Sample records for rape fields electronic

  1. Endogaeic ground beetles fauna in oilseed rape field in Croatia

    Directory of Open Access Journals (Sweden)

    Zrinka DRMIĆ


    Full Text Available The abundance of ground beetles (Coleoptera, Carabidae in oilseed rape field can be an important indicator of different agricultural measures in arable land fauna. Surveys about ground beetle fauna in Croatia are generally very scarce and only few research on oilseed rape were conducted. The aim of this study was to determine the endogaeic ground beetle fauna in oilseed rape field and to determine species abundance and frequency. The study was carried out in Podravina region of Croatia, from the end of May till the mid-September in 2015. Ground beetles were collected using endogaeic traps incorporated in the soil. Altogether, 487 individuals classified into 8 species were collected. Species with the highest abundance and frequency was Brachinus (Brachinus psophia Audinet-Serville, 1821, which was classified as eudominant and constant species. The highest ground beetle abundance was observed in summer period. All of the species found were spring breeders, except for species Trechus (Trechus quadristriatus (Schrank, 1781 which breeds in autumn.

  2. Biological control of Sclerotinia disease by Aspergillus sp. on oilseed rape in the field (United States)

    Sclerotinia sclerotiorum causes serious yield losses on oilseed rape and other crops worldwide. Aspergillus sp. Asp-4, previously shown to inhibit germination of sclerotia of S. sclerotiorum in vitro and in the field, was evaluated in field trials for suppression of this pathogen on oilseed rape. S...

  3. Dispersal of solitary bees and bumblebees in a winter oilseed rape field

    DEFF Research Database (Denmark)

    Calabuig, Isabel


    Dispersal distributions of solitary bees and bumblebees were studied in a winter oilseed rape field. Window-traps were placed in the rape field along a line transect perpendicular to the field edge. 19 species of solitary bees were recorded and all but four species are polylectic, including...... Brassicaceae as host-plant family. Through non-linear regression, the decline in solitary bee individuals versus distance from field edge significantly fitted a steep two-parameter exponential decay function. Activity of solitary bees was clearly highest within 30 metres from the field edge. Apparently......, solitary bees do not play any noteworthy role in the pollination of winter oilseed rape in Denmark. The traps yielded ten species of bumblebees, and a significant linear correlation was found between numbers of individuals and distance from the field edge. This result is attributed to bumblebee foraging...

  4. Occurrence of Plasmodiophora brassicae in Finnish turnip rape and oilseed rape fields

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    Marika Rastas


    Full Text Available Clubroot, caused by Plasmodiophora brassicae Woronin, is a serious plant disease of cruciferous plants. A field survey of occurrence of clubroot in oilseed fields was conducted in Finland in 2007−2009 and in 1984−1989. At present, the disease is distributed throughout the oilseed cultivation area. Clubroot was found on average from 30% of fields, but its severity was low; fields with high numbers of infected plants and plants with severe symptoms were rare. According to the survey, cultivation frequency of cruciferous plants is the most important factor affecting clubroot occurrence and severity. Clubroot was found in soils with a wide range of pH-values (pH 5-7.6, but symptoms were most severe at low pH. According to the survey, and greenhouse and field trials, high temperature and moisture during the early growth period seem to favour disease development and can cause significant yield losses. In a survival trial, clubroot declined to close to zero after four years in the absence of host plants, but traces of the pathogen were still detectable after a 19-year trial period, making eradication of the pathogen very difficult.

  5. Distance from forest edge affects bee pollinators in oilseed rape fields


    Bailey, S.; Requier, F.; Nusillard, B.; Roberts, Stuart; Potts, Simon; Bouget, C.


    Wild pollinators have been shown to enhance the pollination of Brassica napus(oilseed rape) and thus increase its market value. Several studies have previously shown that pollination services are greater in crops adjoining forest patches or other seminatural habitats than in crops completely surrounded by other crops.\\ud In this study, we investigated the specific importance of forest edges in providing potential pollinators in B. napus fields in two areas in France. Bees were caught with yel...

  6. Bacillus megaterium A6 suppresses Sclerotinia sclerotiorum on oilseed rape in the field and promotes oilseed rape growth (United States)

    Sclerotinia sclerotiorum causes serious yield losses in crops in The People’s Republic of China and other regions of the world. Two formulations of oilseed rape seed containing the plant-growth promoting bacterium Bacillus megaterium A6 were evaluated for suppression of this pathogen on oilseed rap...

  7. Seed Vigor and Field Performance of Winter Oilseed Rape (Brassica napus L.) Cultivars




    The effect of seed vigor on field performance of two oilseed rape cultivars (Licord and Okapi) was investigated in 2008 at the Research Farm of the University Tabriz, Iran. The experiment was arranged as factorial based on RCB design with three replications. A sub-sample of seeds of each cultivar was kept as control. The other two sub-samples of each cultivar with about 15% moisture content were artificially deteriorated at 40C for 9 and 12 days (Licord) and 7 and 10 days (Okapi). Cons...

  8. Characterization of Rape Field Microwave Emission and Implications to Surface Soil Moisture Retrievals

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    Alexander Loew


    Full Text Available In the course of Soil Moisture and Ocean Salinity (SMOS mission calibration and validation activities, a ground based L-band radiometer ELBARA II was situated at the test site Puch in Southern Germany in the Upper Danube Catchment. The experiment is described and the different data sets acquired are presented. The L-band microwave emission of the biosphere (L-MEB model that is also used in the SMOS L2 soil moisture algorithm is used to simulate the microwave emission of a winter oilseed rape field in Puch that was also observed by the radiometer. As there is a lack of a rape parameterization for L-MEB the SMOS default parameters for crops are used in a first step which does not lead to satisfying modeling results. Therefore, a new parameterization for L-MEB is developed that allows us to model the microwave emission of a winter oilseed rape field at the test site with better results. The soil moisture retrieval performance of the new parameterization is assessed in different retrieval configurations and the results are discussed. To allow satisfying results, the periods before and after winter have to be modeled with different parameter sets as the vegetation behavior is very different during these two development stages. With the new parameterization it is possible to retrieve soil moisture from multiangular brightness temperature data with a root mean squared error around 0.045–0.051 m³/m³ in a two parameter retrieval with soil moisture and roughness parameter Hr as free parameters.

  9. Field emission electronics

    CERN Document Server

    Egorov, Nikolay


    This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

  10. The effect of electric field on callus induction with rape hypocotyls

    Energy Technology Data Exchange (ETDEWEB)

    Filek, M.; Holda, M. [Inst. of Plant Physiology, Polish Academy of Sciences, Krakow (Poland); Machackova, I.; Krekule, J. [Inst. of Experimental Botany, Academy of Sciences of the Czech Republic, Praha (Czech Republic)


    The influence of electric field treatment on dedifferentiation and calli formation on rape hypocotyls was investigated. Segments, 10 mm long, of the upper part of rape (Brassica napus L., cv. Gorcza{delta}ski) hypocotyls were stimulated by different combinations of voltage/time (1.5 V/120 h, 3 V/3 h, 10 V/15 min and 30 V/30 s) under in vitro conditions. With all electric field treatments, segments oriented with their apical part towards the cathode produced more calli as compared to control (non-treated with electric field). Under opposite orientation slight inhibition of callus growth was observed. As the strongest effect on callus growth was observed after treatment with 30 V/30 s, this electric field treatment was selected for following analyses: the incorporation of [{sup 14}C]-2,4-D (2,4-dichlorophenoxyacetic acid) and [{sup 14}C]-BAP (benzylaminopurine) from the culture medium, changes in ACC (1-aminocyclopropane-1-carboxylic acid) level and the redox activity in apical and bottom parts of hypocotyls during 18 d of culture. In contrast to changes in fresh weight, electric field treatment (30 V/30 s) stimulated a higher accumulation of 2,4-D and BAP in basal parts of hypocotyls than in apical ones. Moreover, orienting the apical part towards the cathode resulted in lower uptake of hormones as compared with the opposite orientation. The ACC concentration increased, especially in the basal parts of hypocotyls, independently on electric field application. However, the highest level was observed after electric field treatment with orientation of the apical part towards the anode. The distribution of oxidative substances (measured as the amount of ferric ions) between the apical and bottom part of hypocotyls was not changed when the apical parts were oriented towards the cathode. Under these conditions a decrease in apical and an increase in basal parts was observed during culture. Opposite orientation influenced the redistribution of oxidative substances from the

  11. Formulations of Bacillus subtilis BY-2 suppress Sclerotinia sclerotiorum on oilseed rape in the field (United States)

    We are developing a collection of Bacillus strains, isolated from different environments, for use in controlling Sclerotinia sclerotiorum on oilseed rape in China and elsewhere. Strain BY-2, isolated from internal tissues of an oilseed rape root, was demonstrated to be Bacillus subtilis based on bi...

  12. Unbalanced field RF electron gun (United States)

    Hofler, Alicia


    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  13. Date Rape (For Teens) (United States)

    ... Breath? Talking to Your Parents - or Other Adults Date Rape KidsHealth > For Teens > Date Rape Print A ... Yourself Getting Help Reporting a Rape What Is Date Rape? When people think of rape , they might ...

  14. Effects of Field Conditions on Emergence of Oilseed Rape Seed lots Grown in Khorasan Province

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    A Yanegh


    Full Text Available Nineteen irrigated farms of canola from six cities of Khorasan selected to assess the seedling emergence one month after sowing in 2009. Soil texture of each farm determined using the Hydrometer method. The results showed that weather conditions of sowing areas had no significant effect on emergence of oilseed rape. With increasing the temperature (within the range of 19.5 to 21.5 ˚C emergence percentage was not increased significantly. Rainfall also caused no significant effect on seedling emergence. The percentage of emergence in machine-sowing and hand-sowing were 38.4% and 28%, respectively. Soils with loam silt, silt clay loam and loam texture had emergence of 27.2%, 31.2% and 47% respectively. It seems soil texture plays a great roll on the emergence of oilseed rape with epigeal seedlings.

  15. Rape sentencing

    DEFF Research Database (Denmark)

    Ó Cathaoir, Katharina Eva

    This handbook conducts an analysis of the sentences imposed for rape by Irish courts. Part I examines The People (DPP) v. WD [2007] IEHC 310 by outlining the salient points of the decision, in particular the separation of rape sentences into categories of punishments. The mitigating and aggravati...... factors are also laid out. Part II analyses recent sentences for rape since 2007. All reported Court of Criminal Appeal (CCA) cases post The People (DPP) v. WD are included as well as a survey of two years of Irish Times reports (covering the period November 2010 to November 2012)....

  16. Genotypic Variation in Nitrogen Utilization Efficiency of Oilseed Rape (Brassica napus) Under Contrasting N Supply in Pot and Field Experiments (United States)

    He, Huiying; Yang, Rui; Li, Yajun; Ma, Aisheng; Cao, Lanqin; Wu, Xiaoming; Chen, Biyun; Tian, Hui; Gao, Yajun


    Oilseed rape (Brassica napus) characteristically has high N uptake efficiency and low N utilization efficiency (NUtE, seed yield/shoot N accumulation). Determining the NUtE phenotype of various genotypes in different growth conditions is a way of finding target traits to improve oilseed rape NUtE. The aim of this study was to compare oilseed rape genotypes grown on contrasting N supply rates in pot and field experiments to investigate the genotypic variations of NUtE and to identify indicators of N efficient genotypes. For 50 oilseed rape genotypes, NUtE, dry matter and N partitioning, morphological characteristics, and the yield components were investigated under high and low N supplies in a greenhouse pot experiment and a field trial. Although the genotype rankings of NUtE were different between the pot experiment and the field trial, some genotypes performed consistently in both two environments. N-responder, N-nonresponder, N-efficient and N-inefficient genotypes were identified from these genotypes with consistent NUtE. The correlations between the pot experiment and the field trial in NUtE were only 0.34 at high N supplies and no significant correlations were found at low N supplies. However, Pearson coefficient correlation (r) and principal component analysis showed NUtE had similar genetic correlations with other traits across the pot and field experiment. Among the yield components, only seeds per silique showed strong and positive correlations with NUtE under varying N supply in both experiments (r = 0.47**; 0.49**; 0.47**; 0.54**). At high and low N supply, NUtE was positively correlated with seed yield (r = 0.45**; 0.53**; 0.39**; 0.87**), nitrogen harvest index (NHI, r = 0.68**; 0.82**; 0.99**; 0.89**), and harvest index (HI, r = 0.79**; 0.83**; 0.90**; 0.78**) and negatively correlated with biomass distribution to stem and leaf (r = −0.34**; −0.45**; −0.37**; 0.62**), all aboveground plant section N concentration (r from −0.30* to −0

  17. Genotypic Variation in Nitrogen Utilization Efficiency of Oilseed Rape (Brassica napus Under Contrasting N Supply in Pot and Field Experiments

    Directory of Open Access Journals (Sweden)

    Huiying He


    Full Text Available Oilseed rape (Brassica napus characteristically has high N uptake efficiency and low N utilization efficiency (NUtE, seed yield/shoot N accumulation. Determining the NUtE phenotype of various genotypes in different growth conditions is a way of finding target traits to improve oilseed rape NUtE. The aim of this study was to compare oilseed rape genotypes grown on contrasting N supply rates in pot and field experiments to investigate the genotypic variations of NUtE and to identify indicators of N efficient genotypes. For 50 oilseed rape genotypes, NUtE, dry matter and N partitioning, morphological characteristics, and the yield components were investigated under high and low N supplies in a greenhouse pot experiment and a field trial. Although the genotype rankings of NUtE were different between the pot experiment and the field trial, some genotypes performed consistently in both two environments. N-responder, N-nonresponder, N-efficient and N-inefficient genotypes were identified from these genotypes with consistent NUtE. The correlations between the pot experiment and the field trial in NUtE were only 0.34 at high N supplies and no significant correlations were found at low N supplies. However, Pearson coefficient correlation (r and principal component analysis showed NUtE had similar genetic correlations with other traits across the pot and field experiment. Among the yield components, only seeds per silique showed strong and positive correlations with NUtE under varying N supply in both experiments (r = 0.47**; 0.49**; 0.47**; 0.54**. At high and low N supply, NUtE was positively correlated with seed yield (r = 0.45**; 0.53**; 0.39**; 0.87**, nitrogen harvest index (NHI, r = 0.68**; 0.82**; 0.99**; 0.89**, and harvest index (HI, r = 0.79**; 0.83**; 0.90**; 0.78** and negatively correlated with biomass distribution to stem and leaf (r = −0.34**; −0.45**; −0.37**; 0.62**, all aboveground plant section N concentration (r from −0.30* to

  18. Formulations of the endophytic bacterium Bacillus subtilis Tu-100 suppress Sclerotinia sclerotiorum on oilseed rape and improve plant vigor in field trials conducted at separate locations (United States)

    Sclerotinia sclerotiorum causes serious yield losses in crops in The People’s Republic of China. Two formulations of oilseed rape seed containing the endophytic bacterium Bacillus subtilis Tu-100 were evaluated for suppression of this pathogen in field trials conducted at two independent locations....

  19. Genetic Diversity of Oilseed Rape Fields and Feral Populations in the Context of Coexistence with GM Crops.

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    Diane Bailleul

    Full Text Available Despite growing concern about transgenes escaping from fields, few studies have analysed the genetic diversity of crops in an agroecosystem over several years. Accurate information about the dynamics and relationship of the genetic diversity of crops in an agroecosystem is essential for risk assessment and policies concerning the containment of genetically modified crops and their coexistence with crops grown by conventional practices. Here, we analysed the genetic diversity of oilseed rape plants from fields and feral populations over 4 years in an agricultural landscape of 41 km2. We used exact compatibility and maximum likelihood assignment methods to assign these plants to cultivars. Even pure lines and hybrid cultivar seed lots contained several genotypes. The cultivar diversity in fields reflected the conventional view of agroecosystems quite well: that is, there was a succession of cultivars, some grown for longer than others because of their good performance, some used for one year and then abandoned, and others gradually adopted. Three types of field emerged: fields sown with a single cultivar, fields sown with two cultivars, and unassigned fields (too many cultivars or unassigned plants to reliably assign the field. Field plant diversity was higher than expected, indicating the persistence of cultivars that were grown for only one year. The cultivar composition of feral populations was similar to that of field plants, with an increasing number of cultivars each year. By using genetic tools, we found a link between the cultivars of field plants in a particular year and the cultivars of feral population plants in the following year. Feral populations on road verges were more diverse than those on path verges. All of these findings are discussed in terms of their consequences in the context of coexistence with genetically modified crops.

  20. Genetic Diversity of Oilseed Rape Fields and Feral Populations in the Context of Coexistence with GM Crops. (United States)

    Bailleul, Diane; Ollier, Sébastien; Lecomte, Jane


    Despite growing concern about transgenes escaping from fields, few studies have analysed the genetic diversity of crops in an agroecosystem over several years. Accurate information about the dynamics and relationship of the genetic diversity of crops in an agroecosystem is essential for risk assessment and policies concerning the containment of genetically modified crops and their coexistence with crops grown by conventional practices. Here, we analysed the genetic diversity of oilseed rape plants from fields and feral populations over 4 years in an agricultural landscape of 41 km2. We used exact compatibility and maximum likelihood assignment methods to assign these plants to cultivars. Even pure lines and hybrid cultivar seed lots contained several genotypes. The cultivar diversity in fields reflected the conventional view of agroecosystems quite well: that is, there was a succession of cultivars, some grown for longer than others because of their good performance, some used for one year and then abandoned, and others gradually adopted. Three types of field emerged: fields sown with a single cultivar, fields sown with two cultivars, and unassigned fields (too many cultivars or unassigned plants to reliably assign the field). Field plant diversity was higher than expected, indicating the persistence of cultivars that were grown for only one year. The cultivar composition of feral populations was similar to that of field plants, with an increasing number of cultivars each year. By using genetic tools, we found a link between the cultivars of field plants in a particular year and the cultivars of feral population plants in the following year. Feral populations on road verges were more diverse than those on path verges. All of these findings are discussed in terms of their consequences in the context of coexistence with genetically modified crops.

  1. Hydroponics versus field lysimeter studies of urea, ammonium and nitrate uptake by oilseed rape (Brassica napus L.). (United States)

    Arkoun, Mustapha; Sarda, Xavier; Jannin, Laëtitia; Laîné, Philippe; Etienne, Philippe; Garcia-Mina, José-Maria; Yvin, Jean-Claude; Ourry, Alain


    N-fertilizer use efficiencies are affected by their chemical composition and suffer from potential N-losses by volatilization. In a field lysimeter experiment, (15)N-labelled fertilizers were used to follow N uptake by Brassica napus L. and assess N-losses by volatilization. Use of urea with NBPT (urease inhibitor) showed the best efficiency with the lowest N losses (8% of N applied compared with 25% with urea alone). Plants receiving ammonium sulphate, had similar yield achieved through a better N mobilization from vegetative tissues to the seeds, despite a lower N uptake resulting from a higher volatilization (43% of applied N). Amounts of (15)N in the plant were also higher when plants were fertilized with ammonium nitrate but N-losses reached 23% of applied N. In parallel, hydroponic experiments showed a deleterious effect of ammonium and urea on the growth of oilseed rape. This was alleviated by the nitrate supply, which was preferentially taken up. B. napus was also characterized by a very low potential for urea uptake. BnDUR3 and BnAMT1, encoding urea and ammonium transporters, were up-regulated by urea, suggesting that urea-grown plants suffered from nitrogen deficiency. The results also suggested a role for nitrate as a signal for the expression of BnDUR3, in addition to its role as a major nutrient. Overall, the results of the hydroponic study showed that urea itself does not contribute significantly to the N nutrition of oilseed rape. Moreover, it may contribute indirectly since a better use efficiency for urea fertilizer, which was further increased by the application of a urease inhibitor, was observed in the lysimeter study.

  2. Institutional Perpetuation of Rape Culture: A Case Study of the University of Colorado Football Rape and Recruiting Scandal


    Folchert, Kristi Engle


    Heterosexual rape among university students is neither new nor uncommon. Research in rape prevention is largely limited to two areas: (1) what women can do to protect themselves from rape, which continues to place the burden of prevention on women; and (2) understanding why men rape. The studies in these fields have added to the body of knowledge surrounding rape on university campuses. The current study takes this information into consideration while using a different lens to examine the...

  3. Rice Yield and the Fate of Fertilizer Nitrogen as Affected by Addition of Earthworm Casts Collected from Oilseed Rape Fields: A Pot Experiment.

