01

    利用反应烧结机制,在1 450 ℃制备了Si3N4结合SiC材料,研究表明,在引入微量纳米Si3N4粉后,材料的力学性能得到 明显提高,材料的组织也更加致密和均匀。通过X-ary、扫描电镜等技术手段分析表明,由 于纳米Si3N4粉的高表面能、高活性以及颗粒小等特点,加大了反应生成的Si3N4在 纳米Si3N4上沉积的几率,增大了氮化率,效果显著。%Si3N4 reaction bonded SiC with the addition of a small amount of nano-Si3N4 was produced at 1 450 ℃. The result showed that the mechanic properties of the material were greatly improved. The microstructu re of the material became more uniform. The mechanism of the strength improvemen t of the material was attributed to the addition. The nano-Si3N4 properties of high surface energy,high activity and small size particles increased the dep osit of Si3N4 reacted on the nano-Si3N4 and the nitriding rate of Si,th en improved the properties of the material.

  2. Electromagnetic field anomalies above an isometric depression

    Science.gov (United States)

    Golubtsova, N. S.

    1981-12-01

    The paper examines the three-dimensional simulation of the electromagnetic field above an isometric depression with conducting deposits. The model makes it possible to study the development of electromagnetic anomalies over such a depression and to make qualitative as well as quantitative assessments of the dependence of electromagnetic anomalies on field frequency, the dimensions of geoelectric inhomogeneities, and the specific resistance of the foundation of the depression. The present approach can be used in geoelectric and magnetotelluric studies of electromagnetic anomalies.

  3. Network anomaly detection a machine learning perspective

    CERN Document Server

    Bhattacharyya, Dhruba Kumar

    2013-01-01

    With the rapid rise in the ubiquity and sophistication of Internet technology and the accompanying growth in the number of network attacks, network intrusion detection has become increasingly important. Anomaly-based network intrusion detection refers to finding exceptional or nonconforming patterns in network traffic data compared to normal behavior. Finding these anomalies has extensive applications in areas such as cyber security, credit card and insurance fraud detection, and military surveillance for enemy activities. Network Anomaly Detection: A Machine Learning Perspective presents mach

  4. Development and Congenital Anomalies of the Pancreas

    OpenAIRE

    Hiroyuki Tadokoro; Masaru Takase; Bunsei Nobukawa

    2011-01-01

    Understanding how the pancreas develops is essential to understand the pathogenesis of congenital pancreatic anomalies. Recent studies have shown the advantages of investigating the development of frogs, mice, and chickens for understanding early embryonic development of the pancreas and congenital anomalies, such as choledochal cysts, anomalous pancreaticobiliary junction, annular pancreas, and pancreas divisum. These anomalies arise from failure of complete rotation and fusion during embryo...

  5. Chart Series

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Centers for Medicare and Medicaid Services (CMS) offers several different Chart Series with data on beneficiary health status, spending, operations, and quality...

  6. Case series

    African Journals Online (AJOL)

    abp

    2013-06-20

    Jun 20, 2013 ... Upper cervical spine injuries: a management of a series of 70 cases. El Fatemi ... women, with traffic accidents being the major traumatic cause. .... osteosynthesis is preferred to respect the biomechanics of the cervical spine ...

  7. Anomaly Detection from Hyperspectral Remote Sensing Imagery

    Directory of Open Access Journals (Sweden)

    Qiandong Guo

    2016-12-01

    Full Text Available Hyperspectral remote sensing imagery contains much more information in the spectral domain than does multispectral imagery. The consecutive and abundant spectral signals provide a great potential for classification and anomaly detection. In this study, two real hyperspectral data sets were used for anomaly detection. One data set was an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS data covering the post-attack World Trade Center (WTC and anomalies are fire spots. The other data set called SpecTIR contained fabric panels as anomalies compared to their background. Existing anomaly detection algorithms including the Reed–Xiaoli detector (RXD, the blocked adaptive computation efficient outlier nominator (BACON, the random selection based anomaly detector (RSAD, the weighted-RXD (W-RXD, and the probabilistic anomaly detector (PAD are reviewed here. The RXD generally sets strict assumptions to the background, which cannot be met in many scenarios, while BACON, RSAD, and W-RXD employ strategies to optimize the estimation of background information. The PAD firstly estimates both background information and anomaly information and then uses the information to conduct anomaly detection. Here, the BACON, RSAD, W-RXD, and PAD outperformed the RXD in terms of detection accuracy, and W-RXD and PAD required less time than BACON and RSAD.

  8. MRI of central nervous system anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Izawa, M.; Oikawa, A.; Matoba, A.

    1987-05-01

    MRI was very useful in the evaluation of congenital anomalies of central nervous system as well as other nervous system disease with three-dimensional spatial resolution. We had experienced MRI of central nervous system anomalies, demonstrated characterisitic findings in each anomaly. MRI is useful to observe the coronal, horizontal and sagittal images of the brain and spinal cord in order to discuss the etiological mechanisms of spinal dysraphysm and its associated anomalies. In case of spina bifida cystica MRI was available to decide operative indication for radical operation and tetherd cord developed from postoperative scar or accompanied intraspinal lesions.

  9. Vascular anomalies: differential diagnosis and mimickers.

    Science.gov (United States)

    Garzon, Maria C; Weitz, Nicole; Powell, Julie

    2016-09-01

    Vascular anomalies are very common in children and encompass a wide spectrum of diseases. Many vascular anomalies can be mistaken for infantile hemangioma (IH). In addition, there is a variety of rare disorders including benign and malignant tumors that may mimic IH and other types of vascular anomalies. Understanding the clinical features, natural history, and typical clinical course of different types of vascular anomalies is essential in order to make the correct diagnosis and guide management. Radiologic imaging plays an important role in establishing the diagnosis; and when the diagnosis remains in doubt, a biopsy performed by a surgical specialist with expertise may prove to be lifesaving.

  10. The "Parity" Anomaly On An Unorientable Manifold

    CERN Document Server

    Witten, Edward

    2016-01-01

    The "parity" anomaly -- more accurately described as an anomaly in time-reversal or reflection symmetry -- arises in certain theories of fermions coupled to gauge fields and/or gravity in a spacetime of odd dimension. The "parity" anomaly has traditionally been studied on orientable manifolds only, but recent developments involving topological superconductors have made it clear that one can get more information by asking what happens on an unorientable manifold. In this paper, we analyze the "parity" anomaly for fermions coupled to gauge fields and gravity in $2+1$ dimensions. We consider applications to gapped boundary states of a topological superconductor and to M2-branes in string/M-theory.

  11. Anomaly-free sets of fermions

    Energy Technology Data Exchange (ETDEWEB)

    Batra, Puneet; /Argonne; Dobrescu, Bogdan A.; /Fermilab; Spivak, David; /UC, Berkeley, Math. Dept.

    2005-10-01

    We present new techniques for finding anomaly-free sets of fermions. Although the anomaly cancellation conditions typically include cubic equations with integer variables that cannot be solved in general, we prove by construction that any chiral set of fermions can be embedded in a larger set of fermions which is chiral and anomaly-free. Applying these techniques to extensions of the Standard Model, we find anomaly-free models that have arbitrary quark and lepton charges under an additional U(1) gauge group.

  12. Consistent anomalies of the induced W gravities

    CERN Document Server

    Abud, M; Cappiello, L

    1995-01-01

    The BRST anomaly which may be present in the induced W_n gravity quantized on the light-cone is evaluated in the geometrical framework of Zucchini. The cocycles linked by the cohomology of the BRST operator to the anomaly are straightforwardly calculated thanks to the analogy between this formulation and the Yang-Mills theory. We give also a conformally covariant formulation of these quantities including the anomaly, which is valid on arbitrary Riemann surfaces. The example of the W_3 theory is discussed and a comparison with other candidates for the anomaly available in the literature is presented.

  13. The prevalence of congenital anomalies in Europe

    DEFF Research Database (Denmark)

    Dolk, Helen; Loane, Maria; Garne, Ester

    2010-01-01

    anomalies overwhelmingly concern children surviving the early neonatal period, who have important medical, social or educational needs. The prevalence of chromosomal anomalies was 3.6 per 1,000 births, contributing 28% of stillbirths/fetal deaths from 20 weeks gestation with congenital anomaly, and 48...... of 23.9 per 1,000 births for 2003-2007. 80% were livebirths. 2.5% of livebirths with congenital anomaly died in the first week of life. 2.0% were stillbirths or fetal deaths from 20 weeks gestation. 17.6% of all cases were terminations of pregnancy following prenatal diagnosis (TOPFA). Thus, congenital...

  14. Anomaly-Free Sets of Fermions

    CERN Document Server

    Batra, P; Spivak, D; Batra, Puneet; Dobrescu, Bogdan A.; Spivak, David

    2006-01-01

    We present new techniques for finding anomaly-free sets of fermions. Although the anomaly cancellation conditions typically include cubic equations with integer variables that cannot be solved in general, we prove by construction that any chiral set of fermions can be embedded in a larger set of fermions which is chiral and anomaly-free. Applying these techniques to extensions of the Standard Model, we find anomaly-free models that have arbitrary quark and lepton charges under an additional U(1) gauge group.

  15. The history and transitent nature of salinity anomalies in the Mediterranean Sea from advanced reanalysis

    Science.gov (United States)

    Pinardi, Nadia; Fratianni, Claudia; Lyubartsev, Vladyslav

    2015-04-01

    Long term, high resolution re-analyses of the Mediterranean Sea circulation and thermohaline structure are now available from the NextData and MyOcean projects. The first is a 60 years re-analysis (1953-2012) done with atmospheric AMIP forcing and the second is 25 years re-analysis (1987-2012) done with ECMWF atmospheric forcing re-analysis. Both concur to have a representation of the longest time series of salinity anomalies in the Mediterranean Sea, the highest space-time reconstruction ever done for the whole basin. The salinity anomalies of the Mediterranean Sea below seven hundred meters of the past 60 years are examined in comparison with the Eastern Mediterranean Transient, a phenomenon Dr. A.Hecht contributed to discover during POEM. Deep water salinity changes and Gibraltar Strait anomalies are also examined in the light of possible feedback mechanisms, as well as the structure and correlation of such salinity anomalies with atmospheric forcing.

  16. GRAVITY ANOMALIES OF THE MOON

    Directory of Open Access Journals (Sweden)

    S. G. Pugacheva

    2015-01-01

    Full Text Available The source of gravity anomalies of the Moon are large mascons with a high mass concentration at a depth of volcanic plains and lunar Maria. New data on the gravitational field of the Moon were obtained from two Grail spacecrafts. The article presents the data of physical and mechanical properties of the surface soil layer of the lunar Maria and gives an assessment of the chemical composition of the soil. There have been calculated heterogeneity parameters of the surface macro-relief of the lunar Maria: albedo, soil density, average grain diameter of the particles forming the surface layer and the volume fraction occupied by particles. It can be assumed that mascons include rich KREEP rocks with a high content of thorium and iron oxide. Formation of mascons is connected with intensive development of basaltic volcanism on the Moon in the early periods of its existence.

  17. Study to Material Al-Si3N4 Infiltration Technique%Al-Si3N4材料浸渗工艺研究

    Institute of Scientific and Technical Information of China (English)

    吴冉; 王雅红

    2007-01-01

    用β-Si3N4纳米颗粒浆料浸渍多孔聚合物材料,通过加热烧蚀掉聚合物,制备出三维空间连续网络结构预制块体,再通过无压浸渗将已熔炼好的铝液浸渗到预制体中,成功制备出陶瓷与金属相互贯穿的Si3N4/Al金属基复合材料.利用座滴定法测试了Al在Si3N4基片上的润湿角,探讨了其浸渗机理,分析了润湿角、浸渗力、浸渗温度和浸渗时间对Si3N4/Al金属基复合材料浸渗行为的影响.

  18. Si3N4-SiCp Composites Reinforced by In Situ Co-Catalyzed Generated Si3N4 Nanofibers

    Directory of Open Access Journals (Sweden)

    Juntong Huang

    2014-01-01

    Full Text Available Si3N4-SiCp composites reinforced by in situ catalytic formed nanofibers were prepared at a relatively low sintering temperature. The effects of catalyst Co on the phase compositions, microstructures, and physicochemical-mechanical properties of samples sintered at 1350°C–1450°C were investigated. The results showed that the catalyst Co enhanced the nitridation of Si. With the increase of Co addition (from 0 wt% to 2.0 wt.%, the apparent porosity of as-prepared refractories was initially decreased and subsequently increased, while the bulk density and the bending strength exhibited an opposite trend. The Si3N4-SiCp composites sintered at 1400°C had the highest strength of 60.2 MPa when the Co content was 0.5 wt.%. The catalyst Co facilitated the sintering of Si3N4-SiCp composites as well as the formation of Si3N4 nanofibers which exhibited network connection and could improve their strength.

  19. Fabrication and Properties of Porous Si_3N_4 Ceramic with High Porosity

    Institute of Scientific and Technical Information of China (English)

    Xiangming Li; Litong Zhang; Xiaowei Yin

    2012-01-01

    A novel process combining oxidation-bonding and sintering was developed to fabricate porous Si3N4 ceramic with high porosity. After sintering at 1800℃, the SiO2 in porous Si3N4 ceramic transforms into Si2N2O because of the reaction of SiO2 and Si3N4 . Due to the reaction of SiO2 and carbon, the porosity of porous Si3N4 ceramic increases obviously from 40.2% to 76.8% with the weight decreasing by 35.6%. As the porosity increases, the dielectric constant and loss of the porous Si3N4 ceramic decrease obviously from 3.08 to 1.61 and from 3.70×10(-3) to 0.74×10(-3) , but due to the production of Si2N2O whose mechanical properties are much higher than SiO2 and the increase of the bonding strength among Si3N4 particles, the flexural strength and the fracture toughness of the porous Si3N4 ceramic decrease from 55 to 39 MPa and from 0.7 to 0.5 MPa·m(1/2) , respectively, but its Vickers hardness increases from 1.2 to 1.3 GPa.

  20. Pulse electrodeposition and corrosion properties of Ni–Si3N4 nanocomposite coatings

    Indian Academy of Sciences (India)

    S Kasturibai; G Paruthimal Kalaignan

    2014-05-01

    The development of modern technology requires metallic materials with better surface properties. In the present investigation; Si3N4-reinforced nickel nanocomposite coatings were deposited on a mild steel substrate using pulse current electrodeposition process employing a nickel acetate bath. Surface morphology, composition, microstructure and crystal orientation of Ni and Ni–Si3N4 nanocomposite coatings were investigated by scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction analysis, respectively. The effect of incorporation of Si3N4 particles in the Ni nanocomposite coating on the micro hardness, corrosion behaviour has been evaluated. Smooth composite deposits containing well-distributed silicon nitride particles were obtained and the crystal grains on the surface of Ni–Si3N4 composite coating are compact. The crystallite structure was face centred cubic () for electrodeposited nickel and Ni–Si3N4 nanocomposite coatings. The micro hardness of the composite coatings (720 HV) was higher than that of pure nickel (310 HV) due to dispersion-strengthening and matrix grain refining and increased with the increase of incorporated Si3N4 particle content. The corrosion potential (corr) in the case of Ni–Si3N4 nanocomposite had shown a negative shift, confirming the cathodic protective nature of the coating.

  1. Hydrothermal synthesis of C3N4/BiOIO3 heterostructures with enhanced photocatalytic properties.

    Science.gov (United States)

    Wang, Wenjun; Cheng, Hefeng; Huang, Baibiao; Liu, Xiaolei; Qin, Xiaoyan; Zhang, Xiaoyang; Dai, Ying

    2015-03-15

    The C3N4/BiOIO3 composites with heterostructures have been fabricated by simply depositing BiOIO3 on the surface of C3N4 at hydrothermal conditions, using bismuth nitrate and potassium iodate as precursors. C3N4 is an excellent organic semiconductor, which can be excited by visible light. BiOIO3 is a layered bismuth-based compound that has an internal polar field. Coupling C3N4 with BiOIO3 can combine the advantages of the two compounds and obtain better photocatalytic properties. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transformation infrared spectra have been carried out to confirm the structures and morphologies of as-prepared products. The absorption properties have been characterized by diffuse reflectance spectra and the photocatalytic activities have been evaluated by photodegradation of methyl orange, Rhodamine B and 2,4-dichlorophenol. Compared with C3N4, all C3N4/BiOIO3 composites exhibit better visible-light-driven photocatalytic properties. It is a synergetic effect that enables the composites to harvest light and promote charge separation, which eventually leads to the enhancement of the photocatalytic efficiencies. Under UV-vis light irradiation, C3N4/BiOIO3 composites also exhibit better activities, and the charge transfer process is similar to a redox mediator-free Z-scheme system. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Development of Si3N4/Al composite by pressureless melt infiltration

    Institute of Scientific and Technical Information of China (English)

    Akhtar Farid; GUO Shi-ju

    2006-01-01

    Pressureless infiltration process to synthesize Si3N4/Al composite was investigated. Al-2%Mg alloy was infiltrated into Si3N4 and Si3N4 containing 10% Al2O3 preforms in the atmosphere of nitrogen. It is possible to infiltrate Al-2%Mg alloy in Si3N4 and Si3N4 containing 10% Al2O3 preforms. The growth of the dense composite of useful thickness was facilitated by the presence of magnesium powder at the interface and by flowing nitrogen. During infiltration Si3N4 reacted with aluminium to form Si and AlN,the growth of composite was found to proceed in two ways, depending on the Al2O3 content in the initial preform. Firstly, preform without Al2O3 content gives rise to AlN, Al3.27Si0.47 and Al type phases after infiltration. Secondly, perform with 10% Al2O3 content gives rise to AlN-Al2O3 solid solution phase (AlON), MgAl2O4, Al and Si type phases. AlON phase was only present in composite,containing 10% Al2O3 in the Si3N4 preforms before infiltration.

  3. Effect of Si3N4 on Resistance of Magnesia Based Castable

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The magnesia based curable specimens with different Si3N4 contents were casted using sintered magnesite (w(MgO)=95%) as starting material, 5iO2 micro-powder as binder, 0, 3%, 4% and 5% β-Si3N4 powder replacing the equal addition of magnesia powder respectively. The slag resistance test was carried out at 1550℃ for 3h using Baosteel tundish slag and static crucible method. The result indicates that: introducing Si3N4 could obviously improve the slag resistance of MgO based castable, which increased with increasing Si3N4 Dense SiO2 sintered layer formed on the surface of magnesia based castable because of the oxidation of Si3N4 addition, which can prevent the further slag penetration. In the deep inner of castable, the partial-pressure of oxygen was very low, so Si3N4 can exist stably. Meanwhile in reducing atmosphere, Si3N4 was hard to be sintered, which resulted in the loose interior structure of MgO based castable.

  4. 26 CFR 1.103(n)-4T - Elective carryforward of unused private activity bond limit (temporary).

    Science.gov (United States)

    2010-04-01

    ... bond limit (temporary). 1.103(n)-4T Section 1.103(n)-4T Internal Revenue INTERNAL REVENUE SERVICE... Excluded from Gross Income § 1.103(n)-4T Elective carryforward of unused private activity bond limit... carryforward for any one or more projects described in A-5 of this § 1.103(n)-4T (carryforward projects). Q-2...

  5. Temperature extremes in Western Europe and associated atmospheric anomalies

    Science.gov (United States)

    Carvalho, V. A.; Santos, J. A.

    2009-09-01

    This worḱs focal point is the analysis of temperature extremes over Western Europe in the period 1957-2007 and their relationship to large-scale anomalies in the atmospheric circulation patterns. The study is based on temperature daily time series recorded at a set of meteorological stations covering the target area. The large-scale anomalies are analyzed using data from the National Centers for Environmental Prediction reanalysis project. Firstly, a preliminary statistical analysis was undertaken in order to identify data gaps and erroneous values and to check the homogeneity of the time series, using not only elementary statistical approaches (e.g., chronograms, box-plots, scatter-plots), but also a set of non-parametric statistical tests particularly suitable for the analysis of monthly and seasonal mean temperature time series (e.g., Wald-Wolfowitz serial correlation test, Spearman and Mann-Kendall trend tests). Secondly, based on previous results, a selection of the highest quality time series was carried out. Aiming at identifying temperature extremes, we then proceed to the isolation of months with temperature values above or below pre-selected thresholds based on the empirical distribution of each time series. In particular, thresholds are based on percentiles specifically computed for each individual temperature record (data adaptive) and not on fixed values. As a result, a calendar of extremely high and extremely low monthly mean temperatures is obtained and the large-scale atmospheric conditions during each extreme are analyzed. Several atmospheric fields are considered in this study (e.g., 2-m maximum and minimum air temperature, sea level pressure, geopotential height, zonal and meridional wind components, vorticity, relative humidity) at different isobaric levels. Results show remarkably different synoptic conditions for temperature extremes in different parts of Western Europe, highlighting the different dynamical mechanisms underlying their

  6. Thermal conductivity of pressureless sintered Si3N4 ceramics with Li-exchanged zeolite

    Directory of Open Access Journals (Sweden)

    SNEZANA BOSKOVIC

    2004-09-01

    Full Text Available The effects of temperature on the thermal conductivity of Si3N4 sintered with Li-exchanged zeolite were investigated. The highest conductivity was measured for the ceramics sintered with 10 % of additive. The complete a->b-Si3N4 transformation and maximum density (> 98 % TD were attained with the sample sintered at 1650 ºC. However, the results show that Al and O from the additive dissolve into the b-Si3N4 structure which act as phonon scattering sites resulting in a lowering of the conductivity and a weaker temperature dependance of the conductivity.