    Directory of Open Access Journals (Sweden)

    Min Huang

    Full Text Available The mechanism associated with improvement of soil nutritional status by oilseed rape crop, leading to better performance of rice crop, in rice-oilseed rape cropping systems is little known. The present study was aimed to test the hypothesis that earthworm casts produced during oilseed rape-growing season have positive effects on grain yield and fertilizer nitrogen (N utilization in the subsequent flooded rice crop. A 15N-tracing pot experiment was conducted to determine the effects of earthworm casts collected from oilseed rape fields on yield attributes in rice and the fate of fertilizer N. Soil treated with earthworm casts (soil: earthworm casts = 4: 1, w/w (EC1 produced 39% higher grain yield than soil only (EC0. EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. Aboveground biomass and harvest index were higher in EC1 than in EC0 by 20% and 15%, respectively. SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0 at 15 and 20 days after heading, respectively. EC1 had 19% higher total N uptake and 18% higher physiological N-use efficiency than EC0. These positive effects of earthworm casts on yield attributes offset negative effects of decreasing N rate from 0.74 g pot-1 (equivalent to the recommended field rate of 150 kg ha-1 to 0.44 g pot-1 (equivalent to 60% of the recommended rate. Fertilizer N retention rate was 7% higher while fertilizer N loss rate was 6% lower in EC1 than in EC0. Our study suggests that earthworm casts produced during oilseed rape-growing season are expected to have the following benefits on the subsequent flooded rice system: (1 improving growth and physiological processes in rice plants and consequently increasing rice grain yield, and (2 increasing fertilizer N retention rate and hence decreasing fertilizer N loss rate and reducing environmental risk.

  4. Rice Yield and the Fate of Fertilizer Nitrogen as Affected by Addition of Earthworm Casts Collected from Oilseed Rape Fields: A Pot Experiment. (United States)

    Huang, Min; Zhou, Xuefeng; Xie, Xiaobing; Zhao, Chunrong; Chen, Jiana; Cao, Fangbo; Zou, Yingbin


    The mechanism associated with improvement of soil nutritional status by oilseed rape crop, leading to better performance of rice crop, in rice-oilseed rape cropping systems is little known. The present study was aimed to test the hypothesis that earthworm casts produced during oilseed rape-growing season have positive effects on grain yield and fertilizer nitrogen (N) utilization in the subsequent flooded rice crop. A 15N-tracing pot experiment was conducted to determine the effects of earthworm casts collected from oilseed rape fields on yield attributes in rice and the fate of fertilizer N. Soil treated with earthworm casts (soil: earthworm casts = 4: 1, w/w) (EC1) produced 39% higher grain yield than soil only (EC0). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. Aboveground biomass and harvest index were higher in EC1 than in EC0 by 20% and 15%, respectively. SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0 at 15 and 20 days after heading, respectively. EC1 had 19% higher total N uptake and 18% higher physiological N-use efficiency than EC0. These positive effects of earthworm casts on yield attributes offset negative effects of decreasing N rate from 0.74 g pot-1 (equivalent to the recommended field rate of 150 kg ha-1) to 0.44 g pot-1 (equivalent to 60% of the recommended rate). Fertilizer N retention rate was 7% higher while fertilizer N loss rate was 6% lower in EC1 than in EC0. Our study suggests that earthworm casts produced during oilseed rape-growing season are expected to have the following benefits on the subsequent flooded rice system: (1) improving growth and physiological processes in rice plants and consequently increasing rice grain yield, and (2) increasing fertilizer N retention rate and hence decreasing fertilizer N loss rate and reducing environmental risk.

  5. The Effects of Rape Residue Mulching on Net Global Warming Potential and Greenhouse Gas Intensity from No-Tillage Paddy Fields (United States)

    Zhang, Zhi-Sheng; Cao, Cou-Gui; Guo, Li-Jin; Li, Cheng-Fang


    A field experiment was conducted to provide a complete greenhouse gas (GHG) accounting for global warming potential (GWP), net GWP, and greenhouse gas intensity (GHGI) from no-tillage (NT) paddy fields with different amounts of oilseed rape residue mulch (0, 3000, 4000, and 6000 kg dry matter (DM) ha−1) during a rice-growing season after 3 years of oilseed rape-rice cultivation. Residue mulching treatments showed significantly more organic carbon (C) density for the 0–20 cm soil layer at harvesting than no residue treatment. During a rice-growing season, residue mulching treatments sequestered significantly more organic C from 687 kg C ha−1 season−1 to 1654 kg C ha−1 season−1 than no residue treatment. Residue mulching significantly increased emissions of CO2 and N2O but decreased CH4 emissions. Residue mulching treatments significantly increased GWP by 9–30% but significantly decreased net GWP by 33–71% and GHGI by 35–72% relative to no residue treatment. These results suggest that agricultural economic viability and GHG mitigation can be achieved simultaneously by residue mulching on NT paddy fields in central China. PMID:25140329

  6. Long-Term Monitoring of Field Trial Sites with Genetically Modified Oilseed Rape (Brassica napus L.) in Saxony-Anhalt, Germany. Fifteen Years Persistence to Date but No Spatial Dispersion. (United States)

    Belter, Anke


    Oilseed rape is known to persist in arable fields because of its ability to develop secondary seed dormancy in certain agronomic and environmental conditions. If conditions change, rapeseeds are able to germinate up to 10 years later to build volunteers in ensuing crops. Extrapolations of experimental data acted on the assumption of persistence periods for more than 20 years after last harvest of rapeseed. Genetically-modified oilseed rape-cultivated widely in Northern America since 1996-is assumed not to differ from its conventional form in this property. Here, experimental data are reported from official monitoring activities that verify these assumptions. At two former field trial sites in Saxony-Anhalt genetically-modified herbicide-resistant oilseed rape volunteers are found up to fifteen years after harvest. Nevertheless, spatial dispersion or establishment of GM plants outside of the field sites was not observed within this period.

  7. Rape and Seduction Scripts. (United States)

    Ryan, Kathryn M.


    College students (N=18) wrote scripts about "typical" rape and "typical" seduction. Scripts were coded on 20 dimensions. Results showed that rape and seduction scripts were very different. Most subjects described blitz rape in which woman outdoors was attacked by male stranger. Seductions described were usually indoors and…

  8. Atomic electron correlations in intense laser fields

    Energy Technology Data Exchange (ETDEWEB)

    DiMauro, L.F.; Sheehy, B.; Walker, B. [Brookhaven National Lab., Upton, NY (United States); Agostini, P.A. [SPAM, Gif Sur Yvette (France). Centre d`Etudes de Saclay; Kulander, K.C. [Lawrence Livermore National Lab., CA (United States)


    This talk examines two distinct cases in strong optical fields where electron correlation plays an important role in the dynamics. In the first example, strong coupling in a two-electron-like system is manifested as an intensity-dependent splitting in the ionized electron energy distribution. This two-electron phenomenon (dubbed continuum-continuum Autler-Townes effect) is analogous to a strongly coupled two-level, one-electron atom but raises some intriguing questions regarding the exact nature of electron-electron correlation. The second case examines the evidence for two-electron ionization in the strong-field tunneling limit. Although their ability to describe the one-electron dynamics has obtained a quantitative level of understanding, a description of the two (multiple) electron ionization remains unclear.

  9. Nongyrotropic Electrons in Guide Field Reconnection (United States)

    Wendel, D. E.; Hesse, M.; Bessho, N.; Adrian, M. L.; Kuznetsova, M.


    We apply a scalar measure of nongyrotropy to the electron pressure tensor in a 2D particle-in-cell simulation of guide field reconnection and assess the corresponding electron distributions and the forces that account for the nongyrotropy. The scalar measure reveals that the nongyrotropy lies in bands that straddle the electron diffusion region and the separatrices, in the same regions where there are parallel electric fields. Analysis of electron distributions and fields shows that the nongyrotropy along the inflow and outflow separatrices emerges as a result of multiple populations of electrons influenced differently by large and small-scale parallel electric fields and by gradients in the electric field. The relevant parallel electric fields include large-scale potential ramps emanating from the x-line and sub-ion inertial scale bipolar electron holes. Gradients in the perpendicular electric field modify electrons differently depending on their phase, thus producing nongyrotropy. Magnetic flux violation occurs along portions of the separatrices that coincide with the parallel electric fields. An inductive electric field in the electron EB drift frame thus develops, which has the effect of enhancing nongyrotropies already produced by other mechanisms and under certain conditions producing their own nongyrotropy. Particle tracing of electrons from nongyrotropic populations along the inflows and outflows shows that the striated structure of nongyrotropy corresponds to electrons arriving from different source regions. We also show that the relevant parallel electric fields receive important contributions not only from the nongyrotropic portion of the electron pressure tensor but from electron spatial and temporal inertial terms as well.

  10. Crystal fields and conduction electrons in praseodymium

    DEFF Research Database (Denmark)

    Clausen, K.N.; Aagaard Sørensen, S.; McEwen, K.A.


    The interactions between the crystal-field excitations, the phonons and the conduction electrons in Pr have been studied further. The low-energy satellites to the crystal-field excitations, which are believed to be associated with propagating paramagnon modes in the conduction-electron gas, appea...

  11. Secondary victims of rape

    DEFF Research Database (Denmark)

    Christiansen, Dorte Mølgaard; Bak, Rikke; Elklit, Ask


    Rape is often a very traumatic experience, which affects not only the primary victim (PV) but also his/her significant others. Studies on secondary victims of rape are few and have almost exclusively studied male partners of female rape victims. This study examined the impact of rape on 107...... secondary victims, including family members, partners, and friends of male and female rape victims. We found that many respondents found it difficult to support the PV and that their relationship with the PV was often affected by the assault. Furthermore, the sample showed significant levels...... of social support for the respondent, and feeling let down by others. The respondents were generally interested in friend-, family-, and partner-focused interventions, particularly in receiving education about how best to support a rape victim...

  12. Rape in Rural Bangladesh

    Directory of Open Access Journals (Sweden)

    Nowsher Ali


    Full Text Available Background: Rape is one of the silent brutal sexual offences in Bangladesh. Despite strong laws against it, the evil of rape continues to rise. Increasing trend of the silent cruel sexual offence (rape represents a major psychopath sexual disorder and public health problem and progress of the country. Objective: The aim of the study was to determine the pattern of alleged rape victims in a rural district of Bangladesh with the ultimate aim to create public awareness about the brutal crime. Materials and method: This retrospective study was carried out on 330 sexually assailed alleged rape victims’ report forms, who reported at Faridpur Medical College, Bangladesh from 2007 to 2011 for medical examination. Results: Among the study subjects maximum number (70.0% of alleged rape cases were under the age of 20 years. More than two-thirds (64.60% of the assailants were known to the victims, most of the incidents (64.20% occurred in the victims’ houses and nearby places. The study also revealed that minimum number of victims (14.20% reported within 24 hours for medical examination. Almost one fourth of the alleged rape cases were gang rape and no positive finding in favour of sexual intercourse was found in about three fourth (72.40% of cases. Conclusion: Public awareness about rape would be effective to report in due time with preserving the evidence of crime and modern techniques like DNA diagnosis may be of help to detect the assailant.

  13. Electron-electron interactions in graphene field-induced quantum dots in a high magnetic field

    DEFF Research Database (Denmark)

    Orlof, A.; Shylau, Artsem; Zozoulenko, I. V.


    We study the effect of electron-electron interaction in graphene quantum dots defined by an external electrostatic potential and a high magnetic field. To account for the electron-electron interaction, we use the Thomas-Fermi approximation and find that electron screening causes the formation...

  14. War rape, natality and genocide. (United States)

    Schott, Robin May


    Feminist philosophy can make an important contribution to the field of genocide studies, and issues relating to gender and war are gaining new attention. In this article I trace legal and philosophical analyses of sexual violence against women in war. I analyze the strengths and limitations of the concept of social death—introduced into this field by Claudia Card—for understanding the genocidal features of war rape, and draw on the work of Hannah Arendt to understand the central harm of genocide as an assault on natality. The threat to natality posed by the harms of rape, forced pregnancy and forced maternity lie in the potential expulsion from the public world of certain groups—including women who are victims, members of the 'enemy' group, and children born of forced birth.

  15. Rape: an Asian perspective. (United States)

    Nadesan, K


    Rape is one of the fastest growing violent crimes in many parts of the world. Rape laws have been amended in most countries in an attempt to cope with the proliferation of this crime. Even though the legal definition of rape and the procedural laws have been amended, rape remains a serious problem in both the developed and developing nations. In some countries the offence of rape carries severe punishment sometimes even the death sentence. In many jurisdictions the term 'sexual penetration' is being used instead of 'sexual intercourse'. Sexual penetration includes sexual intercourse, anal intercourse, cunnilingus, fellatio or any other intrusions involving any part of a human body or of any object into the genital or anal opening of a person's body. In many countries rape and other sexual offences have been replaced with a series of gender neutral and graded offences with appropriate punishments. Medical examination can provide independent, scientific, corroborative evidence that may be of value to the court in arriving at a judgement. Doctors should have a clear understanding of different rape laws in order to apprectiate the various issues involved. Special knowledge, skill and experience are essential to conduct a good-quality medical examination. There is a dearth of trained forensic physicians in many Asian countries. However, managing a rape victim (survivor) goes for beyond proving the case in a court of law. There should be an adequate rehabilitation programme available to the victims to help them cope.

  16. Explaining wartime rape. (United States)

    Gottschall, Jonathan


    In the years since the first reports of mass rapes in the Yugoslavian wars of secession and the genocidal massacres in Rwanda, feminist activists and scholars, human rights organizations, journalists, and social scientists have dedicated unprecedented efforts to document, explain, and seek solutions for the phenomenon of wartime rape. While contributors to this literature agree on much, there is no consensus on causal factors. This paper provides a brief overview of the literature on wartime rape in historical and ethnographical societies and a critical analysis of the four leading explanations for its root causes: the feminist theory, the cultural pathology theory, the strategic rape theory, and the biosocial theory. The paper concludes that the biosocial theory is the only one capable of bringing all the phenomena associated with wartime rape into a single explanatory context.

  17. Electromagnetic radiation field of an electron avalanche (United States)

    Cooray, Vernon; Cooray, Gerald


    Electron avalanches are the main constituent of electrical discharges in the atmosphere. However, the electromagnetic radiation field generated by a single electron avalanche growing in different field configurations has not yet been evaluated in the literature. In this paper, the electromagnetic radiation fields created by electron avalanches were evaluated for electric fields in pointed, co-axial and spherical geometries. The results show that the radiation field has a duration of approximately 1-2 ns, with a rise time in the range of 0.25 ns. The wave-shape takes the form of an initial peak followed by an overshoot in the opposite direction. The electromagnetic spectrum generated by the avalanches has a peak around 109 Hz.

  18. Long-Term Monitoring of Field Trial Sites with Genetically Modified Oilseed Rape (Brassica napus L.) in Saxony-Anhalt, Germany. Fifteen Years Persistence to Date but No Spatial Dispersion (United States)

    Belter, Anke


    Oilseed rape is known to persist in arable fields because of its ability to develop secondary seed dormancy in certain agronomic and environmental conditions. If conditions change, rapeseeds are able to germinate up to 10 years later to build volunteers in ensuing crops. Extrapolations of experimental data acted on the assumption of persistence periods for more than 20 years after last harvest of rapeseed. Genetically-modified oilseed rape—cultivated widely in Northern America since 1996—is assumed not to differ from its conventional form in this property. Here, experimental data are reported from official monitoring activities that verify these assumptions. At two former field trial sites in Saxony-Anhalt genetically-modified herbicide-resistant oilseed rape volunteers are found up to fifteen years after harvest. Nevertheless, spatial dispersion or establishment of GM plants outside of the field sites was not observed within this period. PMID:26784233

  19. What Is Rape and Date Rape? (United States)

    ... fault. What is sexual assault? Sexual assault and abuse is any kind of sexual activity that you do not agree to, including: inappropriate touching vaginal, anal, or oral sex sex that you say ‘no’ to rape ...

  20. The Culture of Rape (United States)



  1. High-throughput phenotyping (HTP) identifies seedling root traits linked to variation in seed yield and nutrient capture in field-grown oilseed rape (Brassica napus L.). (United States)

    Thomas, C L; Graham, N S; Hayden, R; Meacham, M C; Neugebauer, K; Nightingale, M; Dupuy, L X; Hammond, J P; White, P J; Broadley, M R


    Root traits can be selected for crop improvement. Techniques such as soil excavations can be used to screen root traits in the field, but are limited to genotypes that are well-adapted to field conditions. The aim of this study was to compare a low-cost, high-throughput root phenotyping (HTP) technique in a controlled environment with field performance, using oilseed rape (OSR;Brassica napus) varieties. Primary root length (PRL), lateral root length and lateral root density (LRD) were measured on 14-d-old seedlings of elite OSR varieties (n = 32) using a 'pouch and wick' HTP system (∼40 replicates). Six field experiments were conducted using the same varieties at two UK sites each year for 3 years. Plants were excavated at the 6- to 8-leaf stage for general vigour assessments of roots and shoots in all six experiments, and final seed yield was determined. Leaves were sampled for mineral composition from one of the field experiments. Seedling PRL in the HTP system correlated with seed yield in four out of six (r = 0·50, 0·50, 0·33, 0·49;P < 0·05) and with emergence in three out of five (r = 0·59, 0·22, 0·49;P < 0·05) field experiments. Seedling LRD correlated positively with leaf concentrations of some minerals, e.g. calcium (r = 0·46;P < 0·01) and zinc (r = 0·58;P < 0·001), but did not correlate with emergence, general early vigour or yield in the field. Associations between PRL and field performance are generally related to early vigour. These root traits might therefore be of limited additional selection value, given that vigour can be measured easily on shoots/canopies. In contrast, LRD cannot be assessed easily in the field and, if LRD can improve nutrient uptake, then it may be possible to use HTP systems to screen this trait in both elite and more genetically diverse, non-field-adapted OSR. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.

  2. NMR metabolomics of ripened and developing oilseed rape (Brassica napus) and turnip rape (Brassica rapa). (United States)

    Kortesniemi, Maaria; Vuorinen, Anssi L; Sinkkonen, Jari; Yang, Baoru; Rajala, Ari; Kallio, Heikki


    The oilseeds of the commercially important oilseed rape (Brassica napus) and turnip rape (Brassica rapa) were investigated with (1)H NMR metabolomics. The compositions of ripened (cultivated in field trials) and developing seeds (cultivated in controlled conditions) were compared in multivariate models using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA). Differences in the major lipids and the minor metabolites between the two species were found. A higher content of polyunsaturated fatty acids and sucrose were observed in turnip rape, while the overall oil content and sinapine levels were higher in oilseed rape. The genotype traits were negligible compared to the effect of the growing site and concomitant conditions on the oilseed metabolome. This study demonstrates the applicability of NMR-based analysis in determining the species, geographical origin, developmental stage, and quality of oilseed Brassicas. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Older women: victims of rape. (United States)

    Tyra, P A


    Older female rape victims usually live alone, are raped by strangers, experience physical force and injury, and also are robbed. Rape trauma syndrome, a nursing diagnosis, consists of an acute phase of disorganization, and a long-term phase of reorganization of the victim's lifestyle. Rape victims experience emotional, physical, and cognitive reactions to the trauma of rape. Nursing actions can include providing specific interventions to victims during the acute phase, identifying victims during routine exams, referring victims for ongoing counseling, conducting community education programs on primary prevention and available services, and participating in longitudinal rape studies.

  4. Rape Beyond Crime. (United States)

    Kaplan, Margo


    Public health experts agree that sexual violence constitutes a significant public health issue. Yet criminal law dominates rape law almost completely, with public health law playing at best a small supporting role. Recent civil law developments, such as university disciplinary proceedings, similarly fixate on how best to find and penalize perpetrators. As a result, rape law continues to spin its wheels in the same arguments and obstacles. This Article argues that, without broader cultural changes, criminal law faces a double bind: rape laws will either be ineffective or neglect the importance of individual culpability. Public health law provides more promising terrain for rape prevention because it is a strong legal framework that can engage the complex causes of rape, including the social norms that promote sexual aggression. While criminal law can only punish bad behavior, public health interventions can use the more effective prevention strategy of promoting positive behaviors and relationships. They can also address the myriad sexual behaviors and social determinants that increase the risk of rape but are outside the scope of criminal law. Perhaps most importantly, public health law relies on evidence-based interventions and the expertise of public health authorities to ensure that laws and policies are effective. Transforming rape law in this way provides a framework for legal feminism to undertake the unmet challenge of "theorizing yes," that is, moving beyond how to protect women’s right to refuse sex and toward promoting and exploring positive models of sex. Criminal law is simply incapable of meeting this challenge because it concerns only what sex should not be. A public health framework can give the law a richer role in addressing the full spectrum of sexual attitudes and behaviors.

  5. Dissipation and residues of clethodim and its oxidation metabolites in a rape-field ecosystem using QuEChERS and liquid chromatography/tandem mass spectrometry. (United States)

    You, Xiangwei; Liang, Lin; Liu, Fengmao


    A rapid, sensitive and selective method using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure for simultaneous determination of clethodim and its oxidation metabolites (clethodim sulfoxide and clethodim sulphone) in soil, rape plant and rape seed was developed using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The limits of detection (LODs) of the proposed method ranged from 0.002mg/kg to 0.01mg/kg, and average recoveries were 78.7-104.2%. The trial results showed that clethodim dissipated so rapidly that few clethodim residues were detectable. Clethodim sulfoxide dissipated quickly in rape plant and soil with half-lives of 4.3 and 4.0days, respectively. Clethodim sulphone showed a tendency of rapid increase initially followed by a decrease in rape plant but could not be detected in soil. The terminal residues of clethodim in rape seedsat harvest time were below the maximum residue limit (MRL, 0.5mg/kg). Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Field evidence of cadmium phytoavailability decreased effectively by rape straw and/or red mud with zinc sulphate in a Cd-contaminated calcareous soil. (United States)

    Li, Bo; Yang, Junxing; Wei, Dongpu; Chen, Shibao; Li, Jumei; Ma, Yibing


    To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg-1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by approximately from 34% to 77% in Cd concentration in vegetables. The amendments plus Zn fertilization further decreased the Cd concentration in vegetables. Also cruciferous rape straw was more effective than gramineous corn straw. In all treatments, rape straw plus red mud combined with Zn fertilization was most effective in decreasing Cd phytoavailability in soils, and it is potential to be an efficient and cost-effective measure to ensure food safety for vegetable production in mildly Cd-contaminated calcareous soils.

  7. Flatland Electrons in High Magnetic Fields (United States)

    Shayegan, M.

    This paper provides a review of recent developments in the physics of two-dimensional carrier systems in perpendicular magnetic fields. The emphasis is on many-body phenomena in very clean GaAs/AlGaAs heterostructures, probed via magnetotransport measurements. Topics that are discussed include the integer and fractional quantum Hall effects, Wigner crystallization, composite Fermions, Skyrmions, stripe and bubble phases in single layer systems, and electron-hole pairing and Bose-Einstein condensation in interacting bilayer systems.

  8. Campus Gang Rape: Party Games? (United States)

    Ehrhart, Julie K.; Sandler, Bernice R.

    The phenomenon of gang rape as it sometimes occurs on college campuses is described, with attention to causes, impacts on the victim and other students, responses the college should take, and prevention. Consideration is given to the role of alcohol, drugs, and pornography in fraternity gang rape; successful model programs for rape prevention…

  9. Rape (For Teens) (United States)

    ... traces of a sexual assault. But being examined right away is the best way to ensure you get proper medical treatment. Immediate medical attention also helps when people decide to report the crime, providing evidence needed to prosecute the rapist if a criminal case is pursued. If you've been raped ...

  10. Field evidence of cadmium phytoavailability decreased effectively by rape straw and/or red mud with zinc sulphate in a Cd-contaminated calcareous soil.

    Directory of Open Access Journals (Sweden)

    Bo Li

    Full Text Available To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg-1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by approximately from 34% to 77% in Cd concentration in vegetables. The amendments plus Zn fertilization further decreased the Cd concentration in vegetables. Also cruciferous rape straw was more effective than gramineous corn straw. In all treatments, rape straw plus red mud combined with Zn fertilization was most effective in decreasing Cd phytoavailability in soils, and it is potential to be an efficient and cost-effective measure to ensure food safety for vegetable production in mildly Cd-contaminated calcareous soils.

  11. Precursors to rape: pressuring behaviors and rape proclivity. (United States)

    Strain, Megan L; Hockett, Jericho M; Saucier, Donald A


    We developed measures assessing personal and normative attitudes toward two types of behaviors that are symptomatic of rape culture. We conceptualize sexual violence as existing on a continuum and argue that two types of behaviors may be potential antecedents to (and consequences of) sexual violence: attempts to pressure, which mimic the power dynamics of rape in a less aggressive fashion, and benevolent dating behaviors, which are accepted dating scripts in which men initiate action. We examined individuals' acceptance of these behaviors in relation to their attitudes toward rape victims and among men to rape proclivity. This initial work suggests that these constructs and measures may be useful to investigate in future research.

  12. The costs of rape. (United States)

    Perilloux, Carin; Duntley, Joshua D; Buss, David M


    The current study examined costs experienced by victims of completed rape (n=49) and attempted sexual assault (n=91) using quantitative analyses of 13 domains: health, self-esteem, self-perceived attractiveness, self-perceived mate value, family relationships,work life, social life, social reputation, sexual reputation, desire to have sex, frequency of sex, enjoyment of sex, and long-term, committed relationships. Women also provided descriptive accounts of their experiences, and we used these to illustrate the costs in the victims' own words.Compared to victims of an attempted sexual assault, victims of a completed rape reported significantly more negative outcomes in 11 of the 13 domains. The most negatively affected domains were self-esteem, sexual reputation, frequency of sex, desire to have sex, and self-perceived mate value. Although victims of rape experienced more negative effects than victims of attempted sexual assault,both groups of victims reported negative effects in every domain.Discussion focuses on the implications of the differing degrees and patterns of the costs of attempted and completed sexual victimization.

  13. Rape: Legal issues in mental health perspective. (United States)

    Jiloha, R C


    Rape of women by men has occurred throughout recorded history and across cultures and religions. It is a crime against basic human right and a most common crime against women in India. In this article, rape is discussed from legal and mental health perspective. In India 'rape laws' began with enactment of Indian Penal Code in 1860. There have been subsequent amendments and the main issue of focus remained the definition of 'rape and inclusion of 'marital rape' in the ambit of rape. Law Commission Reports related to rape and the psychological impacts of rape have been discussed.

  14. Profile of rape victims attending the Karl Bremer Hospital Rape ...

    African Journals Online (AJOL)

    In addition, there is a lack of available data on the per-episode risk of HIV infection with specific sexual encounters,1 and in combination with poor ... the incident of sexual assault. • To obtain data regarding the use of newly provided ARV therapy as ..... Baleta A. Journalist's rape adds to rising rape statistics. Lancet 1999 ...

  15. Modified electron acoustic field and energy applied to observation data

    Energy Technology Data Exchange (ETDEWEB)

    Abdelwahed, H. G., E-mail:, E-mail: [College of Science and Humanitarian Studies, Physics Department, Prince Sattam Bin Abdul Aziz University, Alkharj 11942 (Saudi Arabia); Theoretical Physics Research Group, Physics Department, Faculty of Science, Mansoura University, Mansoura 35516 (Egypt); El-Shewy, E. K. [Theoretical Physics Research Group, Physics Department, Faculty of Science, Mansoura University, Mansoura 35516 (Egypt)


    Improved electrostatic acoustic field and energy have been debated in vortex trapped hot electrons and fluid of cold electrons with pressure term plasmas. The perturbed higher-order modified-Korteweg-de Vries equation (PhomKdV) has been worked out. The effect of trapping and electron temperatures on the electro-field and energy properties in auroral plasmas has been inspected.

  16. Rape Myth Consistency and Gender Differences in Perceiving Rape Victims: A Meta-Analysis. (United States)

    Hockett, Jericho M; Smith, Sara J; Klausing, Cathleen D; Saucier, Donald A


    An overview discusses feminist analyses of oppression, attitudes toward rape victims, and previously studied predictors of individuals' attitudes toward rape victims. To better understand such attitudes, this meta-analysis examines the moderating influences of various rape victim, perpetrator, and crime characteristics' rape myth consistency on gender differences in individuals' perceptions of rape victims (i.e., victim responsibility and blame attributions and rape minimizing attitudes). Consistent with feminist theoretical predictions, results indicated that, overall, men perceived rape victims more negatively than women did. However, this sex difference was moderated by the rape myth consistency within the rape vignettes. Implications for research are discussed. © The Author(s) 2015.

  17. Effects of NaCl treatment on the antioxidant enzymes of oilseed rape ...

    African Journals Online (AJOL)

    The effects of NaCl treatment on the activity of antioxidant enzymes in leaves of oilseed rape seedlings (Brassica napus L.) were studied. The results showed that the relative water content from leaves of oilseed rape seedlings was gradually decreased and the electronic conductivity was increased during 0 - 24 h under 200 ...

  18. Effects of NaCl treatment on the antioxidant enzymes of oilseed rape ...

    African Journals Online (AJOL)



    Oct 19, 2009 ... The effects of NaCl treatment on the activity of antioxidant enzymes in leaves of oilseed rape seedlings. (Brassica napus L.) were studied. The results showed that the relative water content from leaves of oilseed rape seedlings was gradually decreased and the electronic conductivity was increased during 0.

  19. Electron vortex beams in a magnetic field and spin filter


    Chowdhury, Debashree; Basu, Banasri; Bandyopadhyay, Pratul


    We investigate the propagation of electron vortex beams in a magnetic field. It is pointed out that when electron vortex beams carrying orbital angular momentum propagate in a magnetic field, the Berry curvature associated with the scalar electron moving in a cyclic path around the vortex line is modified from that in free space. This alters the spin-orbit interaction, which affects the propagation of nonparaxial beams. The electron vortex beams with tilted vortex lead to spin Hall effect in ...

  20. Attitudes toward Rape and Victims of Rape: A Test of the Feminist Theory in Ghana (United States)

    Boakye, Kofi E.


    This study explores the usefulness of the feminist theory in explaining attitudes toward rape and victims of rape in Ghana. The feminist theory of rape posits, inter alia, that patriarchy and gender inequality are major factors in the aetiology of rape and attitudes toward rape and that underlying patriarchy and gender inequality are gender…

  1. ASD and PTSD in Rape Victims (United States)

    Elklit, Ask; Christiansen, Dorte M.


    In recent years, a number of studies have investigated the prediction of posttraumatic stress disorder (PTSD) through the presence of acute stress disorder (ASD). The predictive power of ASD on PTSD was examined in a population of 148 female rape victims who visited a center for rape victims shortly after the rape or attempted rape. The PTSD…

  2. A Synthesized (Biosocial) Theory of Rape. (United States)

    Ellis, Lee


    Integrates features of contemporary theories of rape (feminist theory, social learning theory, evolutionary theory) with information on neurohormonal variables to formulate synthesized theory of rape. Synthesized theory of rape, consisting of four propositions, proposes that people are not all equally prone toward rape and that men are much more…

  3. Electron Dynamics in Nanostructures in Strong Laser Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kling, Matthias


    The goal of our research was to gain deeper insight into the collective electron dynamics in nanosystems in strong, ultrashort laser fields. The laser field strengths will be strong enough to extract and accelerate electrons from the nanoparticles and to transiently modify the materials electronic properties. We aimed to observe, with sub-cycle resolution reaching the attosecond time domain, how collective electronic excitations in nanoparticles are formed, how the strong field influences the optical and electrical properties of the nanomaterial, and how the excitations in the presence of strong fields decay.

  4. Rape-seed oil - a substitute for mineral oil?

    Energy Technology Data Exchange (ETDEWEB)

    Badent, R.; Kist, K.; Schwab, A.J. [University of Karlsruhe (Germany). Institute of Electric Systems and High-Voltage Technology


    This paper presents the results obtained from the study on the basic characteristics of rape-seed oil considered to be a substitute of mineral oil in power transformers. The results show that rape- seed oil is usable as an insulating liquid. Furthermore, results are presented concerning the breakdown behaviour in uniform (plane-plane geometry) and non-uniform (rod-plane geometry) fields under impulse conditions with gaps up to 40 mm and voltages up to 650 kV. A sufficient high 50 Hz breakdown voltage is the most important precondition for a medium to be used as an insulator. The dielectric strength of rape-seed oil exceeds more than 50 kV/2,5 mm and consequently fulfils the requirements of the standards. The measurement of the permittivity and tan {delta} at 90{sup o}C yields to 3,18 and 0,015, respectively and is comparable to the values of standard mineral oil. However, there are still some problems to be overcome. Beside the insulating task the liquid dielectric has also a cooling function in power apparatus. Since the dynamic viscosity of rape-seed oil (about 70 mm{sup 2}/s at 40{sup o}C) is higher than that of mineral oil, rape-seed oil has a lower ability for heat conduction. A further problem is the solidification of rape-seed oil below -5{sup o}C. (author)

  5. Rape: Legal issues in mental health perspective (United States)

    Jiloha, R. C.


    Rape of women by men has occurred throughout recorded history and across cultures and religions. It is a crime against basic human right and a most common crime against women in India. In this article, rape is discussed from legal and mental health perspective. In India ‘rape laws’ began with enactment of Indian Penal Code in 1860. There have been subsequent amendments and the main issue of focus remained the definition of ‘rape and inclusion of ‘marital rape’ in the ambit of rape. Law Commission Reports related to rape and the psychological impacts of rape have been discussed. PMID:24082245

  6. Electronic journal management systems experiences from the field

    CERN Document Server

    Ives, Gary W


    Discover how to manage your library's electronic journals?with tips from those who've already met the challenge!The explosive growth of electronic journals presents unique challenges for libraries. Electronic Journal Management Systems: Experiences from the Field comprehensively examines these complex topics, including explanations of the automated systems libraries have developed or adopted, licensing issues, and the provision of access to electronic journals. Respected library professionals discuss their own experiences in the implementation and use of electronic journal management systems,

  7. Mycobiota of rape seeds in Romania. II. Evaluation of potential antagonistic fungi isolated from rape seeds against the main pathogens of rape crop

    Directory of Open Access Journals (Sweden)

    Tatiana-Eugenia Şesan


    Full Text Available In vitro relationships between identified seed- and soil-borne fungi from rape samples have been investigated in order to evaluate their antagonistic ability as potential biocontrol agents. The bioproduct obtained from the Trichoderma viride Pers. (strain Td50 has been tested in vivo against the main phytopathogens of rape: Sclerotinia sclerotiorum (Lib. de Bary, Botrytis cinerea Pers., Alternaria spp. and Fusarium spp. in greenhouse at the Laboratory of Mycology and Plant Pathology, Biology Faculty, University of Bucharest – Romania and in the field at the Agricultural Experimental Research-Development Station Caracal (AERDS, Olt district. The T. viride (strain Td50 bioproduct formulated as a powder for the seed treatment has been effective in the protection of rape plantlets against the above mentioned phytopathogens.

  8. Rape trauma syndrome as scientific expert testimony. (United States)

    Block, A P


    Behavioral science studies conducted on rape victims reveal a posttraumatic stress disorder which follows the attack known as rape trauma syndrome. Evidence of rape trauma syndrome can be very useful in explaining the behavior of rape victims. Rape trauma syndrome can help corroborate the victim's assertion of lack of consent and also help the jury understand the typical reactions of rape victims. Courts have held that expert testimony of rape trauma syndrome is admissible as evidence of (i) lack of consent, (ii) the amount of damages in civil suits, (iii) a defense to culpable behavior, and (iv) an explanation for behavior of the victim that is inconsistent with the claim of rape. Rape trauma syndrome meets the requirements for admissibility when it is used for the proper purpose and with adequate safeguards to prevent any unfair prejudice. Based on case precedent on the admissibility of rape trauma syndrome as scientific expert testimony, rape trauma syndrome should be admissible if (i) the evidence presented only shows the typical reactions to rape and does not make any legal conclusions as to whether the victim was raped, (ii) the expert is qualified, (iii) a proper foundation is laid, (iv) liberal cross-examination of the expert is allowed, and (v) the defense can introduce its own expert testimony on rape trauma syndrome.

  9. Electron dynamics in metals and semiconductors in strong THz fields

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd


    Semiconductors and metals respond to strong electric fields in a highly nonlinear fashion. Using single-cycle THz field transients it is possible to investigate this response in regimes not accessible by transport-based measurements. Extremely high fields can be applied without material damage......, intrinsic, undoped materials can be studied, and field-induced electron emission into free space can be investigated in detail, thereby offering new knowledge about material response to strong THz-frequency fields relevant for near-future generations of electronic circuitry....

  10. Electronic spin drift in graphene field-effect transistors

    NARCIS (Netherlands)

    Jozsa, C.; Popinciuc, M.; Tombros, N.; Jonkman, H. T.; van Wees, B. J.


    We studied the drift of electron spins under an applied dc electric field in single layer graphene spin valves in a field-effect transport geometry at room temperature. In the metallic conduction regime (n similar or equal to 3.5x10(16) m(-2)), for dc fields of about +/- 70 kV/m applied between the

  11. Electronic properties of asymmetrical quantum dots dressed by laser field

    Energy Technology Data Exchange (ETDEWEB)

    Kibis, O.V. [Department of Applied and Theoretical Physics, Novosibirsk State Technical University, Karl Marx Avenue 20, 630092 Novosibirsk (Russian Federation); Slepyan, G.Ya.; Maksimenko, S.A. [Institute for Nuclear Problems, Belarus State University, Bobruyskaya St. 11, 220050 Minsk (Belarus); Hoffmann, A. [Institut fuer Festkoerperphysik, Technische Universitaet Berlin, Hardenbergstrasse 36, 10623 Berlin (Germany)


    In the present paper, we demonstrate theoretically that the strong non-resonant interaction between asymmetrical quantum dots (QDs) and a laser field results in harmonic oscillations of their band gap. It is shown that such oscillations change the spectrum of elementary electron excitations in QDs: in the absence of the laser pumping there is only one resonant electron frequency, but QDs dressed by the laser field have a set of electron resonant frequencies. One expects that this modification of elementary electron excitations in QDs can be observable in optical experiments. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. An Electronic Weather Vane for Field Science (United States)

    Burman, J.; Talbert, R.; Carlton, K.


    This paper details the construction of a weather vane for the measurement of wind direction in field situations. The purpose of its construction was to analyse how wind direction affected the attractiveness of an insect pheromone in a dynamic outdoor environment, where wind could be a significant contributor to odour movement. The apparatus…

  13. Electron transport in argon in crossed electric and magnetic fields (United States)

    Ness; Makabe


    An investigation of electron transport in argon in the presence of crossed electric and magnetic fields is carried out over a wide range of values of electric and magnetic field strengths. Values of mean energy, ionization rate, drift velocity, and diffusion tensor are reported here. Two unexpected phenomena arise; for certain values of electric and magnetic field we find regions where the swarm mean energy decreases with increasing electric fields for a fixed magnetic field and regions where swarm mean energy increases with increasing magnetic field for a fixed electric field.

  14. An Application of Art Therapy to the Trauma of Rape. (United States)

    Hargrave-Nykaza, Karen


    Explores rape in terms of specific trauma usually experienced after rape: posttraumatic stress disorder, rape trauma syndrome, and permanent life changes. Explores ways in which art therapy can help rape victim engage in healing. Reviews study of one rape victim and current literature as example of life-altering effects of rape and importance of…

  15. Rape reporting: "Classic Rape" and the behavior of law. (United States)

    Clay-Warner, Jody; McMahon-Howard, Jennifer


    Two theories of rape reporting, the Classic Rape perspective and Black's Theory of the Behavior of Law, are tested in this article. We offer the first comprehensive multivariate test of Classic Rape predictions among a nationally representative sample of victims, as well as the first test of Black's predictions for rape reporting. Through the construction of multinomial regression models, we are able to examine reporting patterns for both victims and third parties. Weapon use and physical injury consistently predicted reporting. The likelihood of victim reporting significantly increased when assaults occurred either in public or through a "home blitz," whereas place of assault did not affect the likelihood of third-party reporting. On the other hand, victim-offender relationship significantly affected the likelihood of third-party reporting but was not significant in the victim-reporting models. There were mixed findings regarding Black's stratification and morphology predictions, and we found no significant effects for culture, organization, or social control. Overall, these findings lend greater support to the Classic Rape perspective than to Black's model.

  16. Investigation of electron boost radiotherapy in patients with breast cancer: Is a direct electron field optimal? (United States)

    Aghili, M; Barzegartahamtan, M; Alikhassi, A; Mohammadpour, R


    Historically, electron boost dose mainly was delivered by a direct field in adjuvant radiotherapy of breast cancer. In this prospective study, we investigated direct electron field, in terms of optimal coverage of tumour bed volume following localization using ultrasound and surgical clips. First, for all 24 patients, a breast sonographer drew perimeter of tumour bed on the breast skin. Then an electron boost field was outlined on the demarcated territory, and a lead wire marker compatible with CT scan was placed on the field borders by a 2cm margin. After CT scan simulation, all patients underwent adjuvant whole breast irradiation with 3D-conformal radiotherapy to 50Gy in 25 fractions. Then for boost radiotherapy, lead wire in CT images was countoured as electron boost field. Also, the tumour bed was contoured based on surgical clips (true clinical target volume and true planning target volume). Electron treatment planning was done for electron boost field. Finally isodose coverages for true planning target volume investigated. On average, 16.68% of clips planning target volume (true planning target volume; range: 0.00 to 95%) received 90% oor more of the prescribed dose when the electron treatment plan was made. Isodose curves does not provide adequate coverage on the tumour bed (clips planning target volume) when electron boost treatment planning was generated for electron boost field (en face electron field). In fact, a part of target (planning target volume-c) is missed and more doses is absorbed in normal tissue. Electron boost treatment planning (an en face electron field) following tumour bed localization using ultrasonography does not provide an optimized coverage of tumour bed volume. Copyright © 2017. Published by Elsevier SAS.