  7. High confinement, high yield Si3N4 waveguides for nonlinear optical application

    CERN Document Server

    Epping, Jörn P; Mateman, Richard; Leinse, Arne; Heideman, René G; van Rees, Albert; van der Slot, Peter J M; Lee, Chris J; Boller, Klaus-J

    2014-01-01

    In this paper we present a novel fabrication technique for silicon nitride (Si3N4) waveguides with a thickness of up to 900 nm, which are suitable for nonlinear optical applications. The fabrication method is based on etching trenches in thermally oxidized silicon and filling the trenches with Si3N4. Using this technique no stress-induced cracks in the Si3N4 layer were observed resulting in a high yield of devices on the wafer. The propagation losses of the obtained waveguides were measured to be as low as 0.4 dB/cm at a wavelength of around 1550 nm.

  8. Pyrolysis Synthesized g-C3N4 for Photocatalytic Degradation of Methylene Blue

    OpenAIRE

    2013-01-01

    Graphitic carbon nitride (g-C3N4) was synthesized at 520°C by the pyrolysis of cyanamide, dicyandiamide, and melamine. The samples were characterized by X–ray diffraction (XRD), UV-visible diffuse reflectance spectra, Fourier transform infrared spectroscopy (FT-IR), and elemental analyzer. The photocatalytic activity of g-C3N4 was evaluated by the photodegrading experiments of methylene blue (MB). The results indicated that g-C3N4. A photocatalytic mechanism presumed the MB photodegradation o...

  9. Structural and Biochemical Investigation of Bacteriophage N4-Encoded RNA Polymerases

    Directory of Open Access Journals (Sweden)

    Bryan R. Lenneman

    2015-04-01

    Full Text Available Bacteriophage N4 regulates the temporal expression of its genome through the activity of three distinct RNA polymerases (RNAP. Expression of the early genes is carried out by a phage-encoded, virion-encapsidated RNAP (vRNAP that is injected into the host at the onset of infection and transcribes the early genes. These encode the components of new transcriptional machinery (N4 RNAPII and cofactors responsible for the synthesis of middle RNAs. Both N4 RNAPs belong to the T7-like “single-subunit” family of polymerases. Herein, we describe their mechanisms of promoter recognition, regulation, and roles in the phage life cycle.

  10. First-principles study of TMNa{sub n} (TM = Cr, Mn, Fe, Co, Ni; n = 4-7) clusters

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Kalpataru; Sen, Prasenjit [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Reveles, J Ulises; Khanna, Shiv N [Department of Physics, Virginia Commonwealth University, Richmond, VA 23284-2000 (United States)], E-mail: prasen@hri.res.in

    2008-06-25

    Geometry, electronic structure and magnetic properties of TMNa{sub n} (TM Cr-Ni; n = 4-7) clusters are studied within a gradient-corrected density functional theory (DFT) framework. Two complementary approaches, the first adapted to all-electron calculations on free clusters and the second based on the plane-wave projector augmented wave (PAW) method within a supercell approach, are used. Except for NiNa{sub n}, the clusters in this series are found to retain the atomic moments of the TM atoms, and the magnetic moment presented an odd-even oscillation with respect to the number of Na atoms. The origin of these odd-even oscillations is explained from the nature of the chemical bonding in these clusters. Differences and similarities between the chemical bonding and the magnetic properties of these clusters and the TMNa{sub n} (TM = Sc, V and Ti; n = 4-6) clusters on the one hand and TM-doped Au and Ag clusters on the other hand are discussed.

  11. Anomaly Detection in Clutter using Spectrally Enhanced Ladar

    CERN Document Server

    Chhabra, Puneet S; Hopgood, James R

    2016-01-01

    Discrete return (DR) Laser Detection and Ranging (Ladar) systems provide a series of echoes that reflect from objects in a scene. These can be first, last or multi-echo returns. In contrast, Full-Waveform (FW)-Ladar systems measure the intensity of light reflected from objects continuously over a period of time. In a camouflaged scenario, e.g., objects hidden behind dense foliage, a FW-Ladar penetrates such foliage and returns a sequence of echoes including buried faint echoes. The aim of this paper is to learn local-patterns of co-occurring echoes characterised by their measured spectra. A deviation from such patterns defines an abnormal event in a forest/tree depth profile. As far as the authors know, neither DR or FW-Ladar, along with several spectral measurements, has not been applied to anomaly detection. This work presents an algorithm that allows detection of spectral and temporal anomalies in FW-Multi Spectral Ladar (FW-MSL) data samples. An anomaly is defined as a full waveform temporal and spectral ...

  12. Exploring Patterns and Effects of Aerosol Quantity Flag Anomalies in MODIS Surface Reflectance Products in the Tropics

    Directory of Open Access Journals (Sweden)

    Rasmus Fensholt

    2013-07-01

    Full Text Available The Moderate Resolution Imaging Spectroradiometer (MODIS has been supplying a continuous data stream since 2000, lending to detailed time series analysis of the global terrestrial environment. This paper explores a quality anomaly present in the tropics relating to the aerosol quantity flag in the daily MODIS surface reflectance products (MOD09 series and the 16-day Vegetation Index (VI composite products (MOD13 series derived from the daily observations. While the anomaly is to some extent a known issue reported by the MODIS Land Quality Assessment group, very little is known about the scale of the issue, the nature and patterns of its occurrence, and potential consequences for data analysis, which explains why it is not adequately recognized throughout the literature. Two tropical regions were used to explore the anomaly and demonstrate the effects it has on the quality of selected MODIS products—one in the South American Amazon, the other in mainland Southeast Asia. The origins of the anomaly are described qualitatively in detail, and quantitative estimates of affected evergreen forest area in the MOD13A1 time series are made using blue band thresholding. The anomaly originates in the 1 km State dataset, whereby, under certain conditions, high aerosol quantity pixels are given a low aerosol quantity label, resulting in poor quality pixels with “good” quality labels. MODIS users are advised to investigate whether this anomaly has significant implications for their respective analysis and to consider the effects it may have on past studies.

  13. Magnitude Anomalies and Propagation of Local Phases

    Science.gov (United States)

    1983-01-31

    statistically significant variation of magnitude anomalies versus one of this above parameters. A contrario, we observed a significant dependance between...enough to demand a more detailed analysis. III - Local dependance of magnitude anomalies. A smoothing of our data on all quakes originating in the same

  14. Anomalies of Nuclear Criticality, Revision 6

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, E. D.; Prichard, Andrew W.; Durst, Bonita E.; Erickson, David; Puigh, Raymond J.

    2010-02-19

    This report is revision 6 of the Anomalies of Nuclear Criticality. This report is required reading for the training of criticality professionals in many organizations both nationally and internationally. This report describes many different classes of nuclear criticality anomalies that are different than expected.

  15. Improved prenatal detection of chromosomal anomalies

    DEFF Research Database (Denmark)

    Frøslev-Friis, Christina; Hjort-Pedersen, Karina; Henriques, Carsten U;

    2011-01-01

    Prenatal screening for karyotype anomalies takes place in most European countries. In Denmark, the screening method was changed in 2005. The aim of this study was to study the trends in prevalence and prenatal detection rates of chromosome anomalies and Down syndrome (DS) over a 22-year period....

  16. Remarks on Global Anomalies in RCFT Orientifolds

    CERN Document Server

    Gato-Rivera, Beatriz

    2006-01-01

    We check the list of supersymmetric standard model orientifold spectra of Dijkstra, Huiszoon and Schellekens for the presence of global anomalies, using probe branes. Absence of global anomalies is found to impose strong constraints, but in nearly all cases they are automatically satisfied by the solutions to the tadpole cancellation conditions.

  17. Coronary CTA assessment of coronary anomalies.

    NARCIS (Netherlands)

    Pursnani, A.; Jacobs, J.E.; Saremi, F.; Levisman, J.; Makaryus, A.N.; Capunay, C.; Rogers, I.S.; Wald, C.; Azmoon, S.; Stathopoulos, I.A.; Srichai, M.B.

    2012-01-01

    Coronary anomalies occur in <1% of the general population and can range from a benign incidental finding to the cause of sudden cardiac death. The coronary anomalies are classified here according to the traditional grouping into those of origin and course, intrinsic arterial anatomy, and

  18. Effective action for supersymmetric chiral anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Krivoshchekov, V.K.; Chekhov, L.O.

    1987-05-01

    It is shown that consistency conditions of the type of the Wess-Zumino conditions are necessary and sufficient conditions for local integrability of the supersymmetric chiral anomaly. It follows from the requirement of global integrability that the coefficient of the anomalous action is discrete. Explicit expressions are obtained for consistent anomalies and the corresponding functionals, which depend on superfields of various types.

  19. Coronary CTA assessment of coronary anomalies.

    NARCIS (Netherlands)

    Pursnani, A.; Jacobs, J.E.; Saremi, F.; Levisman, J.; Makaryus, A.N.; Capunay, C.; Rogers, I.S.; Wald, C.; Azmoon, S.; Stathopoulos, I.A.; Srichai, M.B.

    2012-01-01

    Coronary anomalies occur in <1% of the general population and can range from a benign incidental finding to the cause of sudden cardiac death. The coronary anomalies are classified here according to the traditional grouping into those of origin and course, intrinsic arterial anatomy, and terminat

  20. Dental anomalies in Dromiciops gliroides (Microbiotheria, Microbiotheriidae), Caenolestes fuliginosus and Rhyncholestes raphanurus (Paucituberculata, Caenolestidae) Anomalías en la dentición de Dromiciops gliroides (Microbiotheria, Microbiotheriidae), Caenolestes fuliginosus and Rhyncholestes raphanurus (Paucituberculata, Caenolestidae)

    OpenAIRE

    Martin, Gabriel M.

    2007-01-01

    Dental anomalies are described after analyzing series of skulls and mandibles of three species of South American marsupials: the monito del monte {Dromiciops gliroides), the silky shrew-opossum {Caenolestes fuliginosus) and the Chilean shrew-opossum {Rhyncholestes raphanurus). The anomalies are classified into three categories: (1) supernumerary or missing teeth in normal positions of the dental series, (2) morphological anomalies like teeth fusion or anomalous crown shape, and (3) presence o...

  1. Seasonality of congenital anomalies in Europe

    DEFF Research Database (Denmark)

    Luteijn, Johannes Michiel; Dolk, Helen; Addor, Marie-Claude;

    2014-01-01

    with influenza. RESULTS: We detected statistically significant seasonality in prevalence of anomalies previously associated with influenza, but the conception peak was in June (2.4% excess). We also detected seasonality in congenital cataract (April conceptions, 27%), hip dislocation and/or dysplasia (April, 12......%), congenital hydronephrosis (July, 12%), urinary defects (July, 5%), and situs inversus (December, 36%), but not for nonchromosomal anomalies combined, chromosomal anomalies combined, or other anomalies analyzed. CONCLUSION: We have confirmed previously described seasonality for congenital cataract and hip......BACKGROUND: This study describes seasonality of congenital anomalies in Europe to provide a baseline against which to assess the impact of specific time varying exposures such as the H1N1 pandemic influenza, and to provide a comprehensive and recent picture of seasonality and its possible relation...

  2. Regional magnetic anomaly constraints on continental rifting

    Science.gov (United States)

    Vonfrese, R. R. B.; Hinze, W. J.; Olivier, R.; Bentley, C. R.

    1985-01-01

    Radially polarized MAGSAT anomalies of North and South America, Europe, Africa, India, Australia and Antarctica demonstrate remarkably detailed correlation of regional magnetic lithospheric sources across rifted margins when plotted on a reconstruction of Pangea. These major magnetic features apparently preserve their integrity until a superimposed metamorphoric event alters the magnitude and pattern of the anomalies. The longevity of continental scale magnetic anomalies contrasts markedly with that of regional gravity anomalies which tend to reflect predominantly isostatic adjustments associated with neo-tectonism. First observed as a result of NASA's magnetic satellite programs, these anomalies provide new and fundamental constraints on the geologic evolution and dynamics of the continents and oceans. Accordingly, satellite magnetic observations provide a further tool for investigating continental drift to compliment other lines of evidence in paleoclimatology, paleontology, paleomagnetism, and studies of the radiometric ages and geometric fit of the continents.

  3. Selective Oxidation of Alcohols Using Photoactive VO@g‑C3N4

    Data.gov (United States)

    U.S. Environmental Protection Agency — A photoactive VO@g-C3N4 catalyst has been developed for the selective oxidation of alcohols to the corresponding aldehydes and ketones. The visible light mediated...

  4. Complete low-energy effective action in N=4 SYM: a direct N=2 supergraph calculation

    Energy Technology Data Exchange (ETDEWEB)

    Buchbinder, I.L. E-mail: joseph@tspu.edu.ru; Ivanov, E.A. E-mail: eivanov@thsun1.jinr.ru; Petrov, A.Yu. E-mail: petrov@fma.if.usp.brpetrov@tspu.edu.ru

    2003-03-10

    Using the covariant N=2 harmonic supergraph techniques we calculate the one-loop low-energy effective action of N=4 super-Yang-Mills theory in Coulomb branch with gauge group SU(2) spontaneously broken down to U(1). The full dependence of the low-energy effective action on both the hypermultiplet and gauge fields is determined. The direct quantum calculation confirms the correctness of the exact N=4 SYM low-energy effective action derived in on the purely algebraic ground by invoking a hidden N=2 supersymmetry which completes the manifest N=2 one to N=4. Our results provide an exhaustive solution to the problem of finding out the exact completely N=4 supersymmetric low-energy effective action for the theory under consideration.

  5. Conformal kernel for NLO BFKL equation in ${\\cal N}$=4 SYM

    Energy Technology Data Exchange (ETDEWEB)

    Balitsky, Ian; Chirilli, Giovanni

    2009-01-01

    Using the requirement of M\\"{o}bius invariance of ${\\cal N}$=4 SYM amplitudes in the Regge limit we restore the conformal NLO BFKL kernel out of the eigenvalues known from the forward NLO BFKL result.

  6. Photocatalytic C−H Activation of Hydrocarbons over VO@g‑C3N4

    Data.gov (United States)

    U.S. Environmental Protection Agency — A highly selective and sustainable method has been developed for the oxidation of methyl arenes and their analogues. The VO@g-C3N4 catalyst is very efficient in the...

  7. Temperature Influence on the Properties of Thin Si3N4 Films

    Directory of Open Access Journals (Sweden)

    V.S. Zakhvalinskii

    2015-12-01

    Full Text Available Applying Raman spectroscopy, small-angle x-ray scattering, and atomic force microscopy it were studied phase composition and surface morphology of nanoscale films Si3N4 (obtained by RF magnetron sputtering.

  8. Si3N4-SiC材料的腐蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    李杰

    2009-01-01

    利用Si3N4-SiC材料在冰晶石静态融盐电解质中的腐蚀实验研究材料的腐蚀性能,对腐蚀增重率进行记录分析,Si3N4的含量以及腐蚀时间都是影响Si3N4-SiC材料腐蚀性能的重要因素,腐蚀过程主要发生在25h前,并且随着Si3N4的含量增加,腐蚀程度越严重.

  9. Elastic anisotropy and electronic properties of Si3N4 under pressures

    Directory of Open Access Journals (Sweden)

    Qingyang Fan

    2016-08-01

    Full Text Available First principles calculations are performed to systematically investigate the electronic structures, elastic, anisotropic and electronic properties of the monoclinic, tetragonal and orthorhombic structures of Si3N4 under pressure. Anisotropy studies show that three Si3N4 phases exhibit a large anisotropy. Furthermore, using the HSE06 hybrid functional, the monoclinic, tetragonal and orthorhombic phases are found to be wide band-gap semiconductors. The pressure induced band gap direct-indirect transition is found for monoclinic Si3N4. The elastic modulus, compressional and shear wave velocities as well as Debye temperatures as a function of pressure in three Si3N4 phases are also investigated in detail.

  10. Parcels and Land Ownership, 1n4w-indian, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Parcels and Land Ownership dataset, was produced all or in part from Other information as of 2002. It is described as '1n4w-indian'. Data by this publisher are...

  11. Pure and entangled N=4 linear supermultiplets and their one-dimensional sigma-models

    CERN Document Server

    Gonzales, Marcelo; Khodaee, Sadi; Toppan, Francesco

    2012-01-01

    "Pure" homogeneous linear supermultiplets (minimal and non-minimal) of the N=4-Extended one-dimensional Supersymmetry Algebra are classified. "Pure" means that they admit at least one graphical presentation (the corresponding graph/graphs are known as "Adinkras"). We further prove the existence of "entangled" linear supermultiplets which do not admit a graphical presentation, by constructing an explicit example of an entangled N=4 supermultiplet with field content (3,8,5). It interpolates between two inequivalent pure N=4 supermultiplets with the same field content. The one-dimensional N=4 sigma-model with a three-dimensional target based on the entangled supermultiplet is presented. The distinction between the notion of equivalence for pure supermultiplets and the notion of equivalence for their associated graphs (Adinkras) is discussed. Discrete properties such as chirality and coloring can discriminate different supermultiplets. The tools used in our classification have been previously introduced and discu...

  12. KIDNEY ANOMALIES: HORSE SHOE KIDNEY

    Directory of Open Access Journals (Sweden)

    Hemalatha

    2015-03-01

    Full Text Available INTRODUCTION : Horse Shoe Kidney was first recognized during an autopsy by De Carpi in 1521. This anomaly consists of two distinct renal masses lying vertically on either side of the midline and connected at their respective lower poles by a parenchymatous or fibrous isthmus that crosses the mid pl ane of the body. This isthmus lies at the level of 4th lumbar vertebra just beneath the origin of inferior mesenteric artery in about 40% of cases. Fusion of upper poles instead of the lower poles results in a n inverted horse Shoe Kidney which constitute 5 - 10% of ail Horse - Shoe kidneys , (i.e. in 95% of HSK , fusion is at lower poles. HSK is found more commonly in males by a 2 : 1 margin. AIM OF STUDY : An attempt has been made to know the various anomalies . The study has been taken up with the fond hope of helping the clinician , sonologist , and surgeons during their routine work. To apply this knowledge to the incoming post graduates in their research works. EMBRIOLOGICAL BASIS & KDNEY : The abnormality originates between 4th and 6th weeks of gestation , after the ureteral bud has entered the renal blastema. Boyden (1931 postulated that at the 14mm stage (4.5 weeks the developing metanephric masses lie close to one another , any disturbance in their relationship may result in joining at their inferior poles. A slight alteration in the position of the umbilical or common iliac artery could change the orientation of migrating kidneys thus leading to contact and fusion. In 1941 Dees (Nation 1945 , Bell 1946 , Gleen 1959 , Campbell 1970 described horse - shoe kidney di sease occurrence in 0.25% of the population or about 1 in 400. OBSERVATION : In the present study 176 specimens of kidneys were studied out of which 40 were fetal specimens and the rest were adult specimens consisting of both cadaveric and sonograms. The ad ult specimens from cadavers were 76 and 60 from sonograms. MATERIAL & METHODS : Abdomen is opened ; superficial viscera and

  13. Hecke Operator and S-Duality of N=4 ADE Gauge Theory on K3

    CERN Document Server

    Sasaki, T

    2003-01-01

    We determine ${\\cal N}=4$ partition functions on K3 for some ADE gauge groups, on the assumption that they are holomorphic. Our partition functions satisfy the gap condition and Montonen-Olive duality at the same time, like the SU(N) partition functions of Vafa and Witten. As a result, we reveal a close relation between Hecke operator and S-duality of ${\\cal N}=4 ADE$ gauge theory on K3.