  17. Evaluation of Yield and Yield Components of Oilseed Rape in the Wheat-Oilseed Rape Strip Intercropping Influenced by Chemical and Biological Fertilizers

    Directory of Open Access Journals (Sweden)

    R Amirmardfar


    Full Text Available To evaluate the effects of wheat (Triticum aestivum and oilseed rape (Brassica napus strip intercropping on yield components, seed and biological yields of oilseed rape, field experiments were carried out as factorial based on randomized complete block design with three replications at Research Farm of Tabriz University, Tabriz, Iran during 2010-2012 cropping seasons. The first factor consisted of four types of wheat and oilseed rape cropping system, sole crop of oilseed rape (A1,: strip intercropping with 8:3 (A2, 12:4 (A3 and 16:5 (A4 of wheat and oilseed rape rows, respectively and the other factor consisted of two fertilizer levels, B1: 100% chemical fertilizers (urea and triple superphosphate and B2: 50% chemical fertilizers + biofertilizers (Nitrazhin and Barvar2. The results showed that strip intercropping of wheat- oilseed rape resulted in significant increase in yield components, seed yield per occupied unit area and biological yield per occupied unit area of oilseed rape as compared with mono-cropping. The number of silique per plant in intercropping systems was significantly higher than that of mono-cropping. The highest seed yield was obtained in the 16:5 rows of wheat-oilseed rape with 343.76 g.m-2 and the lowest mean was observed in mono-cropping of oilseed rape with 260.21 g.m-2. Biological yield per occupied unit area and seed yield per intercropped unit area in B1 were significantly greater than that of B2, but this treatment had no significant effect on the other traits. Because, B1 and B2 had no significant difference in seed yield per occupied unit area and due to the importance of reduction in chemical fertilizers consumption and food and environmental health care, strip intercropping of wheat-oilseed rape under 50% chemical fertilizers + biofertilizers can be recommended as a suitable cultural method.

  18. Carbon adsorption on tungsten and electronic field emission (United States)

    Márquez-Mijares, Maykel; Lepetit, Bruno; Lemoine, Didier


    Electronic emission taking place at the electrodes of high voltage systems and responsible for detrimental breakdown processes is known to be strongly dependent on the cathode surface state and in particular on the presence of carbon contamination. To understand better the effect of carbon adsorption on cathode electronic emission, density functional theory calculations are reported for bulk bcc tungsten as well as for clean and carbon-covered W(100) surfaces for several coverages up to 2 ML. Adsorption geometries and energies, work functions and electronic densities of states are analyzed to assess the effect of the presence of adlayers on surface electronic field emission properties. It is shown that flat carbon adlayer deposition on clean W(100) surfaces induces an increase of the surface work function and a decrease of electronic density near the Fermi level. Both factors contribute to reducing electronic field emission levels.

  19. Development of Field-Emission Electron Gun from Carbon Nanotubes

    CERN Document Server

    Hozumi, Y


    Aiming to use a narrow energy-spread electron beam easily and low costly on injector electron guns, we have been tested field emission cathodes of carbon nanotubes (CNTs). Experiments for these three years brought us important suggestions and a few rules of thumb. Now at last, anode current of 3.0 [A/cm2

  20. Convection electric field effects on outer radiation belt electron precipitation (United States)

    Gelpi, C.; Benbrook, J. R.; Sheldon, W. R.


    A model is presented for the possible diurnal modulation of outer radiation belt electron precipitation by considering the effect of the convection electric field on geomagnetically trapped electrons. The modulation flux is the flux due to electrons in the drift loss cone, i.e., those which drift into the bounce loss cone. The electron flux in the drift loss cone is related to the time allowable for diffusion from the stably trapped population to the drift loss cone for precipitation at a specific geographic location. This time, which is termed the maximum L-shell lifetime, is obtained by computing electron trajectories, using a realistic magnetic field model and a simple model for the electric field. The maximum L-shell lifetimes are taken to be the times between successive entries into the bounce loss cone. Conservation of the first two adiabatic invariants, as electrons are slowly energized by the convection electric field, leads to variations in pitch angle, maximum L-shell lifetimes, and, consequently, to changes in the electron flux in the drift loss cone. These results are compared with observations of precipitating electrons made with sounding rocket payloads.

  1. Coherent single electron spin control in a slanting Zeeman field

    NARCIS (Netherlands)

    Tokura, Yasuhiro; van der Wiel, Wilfred Gerard; Obata, Toshiaki; Tarucha, Seigo


    We consider a single electron in a 1D quantum dot with a static slanting Zeeman field. By combining the spin and orbital degrees of freedom of the electron, an effective quantum two-level (qubit) system is defined. This pseudospin can be coherently manipulated by the voltage applied to the gate

  2. Radiation-Reaction Trapping of Electrons in Extreme Laser Fields

    CERN Document Server

    Ji, L L; Kostyukov, I Yu; Shen, B F; Akli, K


    proposed analysis shows that the threshold of laser field amplitude for RRT is approximately the cubic root of laser wavelength over classical electron radius. Because of the pinching effect of the trapped electron bunch, the required laser intensity for RRT can be further reduced.

  3. Magnetic field effects in electron systems with imperfect nesting (United States)

    Sboychakov, A. O.; Rakhmanov, A. L.; Kugel, K. I.; Rozhkov, A. V.; Nori, Franco


    We analyze the effects of an applied magnetic field on the phase diagram of a weakly correlated electron system with imperfect nesting. The Hamiltonian under study describes two bands: electron and hole ones. Both bands have spherical Fermi surfaces, whose radii are slightly mismatched due to doping. These types of models are often used in the analysis of magnetic states in chromium and its alloys, superconducting iron pnictides, AA-type bilayer graphene, borides, etc. At zero magnetic field, the uniform ground state of the system turns out to be unstable against electronic phase separation. The applied magnetic field affects the phase diagram in several ways. In particular, the Zeeman term stabilizes new antiferromagnetic phases. It also significantly shifts the boundaries of inhomogeneous (phase-separated) states. At sufficiently high fields, the Landau quantization gives rise to oscillations of the order parameters and of the Néel temperature as a function of the magnetic field.

  4. The impact of rape acknowledgment on survivor outcomes: The moderating effects of rape myth acceptance. (United States)

    Wilson, Laura C; Newins, Amie R; White, Susan W


    Little is known about how rape acknowledgment relates to posttrauma functioning; recent research suggests the effect may depend on additional factors. In the current study, the moderating effect of rape myth acceptance (RMA) on the relationships between rape acknowledgment and mental health outcomes was examined. A sample of 181 female rape survivors recruited from a university completed an online survey assessing RMA, rape acknowledgment, depression symptoms, and alcohol use. Generally, the results supported that RMA moderated the influence of rape acknowledgment on depression symptoms and average quantity per drinking episode, but not frequency of alcohol use. The findings demonstrated that when individuals endorsed high levels of RMA, acknowledged rape survivors reported worse outcomes than unacknowledged rape survivors. Among individuals low on RMA, unacknowledged rape survivors reported worse outcomes than acknowledged rape survivors. It is recommended that clinicians recognize the role of survivor beliefs, such as RMA, in the relationship between labeling sexual assault experiences and mental health consequences. © 2017 Wiley Periodicals, Inc.

  5. Proposed Recruit Training Topic: Rape Awareness. (United States)


    Washington, DC. Medea , A. and Thompson, K. Against Rape. New York: Farrar, Straus, and Giroud, 1974. Rape: A Preventative Inquiry (film) 345-10 DN...programmed text study guide. UNITED STATES COAST GUARD The Coast Guard Training Center, Cape May, New Jersey, does not include rape awareness/prevention...82. September 1982. Arlington, Virginia. Connell, N. and Wilson, C. Rape: The First Resource Book for Women. New York: New American Library, 1974

  6. Electron holographic visualization of collective motion of electrons through electric field variation. (United States)

    Shindo, Daisuke; Aizawa, Shinji; Akase, Zentaro; Tanigaki, Toshiaki; Murakami, Yasukazu; Park, Hyun Soon


    This study demonstrates the accumulation of electron-induced secondary electrons by utilizing a simple geometrical configuration of two branches of a charged insulating biomaterial. The collective motion of these secondary electrons between the branches has been visualized by analyzing the reconstructed amplitude images obtained using in situ electron holography. In order to understand the collective motion of secondary electrons, the trajectories of these electrons around the branches have also been simulated by taking into account the electric field around the charged branches on the basis of Maxwell's equations.


    Energy Technology Data Exchange (ETDEWEB)



    The design of the higher-energy cooler for Relativistic Heavy Ion Collider (RHIC) recently adopted a non-magnetized approach which requires a low temperature electron beam. However, to avoid significant loss of heavy ions due to recombination with electrons in the cooling section, the temperature of the electron beam should be high. These two contradictory requirements are satisfied in the design of the RWIC cooler with the help of the undulator fields. The model of the friction force in the presence of an undulator field was benchmarked vs. direct numerical simulations with an excellent agreement. Here, we discuss cooling dynamics simulations with a helical undulator, including recombination suppression and resulting luminosities.

  8. Male Rape Victim and Perpetrator Blaming (United States)

    Sleath, Emma; Bull, Ray


    One of four possible vignettes manipulated by (a) level of rape myth contained within them (low vs. high) and (b) type of rape (stranger vs. acquaintance) was presented to participants followed by scales measuring victim blame, perpetrator blame, belief in a just world, sex-role egalitarian beliefs, and male rape myth acceptance. Victim blaming…

  9. Rape and Women's Sexual Health in Nigeria

    African Journals Online (AJOL)


    Feminist theory is used to explain rape, the societal reaction to it and the health outcomes for the victims. The paper concludes that many health problems suffered by women in Nigeria are as a result of rape. Public health practitioners should devise mechanisms of eliciting rape information from victims so as to effectively ...

  10. Conditional electron confinement in graphene via smooth magnetic fields (United States)

    Le, Dai-Nam; Le, Van-Hoang; Roy, Pinaki


    In this article we discuss confinement of electrons in graphene via smooth magnetic fields which are finite everywhere on the plane. We shall consider two types of magnetic fields leading to systems which are conditionally exactly solvable and quasi exactly solvable. The bound state energies and wavefunctions in both cases have been found exactly.

  11. Phase-space dynamics of runaway electrons in magnetic fields (United States)

    Guo, Zehua; McDevitt, Christopher J.; Tang, Xian-Zhu


    Dynamics of runaway electrons in magnetic fields are governed by the competition of three dominant physics: parallel electric field acceleration, Coulomb collision, and synchrotron radiation. Examination of the energy and pitch-angle flows reveals that the presence of local vortex structure and global circulation is crucial to the saturation of primary runaway electrons. Models for the vortex structure, which has an O-point to X-point connection, and the bump of runaway electron distribution in energy space have been developed and compared against the simulation data. Identification of these velocity-space structures opens a new venue to re-examine the conventional understanding of runaway electron dynamics in magnetic fields.

  12. Field measurements in the Fermilab electron cooling solenoid prototype

    Energy Technology Data Exchange (ETDEWEB)

    A. C. Crawford et al.


    To increase the Tevatron luminosity, Fermilab is developing a high-energy electron cooling system [1] to cool 8.9-GeV/c antiprotons in the Recycler ring. The schematic layout of the Recycler Electron Cooling (REC) system is shown in Figure 1. Cooling of antiprotons requires a round electron beam with a small angular spread propagating through a cooling section with a kinetic energy of 4.3 MeV. To confine the electron beam tightly and to keep its transverse angles below 10{sup -4} rad, the cooling section will be immersed into a solenoidal field of 50-150G. As part of the R&D effort, a cooling section prototype consisting of 9 modules (90% of the total length of a future section) was assembled and measured. This paper describes the technique of measuring and adjusting the magnetic field quality in the cooling section and presents preliminary results of solenoid prototype field measurements. The design of the cooling section solenoid is discussed in Chapter 2. Chapter 3 describes details of a dedicated measurement system, capable of measuring small transverse field components, while the system's measurement errors are analyzed in Chapter 4. Chapter 5 contains measured field distributions of individual elements of the cooling section as well as an evaluation of the magnetic shielding efficiency. An algorithm of field adjustments for providing lowest possible electron trajectory perturbations is proposed in Chapter 6; also, this chapter shows the results of our first attempts of implementing the algorithm.

  13. Small field electron beam dosimetry using MOSFET detector. (United States)

    Amin, Md Nurul; Heaton, Robert; Norrlinger, Bern; Islam, Mohammad K


    The dosimetry of very small electron fields can be challenging due to relative shifts in percent depth-dose curves, including the location of dmax, and lack of lateral electronic equilibrium in an ion chamber when placed in the beam. Conventionally a small parallel plate chamber or film is utilized to perform small field electron beam dosimetry. Since modern radiotherapy departments are becoming filmless in favor of electronic imaging, an alternate and readily available clinical dosimeter needs to be explored. We have studied the performance of MOSFET as a relative dosimeter in small field electron beams. The reproducibility, linearity and sensitivity of a high-sensitivity microMOSFET were investigated for clinical electron beams. In addition, the percent depth doses, output factors and profiles have been measured in a water tank with MOSFET and compared with those measured by an ion chamber for a range of field sizes from 1 cm diameter to 10 cm × 10 cm for 6, 12, 16 and 20 MeV beams. Similar comparative measurements were also per-formed with MOSFET and films in solid water phantom. The MOSFET sensitivity was found to be practically constant over the range of field sizes investigated. The dose response was found to be linear and reproducible (within ± 1% for 100 cGy). An excellent agreement was observed among the central axis depth dose curves measured using MOSFET, film and ion chamber. The output factors measured with MOSFET for small fields agreed to within 3% with those measured by film dosimetry. Overall results indicate that MOSFET can be utilized to perform dosimetry for small field electron beam.

  14. Why, when and how men rape: Understanding rape perpetration in ...

    African Journals Online (AJOL)

    This research confirms that rape is highly prevalent in South Africa, with only a small proportion of incidents reported to the police. Many of the roots of the problem lie in our accentuated gender hierarchy. This highlights the importance of interventions and policies that start in childhood and seek to change the way in which ...

  15. Cultural and legal accounts of rape

    Directory of Open Access Journals (Sweden)

    Fernández Villanueva, Concepción


    Full Text Available The present paper attempts to show how rape is represented in a variety of historical and contemporary discourses. Examples of rapes in Greek mythology, in the Bible, in medieval iconography, in literature, and in scientific theories, are compared and contrasted. Analysis suggests that such discourses tend to make sexual aggression (and specifically the rape of women legitimate, be it by minimizing the harm done; by normalizing and naturalizing sexual violence; or by aesthetisizing rape as art. Finally, the paper argues that putting modern legal accounts of rape into their historical perspective brings into sharper focus the persistence of ancient myths and discourses

  16. Marital rape: history, research, and practice. (United States)

    Bennice, Jennifer A; Resick, Patricia A


    Despite the increased recognition that the topic of marital rape has generated in the past 2 decades, the literature in this area remains sparse. This article provides a comprehensive review of the current state of the marital rape literature. First, the lengthy history of legal, cultural, and professional invalidation of marital rape victims, and the resulting negative treatment implications, is discussed. Second, marital rape research is reviewed, including prevalence, descriptive, and comparison studies. This review highlights the seriousness of marital rape, in terms of prevalence and posttrauma distress, as well as the limitations of extant research. Finally, barriers to treatment and recommendations for professionals are discussed.

  17. Electron beam confinement and image contrast enhancement in near field emission scanning electron microscopy. (United States)

    Kirk, T L; De Pietro, L G; Pescia, D; Ramsperger, U


    In conventional scanning electron microscopy (SEM), the lateral resolution is limited by the electron beam diameter impinging on the specimen surface. Near field emission scanning electron microscopy (NFESEM) provides a simple means of overcoming this limit; however, the most suitable field emitter remains to be determined. NFESEM has been used in this work to investigate the W (110) surface with single-crystal tungsten tips of (310), (111), and (100)-orientations. The topographic images generated from both the electron intensity variations and the field emission current indicate higher resolution capabilities with decreasing tip work function than with polycrystalline tungsten tips. The confinement of the electron beam transcends the resolution limitations of the geometrical models, which are determined by the minimum beam width.

  18. Theory of Carbon Nanotube (CNT)-Based Electron Field Emitters (United States)

    Bocharov, Grigory S.; Eletskii, Alexander V.


    Theoretical problems arising in connection with development and operation of electron field emitters on the basis of carbon nanotubes are reviewed. The physical aspects of electron field emission that underlie the unique emission properties of carbon nanotubes (CNTs) are considered. Physical effects and phenomena affecting the emission characteristics of CNT cathodes are analyzed. Effects given particular attention include: the electric field amplification near a CNT tip with taking into account the shape of the tip, the deviation from the vertical orientation of nanotubes and electrical field-induced alignment of those; electric field screening by neighboring nanotubes; statistical spread of the parameters of the individual CNTs comprising the cathode; the thermal effects resulting in degradation of nanotubes during emission. Simultaneous consideration of the above-listed effects permitted the development of the optimization procedure for CNT array in terms of the maximum reachable emission current density. In accordance with this procedure, the optimum inter-tube distance in the array depends on the region of the external voltage applied. The phenomenon of self-misalignment of nanotubes in an array has been predicted and analyzed in terms of the recent experiments performed. A mechanism of degradation of CNT-based electron field emitters has been analyzed consisting of the bombardment of the emitters by ions formed as a result of electron impact ionization of the residual gas molecules. PMID:28348342

  19. Theory of Carbon Nanotube (CNT-Based Electron Field Emitters

    Directory of Open Access Journals (Sweden)

    Alexander V. Eletskii


    Full Text Available Theoretical problems arising in connection with development and operation of electron field emitters on the basis of carbon nanotubes are reviewed. The physical aspects of electron field emission that underlie the unique emission properties of carbon nanotubes (CNTs are considered. Physical effects and phenomena affecting the emission characteristics of CNT cathodes are analyzed. Effects given particular attention include: the electric field amplification near a CNT tip with taking into account the shape of the tip, the deviation from the vertical orientation of nanotubes and electrical field-induced alignment of those; electric field screening by neighboring nanotubes; statistical spread of the parameters of the individual CNTs comprising the cathode; the thermal effects resulting in degradation of nanotubes during emission. Simultaneous consideration of the above-listed effects permitted the development of the optimization procedure for CNT array in terms of the maximum reachable emission current density. In accordance with this procedure, the optimum inter-tube distance in the array depends on the region of the external voltage applied. The phenomenon of self-misalignment of nanotubes in an array has been predicted and analyzed in terms of the recent experiments performed. A mechanism of degradation of CNT-based electron field emitters has been analyzed consisting of the bombardment of the emitters by ions formed as a result of electron impact ionization of the residual gas molecules.

  20. Contribution of Metal Layer Thickness for Quantitative Backscattered Electron Imaging of Field Emission Scanning Electron Microscopy

    National Research Council Canada - National Science Library

    Kim, Hyonchol; Takei, Hiroyuki; Negishi, Tsutomu; Kudo, Masato; Terazono, Hideyuki; Yasuda, Kenji


    ...) imaging in field emission scanning electron microscopy (FE-SEM) were studied to evaluate the potential of using these particles as simultaneously distinguishable labels of target molecules in FE-SEM studies...

  1. Patterns of rape and approaches to care. (United States)

    Pepiton-Rockwell, F


    The family physician is likely to be involved in the care of the rape victim. This paper focuses on the social and legal definitions of rape as well as the incidence of rape. The Rape Trauma Syndrome is explained and normative responses of victims are discussed. Eight common myths about rape are identified which the victim and the physician may share. In discussing the myths, guidelines for counseling the rape victim are delineated: encourage the victim to talk about her feelings; as the physician, remain nonjudgmental; provide information or resources to the victim; view the aftermath of rape as a response to a life-threatening event; and enlist the support of the victim's significant others. Finally, the importance of understanding the available community resources is stressed.