  14. Two-Loop Iteration of Five-Point N=4 Super-Yang-Mills Amplitudes

    CERN Document Server

    Bern, Z; Kosower, D A; Roiban, R; Smirnov, V A

    2006-01-01

    We confirm by explicit computation the conjectured all-orders iteration of planar maximally supersymmetric N=4 Yang-Mills theory in the nontrivial case of five-point two-loop amplitudes. We compute the required unitarity cuts of the integrand and evaluate the resulting integrals numerically using a Mellin--Barnes representation and the automated package of ref.~[1]. This confirmation of the iteration relation provides further evidence suggesting that N=4 gauge theory is solvable.

  15. N=4 Super-Yang-Mills Theory, QCD and Collider Physics

    CERN Document Server

    Bern, Z; Kosower, D A

    2004-01-01

    We review how (dimensionally regulated) scattering amplitudes in N=4 super-Yang-Mills theory provide a useful testing ground for perturbative QCD calculations relevant to collider physics, as well as another avenue for investigating the AdS/CFT correspondence. We describe the iterative relation for two-loop scattering amplitudes in N=4 super-Yang-Mills theory found in C. Anastasiou et al., Phys. Rev. Lett. 91:251602 (2003), and discuss recent progress toward extending it to three loops.

  16. Anomaly Detection in Dynamic Networks

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, Melissa [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-14

    Anomaly detection in dynamic communication networks has many important security applications. These networks can be extremely large and so detecting any changes in their structure can be computationally challenging; hence, computationally fast, parallelisable methods for monitoring the network are paramount. For this reason the methods presented here use independent node and edge based models to detect locally anomalous substructures within communication networks. As a first stage, the aim is to detect changes in the data streams arising from node or edge communications. Throughout the thesis simple, conjugate Bayesian models for counting processes are used to model these data streams. A second stage of analysis can then be performed on a much reduced subset of the network comprising nodes and edges which have been identified as potentially anomalous in the first stage. The first method assumes communications in a network arise from an inhomogeneous Poisson process with piecewise constant intensity. Anomaly detection is then treated as a changepoint problem on the intensities. The changepoint model is extended to incorporate seasonal behavior inherent in communication networks. This seasonal behavior is also viewed as a changepoint problem acting on a piecewise constant Poisson process. In a static time frame, inference is made on this extended model via a Gibbs sampling strategy. In a sequential time frame, where the data arrive as a stream, a novel, fast Sequential Monte Carlo (SMC) algorithm is introduced to sample from the sequence of posterior distributions of the change points over time. A second method is considered for monitoring communications in a large scale computer network. The usage patterns in these types of networks are very bursty in nature and don’t fit a Poisson process model. For tractable inference, discrete time models are considered, where the data are aggregated into discrete time periods and probability models are fitted to the

  17. Preparation of Si3N4–SiC composites by microwave route

    Indian Academy of Sciences (India)

    M Panneerselvam; K J Rao

    2002-12-01

    Si3N4–SiC composites have been microwave sintered using -Si3N4 and -SiC as starting materials. Si3N4 rich compositions (95 and 90 vol.% Si3N4) have been sintered above 96% of theoretical density without using any sintering additives in 40 min. A monotonic decrease in relative density is observed with increase in SiC proportion in the composite. Decrease in relative density has manifested in the reduction of fracture toughness and microhardness values of the composite with increase in SiC content although the good sintering of matrix Si3N4 limits the decrease of fracture toughness. Highest value of fracture toughness of 6.1 MPa m1/2 is observed in 10 vol.% SiC composite. Crack propagation appears to be transgranular in the Si3N4 matrix and the toughening of the composites is through crack deflection around hard SiC particles in addition to its debonding from the matrix.

  18. Boron doped g-C3N4 with enhanced photocatalytic UO22+ reduction performance

    Science.gov (United States)

    Lu, Changhai; Chen, Rongyue; Wu, Xi; Fan, Meifeng; Liu, Yunhai; Le, Zhanggao; Jiang, Shujuan; Song, Shaoqing

    2016-01-01

    Tuning the band gap and absorption intensity of visible-light by element doping is an attractive strategy to enhance the photocatalytic activity of semiconductor materials. Here we doped boron into g-C3N4 to construct highly efficient photocatalysts (B-g-C3N4) for the photocatalytic reduction of UO22+. Characterization and photocatalysis tests showed the band gap of B-g-C3N4 was narrowed, and the absorption intensity of visible-light was enhanced with increasing the formed N-B-C (BCN) of B-g-C3N4, which is consistent with the trend of the photocatalytic performance of B-g-C3N4. The optimized B-g-C3N4 photocatalyst with BCN content of 1.01 at.% exhibited excellent removal efficiency of UO22+ and good photocatalytic stability. Therefore, these results may lead to a new strategy for exploring the advanced photocatalysts based on the carbon nanomaterials with abundant BCN for the photocatalytic reduction of U(VI) pollutant.

  19. N=4 supersymmetric multidimensional quantum mechanics, partial SUSY breaking, and superconformal quantum mechanics

    Science.gov (United States)

    Donets, E. E.; Pashnev, A.; Juan Rosales, J.; Tsulaia, M. M.

    2000-02-01

    The multidimensional N=4 supersymmetric (SUSY) quantum mechanics (QM) is constructed using the superfield approach. As a result, the component form of the classical and quantum Lagrangian and Hamiltonian is obtained. In the SUSY QM considered, both classical and quantum N=4 algebras include central charges, and this opens various possibilities for partial supersymmetry breaking. It is shown that quantum-mechanical models with one-quarter, one-half, and three-quarters of unbroken (broken) supersymmetries can exist in the framework of the multidimensional N=4 SUSY QM, while the one-dimensional N=4 SUSY QM, constructed earlier, admits only one half or total supersymmetry breakdown. We illustrate the constructed general formalism, as well as all possible cases of partial SUSY breaking taking as an example a direct multidimensional generalization of the one-dimensional N=4 superconformal quantum-mechanical model. Some open questions and possible applications of the constructed multidimensional N=4 SUSY QM to the known exactly integrable systems and problems of quantum cosmology are briefly discussed.

  20. Synthesis and photocatalytic performance of g-C3N4 nanosheets via liquid phase stripping

    Science.gov (United States)

    Miao, Jilin; Xu, Guangqing; Liu, Jiaqin; Lv, Jun; Wu, Yucheng

    2017-02-01

    Well dispersed g-C3N4 nanosheets were prepared by exfoliating the bulk g-C3N4 in concentrated sulfuric acid. Phase structures, morphologies and elemental compositions were characterized by X-ray diffractometer, scanning electron microscope, transmission electron microscope and X-ray photoelectron spectrometer, respectively. Optical absorption and photoluminescence were also used to explain the optical performances of samples. NaI, BQ and IPA were used as the sacrificial agents for studying the surface reactions in the photocatalytic process. By the precipitation of g-C3N4 nanosheets in ethanol with different ratios between concentrated sulfuric acid and ethyl alcohol, well dispersed g-C3N4 nanosheets with high specific surface area can be obtained. The optimized g-C3N4 (1:10) nanosheets achieve the highest photocatalytic activities under UV light illumination, which can degrade 10 mg/L RhB about 98% in 60 min, which is 6 times that of bulk g-C3N4 under UV light.

  1. Recent Progress in Photocatalysis of g-C3N4%g-C3N4光催化性能的研究进展

    Institute of Scientific and Technical Information of China (English)

    楚增勇; 原博; 颜廷楠

    2014-01-01

    利用光催化剂将太阳能转化为人类可以直接利用的能量,并用其解决地球资源的枯竭和生存环境的恶化是可再生清洁能源研究的一个方向。g-C3N4的独特结构赋予其良好的光催化性能,使之成为光催化领域的研究热点。目前在光催化领域, g-C3N4主要用于催化污染物分解、水解制氢制氧、有机合成及氧气还原。在实际应用中,为进一步提高 g-C3N4的光催化效果,科研工作者开发了多种改进方法,例如物理复合改性、化学掺杂改性、微观结构调整等。本文主要论述了 g-C3N4在光催化领域的应用以及光催化性能的改进方法,简要阐述了光催化和各种改进方法的机理,分析了目前g-C3N4在光催化领域面临的问题和挑战,展望了g-C3N4的应用前景。%Based on photocatalysts, solar energy can be converted into the energy that human can directly utilize, so as to solve the problems such as the depletion of the Earth’s resources and the deterioration of living environments. The unique structure of g-C3N4 gives it good photocatalytic performance. Its development and utilization have been a research hotspot recently. Generally, g-C3N4 can be used in the degradation of pollutions, hydrolysis to generate hy-drogen and oxygen, organic synthesis and oxygen reduction. However, in practical, its performance is not satisfactory. Researchers have tried many new methods to improve its photocatalysis, which include physical coupling modification, chemical bonding modification and microstructural modification. The review summarizes its photocatalysis and im-proving methods, briefly illustrates the catalysis mechanism, and presents detailed discussions and analysis on the ex-isting problems as well as potential applications.

  2. Third-order nonlinear optical properties and structures of ( E)- N-(4-nitrobenzylidene)-2,6-dimethylaniline and ( E)- N-(4-nitrobenzylidene)-2,3-dimethylaniline

    Science.gov (United States)

    Karakas, Asli; Ünver, Hüseyin

    2010-05-01

    ( E)- N-(4-Nitrobenzylidene)-2,6-dimethylaniline ( 1) and ( E)- N-(4-nitrobenzylidene)-2,3-dimethylaniline ( 2) have been synthesized. The crystal structures of both compounds have been defined by X-ray diffraction analysis. The maximum one-photon absorption (OPA) wavelengths recorded by quantum mechanical computations using a configuration interaction (CI) method are estimated in the UV region to be shorter than 450 nm, showing good optical transparency to the visible light. To provide an insight into the microscopic third-order nonlinear optical (NLO) properties of the investigated molecules, both dispersion-free (static) and also frequency-dependent (dynamic) linear polarizabilities ( α) and second hyperpolarizabilities ( γ) at λ = 825-1125 nm and 1050-1600 nm wavelength areas have been computed using time-dependent Hartree-Fock (TDHF) method. According to the ab initio calculation results, the title molecules exhibit second hyperpolarizabilities with non-zero values, implying microscopic third-order NLO behavior.

  3. Vitellointestinal Duct Anomalies in Infancy

    Science.gov (United States)

    Kadian, Yogender Singh; Verma, Anjali; Rattan, Kamal Nain; Kajal, Pardeep

    2016-01-01

    Background: Vitellointestinal duct (VID) or omphalomesenteric duct anomalies are secondary to the persistence of the embryonic vitelline duct, which normally obliterates by weeks 5–9 of intrauterine life. Methods: This is a retrospective analysis of a total of 16 patients of symptomatic remnants of vitellointestinal duct from period of Jan 2009 to May 2013. Results: Male to female ratio (M:F) was 4.3:1 and mean age of presentation was 2 months and their mode of presentation was: patent VID in 9 (56.25%) patients, umbilical cyst in 2(12.25%), umbilical granuloma in 2 (12.25%), and Meckel diverticulum as content of hernia sac in obstructed umbilical hernia in 1 (6.25%) patient. Two patients with umbilical fistula had severe electrolyte disturbance and died without surgical intervention. Conclusion: Persistent VID may have varied presentations in infancy. High output umbilical fistula and excessive bowel prolapse demand urgent surgical intervention to avoid morbidity and mortality. PMID:27433448

  4. Holography and Conformal Anomaly Matching

    CERN Document Server

    Cabo-Bizet, Alejandro; Narain, K S

    2013-01-01

    We discuss various issues related to the understanding of the conformal anomaly matching in CFT from the dual holographic viewpoint. First, we act with a PBH diffeomorphism on a generic 5D RG flow geometry and show that the corresponding on-shell bulk action reproduces the Wess-Zumino term for the dilaton of broken conformal symmetry, with the expected coefficient aUV-aIR. Then we consider a specific 3D example of RG flow whose UV asymptotics is normalizable and admits a 6D lifting. We promote a modulus \\rho appearing in the geometry to a function of boundary coordinates. In a 6D description {\\rho} is the scale of an SU(2) instanton. We determine the smooth deformed background up to second order in the space-time derivatives of \\rho and find that the 3D on-shell action reproduces a boundary kinetic term for the massless field \\tau= log(\\rho) with the correct coefficient \\delta c=cUV-cIR. We further analyze the linearized fluctuations around the deformed background geometry and compute the one-point functions ...

  5. Synthesis of porous g-C3N4/La and enhanced photocatalytic activity for the degradation of phenol under visible light irradiation

    Science.gov (United States)

    Rong, Xinshan; Qiu, Fengxian; Rong, Jian; Yan, Jie; Zhao, Hao; Zhu, Xiaolu; Yang, Dongya

    2015-10-01

    A series of porous g-C3N4/La (PGCN/La) materials used as photocatalyst for the degradation of phenol were prepared by two steps. The photocatalysts were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), thermogravimetry (TG), Brunauer-Emmett-Teller (BET), Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). From the TEM morphology, the porous structure of g-C3N4 could be successfully controlled; from BET results, BET specific surface area of porous g-C3N4 (PGCN) sample increases with the increasing of urea mass ratio. Compared with PGCN material (PGCN-50), PGCN/La sample (PGCN-50/La-5) could exhibit an enhanced photocatalytic activity and has the best degradation efficiency of 98.6% within 50 min under visible light irradiation. Photocatalytic reaction follows the first-order model kinetics; and PGCN-50/La-5 photocatalyst shows the largest reaction rate among all samples which is nearly 2.96 times higher than that of pure PGCN-50. The present work illustrates that the photocatalytic activity of porous g-C3N4 was improved by the addition of La and PGCN-50/La-5 has potential application in the removal of phenol or other organic molecular from wastewater.

  6. N(4)-Acyl derivatives as lipophilic prodrugs of cidofovir and its 5-azacytosine analogue, (S)-HPMP-5-azaC: chemistry and antiviral activity.

    Science.gov (United States)

    Krečmerová, Marcela; Pohl, Radek; Masojídková, Milena; Balzarini, Jan; Snoeck, Robert; Andrei, Graciela

    2014-05-15

    Even number fatty acid residues-docosanoyl (behenoyl) and stearoyl were selected for introduction to the N(4)-position of (S)-1-[3-hydroxy-2-(phosphonomethoxy)propyl]cytosine) (HPMPC, cidofovir), and its 5-azacytosine counterpart, (S)-1-[3-hydroxy-2-(phosphonomethoxy)propyl]cytosine) (HPMP-5-azaC) with the aim to prepare a new type of lipophilic prodrugs. The study on the influence of these modifications to the stability and biological activity of both antivirals was performed. Different reactivity of both systems towards acylation reactions was also found: the 4-NH2 group of cidofovir was more reactive compared to that of HPMP-5-azaC. In 5-azacytosine derivatives, we found mostly a destabilizing effect of the N(4)-acylation but this could be compensated by a positive influence of the esterification of the phosphonate group. Chemical stability of the 5-azacytosine moiety in the HPMP series is increasing in the following order: HPMP-5-azaCN(4)-behenoyl derivative of the hexadecyloxyethyl ester of cyclic HPMP-5-azaC. The free phosphonic acid (N(4)-behenoyl-HPMPC) appeared to be a more potent and selective inhibitor of herpesvirus replication than the parent HPMPC derivative.

  7. The g-C3 N4 /C2 N Nanocomposite: A g-C3 N4 -Based Water-Splitting Photocatalyst with Enhanced Energy Efficiency.

    Science.gov (United States)

    Wang, Huimin; Li, Xingxing; Yang, Jinlong

    2016-07-01

    Water-splitting photocatalysts with good energy efficiency are highly desirable, among which metal-free graphitic carbon nitride (g-C3 N4 ) is considered to be very promising and has been intensively studied in recent years. However, its practical application is hindered by the relatively low efficiencies of visible-light absorption and electron-hole separation. Herein, based on first-principles calculations, it is predicted that, by forming nanocomposites with another carbon nitride (C2 N), the energy efficiency of g-C3 N4 can be significantly improved. On one hand, C2 N has a wide, strong optical absorption in the visible-light region, which acts as a photosensitizer and enhances the photoabsorption efficiency of the composite photocatalyst. On the other hand, C2 N forms a type II heterojunction with g-C3 N4 , which leads to efficient separation of photogenerated electron-hole pairs through the chemical potential difference between the two components. These results provide a potential route to achieve highly efficient metal-free photocatalysts for water splitting.

  8. BPS state counting using wall-crossing, holomorphic anomalies and modularity

    Energy Technology Data Exchange (ETDEWEB)

    Wotschke, Thomas

    2013-05-15

    In this thesis we examine the counting of BPS states using wall-crossing, holomorphic anomalies and modularity. We count BPS states that arise in two setups: multiple M5-branes wrapping P x T{sup 2}, where P denotes a divisor inside a Calabi-Yau threefold and topological string theory on elliptic Calabi-Yau threefolds. The first setup has a dual description as type IIA string theory via a D4-D2-D0 brane system. Furthermore it leads to two descriptions depending on the size of P and T{sup 2} relative to each other. For the case of a small divisor P this setup is described by the (0,4) Maldacena-Strominger-Witten conformal field theory of a black hole in M-theory and for the case of small T{sup 2} the setup can by described by N=4 topological Yang-Mills theory on P. The BPS states are counted by the modified elliptic genus, which can be decomposed into a vector-valued modular form that provides the generating function for the BPS invariants and a Siegel-Narain theta function. In the first part we discuss the holomorphic anomaly of the modified elliptic genus for the case of two M5-branes and divisors with b{sup +}{sub 2}(P)=1. Due to the wall-crossing effect the change in the generating function is captured by an indefinite theta function, which is a mock modular form. We use the Kontsevich-Soibelman wall-crossing formula to determine the jumps in the modified elliptic genus. Using the regularisation procedure for mock modular forms of Zwegers, modularity can be restored at the cost of holomorphicity. We show that the non-holomorphic completion is due to bound states of single M5-branes. At the attractor point in the moduli space we prove the holomorphic anomaly equation, which is compatible with the holomorphic anomaly equations observed in the context of N=4 Yang-Mills theory on P{sup 2} and E-strings on a del Pezzo surface. We calculate the generating functions of BPS invariants for the divisors P{sup 2}, F{sub 0}, F{sub 1} and the del Pezzo surface dP{sub 8} and

  9. Thermal infrared anomalies of several strong earthquakes.

    Science.gov (United States)

    Wei, Congxin; Zhang, Yuansheng; Guo, Xiao; Hui, Shaoxing; Qin, Manzhong; Zhang, Ying

    2013-01-01

    In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of "time-frequency relative power spectrum." (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting.

  10. MR imaging of paediatric uterovaginal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Lang, I.M.; Babyn, P. [Hospital for Sick Children, Toronto, ON (Canada). Dept. of Diagnostic Imaging; Oliver, G.D. [Hospital for Sick Children, Toronto, ON (Canada). Dept. of Gynaecology

    1999-03-01

    Background. Transabdominal ultrasound (US) has not proved completely reliable in Muellerian duct anomalies. One study has shown it useful in obstructed uterovaginal anomalies. We are unaware of a study that has used endovaginal ultrasound in children to investigate uterovaginal anomalies. Magnetic resonance imaging (MRI) is now gaining wide acceptance in imaging congenital abnormalities of the genital tract. Objective. To identify the problems and potential pitfalls of using MRI to evaluate the female genital tract in paediatric patients. Materials and methods. A retrospective review of the MRI scans of 19 patients, aged 3 months to 19 years (mean 14 years), with uterovaginal anomalies. Results. The uterovaginal anomalies were categorised into three groups: (1) congenital absence of the Muellerian ducts, or the Mayer-Rokitansky-Kuster-Hauser syndrome (n = 7), (2) disorders of vertical fusion (n = 2) and (3) disorders of lateral fusion (n = 10). Conclusions. MRI is a reliable method for evaluating paediatric uterovaginal anomalies, but should be analysed in conjunction with other imaging modalities (US and genitography). Previous surgery makes interpretation more difficult and, if possible, MRI should be carried out prior to any surgery. An accurate MRI examination can be extremely helpful prior to surgery and it is important for the radiologist to have knowledge of how these complex anomalies are managed and what pitfalls to avoid. (orig.) With 7 figs., 4 tabs., 24 refs.