  2. Components of a Rice-Oilseed Rape Production System Augmented with Trichoderma sp. Tri-1 Control Sclerotinia sclerotiorum on Oilseed Rape. (United States)

    Hu, Xiaojia; Roberts, Daniel P; Xie, Lihua; Maul, Jude E; Yu, Changbing; Li, Yinshui; Zhang, Yinbo; Qin, Lu; Liao, Xing


    Sclerotinia sclerotiorum causes serious yield losses on many crops throughout the world. A multicomponent treatment that consisted of the residual rice straw remaining after rice harvest and Trichoderma sp. Tri-1 (Tri-1) formulated with the oilseed rape seedcake fertilizer was used in field soil infested with S. sclerotiorum. This treatment resulted in oilseed rape seed yield that was significantly greater than the nontreated control or when the fungicide carbendizem was used in the presence of this pathogen in field trials. Yield data suggested that the rice straw, oilseed rape seedcake, and Tri-1 components of this treatment all contributed incrementally. Similar treatment results were obtained regarding reduction in disease incidence. Slight improvements in yield and disease incidence were detected when this multicomponent treatment was combined with a fungicide spray. Inhibition of sclerotial germination by this multicomponent treatment trended greater than the nontreated control at 90, 120, and 150 days in field studies but was not significantly different from this control. This multicomponent treatment resulted in increased yield relative to the nontreated control in the absence of pathogen in a greenhouse pot study, while the straw alone and the straw plus oilseed rape seedcake treatments did not; suggesting that Tri-1 was capable of promoting growth. Experiments reported here indicate that a treatment containing components of a rice-oilseed rape production system augmented with Tri-1 can control S. sclerotiorum on oilseed rape, be used in integrated strategies containing fungicide sprays for control of this pathogen, and promote plant growth.

  3. Breaking the silence surrounding rape. (United States)

    Ramsay, S


    This article documents the turning points in the rape issue, which led to the acknowledgement of its prevalence in the world, especially in South Africa. November 25 marked the first day of the "Take a Stand" movement in South Africa, which coincided with the International Day Against Violence Against Women. This movement involves peaceful protests and poster campaigns, followed by months of sustained news coverage of rape. This was launched by a coalition of organizations, including women's groups, churches, businesses, and trades unions, that are speaking out against all forms of sexual violence. In the international community, rape is starting to be taken seriously. In 1996, sexual assault was cited as a crime against humanity by the International Criminal Tribunal for the former Yugoslavia. In addition, a forum in London, UK, on November 25, discussed rape issues and recommendations on how to prevent such violence were given. The need for a change in legal systems, which currently discourage women from taking legal actions, was also recognized. In view of this, the medical community is challenged to provide sensitive and appropriate help to women who have been assaulted.

  4. Romeo, Juliet, and Statutory Rape. (United States)

    Bierie, David M; Budd, Kristen M


    Statutory rape is an important yet understudied topic. There is broad public support for the prosecution of older adults who engage in sexual relationships with minors regardless of perceptions of consent by either party. However, some scholars worry that expansive definitions within these laws have led to the widespread involvement of the justice system in the lives of similarly aged teenagers engaging in relatively normal sexual behavior, so called "Romeo and Juliet" liaisons. This, in turn, has called into question the legitimacy of national policies, such as sex offender registration, because of the presumption that registries are likely filled with these kinds of cases which may not represent the intent of legislatures and the public. Despite the importance of these debates, there is little research assessing the prevalence of Romeo and Juliet cases in official crime statistics or that analyze differences in characteristics of statutory rape as a function of victim-offender age differences. Drawing on more than 20 years of police data from over 6,000 police departments in the United States, this study found statutory rape cases were rare and Romeo and Juliet cases were even rarer. Multivariate models showed several distinctions between statutory rape cases as a function of the age differences between victim and offender. Of note, the odds that additional forms of sexual aggression occurred in the incident grew as the age difference expanded. © The Author(s) 2016.

  5. Electric field effects on electronic characteristics of arsenene nanoribbons (United States)

    Luo, Yanwei; Li, Yuxiao; Wang, Fei; Guo, Peng; Jia, Yu


    By using the first-principles calculations, we investigate the effects of electric field on electronic structures of armchair and zigzag arsenene nanoribbons (AsNRs) with different widths. The results show that for each case, quantum size effects induce a smaller band gap in larger AsNRs. Moreover, electric field can reduce effectively the band gap of AsNRs. In addition, the electric field can induce only the transition of band structures in the A-AsNRs or Z-AsNRs with narrow size. The band gap decrease more rapidly and the threshold electric field induced metal becomes smaller in the wider AsNRs.

  6. Effect of Secondary Electron Emission on Electron Cross-Field Current in E×B Discharges

    Energy Technology Data Exchange (ETDEWEB)

    Yevgeny Raitses, Igor D. Kaganovich, Alexander Khrabrov, Dmytro Sydorenko, Nathaniel J. Fisch and Andrei Smolyakov


    This paper reviews and discusses recent experimental, theoretical, and numerical studies of plasma-wall interaction in a weakly collisional magnetized plasma bounded with channel walls made from different materials. A lowpressure ExB plasma discharge of the Hall thruster was used to characterize the electron current across the magnetic field and its dependence on the applied voltage and electron-induced secondary electron emission (SEE) from the channel wall. The presence of a depleted, anisotropic electron energy distribution function with beams of secondary electrons was predicted to explain the enhancement of the electron cross-field current observed in experiments. Without the SEE, the electron crossfield transport can be reduced from anomalously high to nearly classical collisional level. The suppression of SEE was achieved using an engineered carbon velvet material for the channel walls. Both theoretically and experimentally, it is shown that the electron emission from the walls can limit the maximum achievable electric field in the magnetized plasma. With nonemitting walls, the maximum electric field in the thruster can approach a fundamental limit for a quasineutral plasma.

  7. Quantum statistical mechanics of electron gas in magnetic field

    Directory of Open Access Journals (Sweden)



    Full Text Available Electron eigenstates in a magnetic field are considered. Density of the probability current and an averaged magnetic moment are obtained. Density of states is investigated for two-dimensional electron in a circle that is bound by the infinite potential barrier. The present study shows that the common quantum statistical mechanics of electron gas in a magnetic field leads to incorrect results. The magnetic moment of electron gas can be computed as the sum of averaged moments of the occupied states. The computations lead to the results that differ from the ones obtained as the derivative of the thermodynamical potential with respect to the magnetic field. Other contradictions in common statistical thermodynamics of electron gas in a magnetic field are pointed out. The conclusion is done that these contradictions arise from using the incorrect statistical operator. A new quantum function of distribution is derived from the basic principles, taking into account the law of conservation of an angular momentum. These results are in accord with the theory that has been obtained within the framework of classical statistical thermodynamics in the previous work.

  8. A quantum field theory of the extended electron

    Energy Technology Data Exchange (ETDEWEB)

    Salesi, Giovanni [Universita Statale di Catania (Italy). Dipt. di Fisica; Recami, Erasmo [Universita Statale di Bergamo, Dalmine, BG (Italy). Facolta di Ingegneria]|[Universidade Estadual de Campinas, SP (Brazil). Dept. de Matematica Aplicada


    In a recent paper, the classical model of Barut and Zanghi (BZ) for the electron spin which interpreted the Zitterbewegung (zbw) motion along helical paths and its quantum version have been investigated by using the language of Clifford algebras. In also doing, a new non-linear Dirac-like equation (NDE) was derived. We want to readdress the whole subject, and complete it, by adopting - for the sake of physical clarity - the ordinary tensorial language. In particular, we re-derive here the NDE for the electron quantum field, show it to be associated with a new conserved probability current, and stress its importance for a quantum field theory of spin 1/2 fermions. Actually, we propose this equation in substitution for the Dirac equation, which comes from the former by averaging over a zbw cycle. We then derive a new equation of motion for the quantum field velocity, which will allow us to regard the electron as an extended object, with a classically intelligible internal structure (thus overcoming some known, long-standing problems). We carefully the solutions of the NDE; with special attention to those implying (at the classical limit) light-like helical motions, since these appear to be the most adequate equations for the electron description, from the kinematical and physical points of view, and do cope with the electron electromagnetic properties (such as Coulomb field and intrinsic magnetic moment). (author). 18 refs.

  9. Field electron emission from a carbon-covered iridium tip (United States)

    Bernatskii, D. P.; Pavlov, V. G.


    The formation of a carbon coating on an iridium field-emission electron emitter by benzene vapor pyrolysis has been studied. Processes on an emitting tip differ from those studied earlier on flat metal surfaces. The resulting coating either represents a monoatomic graphene film on the flat faces of the emitter or consists of graphene clusters. The field electron emission is localized on the edges and in the corners of a faceted graphite outgrowth. After alkali metals are adsorbed on the carbon coating, emissions from the flat faces anomalously grows and localizes on graphene-coated faces with alkali atoms present on the surface and under the graphene film.

  10. Atomic and free electrons in a strong light field

    CERN Document Server

    Fedorov, Mikhail V


    This book presents and describes a series of unusual and striking strong-field phenomena concerning atoms and free electrons. Some of these phenomena are: multiphoton stimulated bremsstrahlung, free-electron lasers, wave-packet physics, above-threshold ionization, and strong-field stabilization in Rydberg atoms. The theoretical foundations and causes of the phenomena are described in detail, with all the approximations and derivations discussed. All the known and relevant experiments are described too, and their results are compared with those of the existing theoretical models.An extensive ge

  11. The Geography of Rape: Rape Victims in Urban and Rural Communities

    DEFF Research Database (Denmark)

    Nielsen, Louise Hjort

    in Denmark. It was hypothesized that there would be a lower representation of rape victims, measured by the number of calls, to a regional rape crisis center in the rural communities further away from the regional rape crisis center of Aarhus compared to the urban communities closer to the rape crisis center....... A one-way ANOVA analysis showed that there was a significant association between the number of victim calls and the distance to the rape crisis center. The closer the residence of the victim was to the rape crisis center the more victim calls were registered. The study also examined what types of help...

  12. Localized Electron Heating by Strong Guide-Field Magnetic Reconnection (United States)

    Guo, Xuehan; Sugawara, Takumichi; Inomoto, Michiaki; Yamasaki, Kotaro; Ono, Yasushi; UTST Team


    Localized electron heating of magnetic reconnection was studied under strong guide-field (typically Bt 15Bp) using two merging spherical tokamak plasmas in Univ. Tokyo Spherical Tokamak (UTST) experiment. Our new slide-type two-dimensional Thomson scattering system documented for the first time the electron heating localized around the X-point. The region of high electron temperature, which is perpendicular to the magnetic field, was found to have a round shape with radius of 2 [cm]. Also, it was localized around the X-point and does not agree with that of energy dissipation term Et .jt . When we include a guide-field effect term Bt / (Bp + αBt) for Et .jt where α =√{ (vin2 +vout2) /v∥2 } , the energy dissipation area becomes localized around the X-point, suggesting that the electrons are accelerated by the reconnection electric field parallel to the magnetic field and thermalized around the X-point. This work was supported by JSPS A3 Foresight Program ``Innovative Tokamak Plasma Startup and Current Drive in Spherical Torus,'' a Grant-in-Aid from the Japan Society for the Promotion of Science (JSPS) Fellows 15J03758.

  13. Scanning Electron Microscopy with Samples in an Electric Field (United States)

    Frank, Ludĕk; Hovorka, Miloš; Mikmeková, Šárka; Mikmeková, Eliška; Müllerová, Ilona; Pokorná, Zuzana


    The high negative bias of a sample in a scanning electron microscope constitutes the “cathode lens” with a strong electric field just above the sample surface. This mode offers a convenient tool for controlling the landing energy of electrons down to units or even fractions of electronvolts with only slight readjustments of the column. Moreover, the field accelerates and collimates the signal electrons to earthed detectors above and below the sample, thereby assuring high collection efficiency and high amplification of the image signal. One important feature is the ability to acquire the complete emission of the backscattered electrons, including those emitted at high angles with respect to the surface normal. The cathode lens aberrations are proportional to the landing energy of electrons so the spot size becomes nearly constant throughout the full energy scale. At low energies and with their complete angular distribution acquired, the backscattered electron images offer enhanced information about crystalline and electronic structures thanks to contrast mechanisms that are otherwise unavailable. Examples from various areas of materials science are presented.

  14. Immunity of electronic devices against radio-frequency electromagnetic fields

    Directory of Open Access Journals (Sweden)

    Urbancokova Hana


    Full Text Available One of the major types of electromagnetic interference, which affect electronic devices in their normal operation, is the interference with radio-frequency electromagnetic fields. This interference is generated by the mainly radio and television transmitters, industrial equipment and other transmitters and receivers in general use for communication. Testing of electromagnetic susceptibility of electronic devices on radiated radio-frequency electromagnetic field is governed by the basic standard IEC 61000-4-3 and the equipment under test are exposed to test electromagnetic fields with an intensity from 1 V/m to 30 V/m, the most often in the frequency range from 80 MHz to 2 GHz. The aim of this paper is to explain the issue of electromagnetic susceptibility and to present sample the electromagnetic immunity tests of the basic set of the intrusion and hold-up alarm system against the radio-frequency electromagnetic field according to the relevant electromagnetic compatibility standards.

  15. Low-Energy Electron Diffraction Patterns Using Field-Emitted Electrons from Tungsten Tips (United States)

    Mizuno, Seigi; Rahman, F.; Iwanaga, Masayuki


    We have observed low-energy electron diffraction patterns of Cu(001) clean surface using field-emitted electrons from tungsten tips. Only elastically scattered electrons contribute to diffraction patterns. Tip-sample distance, bias voltage, electron beam opening angle and tip apex structure determine the probing diameter and symmetry of diffraction patterns. The emission current, bias voltage and estimated probing diameter for the observed diffraction patterns were 0.15 nA, 75-82 V, and 4-40 μm, respectively.

  16. Child rape: facets of a heinous crime. (United States)

    Gangrade, K D; Sooryamoorthy, R; Renjini, D


    This article discusses the extent of child rape in India, case studies of girl children in legal procedures, rape settings and perpetrators, public morality, and the nature of rape laws in India. It is concluded that there is no safe place for children. Currently, rapists are allowed to go free or are acquitted. Prevention and control of child rape must involve punishment of rapists. It is not appropriate that society ostracize the victim and her family. Victims should not remain silent. National Crime Records Bureau statistics reveal increases in rape during 1986-91. State figures are given for 1986-88. Madhya Pradesh had the highest reported incidence of rape in 1988. In 1993, Madhya Pradesh had a total of 2459 rapes. Nationally, 10,425 women were reported as raped in 1991. 51.7% were 16-30 years old. There were 1099 cases of pedophilia in 1991, which was an increase over 1990. Over 50% of the pedophilia cases were reported in Uttar Pradesh. The record of convictions shows very low figures. 1992 trial results of 276 rape cases indicated that only 46 persons were convicted. Victims suffer from psychological effects of embarrassment, disgust, depression, guilt, and even suicidal tendencies. There is police and prosecution indifference as well as social stigma and social ostracism of the victim and her family. Many cases go unreported. The case studies illustrate the difficulties for the victim of experiencing the rape and the social responses: police harassment, shame and fear, and occasionally public outrage. The case studies illustrate rape in familiar settings, such as schools, family homes, and neighbors and friends' homes; rape by policemen; and rape by political influentials. Most offenders are young, married, and socioeconomically poor. Mass media portrayals fuel the frustrations of poor and lonely men in cities. Rapists exhibit anti-social behavior or psychopathology. Sexual offenses are related to society's moral values.

  17. RAD-TOL Field Electronics for the LHC Cryogenic System

    CERN Document Server

    Agapito, J A; Franco, F J; Palan, B; Rodríguez-Ruiz, M A; RADECS 2003


    The field electronics for the LHC cryogenic system will be subjected to neutron and gamma radiation. Its baseline design is based on COTS and a DMILL ASIC. The COTS include anti-fuse FPGA's, WorldFIP fieldbus interface and discrete integrated circuits.

  18. Electron-Bernstein Waves in Inhomogeneous Magnetic Fields

    DEFF Research Database (Denmark)

    Armstrong, R. J.; Frederiksen, Å.; Pécseli, Hans


    The propagation of small amplitude electron-Bernstein waves in different inhomogeneous magnetic field geometries is investigated experimentally. Wave propagation towards both cut-offs and resonances are considered. The experimental results are supported by a numerical ray-tracing analysis. Spatial...... enhancements of the wave amplitude are interpreted as a result of caustic formation....

  19. Electron field emission from sp 2-induced insulating to metallic ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 33; Issue 3. Electron field emission from 2-induced insulating to metallic behaviour of amorphous carbon (-C) films. Pitamber Mahanandia P N Viswakarma Prasad Vishnu Bhotla S V Subramanyam Karuna Kar Nanda. Thin Films and Nanomatter Volume 33 Issue 3 ...

  20. Comparison of electron cloud mitigating coatings using retarding field analyzers

    Energy Technology Data Exchange (ETDEWEB)

    Calvey, J.R., E-mail:; Hartung, W.; Li, Y.; Livezey, J.A.; Makita, J.; Palmer, M.A.; Rubin, D.


    In 2008, the Cornell Electron Storage Ring (CESR) was reconfigured to serve as a test accelerator (CESRTA) for next generation lepton colliders, in particular for the ILC damping ring. A significant part of this program has been the installation of diagnostic devices to measure and quantify the electron cloud effect, a potential limiting factor in these machines. One such device is the Retarding Field Analyzer (RFA), which provides information on the local electron cloud density and energy distribution. Several different styles of RFAs have been designed, tested, and deployed throughout the CESR ring. They have been used to study the growth of the cloud in different beam conditions, and to evaluate the efficacy of different mitigation techniques. This paper will provide an overview of RFA results obtained in a magnetic field free environment.

  1. Nitrous oxide emission from wetland soil following single and seasonal split application of cattle manure to field tomato (Lycopersicon esculentum, Mill var. Heinz) and rape (Brassica napus, L. var. Giant) crops. (United States)

    Masaka, Johnson; Nyamangara, Justice; Wuta, Menas


    An understanding of the contribution of manure applications to global atmospheric N2O loading is needed to evaluate agriculture's contribution to the global warming process. Two field experiments were carried out at Dufuya wetland (19°17'S; 29°21'E, 1260 m above sea level) to determine the effects of single and split manure applications on emissions of N2O from soil during the growing seasons of two rape and two tomato crops. Two field experiments were established. In the first experiment the manure was applied in three levels of 0, 15, and 30 Mg ha(-1) as a single application just before planting of the first tomato crop. In the second experiment the 15 and 30 Mg ha(-1) manure application rates were divided into four split applications of 3.75 and 7.5 Mg ha(-1) respectively, for each of the four cropping events. Single applications of 15 and 30 Mg ha(-1) manure once in four cropping events had higher emissions of N2O than those recorded on plots that received split applications of 3.75 and 7.5 Mg ha(-1) manure at least up to the second test crop. Thereafter N2O emissions on plots subjected to split applications of manure were higher or equal to those recorded in plots that received single basal applications of 30 Mg ha(-1) applied a week before planting the first crop. Seasonal split applications of manure to wetland vegetable crops can reduce emissions of N2O at least up to the second seasonal split application.

  2. Two-Dimensional Electron System in Electromagnetic Radiation Field (United States)

    Lungu, Radu Paul; Manolescu, Andrei

    We consider a two-dimensional electron gas in the presence of a monochromatic linear polarized electromagnetic field, within the Floquet formalism. The Floquet states have a simple relation with the energy eigenstates in the absence of the field. Therefore the single-particle and the two-particle Green functions of the many-body system with Coulomb interactions, in the radiation field, can be formally calculated by the standard diagrammatic techniques, as for the conservative system. We derive the elementary excitations of quasi-particle type, the plasma dispersion relation, and the ground state quasi-energy, and we relate them to the corresponding results for the conservative system.

  3. Primordial Magnetic Fields, Right Electrons, and the Abelian Anomaly

    CERN Document Server

    Joyce, M


    In the standard model there are charges with abelian anomaly only (e.g. right-handed electron number) which are effectively conserved in the early universe until some time shortly before the electroweak scale. A state at finite chemical potential of such a charge, possibly arising due to asymmetries produced at the GUT scale, is unstable to the generation of hypercharge magnetic field. We argue that quite large magnetic fields ($\\sim 10^{23}$ gauss at $T\\sim 3$ TeV with typical inhomogeneity scale up to $\\sim interest, potentially acting as seeds for amplification to larger scale magnetic fields through non-linear mechanisms.

  4. Electronic field emission models beyond the Fowler-Nordheim one (United States)

    Lepetit, Bruno


    We propose several quantum mechanical models to describe electronic field emission from first principles. These models allow us to correlate quantitatively the electronic emission current with the electrode surface details at the atomic scale. They all rely on electronic potential energy surfaces obtained from three dimensional density functional theory calculations. They differ by the various quantum mechanical methods (exact or perturbative, time dependent or time independent), which are used to describe tunneling through the electronic potential energy barrier. Comparison of these models between them and with the standard Fowler-Nordheim one in the context of one dimensional tunneling allows us to assess the impact on the accuracy of the computed current of the approximations made in each model. Among these methods, the time dependent perturbative one provides a well-balanced trade-off between accuracy and computational cost.

  5. Rape and the prevalence of hybrids in broadly sympatric species: a case study using albatrosses

    Directory of Open Access Journals (Sweden)

    Sievert Rohwer


    Full Text Available Conspecific rape often increases male reproductive success. However, the haste and aggression of forced copulations suggests that males may sometimes rape heterospecific females, thus making rape a likely, but undocumented, source of hybrids between broadly sympatric species. We present evidence that heterospecific rape may be the source of hybrids between Black-footed and Laysan Albatrosses (Phoebastria nigripes, and P. immutabilis, respectively. Extensive field studies have shown that paired (but not unpaired males of both of these albatross species use rape as a supplemental reproductive strategy. Between species differences in size, timing of laying, and aggressiveness suggest that Black-footed Albatrosses should be more successful than Laysan Albatrosses in heteropspecific rape attempts, and male Black-footed Albatrosses have been observed attempting to force copulations on female Laysan Albatrosses. Nuclear markers showed that the six hybrids we studied were F1s and mitochondrial markers showed that male Black-footed Albatrosses sired all six hybrids. Long-term gene exchange between these species has been from Black-footed Albatrosses into Laysan Albatrosses, suggesting that the siring asymmetry found in our hybrids has long persisted. If hybrids are sired in heterospecific rapes, they presumably would be raised and sexually imprinted on Laysan Albatrosses, and two unmated hybrids in a previous study courted only Laysan Albatrosses.

  6. Myths and legends: The reality of rape offences reported to a UK police force

    Directory of Open Access Journals (Sweden)

    Genevieve F. Waterhouse


    Full Text Available Rape myths affect many aspects of the investigative and criminal justice systems. One such myth, the ‘real rape’ myth, states that most rapes involve a stranger using a weapon attacking a woman violently at night in an isolated, outdoor area, and that women sustain serious injuries from these attacks. The present study examined how often actual offences reported to a central UK police force over a two year period matched the ‘real rape’ myth. Out of 400 cases of rape reported, not a single incident was found with all the characteristics of the ‘real rape’ myth. The few stranger rapes that occurred had a strong link to night-time economy activities, such as the victim and offender both having visited pubs, bars, and clubs. By contrast, the majority of reported rape offences (280 cases, 70.7% were committed by people known to the victim (e.g., domestic and acquaintance rapes, occurred inside a residence, with most victims sustaining no physical injuries from the attack. The benefits of these naturalistic findings from the field for educating people about the inaccuracy of rape myths are discussed.

  7. Bright-field scanning confocal electron microscopy using a double aberration-corrected transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng; Behan, Gavin; Kirkland, Angus I. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Nellist, Peter D., E-mail: [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Cosgriff, Eireann C.; D' Alfonso, Adrian J.; Morgan, Andrew J.; Allen, Leslie J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Hashimoto, Ayako [Advanced Nano-characterization Center, National Institute for Materials Science (NIMS), 3-13 Sakura, Tsukuba 305-0003 (Japan); Takeguchi, Masaki [Advanced Nano-characterization Center, National Institute for Materials Science (NIMS), 3-13 Sakura, Tsukuba 305-0003 (Japan); High Voltage Electron Microscopy Station, NIMS, 3-13 Sakura, Tsukuba 305-0003 (Japan); Mitsuishi, Kazutaka [Advanced Nano-characterization Center, National Institute for Materials Science (NIMS), 3-13 Sakura, Tsukuba 305-0003 (Japan); Quantum Dot Research Center, NIMS, 3-13 Sakura, Tsukuba 305-0003 (Japan); Shimojo, Masayuki [High Voltage Electron Microscopy Station, NIMS, 3-13 Sakura, Tsukuba 305-0003 (Japan); Advanced Science Research Laboratory, Saitama Institute of Technology, 1690 Fusaiji, Fukaya 369-0293 (Japan)


    Scanning confocal electron microscopy (SCEM) offers a mechanism for three-dimensional imaging of materials, which makes use of the reduced depth of field in an aberration-corrected transmission electron microscope. The simplest configuration of SCEM is the bright-field mode. In this paper we present experimental data and simulations showing the form of bright-field SCEM images. We show that the depth dependence of the three-dimensional image can be explained in terms of two-dimensional images formed in the detector plane. For a crystalline sample, this so-called probe image is shown to be similar to a conventional diffraction pattern. Experimental results and simulations show how the diffracted probes in this image are elongated in thicker crystals and the use of this elongation to estimate sample thickness is explored. -- Research Highlights: {yields} The confocal probe image in a scanning confocal electron microscopy image reveals information about the thickness and height of the crystalline layer. {yields} The form of the contrast in a three-dimensional bright-field scanning confocal electron microscopy image can be explained in terms of the confocal probe image. {yields} Despite the complicated form of the contrast in bright-field scanning confocal electron microscopy, we see that depth information is transferred on a 10 nm scale.

  8. Determinants of nectar production in oilseed rape

    DEFF Research Database (Denmark)

    Enkegaard, Annie; Kryger, Per; Boelt, Birte


    With the aim of contributing to the development of models forecasting the melliferous characteristics and the potential honey yield of oilseed rape, we analyzed data on the temporal pattern of number of oilseed rape flowers, nectar secretion, sugar concentration, and weight of bee hives in relation...... with significantly reduced quality of the nectar in terms of both volume and sugar concentration, and our results suggest that the oilseed rape in this year did not contribute notably to bee colony development. In years in which the oilseed rape flowered around the normal time (beginning of May), the amount...... of secreted sugar decreased over the flowering period, being governed by inherent oilseed rape characteristics modified by climatic factors preceding the onset of flowering, as well as climatic conditions during flowering. The exploitation of oilseed rape nectar by bee colonies was found to be influenced...

  9. Electron transport in reduced graphene oxides in high electric field (United States)

    Jian, Wen-Bin; Lai, Jian-Jhong; Wang, Sheng-Tsung; Tsao, Rui-Wen; Su, Min-Chia; Tsai, Wei-Yu; Rosenstein, Baruch; Zhou, Xufeng; Liu, Zhaoping

    Due to a honeycomb structure, charge carriers in graphene exhibit quasiparticles of linear energy-momentum dispersion and phenomena of Schwinger pair creation may be explored. Because graphene is easily broken in high electric fields, single-layer reduced graphene oxides (rGO) are used instead. The rGO shows a small band gap while it reveals a graphene like behavior in high electric fields. Electron transport in rGO exhibits two-dimensional Mott's variable range hopping. The temperature behavior of resistance in low electric fields and the electric field behavior of resistance at low temperatures are all well explained by the Mott model. At temperatures higher than 200 K, the electric field behavior does not agree with the model while it shows a power law behavior with an exponent of 3/2, being in agreement with the Schwinger model. Comparing with graphene, the rGO is more sustainable to high electric field thus presenting a complete high-electric field behavior. When the rGO is gated away from the charge neutral point, the turn-on electric field of Schwinger phenomena is increased. A summary figure is given to present electric field behaviors and power law variations of resistances of single-layer rGO, graphene, and MoS2.

  10. Electron beam focusing in the magnetic field of a bent electron beam evaporator

    Directory of Open Access Journals (Sweden)

    M Salahshoor


    Full Text Available In this paper, the vacuum film deposition through electron beam evaporation has been reviewed and the effect of magnetic field on the operation of this system has been explained. Then, the magnetic field distribution due to magnetic components configuartion of a commercial evaporation source with 270-degree electron beam gun (manufactured by Sharif University Branch of ACECR, has been simulated by means of a finite element software, ANSYS. The simulation result was verified by comparing with the results obtained from measurement by Hall Effect sensor. Furthermore, by using the ray-tracing capability of the software, the capability of the magnetic lens of this device for electron beam focusing has been investigated. The predicted position of the electron beam spot on the target is in good agreement with experimental observations  

  11. Rape and the Serial Rapist (United States)


    suffered from various personality disorders . "Twenty-two (16 percent) were diagnosed as borderline personalities , and thirteen (10 percent) showed...75 percent) were predominantly diagnosed as suffering from a personality disorder . Richard T. Rada in his study found that the category of the...Rape: The Psychology of the Offender (New York: Plenum Press), 109. 45 Fritz A. Kenn et al., " Forensics Psychiatry: Profiles of Two Types of Sex

  12. Rape: psychopathology, theory and treatment. (United States)

    Gannon, Theresa A; Collie, Rachael M; Ward, Tony; Thakker, Jo


    Whether treatment programs are effective at rehabilitating rapists is yet to be determined empirically. From a scientist-practitioner perspective, treatment should be based on an empirical understanding of rape and rapists, and evidence-based knowledge of treatment outcome with rapists. In this paper we comprehensively review the characteristics of rapists, etiological features implicated in the commission of rape, and relevant treatment outcome research. We pay particular attention to contemporary knowledge about the core vulnerabilities and features required to understand and treat rapists effectively, and, where possible, highlight similarities and differences between rapists, child molesters and non-sexual violent offenders. We use an epistemological framework to (a) critique the various etiological accounts of rape available and (b) help guide professionals' use of such knowledge in both treatment design and evaluation. Gaps in the understanding of rapists' characteristics and etiological features are highlighted, as are discrepancies between current knowledge and treatment approaches. We conclude by highlighting areas for future research and practice innovation.

  13. Violence against women in war: rape, AIDS, sex slavery. International. (United States)

    At an international conference attended by 2000 delegates, violence against women in Rwanda, former Yugoslavia, and Kurdistan was discussed. Kalliope Migirou, of the United Nations Human Rights Field Operation in Rwanda, described the slaughter of between 500,000 and 1.5 million Tutsis and moderate Hutus in 1994; estimates of the number of rapes ranged from 15,700 (Rwandan government) to 250,000-500,000 (UN special representative). Women were gang-raped and sexually mutilated; fathers were forced to rape their daughters, and sons, their mothers. The transmission of HIV was used as a weapon to murder women and their communities. Women were taken to refugee camps as sex slaves and have written their families about their "new marriages" to Hutu militia men. No rape charge is found among the more than 4000 cases prepared for the Rwandan war crimes trial. 80,000 Rwandans are in prison on suspicion of participating in the genocide; 8% are women. Violete Krasnic, of the Autonomous Women's Center Against Sexual Violence in Belgrade, spoke about the war in former Yugoslavia, which increased all forms of violence against women: 1) domestic violence, particularly in inter-ethnic marriages; 2) death threats against women (up 30-50%); 3) rape (up 30%); and 4) threats with weapons (40%). Men, upon exposure to nationalistic propaganda, used violence against their wives. Nazaneen Rasheed, a London-based representative of the Women's Union of Kurdistan, stated that women in northern Iraq had no power or land. While some turned to prostitution to survive, hundreds were killed by male relatives because of shame to the family.

  14. Semi-shunt field emission in electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Karpov, V. G., E-mail: [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Shvydka, Diana, E-mail: [Department of Radiation Oncology, University of Toledo, Toledo, Ohio 43606 (United States)


    We introduce a concept of semi-shunts representing needle shaped metallic protrusions shorter than the distance between a device electrodes. Due to the lightening rod type of field enhancement, they induce strong electron emission. We consider the corresponding signature effects in photovoltaic applications; they are: low open circuit voltages and exponentially strong random device leakiness. Comparing the proposed theory with our data for CdTe based solar cells, we conclude that stress can stimulate semi-shunts' growth making them shunting failure precursors. In the meantime, controllable semi-shunts can play a positive role mitigating the back field effects in photovoltaics.

  15. Field-emission cathode gating for rf electron guns

    Directory of Open Access Journals (Sweden)

    J. W. Lewellen


    Full Text Available We present a novel method of combining the most desirable characteristics of thermionic-cathode and photocathode rf guns, using a field-emission cathode and multiple rf frequencies. Simulations indicate that extremely low-emittance beams (on the order of 2 nm normalized emittance at moderate beam currents (1 mA and beam energies of ∼2  MeV can be obtained using this technique. The resulting gun design promises to be useful as a driver source for a number of applications, including high-voltage electron microscopy, precision electron-beam welding, and long-wavelength (THz radiation generation; we include performance calculations for the electron microscopy and precision welding applications.

  16. Field-emission cathode gating for rf electron guns (United States)

    Lewellen, J. W.; Noonan, J.


    We present a novel method of combining the most desirable characteristics of thermionic-cathode and photocathode rf guns, using a field-emission cathode and multiple rf frequencies. Simulations indicate that extremely low-emittance beams (on the order of 2 nm normalized emittance) at moderate beam currents (1 mA) and beam energies of ˜2 MeV can be obtained using this technique. The resulting gun design promises to be useful as a driver source for a number of applications, including high-voltage electron microscopy, precision electron-beam welding, and long-wavelength (THz) radiation generation; we include performance calculations for the electron microscopy and precision welding applications.

  17. Epidermal electronics with advanced capabilities in near-field communication. (United States)

    Kim, Jeonghyun; Banks, Anthony; Cheng, Huanyu; Xie, Zhaoqian; Xu, Sheng; Jang, Kyung-In; Lee, Jung Woo; Liu, Zhuangjian; Gutruf, Philipp; Huang, Xian; Wei, Pinghung; Liu, Fei; Li, Kan; Dalal, Mitul; Ghaffari, Roozbeh; Feng, Xue; Huang, Yonggang; Gupta, Sanjay; Paik, Ungyu; Rogers, John A


    Epidermal electronics with advanced capabilities in near field communications (NFC) are presented. The systems include stretchable coils and thinned NFC chips on thin, low modulus stretchable adhesives, to allow seamless, conformal contact with the skin and simultaneous capabilities for wireless interfaces to any standard, NFC-enabled smartphone, even under extreme deformation and after/during normal daily activities. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Electromagnetic field generation by ATP-induced reverse electron transfer. (United States)

    Steele, Richard H


    This paper describes a mechanism to explain low-level light emission in biology. A biological analog of the electrical circuitry, modeled on the parallel plate capacitor, traversed by a helical structure, required to generate electromagnetic radiation in the optical spectral range, is described. The charge carrier required for the emissions is determined to be an accelerating electron driven by an ATP-induced reverse electron transfer. The radial velocity component, the emission trajectory, of the moving charges traversing helical protein structures in a cyclotron-type mechanism is proposed to be imposed by the ferromagnetic field components of the iron in the iron-sulfur proteins. The redox systems NADH, riboflavin, and chlorophyll were examined with their long-wavelength absorption maxima determining the energetic parameters for the calculations. Potentials calculated from the axial velocity components for the riboflavin and NADH systems were found to equal the standard redox potentials of these systems as measured electrochemically and enzymatically. The mechanics for the three systems determined the magnetic moments, the angular momenta, and the orbital magnetic fluxes to be adiabatic invariant parameters. The De Broglie dual wave-particle equation, the fundamental equation of wave mechanics, and the key idea of quantum mechanics, establishes the wavelengths for accelerating electrons which, divided into a given radial velocity, gives its respective emission frequency. Electrons propelled through helical structures, traversed by biologically available electric and magnetic fields, make accessible to the internal environment the optical spectral frequency range that the solar spectrum provides to the external environment.

  19. Vlasov simulations of electron trapping on auroral field lines (United States)

    Gunell, H.; Mann, I.; De Keyser, J.; Andersson, L.


    In the auroral zone, electric fields that are parallel to the earth's magnetic field are known to exist and to contribute to the acceleration of auroral electrons. Transverse electric fields at high altitude result in parallel electric fields as a consequence of the closure of the field-aligned currents through the conducting ionosphere (L. R. Lyons, JGR, vol. 85, 1724, 1980). These parallel electric fields can be supported by the magnetic mirror field (Alfvén and Fälthammar, Cosmical Electrodynamics, 2nd ed., 1963). Stationary kinetic models have been used to study the current-voltage characteristics of the auroral current circuit (Knight, Planet. and Space Sci., vol. 21, 741-750, 1973). Fluid and hybrid simulations have been used to model parallel electric fields and Alfvén waves, and to study the relationship between them (e.g., Vedin and Rönnmark, JGR, vol. 111, 12201, 2006). Ergun, et al. (GRL, vol. 27, 4053-4056, 2000) found stationary Vlasov solutions over regions extending several Earth radii, and Main, et al. (PRL, vol. 97, 185001, 2006) performed Vlasov simulations of the auroral acceleration region. Observations have shown that field-aligned potential drops often are concentrated in electric double layers (e.g. Ergun, et al., Phys. Plasmas, vol. 9, 3685-3694, 2002). In the upward current region, 20-50% of the total potential drop has been identified as localised. How the rest of the potential is spread out as function of altitude is not yet known from observations. Gunell et al. (submitted to GRL, 2012) performed Vlasov simulations, using a model that is one-dimensional in configuration space and two-dimensional in velocity space, and found that about half of the potential drop is found in a thin double layer. The other half is in a region, which extends a few earth radii above it. The double layer itself is stationary, while there are oscillations in the longer low-field region. The current-voltage characteristic approximately follows the Knight

  20. Seed dressings to control slug damage in oilseed rape. (United States)

    Simms, Louise C; Mullins, Christopher E; Wilson, Michael J


    Slugs are major pests of oilseed rape that are poorly controlled by conventional bait pellets. A series of laboratory experiments investigated the potential of seed-dressings to control slug damage in this crop. Four compounds: metaldehyde, methiocarb, cinnamamide and 3,5-dimethoxycinnamic acid (DMCA) were tested at a range of doses for phytotoxicity and ability to reduce damage by Deroceras reticulatum (Müller). Metaldehyde and methiocarb were not phytotoxic at any doses, whereas all doses of cinnamamide and DMCA were. All compounds reduced slug damage, but metaldehyde and methiocarb consistently performed better than cinnamamide and DMCA. Metaldehyde and methiocarb seed-dressings were compared with baited pellets containing the same active ingredients at recommended field doses. The seed-dressings protected plants from damage by D reticulatum and Arion subfuscus (Draparnaud) as well as, or better than, baited pellets. We therefore recommend that metaldehyde and methiocarb should be field-tested as seed dressings to control slugs in oilseed rape.

  1. The Stereo Electron Spikes and the Interplanetary Magnetic Field (United States)

    Jokipii, J. R.; Sheeley, N. R., Jr.; Wang, Y. M.; Giacalone, J.


    A recent paper (Klassen etal, 2015) discussed observations of a spike event of 55-65 keV electrons which occurred very nearly simultaneously at STEREO A and STEREO B, which at the time were separated in longitude by 38 degrees. The authors associated the spikes with a flare at the Sun near the footpoint of the nominal Archimedean spiral magnetic field line passing through STEREO A. The spike at STEREO A was delayed by 2.2 minutes from that at STEREOB. We discuss the observations in terms of a model in which the electrons, accelerated at the flare, propagate without significant scattering along magnetic field lines which separate or diverge as a function of radial distance from the Sun. The near simultaneity of the spikes at the two spacecraft is a natural consequence of this model. We interpret the divergence of the magnetic field lines as a consequence of field-line random walk and flux-tube expansion. We show that the field-line random walk in the absence of flux-tube expansion produces an rms spread of field lines significantly less than that which is required to produce to observed divergence. We find that observations of the solar wind and its source region at the time of the event can account for the observations in terms of propagation along interplanetary magnetic field-lines. Klassen, A., Dresing, N., Gomez-Herrero, R, and Heber, B., A&A 580, A115 (2015) Financial support for NS and YMW was provided by NASA and CNR.

  2. Field theory of the spinning electron: I - Internal motions

    Energy Technology Data Exchange (ETDEWEB)

    Salesi, Giovanni [Universita Statale di Catania (Italy). Dipt. di Fisica; Recami, Erasmo [Universita Statale di Bergamo, Dalmine, BG (Italy). Facolta di Ingegneria]|[Universidade Estadual de Campinas, SP (Brazil). Dept. de Matematica Aplicada


    One of the most satisfactory picture of spinning particles is the Barut-Zanghi (BZ) classical theory for the relativistic electron, that relates the electron spin with the so-called Zitterbewegung (zbw). The BZ theory has been recently studied in the Lagrangian and Hamiltonian symplectic formulations, both in flat and in curved space-time. The BZ motion equations constituted the starting point for two recent works about spin and electron structure, co-authored by us, which adopted the Clifford algebra formalism. In this letter, by employing on the contrary the ordinary tensorial language, we first write down a meaningful (real) equation of motion, describing particle classical paths, quite different from the corresponding (complex) equation of the standard Dirac theory. As a consequence, we succeed in regarding the electron as an extended-type object with a classically intelligible structure (thus overcoming some long-standing, well-known problems). Second, we make explicit the kinematical properties of the 4-velocity field v{sup {mu}}, which also result to be quite different from the ordinary ones, valid for scalar particles. At last, we analyze the inner zbw motions, both time-like and light-like, as functions of the initial conditions (in particular, for the case of classical uniform motions, the z component of spin s is shown to be quantized). In so doing, we make explicit the strict correlation existing between electron polarization and zbw kinematics. (author). 9 refs.