  11. Galilean Anomalies and Their Effect on Hydrodynamics

    CERN Document Server

    Jain, Akash

    2015-01-01

    We extend the null background construction of [arXiv:1505.05677,arXiv:1509.04718] to include torsion and a conserved spin current, and use it to study gauge and gravitational anomalies in Galilean theories coupled to torsional Newton-Cartan backgrounds. We establish that the relativistic anomaly inflow mechanism with an appropriately modified anomaly polynomial, can be used to generate these anomalies. Similar to relativistic case, we find that Galilean anomalies also survive only in even dimensions. Further, these anomalies only effect the gauge and rotational symmetries of a Galilean theory; in particular the Milne boost symmetry remains non-anomalous. We also extend the transgression machinery used in relativistic fluids to fluids on null backgrounds, and use it to determine how these anomalies affect the constitutive relations of a Galilean fluid. Unrelated to Galilean fluids, we propose an analogue of the off-shell second law of thermodynamics for relativistic fluids introduced by [arXiv:1106.0277], to i...

  12. Sea surface temperature anomalies in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.

    . Further analysis has shown that the sea surface anomalies are well correlated to the anomalies of air temperature and latent heat flux values; whereas they are least correlated to the anomalies of wind stress and net radiation values, except over...

  13. High pressure synthesis and superconducting properties for the multi-layered Ba{sub 2}Ca {sub n-1}Cu {sub n}O{sub 2n}(O,F){sub 2} (n = 4 and 5)

    Energy Technology Data Exchange (ETDEWEB)

    Kito, Hijiri [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1, Umezono, Tsukuba, Ibaraki, 305-8568 (Japan)]. E-mail: h.kito@aist.go.jp; Iyo, Akira [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1, Umezono, Tsukuba, Ibaraki, 305-8568 (Japan)

    2006-10-01

    We prepared multi-layered oxyfluoride superconductors, Ba{sub 2}Ca {sub n-1}Cu {sub n}O{sub 2n}(O,F){sub 2} (n = 4 and 5) using high-pressure apparatus. These phase are the n = 4 and 5 members of a homologous series, M{sub 2}Ca {sub n-1}Cu {sub n}O{sub 2n}(O,F){sub 2} [0{sup M}2(n - 1)n-F] reported previously. X-ray studies indicated that they have tetragonal structures with a = 3.863 A, c = 33.75 A for n = 4 and a = 3.862 A, c = 40.18 A for n = 5. Superconducting transition temperature were 86.6 K for n = 4 and 75.7 K for n = 5, respectively. The critical current density (J {sub c}) and irreversibility field (H {sub irr}) were determined from M-H curves using the Bean's model. J {sub c} and H {sub irr} of 0{sup Ba}2(n - 1)n-F (n = 4 and 5) decreased rapidly with increasing temperature. J {sub c} (5 K, 1 T) shows 1.70 x 10{sup 6} A/cm{sup 2} for n = 4 and 1.93 x 10{sup 5} A/cm{sup 2} for n = 5. The estimated values of H {sub irr} (5 K) are about 70 T for n = 4 and 17 T for n = 5.

  14. Poland’s Anomaly: Natural History and Long-Term-Results of Chest Wall Reconstruction in 33 Patients

    Science.gov (United States)

    1988-12-01

    Poland’s anomaly is an uncommon congenital aberration of the chest wall characterized by absence of the pectoralis major muscle and other nearby muscu...loskeletal components. In this series, a wide spectrum of thoracic deformities was associated with the Poland anomaly, ranging from segmental agenesis ...of the ribs, sternum, and nearby muscles , to simple aplasia of the pectoralis major muscle . Although little disability was associated with the

  15. Exposures series

    OpenAIRE

    Stimson, Blake

    2011-01-01

    Reaktion Books’ Exposures series, edited by Peter Hamilton and Mark Haworth-Booth, is comprised of 13 volumes and counting, each less than 200 pages with 80 high-quality illustrations in color and black and white. Currently available titles include Photography and Australia, Photography and Spirit, Photography and Cinema, Photography and Literature, Photography and Flight, Photography and Egypt, Photography and Science, Photography and Africa, Photography and Italy, Photography and the USA, P...

  16. Hydrophobic 'lock and key' recognition of N-4-nitrobenzoylamino acid by strychnine.

    Science.gov (United States)

    Białońska, Agata; Ciunik, Zbigniew

    2006-12-01

    During racemic resolution of N-4-nitrobenzoyl-DL-amino acids (alanine, serine and aspartic acid) by a fractional crystallization of strychninium salts, crystals of both diastereomeric salts were grown, and the crystal structures of strychninium N-4-nitrobenzoyl-L-alaninate methanol disolvate (1a), strychninium N-4-nitrobenzoyl-D-alaninate dihydrate (1b), strychninium N-4-nitrobenzoyl-D-serinate dihydrate (2a), strychninium N-4-nitrobenzoyl-L-serinate methanol solvate hydrate (2b), strychninium hydrogen N-4-nitrobenzoyl-L-aspartate 3.75 hydrate (3a) and strychninium hydrogen N-4-nitrobenzoyl-D-aspartate 2.25 hydrate (3b) were determined. The strychninium cations form corrugated layers, which are separated by hydrogen-bonded anions and solvent molecules. Common features of the corrugated layers are deep hydrophobic grooves at their surfaces, which are occupied by the 4-nitrobenzoyl groups of suitable anions. The hydrophobic ;lock and key' recognition of 4-nitrobenzoyl groups of amino acid derivatives in deep grooves of the strychnine self-assembly causes the resulting surface to have more hydrophilic properties, which are more appropriate for interactions in the hydrophilic environments from which strychninium salts were crystallized. In the crystal structure of (2a) and (3a), such hydrophobic ;lock and key' recognition is responsible for the lack of N-H+...O- hydrogen bonds that are usually formed between the protonated tertiary amine N atom of the strychninium cation and the deprotonated carboxyl group of the resolved acid. In the crystal structure of (2a) and (3a), the protonated amine N atom is a donor of hydrogen bonds, while the hydroxyl group of the serine derivative and water molecules are their acceptors. In light of the hydrophobic recognition, chiral discrimination depends on the nature of the hydrogen-bond networks, which involve anions, solvent molecules and the protonated amine N atom of strychninium cations.

  17. The Human Pendrin Promoter Contains two N4 GAS Motifs with Different Functional Relevance

    Directory of Open Access Journals (Sweden)

    Simone Vanoni

    2013-12-01

    Full Text Available Background: Pendrin, an anion exchanger associated with the inner ear, thyroid and kidney, plays a significant role in respiratory tissues and diseases, where its expression is increased following IL-4 and IL-13 exposure. The mechanism leading to increased pendrin expression is in part due to binding of STAT6 to a consensus sequence (N4 GAS motif located in the pendrin promoter. As retrospective analyses of the 5' upstream sequence of the human pendrin promoter revealed an additional N4 GAS motif (1660 base pairs upstream of the one previously identified, we set out to define its contribution to IL-4 stimulated changes in pendrin promoter activity. Methods and Results: Electrophoretic mobility shift assays showed that STAT6 bound to oligonucleotides corresponding to both N4 GAS motifs in vitro, while dual luciferase promoter assays revealed that only one of the N4 GAS motifs was necessary for IL-4 -stimulated increases in pendrin promoter activity in living cells. We then examined the ability of STAT6 to bind each of the N4 GAS motifs in vivo with a site-specific ChIP assay, the results of which showed that STAT6 interacted with only the N4 GAS motif that was functionally implicated in increasing the activity of the pendrin promoter following IL-4 treatment. Conclusions: Of the two N4 GAS motifs located in the human pendrin promoter region analyzed in this study (nucleotides -3906 to +7, only the one located nearest to the first coding ATG participates in IL-4 stimulated increases in promoter activity.

  18. Praenatalt diagnosticeret hydronefrose og andre urologiske anomalier

    DEFF Research Database (Denmark)

    Cortes, Dina; Jørgensen, Troels Munch; Rittig, Søren

    2006-01-01

    By renal ultrasound examination, urological anomalies may be demonstrated in 1-2% of fetuses and in about 0.5% of newborns. Boys have about twice the frequency of girls. Surgical treatment is indicated in about one fourth of these urological anomalies. If all pregnant women in Denmark were to have...... fetal ultrasound examination of the kidneys and the urinary tract, about 70 children would be born each year with a prenatally diagnosed urological anomaly for which surgical procedure is or will be indicated. This paper provides Danish guidelines for prenatal diagnosis, follow-up and intervention...

  19. Anomaly and exotic statistics in one dimension

    CERN Document Server

    Saradzhev, F M

    1995-01-01

    We study the influence of the anomaly on the physical quantum picture of the chiral Schwinger model (CSM) defined on S^1. We show that such phenomena as the total screening of charges and the dynamical mass generation characteristic for the standard Schwinger model do not take place here. Instead of them, the anomaly results in the background linearly rising electric field or, equivalently, in the exotic statistics of the physical matter field. We construct the algebra of the Poincare generators and show that it differs from the Poincare one. For the CSM on R^1, the anomaly influences only the mass generation mechanism.

  20. Simple recipe for holographic Weyl anomaly

    CERN Document Server

    Bugini, F

    2016-01-01

    We propose a recipe - arguably the simplest - to compute the holographic type-B Weyl anomaly for general higher-derivative gravity in asymptotically AdS spacetimes. In 5 and 7 dimensions we identify a suitable basis of curvature invariants that allows to read off easily, without any further computation, the Weyl anomaly coefficients of the dual CFT. We tabulate the contributions from quadratic, cubic and quartic purely algebraic curvature invariants and also from terms involving derivatives of the curvature. We provide few examples, where the anomaly coefficients have been obtained by other means, to illustrate the effectiveness of our prescription.

  1. Considerations in the Interpretation of Cosmological Anomalies

    CERN Document Server

    Peiris, Hiranya V

    2014-01-01

    Anomalies drive scientific discovery -- they are associated with the cutting edge of the research frontier, and thus typically exploit data in the low signal-to-noise regime. In astronomy, the prevalence of systematics --- both "known unknowns" and "unknown unknowns" --- combined with increasingly large datasets, the widespread use of ad hoc estimators for anomaly detection, and the "look-elsewhere" effect, can lead to spurious false detections. In this informal note, I argue that anomaly detection leading to discoveries of new physics requires a combination of physical understanding, careful experimental design to avoid confirmation bias, and self-consistent statistical methods. These points are illustrated with several concrete examples from cosmology.

  2. Multi-Level Anomaly Detection on Time-Varying Graph Data

    Energy Technology Data Exchange (ETDEWEB)

    Bridges, Robert A [ORNL; Collins, John P [ORNL; Ferragut, Erik M [ORNL; Laska, Jason A [ORNL; Sullivan, Blair D [ORNL

    2015-01-01

    This work presents a novel modeling and analysis framework for graph sequences which addresses the challenge of detecting and contextualizing anomalies in labelled, streaming graph data. We introduce a generalization of the BTER model of Seshadhri et al. by adding flexibility to community structure, and use this model to perform multi-scale graph anomaly detection. Specifically, probability models describing coarse subgraphs are built by aggregating probabilities at finer levels, and these closely related hierarchical models simultaneously detect deviations from expectation. This technique provides insight into a graph's structure and internal context that may shed light on a detected event. Additionally, this multi-scale analysis facilitates intuitive visualizations by allowing users to narrow focus from an anomalous graph to particular subgraphs or nodes causing the anomaly. For evaluation, two hierarchical anomaly detectors are tested against a baseline Gaussian method on a series of sampled graphs. We demonstrate that our graph statistics-based approach outperforms both a distribution-based detector and the baseline in a labeled setting with community structure, and it accurately detects anomalies in synthetic and real-world datasets at the node, subgraph, and graph levels. To illustrate the accessibility of information made possible via this technique, the anomaly detector and an associated interactive visualization tool are tested on NCAA football data, where teams and conferences that moved within the league are identified with perfect recall, and precision greater than 0.786.

  3. Gravitational anomalies in higher dimensional Riemann Cartan space

    Science.gov (United States)

    Yajima, S.; Tokuo, S.; Fukuda, M.; Higashida, Y.; Kamo, Y.; Kubota, S.-I.; Taira, H.

    2007-02-01

    By applying the covariant Taylor expansion method of the heat kernel, the covariant Einstein anomalies associated with a Weyl fermion of spin \\frac{1}{2} in four-, six- and eight-dimensional Riemann Cartan space are manifestly given. Many unknown terms with torsion tensors appear in these anomalies. The Lorentz anomaly is intimately related to the Einstein anomaly even in Riemann Cartan space. The explicit form of the Lorentz anomaly corresponding to the Einstein anomaly is also obtained.

  4. Gravitational anomalies in higher dimensional Riemann-Cartan space

    Energy Technology Data Exchange (ETDEWEB)

    Yajima, S [Department of Physics, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Tokuo, S [Department of Physics, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Fukuda, M [Department of Physics, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Higashida, Y [Takuma National College of Technology, 551 kohda, Takuma-cho, Mitoyo, Kagawa 769-1192 (Japan); Kamo, Y [Radioisotope Center, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Kubota, S-I [Computing and Communications Center, Kagoshima University, 1-21-35 Koorimoto, Kagoshima 890-0065 (Japan); Taira, H [Department of Physics, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan)

    2007-02-21

    By applying the covariant Taylor expansion method of the heat kernel, the covariant Einstein anomalies associated with a Weyl fermion of spin 1/2 in four-, six- and eight-dimensional Riemann-Cartan space are manifestly given. Many unknown terms with torsion tensors appear in these anomalies. The Lorentz anomaly is intimately related to the Einstein anomaly even in Riemann-Cartan space. The explicit form of the Lorentz anomaly corresponding to the Einstein anomaly is also obtained.

  5. Using EVT for Geological Anomaly Design and Its Application in Identifying Anomalies in Mining Areas

    Directory of Open Access Journals (Sweden)

    Feilong Qin

    2016-01-01

    Full Text Available A geological anomaly is the basis of mineral deposit prediction. Through the study of the knowledge and characteristics of geological anomalies, the category of extreme value theory (EVT to which a geological anomaly belongs can be determined. Associating the principle of the EVT and ensuring the methods of the shape parameter and scale parameter for the generalized Pareto distribution (GPD, the methods to select the threshold of the GPD can be studied. This paper designs a new algorithm called the EVT model of geological anomaly. These study data on Cu and Au originate from 26 exploration lines of the Jiguanzui Cu-Au mining area in Hubei, China. The proposed EVT model of the geological anomaly is applied to identify anomalies in the Jiguanzui Cu-Au mining area. The results show that the model can effectively identify the geological anomaly region of Cu and Au. The anomaly region of Cu and Au is consistent with the range of ore bodies of actual engineering exploration. Therefore, the EVT model of the geological anomaly can effectively identify anomalies, and it has a high indicating function with respect to ore prospecting.

  6. Unilateral occlusion of duplicated uterus with ipsilateral renal anomaly in young girls: a study with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.W. [Dept. of Medical Imaging, National Taiwan Univ. Hospital, Taipei (Taiwan, Province of China); Shieh, C.P. [Dept. of Pediatric Nephrology, Taipei Municipal Women and Children`s Hospital (Taiwan, Province of China); Chen, W.J. [Dept. of Surgery, National Taiwan Univ. Hospital, Taipei (Taiwan, Province of China)

    1995-11-01

    Twenty-four young girls (mean age 13.0 years) with unilateral occlusion of a duplicated uterus and ipsilateral renal agenesis, dysplasia or hypoplasia were studied with magnetic resonance imaging (MRI) following ultrasound examination. Hydrocolpos (n=4), hydrometrocolpos (n=2), hematocolpos (n=11), hematometrocolpos (n=5), hematocolpometra, hematosalpinx (n=3) and hematometra, hematosalpinx (n=1) were noted (two of these patients had presented with hydrocolpos and hematocolpos before and after the menarche). Twenty-two of these girls presented with ipsilateral renal agenesis (right 11, left 11) with ectopic ureters to Gartner`s dust cysts (GDC) in two, in one renal hypoplasia and in one renal dysplasia with ectopic ureters to GDC. MRI offered specific images of the genital tract, showing the exact type of muellerian duct anomaly and providing high diagnostic accuracy. Such preoperative identification of a uterine anomaly, complemented with appropriate surgical intervention, can assist young girls in achieving normal fertility in the future. (orig.)

  7. A review on g-C3N4-based photocatalysts

    Science.gov (United States)

    Wen, Jiuqing; Xie, Jun; Chen, Xiaobo; Li, Xin

    2017-01-01

    As one of the most appealing and attractive technologies, heterogeneous photocatalysis has been utilized to directly harvest, convert and store renewable solar energy for producing sustainable and green solar fuels and a broad range of environmental applications. Due to their unique physicochemical, optical and electrical properties, a wide variety of g-C3N4-based photocatalysts have been designed to drive various reduction and oxidation reactions under light irradiation with suitable wavelengths. In this review, we have systematically summarized the photocatalytic fundamentals of g-C3N4-based photocatalysts, including fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g-C3N4-based photocatalysts. The versatile properties of g-C3N4-based photocatalysts are highlighted, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties. Various design strategies are also thoroughly reviewed, including band-gap engineering, defect control, dimensionality tuning, pore texture tailoring, surface sensitization, heterojunction construction, co-catalyst and nanocarbon loading. Many important applications are also addressed, such as photocatalytic water splitting (H2 evolution and overall water splitting), degradation of pollutants, carbon dioxide reduction, selective organic transformations and disinfection. Through reviewing the important state-of-the-art advances on this topic, it may provide new opportunities for designing and constructing highly effective g-C3N4-based photocatalysts for various applications in photocatalysis and other related fields, such as solar cell, photoelectrocatalysis, electrocatalysis, lithium battery, supercapacitor, fuel cell and separation and purification.

  8. Investigation on The Properties of Fe-Si3N4 Bonded SiC Composite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong; FENG Di; PENG Dayan

    2005-01-01

    The mechanical properties of pressureless sintering Fe-Si3N4 bonded SiC and Si3 N4 bonded SiC with same manufacture process have been compared in this paper.The oxidizing mechanism of Fe-Si3 N4 bonded SiC ceramic matrix composite has been investigated especially through TG-DSC (thermo gravimetric analysis-differential scanning calorimeter) experiment. During oxidation procedure the main reaction is the oxidation of SiC and Si3N4, SiO2 which form protecting film to prevent further oxidizing. And residual iron in the samples become Fe2 O3 and Fe3O4, the oxidation kinetics at 1100 ~ 1300℃ of re-Si3 N4 bonded SiC has been studied especially. The weight gain per unit area at initial stage changes according to beeline rule, in the middle according to conic, and in the last oxidation period follows parabola rule.

  9. The crystal structures of four N-(4-halophenyl-4-oxo-4H-chromene-3-carboxamides

    Directory of Open Access Journals (Sweden)

    Ligia R. Gomes

    2015-01-01

    Full Text Available Four N-(4-halophenyl-4-oxo-4H-chromene-3-carboxamides (halo = F, Cl, Br and I, N-(4-fluorophenyl-4-oxo-4H-chromene-3-carboxamide, C16H10FNO3, N-(4-chlorophenyl-4-oxo-4H-chromene-3-carboxamide, C16H10ClNO3, N-(4-bromophenyl-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3, N-(4-iodophenyl-4-oxo-4H-chromene-3-carboxamide, C16H10INO3, have been structurally characterized. The molecules are essentially planar and each exhibits an anti conformation with respect to the C—N rotamer of the amide and a cis geometry with respect to the relative positions of the Carom—Carom bond of the chromone ring and the carbonyl group of the amide. The structures each exhibit an intramolecular hydrogen-bonding network comprising an N—H...O hydrogen bond between the amide N atom and the O atom of the carbonyl group of the pyrone ring, forming an S(6 ring, and a weak Carom—H...O interaction with the O atom of the carbonyl group of the amide as acceptor, which forms another S(6 ring. All four compounds have the same supramolecular structure, consisting of R22(13 rings that are propagated along the a-axis direction by unit translation. There is π–π stacking involving inversion-related molecules in each structure.

  10. Perturbative and Non-Perturbative Partial Supersymmetry Breaking $N=4 \\to N=2 \\to N=1$

    CERN Document Server

    Kiritsis, Elias B

    1997-01-01

    We show the existence of a supersymmetry breaking mechanism in string theory, where N=4 supersymmetry is broken spontaneously to N=2 and N=1 with moduli dependent gravitino masses. The spectrum of the spontaneously broken theory with lower supersymmetry is in one-to-one correspondence with the spectrum of the heterotic N=4 string. The mass splitting of the N=4 spectrum depends on the compactification moduli as well as the three R-symmetry charges. In the large moduli limit a restoration of the N=4 supersymmetry is obtained. As expected the graviphotons and some of the gauge bosons become massive in N=1 vacua. At some special points of the moduli space some of the N=4 states with non-zero winding numbers and with spin 0 and {1/2} become massless chiral superfields of the unbroken N=1 supersymmetry. Such vaccua have a dual type II description, in which there are magnetically charged states with spin 0 and {1/2} that become massless. The heterotic-type II duality suggests some novel non-perturbative transitions ...