  3. `Exotic' Electron Spectroscopy of Molecules in Electric Fields (United States)

    Pathak, Rajeev; Gurav, Nalini; Gejji, Shridhar

    Single molecules, whether polar or non-polar (in their free state), when subjected to an externally applied uniform electric field, are observed to exhibit remarkably different UV spectra from those of their zero-field counterparts. Significant spectral line-shifts, line-splitting, line-merging as well as disappearance, and emergence of `exotic' spectral lines are observed as a function of the applied electric field strength. In particular, we simulate the molecular electronic-transition spectra of methanol, hydrogen-peroxide, water and carbon-dioxide in an electric field, employing time dependent density functional theory (TD-DFT) under the versatile M06-2X dispersion-corrected DFT prescription. It is further demonstrated that the Natural Localized Molecular Orbitals (NLMOs), playing a dual donor-acceptor role, can best describe the electron density redistribution and the interplay of various bands in the UV spectrum which is traced back to mutations and crossings of the frontier molecular orbitals. We would like to thank the Center for Advanced Computing, Pune University Campus, for computer time.


    Energy Technology Data Exchange (ETDEWEB)



    It has been shown in this work that the Fourier space approach can be fruitfully applied to the calculation of the fields and the associated electron optical phase shift of several magnetic and electrostatic structures, like superconducting vortices in conventional and high-T{sub c} superconductors, reverse biased p-n junctions, magnetic domains and nanoparticles. In all these cases, this novel approach has led to unexpected but extremely interesting results, very often expressed in analytical form, which allow the quantitative and reliable interpretation of the experimental data collected by means of electron holography or of more conventional Lorentz microscopy techniques. Moreover, it is worth recalling that whenever long-range electromagnetic fields are involved, a physical model of the object under investigation is necessary in order to take into account correctly the perturbation of the reference wave induced by the tail of the field protruding into the vacuum. For these reasons, we believe that the Fourier space approach for phase computations we have introduced and discussed in this chapter will represent an invaluable tool for the investigation of electromagnetic fields at the meso- and nano-scale.

  5. Transport of solar electrons in the turbulent interplanetary magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Ablaßmayer, J.; Tautz, R. C., E-mail: [Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Hardenbergstraße 36, D-10623 Berlin (Germany); Dresing, N., E-mail: [Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Leibnizstraße 11, D-24118 Kiel (Germany)


    The turbulent transport of solar energetic electrons in the interplanetary magnetic field is investigated by means of a test-particle Monte-Carlo simulation. The magnetic fields are modeled as a combination of the Parker field and a turbulent component. In combination with the direct calculation of diffusion coefficients via the mean-square displacements, this approach allows one to analyze the effect of the initial ballistic transport phase. In that sense, the model complements the main other approach in which a transport equation is solved. The major advancement is that, by recording the flux of particles arriving at virtual detectors, intensity and anisotropy-time profiles can be obtained. Observational indications for a longitudinal asymmetry can thus be explained by tracing the diffusive spread of the particle distribution. The approach may be of future help for the systematic interpretation of observations for instance by the solar terrestrial relations observatory (STEREO) and advanced composition explorer (ACE) spacecrafts.

  6. Electronic properites of electron-doped cuprate superconductors probed by high-field magnetotransport

    Energy Technology Data Exchange (ETDEWEB)

    Helm, Toni


    In the present work the normal-state properties of the electron-doped cuprate superconductor Nd{sub 2-x}Ce{sub x}CuO{sub 4} (NCCO) are investigated for a broad doping range, covering almost the whole phase diagram of this material. Magnetotransport measurements in the world's highest non-destructive magnetic fields were used as a spectroscopic tool for probing the electronic structure of single-crystalline NCCO as a function of the carrier concentration x. Quantum and semiclassical oscillations in the magnetoresistance provided new insights into various properties of the Fermi surface and the nature of the ground state in the system. The detailed investigations of the field- and temperature-dependent transport and its dependence on the field orientation have revealed a close correlation between symmetry-breaking ordering instabilities and the superconducting state.

  7. Fear of rape from behind prison walls. (United States)

    Shermer, Lauren O'Neill; Sudo, Heather


    Purpose The Prison Rape Elimination Act has brought significant attention to the issue of sexual victimization within correctional institutions. While the actual risk of sexual victimization remains low, the perception of rape among inmates is high. Given how one's fear can translate into behavior, understanding how institutions impact the culture surrounding prison rape highlights areas for reducing violence within prisons. The paper aims to discuss these issues. Design/methodology/approach This study includes secondary analysis of a quantitative database created from semi-structured interviews with 564 high security, general population inmates. Using fear of rape as the outcome of interest, bivariate and logistic regression analyses are used to comment on the impact of individual and facility level characteristics on this outcome. Findings In general, the results from this study suggest that the greatest risk factors for fearing rape while in prison are being male, having a mental health issue, and hearing about rape within the institution. From these specific findings a few general lessons can be learned with the hope that practitioners can translate these lessons into policy initiatives in order to combat fear of rape among our inmate population. Originality/value This paper aims to fill a gap in the research on how the facility contributes to the fear of rape within prison. The end goal is to inform policy makers so that suggestions can be made to combat this problem and prevent further misconduct within these facilities.

  8. Japanese International Students' Attitudes toward Acquaintance Rape. (United States)

    Motoike, Janice; Stockdale, Margaret

    This study looked at the influence of an Asian sociocultural variable, loss of face or social integrity, as a predictor of perceptions of acquaintance rape among Japanese students. In addition to the expected associations between gender, sexism, and perceptions of rape, loss of face was predicted to interact with the perpetrator's reference group…

  9. Rape victim assessment: Findings by psychiatrists and ...

    African Journals Online (AJOL)

    valid at the lower end of the IQ range. The assessment of rape victims is a sensitive matter and poses a number of challenges to the clinician. Rape victims are often traumatised by their experience, and this can make them reluctant to talk about the incident. In a study done by Elklit et al.,[2] it was found that ~70% of sexual ...

  10. Psychobiological correlates of rape in female adolescents

    NARCIS (Netherlands)

    Bicanic, I.A.E.


    A considerable percentage of youth in the Netherlands has been victimized by rape during adolescence. The present research shows that adolescence rape is correlated with high levels of psychological distress, neurobiological dysregulations and increased risk for problems with sexual and pelvic floor

  11. Negligent Rape and Reasonable Beliefs

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg


    In every known society human sexual intercourse is enacted as a rule-bound practice that involves certain rights and obligations. In Denmark the official policy is that the rules to govern lawful sexual intercourse should be based on the idea of mutual and voluntary consent between two adults......; and as a matter of fact such rules are accepted and followed by far the most. Yet, the approach taken by Danish Criminal Law to rape does not pay heed to these rules, but is rather based on a most narrow conception of male responsibility and obligation that stands in clear opposition with practice and policy...

  12. Field Emitter Arrays for a Free Electron Laser Application

    CERN Document Server

    Shing-Bruce-Li, Kevin; Ganter, Romain; Gobrecht, Jens; Raguin, Jean Yves; Rivkin, Leonid; Wrulich, Albin F


    The development of a new electron gun with the lowest possible emittance would help reducing the total length and cost of a free electron laser. Field emitter arrays (FEAs) are an attractive technology for electron sources of ultra high brightness. Indeed, several thousands of microscopic tips can be deposited on a 1 mm diameter area. Electrons are then extracted by applying voltage to a first grid layer close to the tip apexes, the so called gate layer, and focused by a second grid layer one micrometer above the tips. The typical aperture diameter of the gate and the focusing layer is in the range of one micrometer. One challenge for such cathodes is to produce peak currents in the ampere range since the usual applications of FEAs require less than milliampere. Encouraging peak current performances have been obtained by applying voltage pulses at low frequency between gate and tips. In this paper we report on different tip materials available on the market: diamond FEAs from Extreme Devices Inc., ZrC single ...

  13. Annular dark field transmission electron microscopy for protein structure determination

    Energy Technology Data Exchange (ETDEWEB)

    Koeck, Philip J.B., E-mail:


    Recently annular dark field (ADF) transmission electron microscopy (TEM) has been advocated as a means of recording images of biological specimens with better signal to noise ratio (SNR) than regular bright field images. I investigate whether and how such images could be used to determine the three-dimensional structure of proteins given that an ADF aperture with a suitable pass-band can be manufactured and used in practice. I develop an approximate theory of ADF-TEM image formation for weak amplitude and phase objects and test this theory using computer simulations. I also test whether these simulated images can be used to calculate a three-dimensional model of the protein using standard software and discuss problems and possible ways to overcome these. - Highlights: • I present theory and simulations for imaging proteins using annular dark field transmission electron microscopy and investigate its suitability for 3D-reconstruction. • I show that the images are approximately proportional to the square of the projected electrostatic potential within a given passband ). • 3D-reconstructions show errors in the interior of the molecule. More accurate maps might be calculated by reconstruction algorithms that take into account non-linear image formation.

  14. Field electron emission from dense array of microneedles of tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, F.; Aoyagi, M.; Kitai, T.; Ishikawa, K.


    Characteristics of field electron emission from the dense array of microneedles of tungsten prepared on a tungsten filament were measured at an environmental pressure of approx.1 x 10/sup -8/ Torr (1.33 x 10/sup -6/ Pa). Electron emission was not uniform over the filament surface, but the variation of emission current with applied voltage explicitly obeyed the Fowler-Nordheim relationship. At an emission current of approx.10/sup -4/ A, a vacuum arc was induced that led to a permanent change in current-voltage characteristic. Current fluctuation was dependent on emitter temperature and applied voltage, and the lowest fluctuation of about 4% was routinely obtained at approx.550 K and at applied voltages several percent lower than the arc-inducing voltage. Macroscopic current density amounted to approx.20-80 mA/cm/sup 2/ at the best stability.

  15. Electric field gradient and electronic properties of crown thioether compounds

    Energy Technology Data Exchange (ETDEWEB)

    Camargo Dalmatti Alves Lima, Filipe, E-mail:; Rodrigues do Nascimento, Rafael; Brown Goncalves, Marcos [Universidade de Sao Paulo, Instituto de Fisica (Brazil); Cottenier, Stefaan [Ghent University, Center for Molecular Modeling (Belgium); Caldas, Marilia Junqueira; Petrilli, Helena Maria [Universidade de Sao Paulo, Instituto de Fisica (Brazil)


    We compare published TDPAC experiments on {sup 111}Cd in the crown thioether C{sub 6}H{sub 12}S{sub 3}AgCl with ab-initio electronic structure calculations performed within the framework of the Density Functional Theory using the Projector Augmented Wave method. We conclude from this comparison that the Cd atom at the very moment of the TDPAC experiment is positively charged, and we point out to a methodological difference between reproducing experimental electric-field gradients in molecules versus solid metals.

  16. Wild pollinators enhance oilseed rape yield in small-holder farming systems in China. (United States)

    Zou, Yi; Xiao, Haijun; Bianchi, Felix J J A; Jauker, Frank; Luo, Shudong; van der Werf, Wopke


    Insect pollinators play an important role in crop pollination, but the relative contribution of wild pollinators and honey bees to pollination is currently under debate. There is virtually no information available on the strength of pollination services and the identity of pollination service providers from Asian smallholder farming systems, where fields are small, and variation among fields is high. We established 18 winter oilseed rape (Brassica napus L.) fields along a large geographical gradient in Jiangxi province in China. In each field, oilseed rape plants were grown in closed cages that excluded pollinators and open cages that allowed pollinator access. The pollinator community was sampled by pan traps for the entire oilseed rape blooming period. Oilseed rape plants from which insect pollinators were excluded had on average 38% lower seed set, 17% lower fruit set and 12% lower yield per plant, but the seeds were 17% heavier, and the caged plants had 28% more flowers and 18% higher aboveground vegetative biomass than plants with pollinator access. Oilseed rape plants thus compensate for pollination deficit by producing heavier seeds and more flowers. Regression analysis indicated that local abundance and diversity of wild pollinators were positively associated with seed set and yield/straw ratio, while honey bee abundance was not related to yield parameters. Wild pollinator abundance and diversity contribute to oilseed rape yield by enhancing plant resource allocation to seeds rather than to above-ground biomass. This study highlights the importance of the conservation of wild pollinators to support oilseed rape production in small-holder farming systems in China.

  17. Vlasov simulations of electron hole dynamics in inhomogeneous magnetic field (United States)

    Kuzichev, Ilya; Vasko, Ivan; Agapitov, Oleksiy; Mozer, Forrest; Artemyev, Anton


    Electron holes (EHs) or phase space vortices are solitary electrostatic waves existing due to electrons trapped within EH electrostatic potential. Since the first direct observation [1], EHs have been widely observed in the Earth's magnetosphere: in reconnecting current sheets [2], injection fronts [3], auroral region [4], and many other space plasma systems. EHs have typical spatial scales up to tens of Debye lengths, electric field amplitudes up to hundreds of mV/m and propagate along magnetic field lines with velocities of about electron thermal velocity [5]. The role of EHs in energy dissipation and supporting of large-scale potential drops is under active investigation. The accurate interpretation of spacecraft observations requires understanding of EH evolution in inhomogeneous plasma. The critical role of plasma density gradients in EH evolution was demonstrated in [6] using PIC simulations. Interestingly, up to date no studies have addressed a role of magnetic field gradients in EH evolution. In this report, we use 1.5D gyrokinetic Vlasov code to demonstrate the critical role of magnetic field gradients in EH dynamics. We show that EHs propagating into stronger (weaker) magnetic field are decelerated (accelerated) with deceleration (acceleration) rate dependent on the magnetic field gradient. Remarkably, the reflection points of decelerating EHs are independent of the average magnetic field gradient in the system and depend only on the EH parameters. EHs are decelerated (accelerated) faster than would follow from the "quasi-particle" concept assuming that EH is decelerated (accelerated) entirely due to the mirror force acting on electrons trapped within EH. We demonstrate that EH propagation in inhomogeneous magnetic fields results in development of a net potential drop along an EH, which depends on the magnetic field gradient. The revealed features will be helpful for interpreting spacecraft observations and results of advanced particle simulations. In

  18. Acute stress among adolescents and female rape victims measured by ASC-Kids: a pilot study. (United States)

    Nilsson, Doris; Nordenstam, Carin; Green, Sara; Wetterhall, Annika; Lundin, Tom; Svedin, Carl Göran


    Rape is considered a stressful trauma and often with durable consequences. How the aftermath of rape is for young adolescents' girls considering acute stress is an overlooked field and remains to be studied. In this study, we wanted to investigate acute stress among adolescent victims of rape and the psychometric properties of the Acute Stress Checklist for Children (ASC-Kids). A clinical sample (n = 79) of raped girls, 13-17 years old who had turned to a special rape victim unit for treatment, answered the ASC-Kids. ASC-Kids was also given to a group of minor stressed, non-raped adolescents in the same age range (n = 154) together with the University of California at Los Angeles Post-traumatic Stress Disorder Reaction Index (UCLA PTSD RI), and the Sense of Coherence Scale 13 (SOC-13). The scores from the groups were compared and showed significant differences in mean values on all the diagnostic criteria of acute stress disorder. In the clinical group, 36.7% obtained full ASD criteria. ASC-Kids could discriminate well between groups. Cronbach's alpha was found to be excellent, and the correlation between the UCLA PTSD RI and ASC-Kids found to be good; both ASC-Kids and UCLA PTSD RI had a good and moderate negative correlation with SOC-13. Adolescent female rape victims were shown to have a very high level of acute stress, and the ASC-Kids was found to have sound psychometrics and can be a valuable screening instrument to support clinicians in their assessments of an indication of adolescents after potentially stressful events such as rape.

  19. Mapping of QTL for seed dormancy in a winter oilseed rape doubled haploid population. (United States)

    Schatzki, Jörg; Schoo, Burkhard; Ecke, Wolfgang; Herrfurth, Cornelia; Feussner, Ivo; Becker, Heiko C; Möllers, Christian


    Following winter oilseed rape cultivation, considerable numbers of volunteer oilseed rape plants may occur in subsequent years in following crops. The appearance of volunteer oilseed rape plants is based on the capability of the seeds to become secondary dormant and to survive in this stage for many years in the soil. Genetic reduction of secondary seed dormancy in oilseed rape could provide a means to reduce the frequency of volunteer plants and especially the dispersal of transgenic oilseed rape. The objective of the present study was to analyse the inheritance of primary and secondary seed dormancy in a winter oilseed rape doubled haploid population derived from the cross Express 617 × R53 and to study correlations to other seed traits. Field experiments were performed in Germany for 2 years at two locations with two replicates. Seeds harvested from open pollinated plants were used for all analyses, including a laboratory test for seed dormancy. A previously developed molecular marker map of the doubled haploid population was used to map QTL of the relevant traits. For primary, secondary and total seed dormancy, the results showed significant effects of the genotypes and their interactions, with years and locations. Two, four and five QTL were detected for primary, secondary and total seed dormancy which explained 19, 35 and 42 % of the phenotypic variance, respectively. Results show that secondary seed dormancy is a heritable trait and that selection for low secondary seed dormancy is possible.

  20. Transfer Assessment of Carbendazim Residues from Rape Flowers to Apicultural Products

    Directory of Open Access Journals (Sweden)

    Ying-Hong Li


    Full Text Available Carbendazim is usually used to control the Sclerotinia sclerotiorum of rapes during the flowering period. This paper presents a study on transfer assessment of carbendazim residues from rape flowers to apicultural products. In the field trials, the rapes were sprayed with carbendazim on standard dosage. Bees produced apicultural products (bee pollen, honey, and royal jelly from sprayed rapes. Apicultural products were collected on a regular basis. Carbendazim residues were extracted from bee pollen, honey, and royal jelly, respectively. HPLC/ESI-MS/MS method was developed and partially validated to identify and quantify carbendazim residues. The limits of quantification in pollen, honey, and royal jelly were 0.01 mg/kg. Mathematical curve fitting was carried out on the basis of transfer assessment of carbendazim residues from rape flowers to apicultural products. The respective carbendazim residues were 1.10±0.03 mg/kg in pollen on 18th day, 0.032±0.001 mg/kg in honey on 24th day, and 0.077±0.002 mg/kg in royal jelly on 22nd day. Transfer assessment and mathematical curve fitting of carbendazim residues from rape flowers to apicultural products show carbendazim diminished over spraying time. The gap of carbendazim residues between pollen and honey is decreased with time. The carbendazim residues in pollen are 10 times higher than that of honey and jelly.

  1. Controlling electron-electron correlation in frustrated double ionization of triatomic molecules with orthogonally polarized two-color laser fields (United States)

    Chen, A.; Kling, M. F.; Emmanouilidou, A.


    We demonstrate the control of electron-electron correlation in frustrated double ionization (FDI) of the two-electron triatomic molecule D3 + when driven by two orthogonally polarized two-color laser fields. We employ a three-dimensional semiclassical model that fully accounts for the electron and nuclear motion in strong fields. We analyze the FDI probability and the distribution of the momentum of the escaping electron along the polarization direction of the longer wavelength and more intense laser field. These observables, when considered in conjunction, bear clear signatures of the prevalence or absence of electron-electron correlation in FDI, depending on the time delay between the two laser pulses. We find that D3 + is a better candidate than H2 for demonstrating also experimentally that electron-electron correlation indeed underlies FDI.

  2. Present and future instances of virtual rape in light of three categories of legal philosophical theories on rape

    NARCIS (Netherlands)

    Strikwerda, Litska


    This paper is about the question of whether or not virtual rape should be considered a crime under current law. A virtual rape is the rape of an avatar (a person’s virtual representation) in a virtual world. In the future, possibilities for virtual rape of a person him- or herself will arise in

  3. Electron acceleration by laser fields in a gas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, J.R.


    The purpose of the project is an investigation of topics related to the high-energy acceleration of electrons by means of suitably shaped laser beams in an inert gaseous medium. By slowing down the phase velocity of the fields by its index of refraction, the gas allows a cumulative interaction with the electrons resulting in net acceleration and also focusing. The objectives of the work reported here were twofold: (1) to participate as a consultant in the design and analysis of demonstration experiments performed at the Brookhaven National Laboratory by STI Optronics, a Belleview, WA company, under a separate DOE funded contract; (2) to perform further analytic and design work on the laser acceleration scheme originally proposed and explore a possible extension of the method to acceleration in vacuum using the same field configuration and analogous interaction process as with a gas. This report thus comprises an account of both activities. Section 2 is an overview of the various laser acceleration methods that have been proposed, in order to provide a framework to the work reported. Section 3 contains a list of meetings attended by the Principal Investigator to present his work and interact with research community colleagues and STI staff, and a list of publications containing work he co-authored or was acknowledged for. Section 4 summarizes the work performed by STI to which he contributed. Section 5 consists of the technical reports the Principal Investigator wrote describing his independent theoretical work elaborating and extending the scope of the original project.