  11. Interfacial Bonding Strength of TiN Film Coated on Si3N4 Ceramic Substrate

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The fraction of TiN/Si3N4 in the cross section was observed with scanning electric microscope (SEM), and residual stresses of TiN coated on the surface of Si3N4 ceramic were measured with X-ray diffraction (XRD).The hardness of TiN film was measured, and bonding strength of TiN film coated on Si3N4 substrate was measured by scratching method. The formed mechanism of residual stress and the failure mechanism of the bonding interface in the film were analyzed, and the adhesion mechanism of TiN film was investigated preliminarily. The results show that residual stresses of TiN film are all behaved as compressive stress, and TiN film is represented smoothly with brittle fracture, which is closely bonded with Si3N4 substrate. TiN film has high hardness and bonding strength of about 500 MPa, which could satisfy usage requests of the surface of cutting Si3N4 ceramic.

  12. Ti-decorated graphitic-C3N4 monolayer: A promising material for hydrogen storage

    Science.gov (United States)

    Zhang, Weibin; Zhang, Zhijun; Zhang, Fuchun; Yang, Woochul

    2016-11-01

    Ti-decorated graphitic carbon nitride (g-C3N4) monolayer as a promising material system for high-capacity hydrogen storage is proposed through density functional theory calculations. The stability and hydrogen adsorption of Ti-decorated g-C3N4 is analyzed by computing the adsorption energy, the charge population, and electronic density of states. The most stable decoration site of Ti atom is the triangular N hole in g-C3N4 with an adsorption energy of -7.58 eV. The large diffusion energy barrier of the adsorbed Ti atom of ∼6.00 eV prohibits the cluster formation of Ti atoms. The electric field induced by electron redistribution of Ti-adsorbed porous g-C3N4 significantly enhanced hydrogen adsorption up to five H2 molecules at each Ti atom with an average adsorption energy of -0.30 eV/H2. The corresponding hydrogen capacity reaches up to 9.70 wt% at 0 K. In addition, the hydrogen capacity is predicted to be 6.30 wt% at 233 K and all adsorbed H2 are released at 393 K according to molecular dynamics simulation. Thus, the Ti-decorated g-C3N4 monolayer is suggested to be a promising material for hydrogen storage suggested by the DOE for commercial applications.

  13. Research on C3N4 Superhard Compound Thin Film and Its Application

    Institute of Scientific and Technical Information of China (English)

    Wu Da-wei; Peng Li-li; Lu Ning; Peng You-gui

    2003-01-01

    By combination of DC reactive magnetron sputtering with multiple arcplating, the alternating C3 N4/TiN compound film is deposited onto HSS. The core level binding energy and the contents of carbon and nitrogen are characterized by X-ray photoelectron spectrum. X-ray diffraction(XRD) shows that compound thin film contains hard crystalline phases of α-C3N4 and β-C3N4. The Knoop microhardness in the load range of 50.5-54.1 GPa is measured. According to acoustic emission scratch test, the critical load values for the coatings on HSS substrates are in the range of 40-80 N. The metal coated with C3N4/TiN compound films has a great improvement in the resistance against corrosion. Many tests show that such a coating has a very high wearability. Compared with the uncoated and TiN coated tools, the C3N4/TiN coated tools have a much longer cutting life.

  14. Hermitian separability and transition from singlet to adjoint BFKL equations in $\\mathcal{N}=4$ super Yang-Mills Theory

    CERN Document Server

    Bondarenko, S

    2015-01-01

    We revisit the next-to-leading order~(NLO) correction to the eigenvalue of the BFKL equation in the adjoint representation and investigate its properties in analogy with the singlet BFKL in planar $\\mathcal{N}=4$ super Yang-Mills Theory~(SYM). We show that the adjoint NLO BFKL eigenvalue is needed to be slightly modified in order to have a property of hermitian separability present for the singlet BFKL. After this modification the adjoint NLO BFKL eigenvalue is expressed through holomorphic and antiholomophic parts of the leading order eigenvalue and their derivatives. The proposed choice of the modified NLO expression is supported by the fact that it is possible to obtain the same result in a relatively straightforward way directly from the singlet NLO BFKL eigenvalue replacing alternating series by series of constant sign. This transformation corresponds to changing cylindrical topology of the singlet BFKL to the planar topology of the adjoint BFKL. We believe that the original NLO calculation of Fadin and ...

  15. Prenatal congenital vertical talus (rocker bottom foot): a marker for multisystem anomalies.

    Science.gov (United States)

    Rubio, Eva I; Mehta, Nimisha; Blask, Anna R; Bulas, Dorothy I

    2017-09-06

    Congenital vertical talus is a rare foot anomaly characterized by a prominent calcaneus and rigid forefoot dorsiflexion. While congenital vertical talus has been associated with anomalies such as trisomy 18, myelomeningocele and arthrogryposis, postnatal series have reported cases of isolated congenital vertical talus. The purpose of our study was to determine the incidence of isolated congenital vertical talus prenatally and identify the most common anomalies associated with this finding. A retrospective review was performed of congenital vertical talus cases identified in our fetal center from 2006 to 2015. The prenatal US and MR imaging appearance of congenital vertical talus was evaluated and differentiation from congenital talipes equinovarus was assessed. Studies were evaluated for additional abnormalities affecting the central nervous system, face, limbs, viscera, growth and amniotic fluid. Imaging findings were recorded and correlated with outcomes when available. Twenty-four cases of congenital vertical talus were identified prenatally (gestational age: 19-36 weeks). All 24 had prenatal US and 21 also underwent fetal MRI on the same day. There were no isolated cases of congenital vertical talus in this series; all 24 had additional anomalies identified prenatally. Sixteen cases had bilateral congenital vertical talus (67%). Additional anomalies were identified in the brain (15), spine (11), face (6), abdominal wall (3), heart (8) and other limbs (12). Chromosomal abnormalities were identified in 6 of 20 patients who underwent genetic testing. Overall, US held some advantage in detecting the abnormality: in 10 cases, US depicted congenital vertical talus more clearly than MRI; in 8 cases, US and MRI were equal in detection and in 3 cases, MRI was superior. In 9/15 cases with intracranial abnormalities, MRI was superior to US in demonstrating structural anomalies. Outcomes included termination (11), intrauterine fetal demise (1), stillbirth or immediate

  16. Comparison of Unsupervised Anomaly Detection Methods

    Data.gov (United States)

    National Aeronautics and Space Administration — Several different unsupervised anomaly detection algorithms have been applied to Space Shuttle Main Engine (SSME) data to serve the purpose of developing a...

  17. Magnetic anomalies in Central Bengal fan

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.C.S.; Lakshminarayana, S.; Sarma, K.V.L.N.S.

    Total magnetic field anomalies recorded over the Central Bengal Fan are analysed and the depths to the magnetic basement are computed using the analytical signal and the Werner deconvolution methods. To the west and east of 85 degrees E...

  18. Ionospheric Anomaly before Kyushu|Japan Earthquake

    Directory of Open Access Journals (Sweden)

    YANG Li

    2017-05-01

    Full Text Available GIM data released by IGS is used in the article and a new method of combining the Sliding Time Window Method and the Ionospheric TEC correlation analysis method of adjacent grid points is proposed to study the relationship between pre-earthquake ionospheric anomalies and earthquake. By analyzing the abnormal change of TEC in the 5 grid points around the seismic region, the abnormal change of ionospheric TEC is found before the earthquake and the correlation between the TEC sequences of lattice points is significantly affected by earthquake. Based on the analysis of the spatial distribution of TEC anomaly, anomalies of 6 h, 12 h and 6 h were found near the epicenter three days before the earthquake. Finally, ionospheric tomographic technology is used to do tomographic inversion on electron density. And the distribution of the electron density in the ionospheric anomaly is further analyzed.

  19. SEG US Bouguer Gravity Anomaly Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SEG gravity data are the product of the ad hoc Gravity Anomaly Map (GAM) Committee, sponsored by the Society of Exploration Geophysicists (SEG) and the U.S....

  20. Mexico Terrain Corrected Free Air Anomalies (97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' gravity anomaly grid for Mexico, North-Central America and the Western Caribbean Sea is NOT the input data set used in the development of the MEXICO97 model....

  1. Design and Implementation of an Anomaly Detector

    Energy Technology Data Exchange (ETDEWEB)

    Bagherjeiran, A; Cantu-Paz, E; Kamath, C

    2005-07-11

    This paper describes the design and implementation of a general-purpose anomaly detector for streaming data. Based on a survey of similar work from the literature, a basic anomaly detector builds a model on normal data, compares this model to incoming data, and uses a threshold to determine when the incoming data represent an anomaly. Models compactly represent the data but still allow for effective comparison. Comparison methods determine the distance between two models of data or the distance between a model and a point. Threshold selection is a largely neglected problem in the literature, but the current implementation includes two methods to estimate thresholds from normal data. With these components, a user can construct a variety of anomaly detection schemes. The implementation contains several methods from the literature. Three separate experiments tested the performance of the components on two well-known and one completely artificial dataset. The results indicate that the implementation works and can reproduce results from previous experiments.

  2. Major congenital anomalies in a Danish region

    DEFF Research Database (Denmark)

    Garne, Ester; Hansen, Anne Vinkel; Birkelund, Anne Sofie;

    2014-01-01

    : diabetes, epilepsy, mental disorder, thyroid disease, asthma, or inflammatory bowel disease. Medication for these conditions accounted for 46% of maternal drug use. CONCLUSION: Maternal morbidity and use of potentially teratogenic medication have increased among congenital anomaly cases. Foetal and infant...

  3. Isostatic geoid anomalies on a sphere

    Science.gov (United States)

    Dahlen, F. A.

    1982-01-01

    Long-wavelength geoid anomalies due to lateral variations in the density or thickness of a thin layer in local isostatic equilibrium on the surface of a sphere depend sensitively on the assumed state of stress within the layer. A number of common intuitive definitions of local isostasy generally believed to be essentially identical are associated with quite different states of isostatic stress, and the corresponding theoretical geoid anomalies can vary by more than a factor of 2. This sensitivity of the theoretical anomaly to the exact definition of local isostasy constitutes an obstacle to any proposed program of interpreting or exploiting observed global isostatic geoid anomalies such as those associated with the aging of the oceanic lithosphere.

  4. Coral Reef Watch, Temperature Anomaly, 50 km

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Coral Reef Watch distributes SST anomaly data using a combination of the POES AVHRR Global Area Coverage data, and data from a climatological database. AVHRR...

  5. Congenital microgastria and hypoplastic upper limb anomalies.

    Science.gov (United States)

    Lueder, G T; Fitz-James, A; Dowton, S B

    1989-03-01

    Six cases of congenital microgastria associated with limb anomalies are reviewed. The microgastria-hypoplastic upper limb association may arise as a result of aberrant mesodermal development in the 5th embryonic week.

  6. Dataset of anomalies and malicious acts in a cyber-physical subsystem.

    Science.gov (United States)

    Laso, Pedro Merino; Brosset, David; Puentes, John

    2017-10-01

    This article presents a dataset produced to investigate how data and information quality estimations enable to detect aNomalies and malicious acts in cyber-physical systems. Data were acquired making use of a cyber-physical subsystem consisting of liquid containers for fuel or water, along with its automated control and data acquisition infrastructure. Described data consist of temporal series representing five operational scenarios - Normal, aNomalies, breakdown, sabotages, and cyber-attacks - corresponding to 15 different real situations. The dataset is publicly available in the .zip file published with the article, to investigate and compare faulty operation detection and characterization methods for cyber-physical systems.

  7. Hydrological anomalies connected to earthquakes in southern Apennines (Italy

    Directory of Open Access Journals (Sweden)

    E. Esposito

    2001-01-01

    Full Text Available The study of hydrological variations in the watersheds of seismic areas can be useful in order to acquire a new knowledge of the mechanisms by which earthquakes can produce hydrological anomalies. Italy has the availability of many long historical series both of hydrological parameters and of seismological data, and is an ideal laboratory to verify the validity of theoretical models proposed by various authors. In this work we analyse the hydrological anomalies associated with some of the big earthquakes that occurred in the last century in the southern Apennines: 1930, 1980 and 1984. For these earthquakes we analysed hydrometric and pluviometric data looking for significant anomalies in springs, water wells and mountain streams. The influence of rainfalls on the normal flows of rivers, springs and wells has been ascertained. Also, the earthquake of 1805, for which a lot of hydrological perturbations have been reported, is considered in order to point out effects imputable to this earthquake that can be similar to the effects of the other big earthquakes. The considered seismic events exhibit different modes of energy release, different focal mechanisms and different propagation of effects on the invested areas. Furthermore, even if their epicentres were not localised in contiguous seismogenetic areas, it seems that the hydrological effects imputable to them took place in the same areas. Such phenomena have been compared with macroseismic fields and transformed in parameters, in order to derive empirical relationships between the dimensions of the event and the characteristics of the hydrological variations. The results of this work point to a close dependence among hydrological anomalies, regional structures and fault mechanisms, and indicate that many clear anomalies have been forerunners of earthquakes. In 1993, the Naples Bureau of the Hydrographic National Service started the continuous monitoring of hydrologic parameters by a network of

  8. Viscosity anomaly in core-softened liquids

    OpenAIRE

    Fomin, Yu. D.; Ryzhov, V. N.

    2013-01-01

    The present article presents a molecular dynamics study of several anomalies of core-softened systems. It is well known that many core-softened liquids demonstrate diffusion anomaly. Usual intuition relates the diffusion coefficient to shear viscosity via Stockes-Einstein relation. However, it can break down at low temperature. In this respect it is important to see if viscosity also demonstrates anomalous behavior.

  9. Mullerian anomalies: a cause of primary amenorrhea

    OpenAIRE

    2013-01-01

    Background: The objectives of this study were to determine the etiologic causes of amenorrhea, the prevalence of mullerian anomalies as a cause of primary amenorrhea and the different varieties of mullerian anomalies causing primary amenorrhea. Methods: This study included all the women presenting with primary amenorrhea who presented to the department of obstetrics and gynecology, Sir T Hospital and Government Medical College, Bhavnagar from 1st January 2010 to 30th June 2012. Results: The c...

  10. Efficient Accurate Context-Sensitive Anomaly Detection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    For program behavior-based anomaly detection, the only way to ensure accurate monitoring is to construct an efficient and precise program behavior model. A new program behavior-based anomaly detection model,called combined pushdown automaton (CPDA) model was proposed, which is based on static binary executable analysis. The CPDA model incorporates the optimized call stack walk and code instrumentation technique to gain complete context information. Thereby the proposed method can detect more attacks, while retaining good performance.

  11. Lateral sacral lipomyelomeningocele : a rare anomaly.

    Directory of Open Access Journals (Sweden)

    Shetty D

    2002-04-01

    Full Text Available Lateral sacral lipomyelomeningocele is a rare spinal developmental anomaly. In the case under report, the fat attached to the neural placode was blending with the gluteal fat externally. The cord was tethered at this level. Multiple bony anomalies and diastematomyelia were associated findings. A case of lateral sacral lipomyelomeningocele with excellent imaging detail provided by the multiplanar magnetic resonance (MR scan is reported.

  12. Gauge anomalies in Lorentz-violating QED

    Science.gov (United States)

    Santos, Tiago R. S.; Sobreiro, Rodrigo F.

    2016-12-01

    In this work we study the issue of gauge anomalies in Lorentz-violating QED. To do so, we opt to use the Becchi-Rouet-Stora-Tyutin formalism within the algebraic renormalization approach, reducing our study to a cohomology problem. Since this approach is independent of the renormalization scheme, the results obtained here are expected to be general. We find that the Lorentz-violating QED is free of gauge anomalies to all orders in perturbation theory.

  13. Gauge anomalies in Lorentz-violating QED

    CERN Document Server

    Santos, Tiago R S

    2016-01-01

    In this work we study the issue of gauge anomalies in Lorentz-violating QED. To do so, we opt to use the BRST formalism within of the algebraic renormalization approach, reducing our study to a cohomology problem. Since that this approach is independent of the renormalization scheme, the results here obtained are expected to be general. We find that the Lorentz-violating QED is free of gauge anomalies to all orders in perturbation theory.

  14. Craniofacial anomalies: from development to molecular pathogenesis.

    Science.gov (United States)

    Rice, David P C

    2005-11-01

    Advances in developmental biology combined with progress in human genetics are helping us decipher how the craniofacial region develops and how the consequences of misdirected development result in malformation. This review describes the molecular etiology of a number of craniofacial developmental anomalies. The more common craniofacial anomalies cleft lip and palate and craniosynostosis, as well as cleidocranial dysplasia, hemifacial microsomia, holoprosencephaly, enlarged parietal foramina, Treacher Collins syndrome and cherubism are discussed.

  15. CP-violating CFT and trace anomaly

    CERN Document Server

    Nakayama, Yu

    2012-01-01

    It is logically possible that the trace anomaly in four dimension includes the Hirzebruch-Pontryagin density in CP violating theories. Although the term vanishes at free conformal fixed points, we realize such a possibility in the holographic renormalization group and show that it is indeed possible. The Hirzebruch-Pontryagin term in the trace anomaly may serve as a barometer to understand how much CP is violated in conformal field theories.

  16. Reports on various anomalies of the ribs

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, G.; Brix, F.

    1988-02-01

    Three patients are presented who were suffering from different anomalies of the ribs: There was one each plus and minus variant and a female patient with Gorlin-Goltz syndrome (basal cell nevus syndrome) demonstrating several changes in the ribs as an expression of a genetically determined segmentation disturbance. These presentations are followed by a detailed discussion on the types and causes of such anomalies.

  17. Anomalous transport due to scale anomaly

    CERN Document Server

    Chernodub, M N

    2016-01-01

    We show that the scale anomaly in field theories leads to new anomalous transport effects that emerge in external electromagnetic field in inhomogeneous gravitational background. In inflating geometry the QED scale anomaly generates electric current which flows in opposite direction with respect to background electric field. In static spatially inhomogeneous gravitational background the dissipationless electric current flows transversely both to the magnetic field axis and to the gradient of the inhomogeneity. The anomalous currents are proportional to the beta function of the theory.

  18. On the topological interpretation of gravitational anomalies

    Science.gov (United States)

    Perrot, Denis

    2001-07-01

    We consider the mixed gravitational Yang-Mills anomaly as the coupling between the K-theory and K-homology of a C ∗-algebra crossed product. The index theorem of Connes-Moscovici allows to compute the Chern character of the K-cycle by local formulae involving connections and curvatures. It gives a topological interpretation to the anomaly, in the sense of noncommutative algebras.

  19. One-Loop Gauge Theory Amplitudes in N=4 Super Yang-Mills from MHV Vertices

    CERN Document Server

    Brandhuber, A; Travaglini, G; Brandhuber, Andreas; Spence, Bill; Travaglini, Gabriele

    2004-01-01

    We propose a new, twistor string theory inspired formalism to calculate loop amplitudes in N=4 super Yang-Mills theory. In this approach, maximal helicity violating (MHV) tree amplitudes of N=4 super Yang-Mills are used as vertices, using an off-shell prescription introduced by Cachazo, Svrcek and Witten, and combined into effective diagrams that incorporate large numbers of conventional Feynman diagrams. As an example, we apply this formalism to the particular class of MHV one-loop scattering amplitudes with an arbitrary number of external legs in N=4 super Yang-Mills. Remarkably, our approach naturally leads to a representation of the amplitudes as dispersion integrals, which we evaluate exactly. Our results for the MHV amplitudes are in precise agreement with the expressions for this class of amplitudes obtained previously by Bern, Dixon, Dunbar and Kosower using the cut-constructibility approach.

  20. The Preparation of Cu-g-C3N4/AC Catalyst for Acetylene Hydrochlorination

    Directory of Open Access Journals (Sweden)

    Wenli Zhao

    2016-12-01

    Full Text Available A novel catalyst based on g-C3N4/activated carbon was prepared by adding CuCl2. The catalytic performance of the as-prepared catalyst was investigated in the acetylene hydrochlorination reaction. X-ray photoelectron spectroscopy, temperature programmed desorption, low temperature N2 adsorption/desorption (Brunauer–Emmett–Teller, and thermal gravity analysis showed that Cu-g-C3N4/AC significantly enhanced the catalytic performance of the original catalyst by increasing the relative pyrrolic N content. Cu-g-C3N4/AC also affected the adsorption of hydrogen chloride and acetylene, as well as inhibited the coke deposition during acetylene hydrochlorination.

  1. Production and some properties of Si3N4 reinforced aluminium alloy composites

    Directory of Open Access Journals (Sweden)

    Pardeep Sharma

    2015-09-01

    Full Text Available The present research work focuses on the production of aluminium (AA6082-T6 matrix composites reinforced with various weight percentage of silicon nitride particles by conventional stir casting route. The percentage of reinforcement is varied from 0 wt.% to 12 wt.% in a stage of 3%. The microstructures and mechanical properties of the fabricated aluminium matrix composites are investigated. The scanning electron microstructure images reveal the presence of Si3N4 particles in the aluminium matrix. The distribution of Si3N4 particles has also been recognized with X-ray diffraction technique. The mechanical properties such as ultimate tensile strength and hardness have improved at the cost of reduction in ductility with increase in weight percentage of silicon nitride particulates in the aluminium metal matrix. The density and porosity of the composites also show an increasing trend with increase in volume fraction of Si3N4 particles in the aluminium matrix.

  2. Growth of Co Nanoclusters on Si3N4 Surface Formed on Si(111)

    Institute of Scientific and Technical Information of China (English)

    刘熙; 贾金锋; 王俊忠; 薛其坤

    2003-01-01

    We have grown high density Co dusters with a narrow-sized distribution on the Si3N4(0001)-(8 × 8) surface. In the submonolayer regime, Co clusters tend to keep a certain size (~ 1.45 nm in diameter) irrespective of coverage.With increasing coverage above 0.92 ML, two new clusters with certain but larger sizes are formed. This novel growth behaviour can be explained by the quantum size effect [Phys. Rev. Lett. 90 (2003) 185506]. It is found that the Co cluster size distribution can be improved by post annealing. Even at high temperature (700℃ ), no reaction of Co with Si3N4 is observed, indicating that Si3N4(0001)-(8 × 8) is a promising substrate for growth of magnetic nanostructures.

  3. Preparation of Si3N4 Form Diatomite via a Carbothermal Reduction-Nitridation Process

    Science.gov (United States)

    Ma, Bin; Huang, Zhaohui; Mei, Lefu; Fang, Minghao; Liu, Yangai; Wu, Xiaowen; Hu, Xiaozhi

    2016-05-01

    Si3N4 was produced using diatomite and sucrose as silicon and carbon sources, respectively. The effect of the C/SiO2 molar ratio, heating temperature and soaking time on the morphology and phase compositions of the final products was investigated by scanning electron microscopy, x-ray diffraction analysis and energy dispersive spectroscopy. The phase equilibrium relationships of the system at different heating temperatures were also investigated based on the thermodynamic analysis. The results indicate that the phase compositions depended on the C/SiO2 molar ratio, heating temperature and soaking time. Fabrication of Si3N4 from the precursor via carbothermal reduction nitridation was achieved at 1550°C for 1-8 h using a C/SiO2 molar ratio of 3.0. The as-prepared Si3N4 contained a low amount of Fe3Si (<1 wt.%).

  4. β—Si3N4的Raman光谱研究

    Institute of Scientific and Technical Information of China (English)

    陈祥生; 金宜芬; 等

    1990-01-01

    利用光散射和电子显微镜技术,对β-Si3N4的结构和形貌进行了研究和观察。结果指出:β-Si3N4的Raman光谱由188、210、230、480、624、865、930、936、1047cm-1峰组成,其中480cm-1附近的宽峰可归结为a-Si的Si-Si键振动。β-Si3N4呈透明片状堆积。

  5. Investigation of the chemical interaction in the TiC-Si3N4 system

    Directory of Open Access Journals (Sweden)

    Izhevskyi V.A.

    1999-01-01

    Full Text Available Chemical interaction in the TiCSi3N4 system was investigated. Thermodynamic calculations and kinetic analysis were carried out for a number of powder mixtures with various TiC:Si3N4 molar ratios in the temperature range 1300-1750 °C. Stability regions of the TiC-Si3N4 composites were defined. It was shown that the main reaction products are silicon carbide and titanium carbonitride. The overall chemical interaction is described in terms of chemical reaction between titanium carbide and silicon nitride, and the diffusion of carbon and nitrogen through the coherent reaction products layer after completion of the initial direct interaction of the components.

  6. Presolar Grains and Their Isotopic Anomalies in Meteorites

    Institute of Scientific and Technical Information of China (English)

    林杨挺; 王世杰

    2001-01-01

    Study on presolar grains including diamond, silicon carbide, graphite, silicon nitrite (Si3N4), corundum and spinel isolated from meteorites is summarized in this paper. Except for nanometer-sized diamond, the other grains are micrometers to submicrometers in size. The presolar grains survived mainly in the fine -grained matrix of primitive chondrites and were isolated by chemical treatments. Diamond contains Xe isotopes (Xe-HL), typically produced in p- and r-processes, probably formed in supernovae. Mainstream silicon carbides are enriched in 29, 30Si and 13C, but depleted in 15N. They also contain various s-process products, consistent with calculations of AGB stars. Other silicon carbides exhibit much larger isotopic anomalies and are classified as groups X, Y, Z and AB. Among them, group X of SiC is characterized by enrichment of 28Si and daughter isotopes of various short-lived nuclides, suggesting an origin from supernovae. Graphite can be divided into four density fractions with distinct isotopic compositions. They may form in AGB stars, novae and supernovae, respectively. Si3N4 is similar to X-SiC in isotopic composition. Corundum is classified as four groups based on their oxygen isotopic compositions. AGB and red giant stars are possible sources for the oxide. More comprehensive study of presolar grains, especially discovery of the other types of oxides and silicates, isotopic analyses of individual submicrometer-sized grains and distribution of presolar grains among various chemical groups and petrographic types of chondrites will provide new information on nucleosynthesis, stellar evolution and formation of the solar nebula.

  7. Presolar Grains and Their Isotopic Anomalies in Meteorites

    Institute of Scientific and Technical Information of China (English)

    林杨挺; 王世杰

    2001-01-01

    Study on presolar grains including diamond,silicon carbide,graphite,silicon nitrite(Si3N4),coundum and spinel isolated from meteorites is summarized in this paper.Except for nanometer-sized diamond,the other grains are micrometers to submicrometers in size.The presolar grains survived mainly in the fine-grained matrix of primitive chondrites and were isolated by chemical treatments.Diamond contains Xe isotopes(Xe-HL),typically produced in p-and r-processes,probably formed in supernovae.Mainstream silicon carbides are enriched in 29,30Si and 13C,but depleted in 15N.They also contain various s-process products,consistent with calculations of AGB stars.Other silicon carbides exhibit much larger isotopic anomalies and are classified as groups X,Y,Z and AB.Among them,group X of SiC is characterized by enrichment of 28Si and daughter isotopes of various short-lived nuclides,suggesting an origin from supernovae.Graphite can be divided into four density fractions with distince isotopic compositions.They may form in AGB stars,novae and supernovae,respctively,Si3N4 is similar to X-SiC in isotopic composition.Corundum is classified as four groups based on theid oxygen isotopic compositions.AGB and red giang stare are possible sources for the oxide.More comprehensive study of presolar grains,especially discovery of the other types of oxides and silicates,isotopic analyses of individual submicrometer-sized grains and distribution of presolar grains among various chemical groups and petropaphic types of chondrites will provide new information on nucleosynthesis,stellar evolution and formation of the solar nebula.

  8. catena-Poly[[bis(thiocyanato-κNiron(II]-bis(μ-dipyrazin-2-yl disulfide-κ2N4:N4

    Directory of Open Access Journals (Sweden)

    Susanne Wöhlert

    2013-09-01

    Full Text Available In the title compound, [Fe(NCS2(C8H6N4S22]n, the FeII cation is coordinated by two terminal N-bonded thiocyanate anions and four bridging N:N′-bridging dipyrazin-2-yl disulfide ligands in an octahedral geometry. The FeII cations are connected via bridging 4,4′-dipyrazine ligands into chains along the b-axis direction. The asymmetric unit consists of one FeII cation located on position with site symmetry 2/m, one thiocyanate anion located on a mirror plane and one disulfide ligand located on a twofold rotation axis.

  9. Medical imaging for congenital anomalies of the lung. Focused on tracheobronchial and parenchymal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Kohda, Ehiichi; Shiraga, Nobuyuki; Higuchi, Mutsumi; Ishibashi, Ryouchi [Tachikawa Hospital, Tokyo (Japan)

    2003-02-01

    This is a review of medical imaging studies for congenital anomalies of the lung focused on tracheobronchial and parenchymal anomalies. It is important to know the findings of these developmental anomalies, because they are frequently manifested as infectious diseases or mass. Documented details are pulmonary agenesis, aplasia, pulmonary hypoplasia, tracheal agenesis, bridging bronchus, tracheal bronchus, congenital tracheal stenosis, bronchial atresia, bronchobiliary fistula, bronchogenic cyst, bronchopulmonary sequestration, congenital cystic adenomatoid malformation, and pulmonary lymphangiectasia. (author)

  10. Theoretical study of gallium nitride molecules, GaN2 and GaN4.

    Science.gov (United States)

    Tzeli, Demeter; Theodorakopoulos, Giannoula; Petsalakis, Ioannis D

    2008-09-18

    The electronic and geometric structures of gallium dinitride GaN 2, and gallium tetranitride molecules, GaN 4, were systematically studied by employing density functional theory and perturbation theory (MP2, MP4) in conjunction with the aug-cc-pVTZ basis set. In addition, for the ground-state of GaN 4( (2)B 1) a density functional theory study was carried out combining different functionals with different basis sets. A total of 7 minima have been identified for GaN 2, while 37 structures were identified for GaN 4 corresponding to minima, transition states, and saddle points. We report geometries and dissociation energies for all the above structures as well as potential energy profiles, potential energy surfaces and bonding mechanisms for some low-lying electronic states of GaN 4. The dissociation energy of the ground-state GaN 2 ( X (2)Pi) is 1.1 kcal/mol with respect to Ga( (2)P) + N 2( X (1)Sigma g (+)). The ground-state and the first two excited minima of GaN 4 are of (2)B 1( C 2 v ), (2)A 1( C 2 v , five member ring), and (4)Sigma g (-)( D infinityh ) symmetry, respectively. The dissociation energy ( D e) of the ground-state of GaN 4, X (2)B 1, with respect to Ga( (2)P) + 2 N 2( X (1)Sigma g (+)), is 2.4 kcal/mol, whereas the D e of (4)Sigma g (-) with respect to Ga( (4)P) + 2 N 2( X (1)Sigma g (+)) is 17.6 kcal/mol.

  11. n4Studies: Sample Size Calculation for an Epidemiological Study on a Smart Device

    Directory of Open Access Journals (Sweden)

    Chetta Ngamjarus

    2016-05-01

    Full Text Available Objective: This study was to develop a sample size application (called “n4Studies” for free use on iPhone and Android devices and to compare sample size functions between n4Studies with other applications and software. Methods: Objective-C programming language was used to create the application for the iPhone OS (operating system while javaScript, jquery mobile, PhoneGap and jstat were used to develop it for Android phones. Other sample size applications were searched from the Apple app and Google play stores. The applications’ characteristics and sample size functions were collected. Spearman’s rank correlation was used to investigate the relationship between number of sample size functions and price. Results: “n4Studies” provides several functions for sample size and power calculations for various epidemiological study designs. It can be downloaded from the Apple App and Google play store. Comparing n4Studies with other applications, it covers several more types of epidemiological study designs, gives similar results for estimation of infinite/finite population mean and infinite/finite proportion from GRANMO, for comparing two independent means from BioStats, for comparing two independent proportions from EpiCal application. When using the same parameters, n4Studies gives similar results to STATA, epicalc package in R, PS, G*Power, and OpenEpi. Conclusion: “n4Studies” can be an alternative tool for calculating the sample size. It may be useful to students, lecturers and researchers in conducting their research projects.

  12. Clustering and Recurring Anomaly Identification: Recurring Anomaly Detection System (ReADS)

    Science.gov (United States)

    McIntosh, Dawn

    2006-01-01

    This viewgraph presentation reviews the Recurring Anomaly Detection System (ReADS). The Recurring Anomaly Detection System is a tool to analyze text reports, such as aviation reports and maintenance records: (1) Text clustering algorithms group large quantities of reports and documents; Reduces human error and fatigue (2) Identifies interconnected reports; Automates the discovery of possible recurring anomalies; (3) Provides a visualization of the clusters and recurring anomalies We have illustrated our techniques on data from Shuttle and ISS discrepancy reports, as well as ASRS data. ReADS has been integrated with a secure online search

  13. MAGSAT correlations with geoid anomalies. [magnetic anomalies in the western Gulf of Mexico

    Science.gov (United States)

    Bowin, C. O. (Principal Investigator)

    1984-01-01

    A digital data library of MAGSAT data is described and its applications and capabilities are reviewed. Polynomial trends were removed from each half-orbit in order to estimate and remove ring current effects from the data. The MAGSAT data in the Gulf of Mexico region was analyzed to define better the possible relation of the negative MAGSAT anomaly there to the negative residual geoid anomaly in the western Gulf of Mexico. Since the shape and location of the negative magnetic anomaly are variable depending upon the particular polynomial surface and curve orders used, no definitive conclusion as to the degree of correspondance between the residual geoid and MAGSAT lithosphere anomalies is offered.

  14. N=4 Supersymmetric Yang-Mills Theory on a Kaehler Surface

    CERN Document Server

    Dijkgraaf, R; Schroers, B J

    1998-01-01

    We study N=4 supersymmetric Yang-Mills theory on a Kaehler manifold with $b_2^+ \\geq 3$. Adding suitable perturbations we show that the partition function of the N=4 theory is the sum of contributions from two branches: (i) instantons, (ii) a special class of Seiberg-Witten monopoles. We determine the partition function for the theories with gauge group SU(2) and SO(3), using S-duality. This leads us to a formula for the Euler characteristic of the moduli space of instantons.

  15. Twisted N=4 Super Yang-Mills Theory in Omega-background

    CERN Document Server

    Ito, Katsushi; Sasaki, Shin

    2013-01-01

    We study the twisted N=4 super Yang-Mills theories in the Omega-background with the constant R-symmetry Wilson line gauge field. Based on the classification of topological twists of N=4 supersymmetry (the half, the Vafa-Witten and the Marcus twists), we construct the deformed off-shell supersymmetry associated with the scalar supercharges for these twists. We find that the Omega-deformed action is written in the exact form with respect to the scalar supercharges as in the undeformed case.

  16. Molecular Model Design and Quantum Chemistry Calculation of Cluster B4N4

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The B4N4 configurations were designed by using the molecular figure software. The full geometry optimization and harmonic vibration frequency analysis were performed at the 6-31G(d) level using density functional theory B3LYP method, which indicates that the five isomers are stationary points on the potential energy surface of B4N4 molecules. The geometry structure, frontier molecular orbital (FMO) and mulliken population have been analyzed. The bonding properties and hybrid type were also discussed in detail, showing the addition of hydro- gen atoms to boron or nitrogen atom would increase the stabilities of the BN clusters.

  17. All Tree-Level MHV Form Factors in $\\mathcal{N}=4$ SYM from Twistor Space

    CERN Document Server

    Koster, Laura; Staudacher, Matthias; Wilhelm, Matthias

    2016-01-01

    We incorporate all gauge-invariant local composite operators into the twistor-space formulation of N=4 SYM theory, detailing and expanding on ideas we presented recently in arXiv:1603.04471. The vertices for these operators contain infinitely many terms and we show how they can be constructed by taking suitable derivatives of a light-like Wilson loop in twistor space and shrinking it down to a point. In particular, these vertices directly yield the tree-level MHV super form factors of all composite operators in N=4 SYM theory.

  18. Introduction of atomic H into Si3N4/SiO2/Si stacks

    Institute of Scientific and Technical Information of China (English)

    JIN Hao; WEBER K.J.; LI Weitang; BLAKERS A.W.

    2006-01-01

    Atomic H generated by a plasma NH3 source at 400 ℃ was demonstrated to passivate dehydrogenated Si3N4/SiO2/Si stacks effectively by bonding with defectsin the Si3N4 film and at the Si-SiO2 interface. A subsequent anneal in N2 after atomic H reintroduction was demonstrated to further improve passivation of the Si-SiO2 interface. Isothermal and isochronal anneals in N2 were carried out in order to determine the optimized annealing conditions.

  19. LPCVD制备Si3N4薄膜工艺研究

    Institute of Scientific and Technical Information of China (English)

    潘伟

    2013-01-01

      本文简要介绍了Si3N4薄膜的制备方法,详细介绍了低压化学气相淀积(Low Pressure Chemical Vapor Deposition)LPCVD制备氮化硅的工艺。并对工艺的结果进行了适当的分析,为LPCVD制备高质量的Si3N4薄膜奠定了基础。

  20. The N=4 string is the same as the N=2 string

    CERN Document Server

    Siegel, Warren

    1992-01-01

    We redo the quantization of the N=4 string, taking into account the reducibility of the constraints. The result is equivalent to the N=2 string, with critical dimension D=4 and signature (++--). The N=4 formulation has several advantages: the sigma-model field equations are implied classically, rather than by quantum/beta-function calculations; self-duality/chirality is one of the super-Virasoro constraints; SO(2,2) covariance is manifest. This reveals that the theory includes fermions, and is apparently spacetime supersymmetric.

  1. The operator product expansion between the 16 lowest higher spin currents in the N=4 superspace

    Science.gov (United States)

    Ahn, Changhyun; Kim, Man Hea

    2016-07-01

    Some of the operator product expansions (OPEs) between the lowest 16 higher spin currents of spins (1, 3/2, 3/2, 3/2, 3/2, 2, 2, 2, 2, 2, 2, 5/2, 5/2, 5/2, 5/2, 3) in an extension of the large N=4 linear superconformal algebra were constructed in N=4 superconformal coset SU(5)/SU(3) theory previously. In this paper, by rewriting these OPEs in the N=4 superspace developed by Schoutens (and other groups), the remaining undetermined OPEs in which the corresponding singular terms possess the composite fields with spins s =7/2, 4, 9/2, 5 are completely determined. Furthermore, by introducing arbitrary coefficients in front of the composite fields on the right-hand sides of the above complete 136 OPEs, reexpressing them in the N=2 superspace, and using the N=2 OPEs Mathematica package by Krivonos and Thielemans, the complete structures of the above OPEs with fixed coefficient functions are obtained with the help of various Jacobi identities. We then obtain ten N=2 super OPEs between the four N=2 higher spin currents denoted by (1, 3/2, 3/2, 2), (3/2, 2, 2, 5/2), (3/2, 2, 2, 5/2), and (2, 5/2, 5/2, 3) (corresponding 136 OPEs in the component approach) in the N=4 superconformal coset SU(N+2)/SU(N) theory. Finally, we describe them as one single N=4 super OPE between the above 16 higher spin currents in the N=4 superspace. The fusion rule for this OPE contains the next 16 higher spin currents of spins of (2, 5/2, 5/2, 5/2, 5/2, 3, 3, 3, 3, 3, 3, 7/2, 7/2, 7/2, 7/2, 4) in addition to the quadratic N=4 lowest higher spin multiplet and the large N=4 linear superconformal family of the identity operator. The various structure constants (fixed coefficient functions) appearing on the right-hand side of this OPE depend on N and the level k of the bosonic spin-1 affine Kac-Moody current. For convenience, the above 136 OPEs in the component approach for generic ( N, k) with simplified notation are given.

  2. Integrable amplitude deformations for N =4 super Yang-Mills and ABJM theory

    Science.gov (United States)

    Bargheer, Till; Huang, Yu-Tin; Loebbert, Florian; Yamazaki, Masahito

    2015-01-01

    We study Yangian-invariant deformations of scattering amplitudes in 4d N =4 super Yang-Mills theory and 3d N =6 Aharony-Bergman-Jafferis-Maldacena (ABJM) theory. In particular, we obtain the deformed Graßmannian integral for 4d N =4 supersymmetric Yang-Mills theory, both in momentum and momentum-twistor space. For 3d ABJM theory, we initiate the study of deformed scattering amplitudes. We investigate general deformations of on-shell diagrams, and find the deformed Graßmannian integral for this theory. We furthermore introduce the algebraic R-matrix construction of deformed Yangian invariants for ABJM theory.

  3. Crystal structures of 4-meth-oxy-N-(4-methyl-phenyl)benzene-sulfonamide and N-(4-fluoro-phenyl)-4-meth-oxy-benzene-sulfonamide.

    Science.gov (United States)

    Rodrigues, Vinola Z; Preema, C P; Naveen, S; Lokanath, N K; Suchetan, P A

    2015-11-01

    Crystal structures of two N-(ar-yl)aryl-sulfonamides, namely, 4-meth-oxy-N-(4-methyl-phen-yl)benzene-sulfonamide, C14H15NO3S, (I), and N-(4-fluoro-phen-yl)-4-meth-oxy-benzene-sulfonamide, C13H12FNO3S, (II), were determined and analyzed. In (I), the benzene-sulfonamide ring is disordered over two orientations, in a 0.516 (7):0.484 (7) ratio, which are inclined to each other at 28.0 (1)°. In (I), the major component of the sulfonyl benzene ring and the aniline ring form a dihedral angle of 63.36 (19)°, while in (II), the planes of the two benzene rings form a dihedral angle of 44.26 (13)°. In the crystal structure of (I), N-H⋯O hydrogen bonds form infinite C(4) chains extended in [010], and inter-molecular C-H⋯πar-yl inter-actions link these chains into layers parallel to the ab plane. The crystal structure of (II) features N-H⋯O hydrogen bonds forming infinite one dimensional C(4) chains along [001]. Further, a pair of C-H⋯O inter-molecular inter-actions consolidate the crystal packing of (II) into a three-dimensional supra-molecular architecture.

  4. Structural Anomalies Detected in Ceramic Matrix Composites Using Combined Nondestructive Evaluation and Finite Element Analysis (NDE and FEA)

    Science.gov (United States)

    Abdul-Aziz, Ali; Baaklini, George Y.; Bhatt, Ramakrishna T.

    2003-01-01

    Most reverse engineering approaches involve imaging or digitizing an object and then creating a computerized reconstruction that can be integrated, in three dimensions, into a particular design environment. The rapid prototyping technique builds high-quality physical prototypes directly from computer-aided design files. This fundamental technique for interpreting and interacting with large data sets is being used here via Velocity2 (an integrated image-processing software, ref. 1) using computed tomography (CT) data to produce a prototype three-dimensional test specimen model for analyses. A study at the NASA Glenn Research Center proposes to use these capabilities to conduct a combined nondestructive evaluation (NDE) and finite element analysis (FEA) to screen pretest and posttest structural anomalies in structural components. A tensile specimen made of silicon nitrite (Si3N4) ceramic matrix composite was considered to evaluate structural durability and deformity. Ceramic matrix composites are being sought as candidate materials to replace nickel-base superalloys for turbine engine applications. They have the unique characteristics of being able to withstand higher operating temperatures and harsh combustion environments. In addition, their low densities relative to metals help reduce component mass (ref. 2). Detailed three-dimensional volume rendering of the tensile test specimen was successfully carried out with Velocity2 (ref. 1) using two-dimensional images that were generated via computed tomography. Subsequent, three-dimensional finite element analyses were performed, and the results obtained were compared with those predicted by NDE-based calculations and experimental tests. It was shown that Velocity2 software can be used to render a three-dimensional object from a series of CT scan images with a minimum level of complexity. The analytical results (ref. 3) show that the high-stress regions correlated well with the damage sites identified by the CT scans

  5. Iridium anomaly in the Cretaceous section of the Eastern Kamchatka

    Science.gov (United States)

    Savelyev, Dmitry; Savelyeva, Olga

    2010-05-01

    The origin of iridium anomalies is widely discussed with regard to massive fauna and flora extinction at several geologic boundaries. Two hypotheses are most popular, cosmogenic and volcanogenic. Anomalies of iridium are known at many stratigraphic levels, both at the geologic series borders and within geologic series. Our studies revealed increased content of iridium in a section of Cretaceous oceanic deposits on the Kamchatsky Mys Peninsula (Eastern Kamchatka, Russia). The investigated section (56°03.353´N, 163°00.376´E) includes interbedded jaspers and siliceous limestones overlaying pillow-basalts. These deposits belong to the Smagin Formation of the Albian-Cenomanian age. In the middle and upper parts of the section two beds of black carbonaceous rocks with sapropelic organic matter were observed. Their formation marked likely episodes of oxygen depletion of oceanic intermediate water (oceanic anoxic events). Our geochemical studies revealed an enrichment of the carbonaceous beds in a number of major and trace elements (Al2O3, TiO2, FeO, MgO, K2O, P2O5, Cu, Zn, Ni, Cr, V, Mo, Ba, Y, Zr, Nb, REE, U, Au, Pt etc.) in comparison with associating jaspers and limestones. There are likely different sources which contributed to the enrichment. It is possible however to correlate the excess of Al, Ti, Zr, Nb with volcanogenic admixture, which is absent in limestones and jaspers. A possible source of the volcanogenic material was local volcanism as suggested by the close association of the investigated section with volcanic rocks (basaltic lavas and hyaloclastites). The basalts of the Smagin Formation were previously proposed to originate during Cretaceous activity of the Hawaiian mantle plume (Portnyagin et al., Geology, 2008). Neutron activation analysis indicated increased up to 9 ppb concentration of Ir at the bottom of the lower carbonaceous bed (inorganic part of the sample was analyzed comprising 46% of the bulk rock). In other samples Ir content was below

  6. Abdominal aortic surgery and renal anomalies

    Directory of Open Access Journals (Sweden)

    Ilić Nikola

    2011-01-01

    Full Text Available Introduction. Kidney anomalies present a challenge even for the most experienced vascular surgeon in the reconstruction of the aortoilliac segment. The most significant anomalies described in the surgery of the aortoilliac segment are a horse-shoe and ectopic kidney. Objective. The aim of this retrospective study was to analyze experience on 40 patients with renal anomalies, who underwent surgery of the aortoilliac segment and to determine attitudes on conventional surgical treatment. Methods. In the period from 1992 to 2009, at the Clinic for Vascular Surgery of the Clinical Centre of Belgrade we operated on 40 patients with renal anomalies and aortic disease (aneurysmatic and obstructive. The retrospective analysis involved standard epidemiological data of each patient (gender, age, risk factors for atherosclerosis, type of anomaly, type of aortic disease, presurgical parameter values of renal function, type of surgical approach (laparatomy or retroperitoneal approach, classification of the renal isthmus, reimplantation of renal arteries and perioperative morbidity and mortality. Results. Twenty patients were males In 30 (70% patients we diagnosed a horse-shoe kidney and in 10 (30% ectopic kidney. In the cases of ruptured aneurysm of the abdominal aorta the diagnosis was made by ultrasound findings. Pre-surgically, renal anomalies were confirmed in all patients, except in those with a ruptured aneurysm who underwent urgent surgery. In all patients we applied medial laparatomy, except in those with a thoracoabdominal aneurysm type IV, when the retroperitonal approach was necessary. On average the patients were under follow-up for 6.2 years (from 6 months to 17 years. Conclusion. Under our conditions, the so-called double clamp technique with the preservation of the kidney gave best results in the patients with renal anomalies and aortic disease.

  7. N=4 super-Yang-Mills in LHC superspace. Part I: Classical and quantum theory

    CERN Document Server

    Chicherin, Dmitry

    2017-02-10

    We present a formulation of the maximally supersymmetric N=4 gauge theory in Lorentz harmonic chiral (LHC) superspace. It is closely related to the twistor formulation of the theory but employs the simpler notion of Lorentz harmonic variables. They parametrize a two-sphere and allow us to handle efficiently infinite towers of higher-spin auxiliary fields defined on ordinary space-time. In this approach the chiral half of N=4 supersymmetry is manifest. The other half is realized non-linearly and the algebra closes on shell. We give a straightforward derivation of the Feynman rules in coordinate space. We show that the LHC formulation of the N=4 super-Yang-Mills theory is remarkably similar to the harmonic superspace formulation of the N=2 gauge and hypermultiplet matter theories. In the twin paper \\cite{twin} we apply the LHC formalism to the study of the non-chiral multipoint correlation functions of the N=4 stress-tensor supermultiplet.

  8. An Approach to ${\\cal N}=4$ ADE Gauge Theory on K3

    CERN Document Server

    Jinzenji, M; Jinzenji, Masao; Sasaki, Toru

    2002-01-01

    We propose a recipe for determination of the partition function of ${\\cal N}=4$ $ADE$ gauge theory on $K3$ by generalizing our previous results of the SU(N) case. The resulting partition function satisfies Montonen-Olive duality for $ADE $ gauge group.

  9. 2PI Effective Action and Evolution Equations of N = 4 super Yang-Mills

    CERN Document Server

    Smolic, Jelena

    2011-01-01

    We employ nPI effective action techniques to study N = 4 super Yang-Mills, and write down the 2PI effective action of the theory. We also supply the evolution equations of two-point correlators within the theory.

  10. Mapping the G-structures and supersymmetric vacua of five-dimensional N=4 supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, James T; Mahato, Manavendra; Vaman, Diana [Michigan Center for Theoretical Physics, University of Michigan, Ann Arbor, MI 48109-1040 (United States)

    2007-03-07

    We classify the supersymmetric vacua of N=4, d=5 supergravity in terms of G-structures. We identify three classes of solutions: with R{sup 3}, SU(2) and Id structure. Using the Killing spinor equations, we fully characterize the first two classes and partially solve the latter. With the N=4 graviton multiplet decomposed in terms of N=2 multiplets: the graviton, vector and gravitino multiplets, we obtain new supersymmetric solutions corresponding to turning on fields in the gravitino multiplet. These vacua are described in terms of an SO(5) vector sigma model coupled with gravity, in three or four dimensions. A new feature of these N=4 vacua, which is not seen from an N=2 point of view, is the possibility for preserving more exotic fractions of supersymmetry. We give a few concrete examples of these new supersymmetric (albeit singular) solutions. Additionally, we show how by truncating the N=4, d=5 set of fields to minimal supergravity coupled with one vector multiplet we recover the known two-charge solutions.

  11. Photocatalytic C–H Activation of Hydrocarbons over VO@g-C3N4

    Science.gov (United States)

    A highly selective and sustainable method has been developed for the oxidation of methyl arenes and their analogues. The VO@g-C3N4 catalyst is very efficient in the C–H activation and oxygen insertion reaction resulting in formation of the corresponding carbonyl compounds a...

  12. N = 4 super-Yang-Mills in LHC superspace part I: classical and quantum theory

    Science.gov (United States)

    Chicherin, Dmitry; Sokatchev, Emery

    2017-02-01

    We present a formulation of the maximally supersymmetric N = 4 gauge theory in Lorentz harmonic chiral (LHC) superspace. It is closely related to the twistor formulation of the theory but employs the simpler notion of Lorentz harmonic variables. They parametrize a two-sphere and allow us to handle efficiently infinite towers of higher-spin auxiliary fields defined on ordinary space-time. In this approach the chiral half of N =4 supersymmetry is manifest. The other half is realized non-linearly and the algebra closes on shell. We give a straightforward derivation of the Feynman rules in coordinate space. We show that the LHC formulation of the N = 4 super-Yang-Mills theory is remarkably similar to the harmonic superspace formulation of the N = 2 gauge and hypermultiplet matter theories. In the twin paper arXiv:1601.06804 we apply the LHC formalism to the study of the non-chiral multipoint correlation functions of the N = 4 stress-tensor supermultiplet.

  13. Investigation based on nano-electromechanical system double Si3N4 resonant beam pressure sensor.

    Science.gov (United States)

    Yang, Chuan; Guo, Can; Yuan, Xiaowei

    2011-12-01

    This paper presents a type of NEMS (Nano-Electromechanical System) double Si3N4 resonant beams pressure sensor. The mathematical models are established in allusion to the Si3N4 resonant beams and pressure sensitive diaphragm. The distribution state of stress has been analyzed theoretically based on the mathematical model of pressure sensitive diaphragm; from the analysis result, the position of the Si3N4 resonant beams above the pressure sensitive diaphragm was optimized and then the dominance observed after the double resonant beams are adopted is illustrated. From the analysis result, the position of the Si3N4 resonant beams above the pressure sensitive diaphragm is optimized, illustrating advantages in the adoption of double resonant beams. The capability of the optimized sensor was generally analyzed using the ANSYS software of finite element analysis. The range of measured pressure is 0-400 Kpa, the coefficient of linearity correlation is 0.99346, and the sensitivity of the sensor is 498.24 Hz/Kpa, higher than the traditional sensors. Finally the processing techniques of the sensor chip have been designed with sample being successfully processed.

  14. Photocatalytic oxidation of aqueous ammonia using atomic single layer graphitic-C3N4.

    Science.gov (United States)

    Wang, Hua; Su, Yan; Zhao, Huanxin; Yu, Hongtao; Chen, Shuo; Zhang, Yaobin; Quan, Xie

    2014-10-21

    Direct utilization of solar energy for photocatalytic removal of ammonia from water is a topic of strong interest. However, most of the photocatalysts with effective performance are solely metal-based semiconductors. Here, we report for the first time that a new type of atomic single layer graphitic-C(3)N(4) (SL g-C(3)N(4)), a metal-free photocatalyst, has an excellent photocatalytic activity for total ammonia nitrogen (TAN) removal from water. The results demonstrated that over 80% of TAN (initial concentration 1.50 mg · L(-1)) could be removed in 6 h under Xe lamp irradiation (195 mW · cm(-2)). Furthermore, the SL g-C(3)N(4) exhibited a higher photocatalytic activity in alkaline solution than that in neutral or acidic solutions. The investigation suggested that both photogenerated holes and hydroxyl radicals were involved the TAN photocatalytic oxidation process and that the major oxidation product was NO3(-)-N. In addition, SL g-C(3)N(4) exhibited good photocatalytic stability in aqueous solution. This work highlights the appealing application of an inexpensive metal-free photocatalyst in aqueous ammonia treatment.

  15. Photocatalytic oxidation of aromatic amines using MnO2@g-C3N4

    Data.gov (United States)

    U.S. Environmental Protection Agency — An efficient and direct oxidation of aromatic amines to aromatic azo-compounds has been achieved using a MnO2@g-C3N4 catalyst under visible light as a source of...

  16. 2PI effective action and evolution equations of N=4 super Yang-Mills

    Energy Technology Data Exchange (ETDEWEB)

    Smolic, Jelena; Smolic, Milena [University of Amsterdam, Institute for Theoretical Physics, Amsterdam (Netherlands)

    2012-08-15

    We employ nPI effective action techniques to study N=4 super Yang-Mills, and write down the 2PI effective action of the theory to two-loop order in the symmetric phase. We also supply the evolution equations of two-point correlators within the theory. (orig.)

  17. N=4 super-Yang-Mills in LHC superspace. Part I: Classical and quantum theory

    CERN Document Server

    Chicherin, Dmitry

    2016-01-01

    We present a formulation of the maximally supersymmetric N=4 gauge theory in Lorentz harmonic chiral (LHC) superspace. It is closely related to the twistor formulation of the theory but employs the simpler notion of Lorentz harmonic variables. They parametrize a two-sphere and allow us to handle efficiently infinite towers of higher-spin auxiliary fields defined on ordinary space-time. In this approach the chiral half of N=4 supersymmetry is manifest. The other half is realized non-linearly and the algebra closes on shell. We give a straightforward derivation of the Feynman rules in coordinate space. We show that the LHC formulation of the N=4 super-Yang-Mills theory is remarkably similar to the harmonic superspace formulation of the N=2 gauge and hypermultiplet matter theories. In the twin paper \\cite{twin} we apply the LHC formalism to the study of the non-chiral multipoint correlation functions of the N=4 stress-tensor supermultiplet.

  18. Bifunctional Ag/C3N4.5 composite nanobelts for photocatalysis and antibacterium

    Science.gov (United States)

    Lei, Renbo; Jian, Jikang; Zhang, Zhihua; Song, Bo; Wu, Rong

    2016-09-01

    Multiple functions can be achieved in carbon nitride-based composite nanomaterials by tuning their components and structures. Here, we report on a large-scale synthesis of novel bifunctional Ag/C3N4.5 composite nanobelts (CNBs) with efficient photocatalytic and antibacterial activity. The Ag/C3N4.5 CNBs were synthesized in high yield by a two-step route including a homogeneous precipitation process and a subsequent calcination treatment. The structural, morphological, compositional, and spectroscopic characterizations revealed that the Ag/C3N4.5 CNBs are composed of N-deficient melem ultrathin nanobelts and crystalline Ag nanoparticles attached to the surface of the nanobelts with good contact. The band gap of the Ag/C3N4.5 CNBs is determined to be about 3.04 eV. The efficient photocatalytic and antibacterial activities of the composite nanomaterials are verified by testing the degradation of Rhodamine B (RhB) and the inhibition zone to bacterium E. coli. The work provides a facile route to bifunctional carbon nitride-based composites with potential applications in the fields of the environment and biology.

  19. Eigenvalue spectrum of lattice $\\mathcal{N}=4$ super Yang-Mills

    CERN Document Server

    Weir, David J; Mehta, Dhagash

    2013-01-01

    We present preliminary results for the eigenvalue spectrum of four-dimensional ${\\cal N}=4$ super Yang-Mills theory on the lattice. In particular, by studying the the spectral density a measurement of the anomalous dimension is made and found to be consistent with zero.

  20. Photocatalytic C−H Activation of Hydrocarbons over VO@g‑C3N4

    Science.gov (United States)

    A highly selective and sustainable method has beendeveloped for the oxidation of methyl arenes and their analogues.The VO@g-C3N4 catalyst is very efficient in the C−H activation andoxygen insertion reaction resulting in formation of the correspondingcarbonyl compounds and phenols...

  1. Lable-free Enzyme Sensing with a Si3N4 Grated Waveguide Optical Cavity

    NARCIS (Netherlands)

    Pham, S.V.; Dijkstra, M.; Hollink, A.J.F.; Kauppinen, L.J.; Ridder, de R.M.; Hoekstra, H.J.W.M.

    2011-01-01

    We report the label-free, sensitive detection of PepN enzyme using a Si3N4 grated waveguide optical cavity covered with an immobilized, selective (antibody) receptor layer. The receptor-enzyme reaction was monitored in real-time.

  2. Redefining the structure-activity relationships of 2,6-methano-3-benzazocines. 5. Opioid receptor binding properties of N-((4'-phenyl)-phenethyl) analogues of 8-CAC.

    Science.gov (United States)

    VanAlstine, Melissa A; Wentland, Mark P; Cohen, Dana J; Bidlack, Jean M

    2007-12-01

    A series of aryl-containing N-monosubstituted analogues of the lead compound 8-[N-((4'-phenyl)-phenethyl)]-carboxamidocyclazocine were synthesized and evaluated to probe a putative hydrophobic binding pocket of opioid receptors. Very high binding affinity to the mu opioid receptor was achieved though the N-(2-(4'-methoxybiphenyl-4-yl)ethyl) analogue of 8-CAC. High binding affinity to mu and very high binding affinity to kappa opioid receptors was observed for the N-(3-bromophenethyl) analogue of 8-CAC. High binding affinity to all three opioid receptors were observed for the N-(2-naphthylethyl) analogue of 8-CAC.

  3. Influence of Deposition Temperature on the Structure Of Si3N4 Thin Film Prepared By MWECR-PECVD

    Institute of Scientific and Technical Information of China (English)

    肖化; 陈俊芳; 张镇西

    2004-01-01

    The Si3N4 thin film is prepared by MWECR-PECVD at different deposition temperature and the structure of the Si3N4 thin film is investigated. The results indicate that the structure of the Si3N4 thin film prepared at low deposition temperature is in the amorphous phase. However, when the deposition temperature increases to 280℃, the Si3N4 thin film changes to crystalline -Si3N4 . With a further increase of the deposition temperature, the grain of the Si3N4 thin film becomes more fine, uniform and flat. XRD analysis shows that the structure of the Si3N4 thin film prepared at 280℃ is of a crystalline structure.

  4. Sensitivity of Asian Summer Monsoon precipitation to tropical sea surface temperature anomalies

    Science.gov (United States)

    Fan, Lei; Shin, Sang-Ik; Liu, Zhengyu; Liu, Qinyu

    2016-10-01

    Sensitivity of Asian Summer Monsoon (ASM) precipitation to tropical sea surface temperature (SST) anomalies was estimated from ensemble simulations of two atmospheric general circulation models (GCMs) with an array of idealized SST anomaly patch prescriptions. Consistent sensitivity patterns were obtained in both models. Sensitivity of Indian Summer Monsoon (ISM) precipitation to cooling in the East Pacific was much weaker than to that of the same magnitude in the local Indian-western Pacific, over which a meridional pattern of warm north and cold south was most instrumental in increasing ISM precipitation. This indicates that the strength of the ENSO-ISM relationship is due to the large-amplitude East Pacific SST anomaly rather than its sensitivity value. Sensitivity of the East Asian Summer Monsoon (EASM), represented by the Yangtze-Huai River Valley (YHRV, also known as the meiyu-baiu front) precipitation, is non-uniform across the Indian Ocean basin. YHRV precipitation was most sensitive to warm SST anomalies over the northern Indian Ocean and the South China Sea, whereas the southern Indian Ocean had the opposite effect. This implies that the strengthened EASM in the post-Niño year is attributable mainly to warming of the northern Indian Ocean. The corresponding physical links between these SST anomaly patterns and ASM precipitation were also discussed. The relevance of sensitivity maps was justified by the high correlation between sensitivity-map-based reconstructed time series using observed SST anomaly patterns and actual precipitation series derived from ensemble-mean atmospheric GCM runs with time-varying global SST prescriptions during the same period. The correlation results indicated that sensitivity maps derived from patch experiments were far superior to those based on regression methods.

  5. Gynecologic concerns in patients with cloacal anomaly.

    Science.gov (United States)

    Breech, Lesley

    2016-04-01

    Children with anorectal malformations (ARM) constitute a significant group within a pediatric surgery practice. It is important with female cases of anorectal malformations to consider the association of gynecologic anomalies, especially at the time of the definitive repair. However, it is critical to consider the association of such gynecologic anomalies when caring for patients with a cloacal anomaly. If not recognized, an opportunity to diagnose and treat such anomalies may be missed with the possibility of negative implications for future reproductive capacity. With the knowledge of the associated anomalies and long-term sequelae, surgeons can provide better care for girls and important counseling for parents. Knowledge of reproductive related issues in females with cloaca allows the pediatric surgeon an opportunity both, to provide optimal surgical management in infancy, childhood, and into young adulthood and to collaborate medically and surgically with an experienced gynecologist in patients with more complex anatomic variations. Appropriate counseling for patients and families about potential reproductive concerns that may develop many years after the definitive surgical repair allows preparation and planning to preserve future fertility. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Geopotential field anomalies and regional tectonic features

    Science.gov (United States)

    Mandea, Mioara; Korte, Monika

    2016-07-01

    Maps of both gravity and magnetic field anomalies offer crucial information about physical properties of the Earth's crust and upper mantle, required in understanding geological settings and tectonic structures. Density and magnetization represent independent rock properties and thus provide complementary information on compositional and structural changes. Two regions are considered: southern Africa (encompassing South Africa, Namibia and Botswana) and Germany. This twofold choice is motivated firstly by the fact that these regions represent rather diverse geological and geophysical conditions (old Archean crust with strong magnetic anomalies in southern Africa, and much younger, weakly magnetized crust in central Europe) and secondly by our intimate knowledge of the magnetic vector ground data from these two regions. We take also advantage of the recently developed satellite potential field models and compare magnetic and gravity gradient anomalies of some 200 km resolution. Comparing short and long wavelength anomalies and the correlation of rather large scale magnetic and gravity anomalies, and relating them to known lithospheric structures, we generally find a better agreement over the southern African region than the German territory. This probably indicates a stronger concordance between near-surface and deeper structures in the former area, which can be perceived to agree with a thicker lithosphere.

  7. Etiology and Evaluation of Sperm Chromatin Anomalies

    Directory of Open Access Journals (Sweden)

    Marziyeh Tavalaee

    2008-01-01

    Full Text Available Evidence suggests that human sperm chromatin anomalies adversely affect reproductive outcomesand infertile men possess substantially amount of sperm with chromatin anomalies than fertilemen.Routine semen analysis evaluates parameters such as sperm motility and morphology, but doesnot examine the nuclear DNA integrity of spermatozoa. It has been suggested that altered nuclearchromatin structure or damaged DNA in spermatozoa could modify the special cellular functionsof human spermatozoa, and thereby affect the fertility potential. Intra-cytoplasmic sperm injection(ICSI bypass the barriers to fertilization for such a sperm, then the effect of chromatin anomalies onthe development remains a concern. Therefore, it is essential to develop and use accurate diagnostictests, which may provide better prognostic capabilities than the standard sperm assessments. Thisreview discusses our current understanding of the structure and organization of sperm DNA,the different procedures for assessment of sperm chromatin anomalies including comet assay,Chromomycin A3 (CMA3, sperm chromatin structure assay (SCSA, acridine orange test (AOT,terminal TdT-mediated dUTP-nick-end labelling (TUNEL assay, aniline blue and sperm chromatindispersion (SCD test and the impact of chromatin anomalies on reproductive outcome.

  8. Congenital Malformations of the Inner Ear: Case Series and Review of the Literature.

    Science.gov (United States)

    Piromchai, Patorn; Kasemsiri, Pornthep; Thanawirattananit, Panida; Yimtae, Kwanchanok

    2015-08-01

    Patients with craniofacial anomalies often present to doctors due to their noticeable disfigurement and are routinely assessed by otolaryngologists for hearing evaluation. However, small percentage of craniofacial anomaly patients may present with delayed speech though they may not have initial obvious external deformation. The objective of case series is to identify the congenital inner ear malformation. The series of clinical presentation, physical examination, investigations, treatments and follow-up results were demonstrated followed by the discussion.

  9. DCP Series

    Directory of Open Access Journals (Sweden)

    Philip Stearns

    2011-06-01

    Full Text Available Photo essay. A collection of Images produced by intentionally corrupting the circuitry of a Kodak DC280 2 MP digitalcamera. By rewiring the electronics of a digital camera, glitched images are produced in a manner that parallels chemically processing unexposed film or photographic paper to produce photographic images without exposure to light. The DCP Series of Digital Images are direct visualizations of data generated by a digital camera as it takes a picture. Electronic processes associated with the normal operations of the camera, which are usually taken for granted, are revealed through an act of intervention. The camera is turned inside­out through complexes of short­circuits, selected by the artist, transforming the camera from a picture taking device to a data capturing device that renders raw data (electronic signals as images. In essence, these images are snap­shots of electronic signals dancing through the camera's circuits, manually rerouted, written directly to the on­board memory device. Rather than seeing images of the world through a lens, we catch a glimpse of what the camera sees when it is forced to peer inside its own mind.

  10. 用Cu-Ni-Ti钎料连接Si3N4陶瓷的试验研究%Investigation on the Test of Bonding Si3N4 Ceramics Using Cu-Ni-Ti Fill Metal

    Institute of Scientific and Technical Information of China (English)

    吴斌; 邹家生; 陈铮; 赵其章; 眭润舟; 楼宏青

    2001-01-01

    采用成分不同的Cu-Ni-Ti钎料进行了Si3N4/Si3N4的连接。结果表明:钎料成分、钎焊工艺 参数对连接强度均有重要影响。采用(Cu85Ni15)80Ti20钎料在1 373K×10 min条件下,Si3N4/Si3N4连接 强度达到最大值289 MPa。通过对Si3N4/Si3N4连接界面的微观分析,发现Si向钎料层扩散,钎料中的 Cu在接头中央富集,而Ti、Ni向Si3N4富集。相对Ni而言,Ti的富集区更靠近Si3N4陶瓷。%Si3N4/Si3N4 is bonded by using Cu-Ni-Ti Fill metal with different composition . The effects of the braze metal composition, and the procedure variables such as the brazing temperature and the brazing time on joining strength are investigated. The results show that at the temperature of 1 373 K for 10 min utes, the brazing alloy composition corresponding to the highest strength value (289 MPa) is (Cu85Ni15)80 Ti20. The analysis of the distribution of elements in Si3Na/Si3N4 joint shows that Si diffuses towards braze layer while Ti and Ni towards Si3N4. In the center part of the joint is mainly Cu element and the intensive area of Ti is closer to Si3N4 ceramics.

  11. Multivariate anomaly detection for Earth observations: a comparison of algorithms and feature extraction techniques

    Science.gov (United States)

    Flach, Milan; Gans, Fabian; Brenning, Alexander; Denzler, Joachim; Reichstein, Markus; Rodner, Erik; Bathiany, Sebastian; Bodesheim, Paul; Guanche, Yanira; Sippel, Sebastian; Mahecha, Miguel D.

    2017-08-01

    Today, many processes at the Earth's surface are constantly monitored by multiple data streams. These observations have become central to advancing our understanding of vegetation dynamics in response to climate or land use change. Another set of important applications is monitoring effects of extreme climatic events, other disturbances such as fires, or abrupt land transitions. One important methodological question is how to reliably detect anomalies in an automated and generic way within multivariate data streams, which typically vary seasonally and are interconnected across variables. Although many algorithms have been proposed for detecting anomalies in multivariate data, only a few have been investigated in the context of Earth system science applications. In this study, we systematically combine and compare feature extraction and anomaly detection algorithms for detecting anomalous events. Our aim is to identify suitable workflows for automatically detecting anomalous patterns in multivariate Earth system data streams. We rely on artificial data that mimic typical properties and anomalies in multivariate spatiotemporal Earth observations like sudden changes in basic characteristics of time series such as the sample mean, the variance, changes in the cycle amplitude, and trends. This artificial experiment is needed as there is no gold standard for the identification of anomalies in real Earth observations. Our results show that a well-chosen feature extraction step (e.g., subtracting seasonal cycles, or dimensionality reduction) is more important than the choice of a particular anomaly detection algorithm. Nevertheless, we identify three detection algorithms (k-nearest neighbors mean distance, kernel density estimation, a recurrence approach) and their combinations (ensembles) that outperform other multivariate approaches as well as univariate extreme-event detection methods. Our results therefore provide an effective workflow to automatically detect anomalies

  12. The effects of nonmetal dopants on the electronic, optical and chemical performances of monolayer g-C3N4 by first-principles study

    Science.gov (United States)

    Lu, S.; Li, C.; Li, H. H.; Zhao, Y. F.; Gong, Y. Y.; Niu, L. Y.; Liu, X. J.; Wang, T.

    2017-01-01

    Doping is an effective means to alter the electronic behavior of materials by forming new chemical bond and relaxing the surrounding chemical bonds. With the aid of first-principle studies, the effects of a series of nonmetal (NM) dopants on the geometric, thermodynamic, electronic and optical performances of monolayer g-C3N4 have been investigated. Results shown that, all considered NM atoms except Br and I atoms can be introduced into the monolayer g-C3N4 on account of the thermal stability, the supercell parameter and film thickness have been altered by the newly formed Csbnd NM bonds and the relaxed chemical bonds around them, which have affected their electronic structure. The band gap values were altered less than ±0.14 eV. The optical absorption edge (and intensity) in visible light of all doped specimens red-shift 10-75 nm (and increase about 14%-71%) except for O- and S-doped specimens, and thus the NM dopants can enhance the visible-light response capability. Moreover, the highest occupied molecular orbital and lowest unoccupied molecular orbital of H-, B-, O-, S-, F- and As-doped specimens have been separated adequately, it can effectively separate the photogenerated e-/h+ pairs and enhance the photocatalytic efficiency. Finally, we have confirmed six high efficiency monolayer g-C3N4 based photocatalysts by doping H, B, O, S, F and As atoms.

  13. Assessment of congenital anomalies in infants born to pregnant women enrolled in clinical trials.

    Science.gov (United States)

    Rasmussen, Sonja A; Hernandez-Diaz, Sonia; Abdul-Rahman, Omar A; Sahin, Leyla; Petrie, Carey R; Keppler-Noreuil, Kim M; Frey, Sharon E; Mason, Robin M; Nesin, Mirjana; Carey, John C

    2014-12-15

    In 2011 and 2012, the Division of Microbiology and Infectious Diseases at the National Institute of Allergy and Infectious Diseases, National Institutes of Health, held a series of meetings to provide guidance to investigators regarding study design of clinical trials of vaccines and antimicrobial medications that enroll pregnant women. Assessment of congenital anomalies among infants born to women enrolled in these trials was recognized as a challenging issue, and a workgroup with expertise in epidemiology, pediatrics, genetics, dysmorphology, clinical trials, and infectious diseases was formed to address this issue. The workgroup considered 3 approaches for congenital anomalies assessment that have been developed for use in other studies: (1) maternal report combined with medical records review, (2) standardized photographic assessment and physical examination by a health professional who has received specific training in congenital anomalies, and (3) standardized physical examination by a trained dysmorphologist (combined with maternal interview and medical records review). The strengths and limitations of these approaches were discussed with regard to their use in clinical trials. None of the approaches was deemed appropriate for use in all clinical trials. Instead, the workgroup acknowledged that decisions regarding the optimal method of assessment of congenital anomalies will likely vary depending on the clinical trial, its setting, and the agent under study; in some cases, a combination of approaches may be appropriate. The workgroup recognized the need for more research on approaches to the assessment of congenital anomalies to better guide investigators in optimal design of clinical trials that enroll pregnant women.

  14. Impacted Maxillary Canine Prevalence and Its Association with Other Dental Anomalies in a Mexican Population

    Science.gov (United States)

    Agüayo-de-Pau, María del Rosario; Escoffié-Ramírez, Mauricio; Aguilar-Ayala, Fernando Javier; Carrillo-Ávila, Bertha Arelly; Rejón-Peraza, Marina Eduviges

    2017-01-01

    Objective. We quantified the prevalence of impacted maxillary canines (IMC) and their association with other dental anomalies (DAs). Materials and Methods. A retrospective study was done with 860 patients 12 to 39 years of age. The prevalence of IMC was calculated and compared by sex. The sample was divided into a control group and an impaction group, and the prevalence was calculated in both for a series of anomalies: agenesis, supernumerary teeth, shape anomalies of the upper laterals (microdontia, peg and barrel shape, and talon cusp), fusion, gemination, other impacted teeth, transposition, and amelogenesis imperfecta. The prevalence values for both groups were compared (Pearson's χ2 test, p ≤ 0.05). Results. IMC were present in 6.04% of the sample with no difference by sex (p = 0.540). Other DAs occurred in 51.92% of the IMC group and in 20.17% of the controls (p < 0.05). Significant associations (p < 0.05) were identified between IMC and four other DAs: microdontia, barrel shape, other impacted teeth, and transposition. The prevalence of all anomalies was lower in the control group. Conclusion. IMC were seen in 6.04% of patients. Patients with this condition also had a higher prevalence of other DAs. These other anomalies should be used as risk indicators for early diagnosis. PMID:28326102

  15. Circulation anomalies associated with winter temperature extremes in Athens during the period 1900-2004

    Energy Technology Data Exchange (ETDEWEB)

    Founda, D. [National Observatory of Athens (Greece). Inst. for Environmental Research and Sustainable Development; Loon, H. van [Colorado Univ., Boulder, CO (United States)

    2008-02-15

    We use the long series of temperature observed at the National Observatory of Athens, Greece, to examine the extremes of this element together with associated anomalies in the general circulation of the atmosphere. The 13 extreme-cold and 20 extreme-warm winters during the period 1900-2004 (equal to or below minus one standard deviation, and equal to or above plus one standard deviation respectively) had opposite pressure anomalies, mainly over the North Atlantic and Eurasia. The temperature extremes at Athens were representative of most of the Mediterranean and the Balkans, and their associated pressure anomalies were robust. The extremes of the Index of the North Atlantic Oscillation (the pressure difference between Gibraltar and Iceland) were not a good indicator of the temperature extremes in the Mediterranean. Rather the extreme temperature anomalies over the Mediterranean region are to a large extent controlled by a bipolar pattern of SLP (see level pressure) anomalies with centers over the British Isles and the Arctic. (orig.)

  16. Impacted Maxillary Canine Prevalence and Its Association with Other Dental Anomalies in a Mexican Population

    Directory of Open Access Journals (Sweden)

    José Rubén Herrera-Atoche

    2017-01-01

    Full Text Available Objective. We quantified the prevalence of impacted maxillary canines (IMC and their association with other dental anomalies (DAs. Materials and Methods. A retrospective study was done with 860 patients 12 to 39 years of age. The prevalence of IMC was calculated and compared by sex. The sample was divided into a control group and an impaction group, and the prevalence was calculated in both for a series of anomalies: agenesis, supernumerary teeth, shape anomalies of the upper laterals (microdontia, peg and barrel shape, and talon cusp, fusion, gemination, other impacted teeth, transposition, and amelogenesis imperfecta. The prevalence values for both groups were compared (Pearson’s χ2 test, p≤0.05. Results. IMC were present in 6.04% of the sample with no difference by sex (p=0.540. Other DAs occurred in 51.92% of the IMC group and in 20.17% of the controls (p<0.05. Significant associations (p<0.05 were identified between IMC and four other DAs: microdontia, barrel shape, other impacted teeth, and transposition. The prevalence of all anomalies was lower in the control group. Conclusion. IMC were seen in 6.04% of patients. Patients with this condition also had a higher prevalence of other DAs. These other anomalies should be used as risk indicators for early diagnosis.

  17. Anomaly-based Network Intrusion Detection Methods

    Directory of Open Access Journals (Sweden)

    Pavel Nevlud

    2013-01-01

    Full Text Available The article deals with detection of network anomalies. Network anomalies include everything that is quite different from the normal operation. For detection of anomalies were used machine learning systems. Machine learning can be considered as a support or a limited type of artificial intelligence. A machine learning system usually starts with some knowledge and a corresponding knowledge organization so that it can interpret, analyse, and test the knowledge acquired. There are several machine learning techniques available. We tested Decision tree learning and Bayesian networks. The open source data-mining framework WEKA was the tool we used for testing the classify, cluster, association algorithms and for visualization of our results. The WEKA is a collection of machine learning algorithms for data mining tasks.

  18. Weyl Anomaly and Initial Singularity Crossing

    CERN Document Server

    Awad, Adel

    2015-01-01

    We consider the role of quantum effects, mainly, Weyl anomaly in modifying FLRW model singular behavior at early times. Weyl anomaly corrections to FLRW models have been considered in the past, here we reconsider this model and show the following: The singularity of this model is weak according to Tipler and Krolak, therefore, the spacetime might admit a geodesic extension. Weyl anomaly corrections changes the nature of the initial singularity from a big bang singularity to a sudden singularity. The two branches of solutions consistent with the semiclassical treatment form a disconnected manifold. Joining these two parts at the singularity provides us with a $C^1$ extension to nonspacelike geodesics and leaves the spacetime geodesically complete. Using Gauss-Codazzi equations one can derive generalized junction conditions for this higher-derivative gravity. The extended spacetime obeys Friedmann and Raychaudhuri equations and the junction conditions. The junction does not generate Dirac delta functions in mat...

  19. Anomaly mediation in local effective theories

    Energy Technology Data Exchange (ETDEWEB)

    Dine, Michael; Draper, Patrick [Santa Cruz Institute for Particle Physics and Department of Physics,Santa Cruz CA 95064 (United States)

    2014-02-17

    The phenomenon known as “anomaly mediation” can be understood in a variety of ways. Rather than an anomaly, certain gaugino bilinear terms are required by local supersymmetry and gauge invariance (the derivation of these terms is in some cases related to anomalies in scale invariance or R symmetries). We explain why the gaugino bilinear is required in supersymmetric gauge theories with varying number of colors and flavors. By working in the Higgs phase, gauging a flavor group, or working below the scale of gaugino condensation, each of these theories has a local effective description in which we can identify the bilinear term, establishing its necessity in the microscopic theory. For example, in theories that exhibit gaugino condensation, the potential in the very low energy theory is supersymmetric precisely due to the relation between the nonperturbative superpotential and the gaugino bilinear terms. Similarly, the gravitino mass appears from its coupling to the gaugino bilinear.

  20. The Anomaly Structure of Regularized Supergravity

    CERN Document Server

    Butter, Daniel

    2014-01-01

    On-shell Pauli-Villars regularization of the one-loop divergences of supergravity theories is used to study the anomaly structure of supergravity and the cancellation of field theory anomalies under a $U(1)$ gauge transformation and under the T-duality group of modular transformations in effective supergravity theories with three K\\"ahler moduli $T^i$ obtained from orbifold compactification of the weakly coupled heterotic string. This procedure requires constraints on the chiral matter representations of the gauge group that are consistent with known results from orbifold compactifications. Pauli-Villars regulator fields allow for the cancellation of all quadratic and logarithmic divergences, as well as most linear divergences. If all linear divergences were canceled, the theory would be anomaly free, with noninvariance of the action arising only from Pauli-Villars masses. However there are linear divergences associated with nonrenormalizable gravitino/gaugino interactions that cannot be canceled by PV fields...