  4. Male rape--the silent victims. (United States)

    Ellis, Colin Derek


    This literature review examines the issue of male rape and the possible counselling strategies that may assist in recovery. There are several misconceptions surrounding male rape which can result in the under-reporting and secondary or sanctuary victimisation of the survivor. Men who have been raped may believe that it attacks the very essence of what it is to be masculine and male. Many may not seek help unless they perceive a need for immediate attention, such as physical trauma requiring medical assistance. The literature also reveals that when men do seek help they may be treated poorly. Secondary victimisation or sanctuary trauma results when there is a lack of empathy and understanding of the effect that rape can have on the survivor, such as rape-trauma syndrome. Training in this area is needed for the police, emergency department staff, nurses, general practitioners, and community health services. Management of survivors starts with examining our own beliefs about male rape. Many of the reported counselling strategies are based on therapists' observations, trauma theories, and research related to child abuse or sexual assault of females which may not be transferable to men who have been raped. Education and counselling of survivors' support networks must be considered as part of a holistic approach to management. Secondary prevention strategies aimed at the broader community are required to assist survivors to come forward without fear of further victimisation because of stereotyping.

  5. Spousal rape: A challenge for pastoral counsellors

    Directory of Open Access Journals (Sweden)

    James A. Glanville


    Full Text Available This article reflects on the criticism regarding the pastoral counsellor’s dealings with spousal rape victims. It argues that counsellors should be sensitive not to be biased, either personally or theologically, and should have an understanding of the biopsychosocial (biological, psychological and social impact of spousal rape, such as rape-related post-traumatic stress and other related illnesses such as depression, victimisation and stigmatisation. The pastoral counsellors should be aware of the legal and medical ramifications of spousal rape and have knowledge of the correct referral resources and procedures (trusted professionals, shelters and support structures. They should be self-aware and understand the effect that gender or previous traumatic personal experiences may have on their reactions. The article consists of the following sections: the phenomenon ‘rape’; acquaintance rape; spousal rape; post-traumatic stress; post-traumatic stress disorder; rape trauma syndrome; cognitive behavioural therapy; spirituality; doctrinal matters; social system of patriarchy; a pastoral counselling model; self-care.

  6. Understanding Attribution of Blame in Cases of Rape: An Analysis of Participant Gender, Type of Rape and Perceived Similarity to the Victim (United States)

    Grubb, Amy Rose; Harrower, Julie


    This study examined a variety of factors that may influence attributions towards rape victims. A total of 156 participants completed a questionnaire, which included a measure of attitudes towards rape victims and a vignette depicting one of three rape scenarios (a stranger rape, date rape and seduction rape). Participants rated the extent to which…

  7. Emergent Gauge Fields and Their Nonperturbative Effects in Correlated Electrons (United States)

    Kim, Ki-Seok; Tanaka, Akihiro

    The history of modern condensed matter physics may be regarded as the competition and reconciliation between Stoner's and Anderson's physical pictures, where the former is based on momentum-space descriptions focusing on long wave-length fluctuations while the latter is based on real-space physics emphasizing emergent localized excitations. In particular, these two view points compete with each other in various nonperturbative phenomena, which range from the problem of high Tc superconductivity, quantum spin liquids in organic materials and frustrated spin systems, heavy-fermion quantum criticality, metal-insulator transitions in correlated electron systems such as doped silicons and two-dimensional electron systems, the fractional quantum Hall effect, to the recently discussed Fe-based superconductors. An approach to reconcile these competing frameworks is to introduce topologically nontrivial excitations into the Stoner's description, which appear to be localized in either space or time and sometimes both, where scattering between itinerant electrons and topological excitations such as skyrmions, vortices, various forms of instantons, emergent magnetic monopoles, and etc. may catch nonperturbative local physics beyond the Stoner's paradigm. In this review article we discuss nonperturbative effects of topological excitations on dynamics of correlated electrons. First, we focus on the problem of scattering between itinerant fermions and topological excitations in antiferromagnetic doped Mott insulators, expected to be relevant for the pseudogap phase of high Tc cuprates. We propose that nonperturbative effects of topological excitations can be incorporated within the perturbative framework, where an enhanced global symmetry with a topological term plays an essential role. In the second part, we go on to discuss the subject of symmetry protected topological states in a largely similar light. While we do not introduce itinerant fermions here, the nonperturbative

  8. Advances in electron dosimetry of irregular fields; Avances en dosimetria de electrones de campos irregulares

    Energy Technology Data Exchange (ETDEWEB)

    Mendez V, J. [Departamento de Radioterapia, Instituto de Enfermedades Neoplasicas, Avenida Angamos Este 2520, Lima 34 (Peru)


    In this work it is presented an advance in Electron dosimetry of irregular fields for beams emitted by linear accelerators. At present diverse methods exist which are coming to apply in the Radiotherapy centers. In this work it is proposed a method for irregular fields dosimetry. It will be allow to calculate the dose rate absorbed required for evaluating the time for the treatment of cancer patients. Utilizing the results obtained by the dosimetric system, it has been possible to prove the validity of the method describe for 12 MeV energy and for square field 7.5 x 7.5 cm{sup 2} with percentile error less than 1 % . (Author)

  9. Electron transport in carbon tetrafluoride along a magnetically neutral plane between constant gradient antiparallel magnetic fields


    Sugawara, Hirotake; Sakai, Yosuke


    Electron motion in CF4 at 0.67 Pa under crossed electric (E) and magnetic (B) fields was simulated by a Monte Carlo method to investigate fundamental properties of electron transport in neutral loop discharge plasmas for dry etching. As a simplified model of the electron path in the plasma, a magnetically neutral plane was assumed between linearly gradient antiparallel B fields, and a uniform E field was applied along the neutral plane perpendicularly to the B fields. The electron behavio...

  10. Conversion of output factor from square field into rectangular field in electron beam

    CERN Document Server

    Wang Jian Hua; Xu Yi Fei


    Objective: A simple and accurate calculation method was designed to convert output factor from square field into rectangular field in electron beam, which can be easily implemented in clinical practice. Methods: 6, 12, 15 MeV electron beam, field size 6.0 cm x 7.5 cm, 5.0 cm x 10.0 cm, 6.0 cm x 12.0 cm, TL3000C dosimeter and source-to-surface distance method were used in dose measurement. The measured dose values were compared with the calculated ones from three theoretical equations with the conformation evaluated. Results: The calculated dose values from three theoretical equations differed from the measured ones by 0.23%, 1.30% and 1.10% (6 MeV), 0.63%, 0.90% and 0.73% (12 MeV), 0.50%, 1.80% and 3.40% (15 MeV), conforming best to the equation OUF (X, Y)=[OUF(X,X). OUF(Y,Y)] sup 1 sup / sup 2. When the size of the field was longer than Rp, the difference between the calculated values and measured ones was relatively very small. Conclusions: The output factor in rectangular fields can be accurately calculate...

  11. Radiocaesium activity in rape oil and in rape cake after a wet deposition event

    Energy Technology Data Exchange (ETDEWEB)

    Chaiko, Y.; Rappe-George, M.; Bengtsson, S. [Department of Soil and Environment (Sweden)


    After a release of radionuclides in agricultural areas there can be concerns on the levels of radionuclides in food products produced. The uptake of radionuclides via the above ground plant parts is a very important transport route into the food chain for humans as caesium is relatively mobile inside plants. In the production of rape oil the use of a processing factor (Pf) is used to estimate the activity concentration of radioactivity in the final oil product based on the activity concentration in rape seeds. The processing factor has been estimated to be 0.004 for caesium in rape oil by IAEA, and is based on a limited numbers of studies (1). In this project we analysed the activity concentration of radiocaesium ({sup 134}Cs) in rape oil and in rape cake from rape seeds contaminated after a wet deposition event with {sup 134}Cs. With the information of activity concentration of {sup 134}Cs in rape oil and in rape cake, we calculated the Pf-value and confirm or suggest new enhanced Pf-value. We analysed the activity concentration of {sup 134}Cs in rape oil and in rape cake from spring oilseed rape seeds (Brassica napus L.) that had been contaminated experimentally by wet deposited {sup 134}Cs in an earlier experiment by Bengtsson et al. (2013). The estimation of activity concentration of {sup 134}Cs in rape oil and in rape cake was achieved by performing extraction of the oil (and other extractable compounds) from the seeds based on the Randall extraction method (Randall, 1974) using petroleum ether as extraction chemical. The extracted oil and the rape cake samples were weighed and the activity concentration was measured with High-Purity Germanium (HPGe) detectors. Pf-values were calculated by dividing the measured activity concentration in rape oil after extraction by the activity concentration in oilseed rape seeds before extraction. Results from the present study will be presented at the international conference on radioecology and environmental radioactivity

  12. What is a typical rape? Effects of victim and participant gender in female and male rape perception. (United States)

    Anderson, Irina


    The study had three research aims: (1) to examine the current perception of female rape. Given recent changes in public awareness of female rape, it was predicted that respondents would conceptualize a typical female rape as an acquaintance rape rather than as the stranger rape stereotype; (2) to examine whether these perceptions differ according to respondents' gender; (3) to examine the 'cultural lag' theory of male rape, where it was hypothesized that if the public perception of male rape lags behind female rape, then a typical male rape will be conceptualized as the classic stranger rape stereotype. Findings showed that contrary to predictions, a typical female rape was conceptualized according to the stranger rape stereotype. It was also found that instead of lagging behind female rape along the stranger-acquaintance rape dimension, male rape was viewed predominantly in terms of 'other' factors (factors not found on the stranger-acquaintance dimension, e.g. victim/rapist sexual orientation, rapist calls victim names), which were erroneous, sexualizing and homophobic.

  13. ASD and PTSD in Rape Victims

    DEFF Research Database (Denmark)

    Elklit, Ask; Christiansen, Dorte M


    In recent years, a number of studies have investigated the prediction of posttraumatic stress disorder (PTSD) through the presence of acute stress disorder (ASD). The predictive power of ASD on PTSD was examined in a population of 148 female rape victims who visited a center for rape victims...... shortly after the rape or attempted rape. The PTSD diagnosis based solely on the three core symptom clusters was best identified by a subclinical ASD diagnosis based on all ASD criteria except dissociation. However, a full PTSD diagnosis including the A2 and F criteria was best identified by classifying...... victims according to a full ASD diagnosis. Regardless of whether cases were classified according to full PTSD status or according to meeting the criteria for the three PTSD core symptom clusters, the classification was correct only in approximately two thirds of the cases. A regression analysis based...

  14. Components of a rice-oilseed rape production system augmented with trichoderma sp. Tri-1 control sclerotinia sclerotiorum on oilseed rape (United States)

    Sclerotinia sclerotiorum causes serious yield losses on many crops throughout the world. In two field trials conducted at the same location in consecutive years, a treatment containing formulated Trichoderma harzianum-1 (Tri-1) resulted in oilseed rape seed yield that was significantly greater than...

  15. Understanding rape perpetration in South Africa

    African Journals Online (AJOL)

    a child. <15. Raped in the last. 12 months. Raped a man. SA Crime Quarterly no 34 • December 2010. 25 woman or girl when she didn't consent to sex or after you .... Secondary schooling. 26.7. 22.7, 30.7. 182 / 682. Matric complete. 28.9. 24.2, 33.5. 130/ 450. Incomplete tertiary education. 38.8. 30.4, 47.2. 57 / 147. Degree.

  16. Clubroot – An Emerging Disease Faced by Czech Oilseed Rape Growers

    Directory of Open Access Journals (Sweden)

    Řičařová V.


    Full Text Available Clubroot is caused by the pathogen Plasmodiophora brassicae Woronin and has become a serious problem in oilseed rape production in the Czech Republic. The disease was previously widespread in commercial vegetable production and in hobby gardens. Whereas previously restricted only to the NE, since 2010 oilseed rape clubroot has been spreading across the whole country. A five-year monitoring of clubroot occurrence based on disease symptoms detection on oilseed rape fields was accomplished by the Union of Oilseed Growers and Processors. The presence of P. brassicae and clubroot symptoms was reported in all regions of the Czech Republic, except the Ústecký region, and in 31 out of 76 districts. At present, at least 130 fields are known to be infested by the pathogen, but this number is very likely underestimated. Some soil samples were also tested using the conventional polymerase chain reaction (PCR method to evaluate the soil usability. All 14 suspected samples tested positive.

  17. Populations of selected microbial and fungal species growing on the surface of rape seeds following treatment with desiccants or plant growth regulators. (United States)

    Frac, Magdalena; Jezierska-Tys, Stefania; Tys, Jerzy


    The aim of this study was to determine the effects of desiccants and plant growth regulators on selected microbial species affecting rape seeds, with special emphasis on the growth of fungi and identification of the genus and species composition. The experimental material in the study was seeds of winter rape cv. Californium that were collected from the field during combine harvest. The chemical agents applied, both desiccants and growth regulators, generally decreased the populations of bacteria occurring on the surface of rape seeds. The responses of fungi depended upon the type of agent applied and were manifested as either stimulation or inhibition of the growth of the fungal species. The fungi isolated from the surface of rape seeds were characteristic of those found in the field environment (Cladosporium and Penicillium) and typical for those present on the surface of rape seeds (Alternaria).

  18. Sensitization to turnip rape and oilseed rape in children with atopic dermatitis: a case-control study. (United States)

    Poikonen, Sanna; Puumalainen, Tuija J; Kautiainen, Hannu; Palosuo, Timo; Reunala, Timo; Turjanmaa, Kristiina


    Turnip rape and oilseed rape 2S albumins are new allergens in children with atopic dermatitis suspected for food allergy. We recently found that 11% (206/1887) of these children had a positive skin prick test to seeds of oilseed rape (Brassica napus) and/or turnip rape (Brassica rapa). In the present case-control study we examined how the children with atopic dermatitis sensitized to turnip rape and oilseed rape had been breast-fed and whether they had some common sensitization pattern to certain foods or pollens. A total of 64 children with atopic dermatitis and a positive skin prick test to turnip rape and/or oilseed rape (>or=5 mm) were examined. Sixty-four age- and sex-matched children with atopic dermatitis but negative skin prick tests to turnip rape and oilseed rape served as case controls. The turnip rape and/or oilseed rape sensitized children with atopic dermatitis had significantly more often positive skin prick tests reactions and IgE antibodies to various foods (cow's milk, egg, wheat, mustard; p children. They had been exclusively breast-fed for a longer period (median 4 months; p Children with atopic dermatitis sensitized to oilseed rape and turnip rape had high frequency of associated sensitizations to all foods and pollens tested showing that oilseed plant sensitization affects especially atopic children who have been sensitized to multiple allergens.

  19. Taking About Rape-and Why it Matters: Adjudicating rape in the ...

    African Journals Online (AJOL)

    ... begins by establishing why judgements are an important source for understanding what rape means in society at large; it then discusses the relationship between power, language, and the law. This is followed by specific analyses of cases that show how patriarchy still defines how judges express themselves about rape.

  20. Ethanol production from rape straw: Part of an oilseed rape biorefinery

    DEFF Research Database (Denmark)

    Arvaniti, Efthalia

    The aim of this study was 1) present an oilseed rape whole crop biorefinery; 2) to investigate the best available experimental conditions for production of cellulosic ethanol from rape straw, and included the processes of thermo-chemical pretreatment, enzymatic hydrolysis, and C6 fermentation......, and 3) to couple cellulosic ethanol production to production of cellulolytic enzymes that are needed for cellulosic ethanol production, inside a rape straw biorefinery. For the first is based less on available experiments, and more on literature review. The second and third study conclusions were drawn...... rapeseed biodiesel plant of Europe to an oilseed rape whole-crop biorefinery by 2020 is envisioned and discussed. The description and discussion of this biorefinery is based partly on literature review, and partly on own experimental data, especially on pretreatment of rape straw, and production...

  1. Exploring rape myths, gendered norms, group processing, and the social context of rape among college women: a qualitative analysis. (United States)

    Deming, Michelle E; Covan, Eleanor Krassen; Swan, Suzanne C; Billings, Deborah L


    The purpose of this research is to explore the negotiation strategies of college women as they interpret ambiguous rape scenarios. In focus groups, 1st- and 4th-year college women were presented with a series of three vignettes depicting incidents that meet the legal criteria for rape yet are ambiguous due to the presence of cultural rape myths, contexts involving alcohol consumption, varying degrees of consent, and a known perpetrator. These contexts are critical in understanding how college women define rape. Key findings indicated many of these college women utilized rape myths and norms within their peer groups to interpret rape scenarios.

  2. Space-Time mapping of terahertz-induced electron field emission

    DEFF Research Database (Denmark)

    Lange, Simon Lehnskov; Kristensen, Thea M. B.; Iwaszczuk, Krzysztof


    We present simulations and experiments showing how THz induced electron field emission from gold antennas can be mapped indirectly in space and time. Our simulations predict the spatiotemporal electron distribution after single-cycle THz-induced field emission. Two different experiments validate...... this through a time-accumulated, spatial electron mapping due to both short- and long-time irradiation with THz transients....

  3. Field emission from individual multiwalled carbon nanotubes prepared in an electron microscope

    NARCIS (Netherlands)

    de Jonge, N.; van Druten, N.J.


    Individual multiwalled carbon nanotube field emitters were prepared in a scanning electron microscope. The angular current density, energy spectra, and the emission stability of the field-emitted electrons were measured. An estimate of the electron source brightness was extracted from the

  4. The use of Pseudomonas fluorescens P13 to control sclerotinia stem rot (Sclerotinia sclerotiorum) of oilseed rape. (United States)

    Li, Hui; Li, Huaibo; Bai, Yan; Wang, Jing; Nie, Ming; Li, Bo; Xiao, Ming


    Sclerotinia stem rot (SSR) caused by the fungus Sclerotinia sclerotiorum has been an increasing threat to oilseed rape (Brassica napus L.) cultivation. Efficient and environment-friendly treatments are much needed. Here we focus on microbial control. The Pseudomonas fluorescens P13 that was isolated from oilseed rape cultivation soil, proved to be a useful biocontrol strain for application. Morphology, physiological and biochemical tests and 16S rDNA analysis demonstrated that it was P. fluorescens P13 and that it had a broad antagonistic spectrum, significantly lessening the mycelial growth of S. sclerotiorum by 84.4% and suppressing sclerotial formation by 95-100%. Scanning electron microscopy studies attested that P13 deformed S. sclerotiorum mycelia when they were cultured together. P13 did not produce chitinase but did produce hydrogen cyanide (HCN) which was likely one of the antagonistic mechanisms. The density of P13 remained at a high level (≥10(6) CFU/ml) during 5 weeks in the rhizosphere soil and roots. P13 reduced SSR severity at least by 59% in field studies and also promoted seedling growth (psclerotiorum.

  5. Electronic Model of a Ferroelectric Field Effect Transistor (United States)

    MacLeod, Todd C.; Ho, Fat Duen; Russell, Larry (Technical Monitor)


    A pair of electronic models has been developed of a Ferroelectric Field Effect transistor. These models can be used in standard electrical circuit simulation programs to simulate the main characteristics of the FFET. The models use the Schmitt trigger circuit as a basis for their design. One model uses bipolar junction transistors and one uses MOSFET's. Each model has the main characteristics of the FFET, which are the current hysterisis with different gate voltages and decay of the drain current when the gate voltage is off. The drain current from each model has similar values to an actual FFET that was measured experimentally. T'he input and o Output resistance in the models are also similar to that of the FFET. The models are valid for all frequencies below RF levels. No attempt was made to model the high frequency characteristics of the FFET. Each model can be used to design circuits using FFET's with standard electrical simulation packages. These circuits can be used in designing non-volatile memory circuits and logic circuits and is compatible with all SPICE based circuit analysis programs. The models consist of only standard electrical components, such as BJT's, MOSFET's, diodes, resistors, and capacitors. Each model is compared to the experimental data measured from an actual FFET.

  6. Researches of Optimum Leaf Area Index Dynamicmodels for Rape(brassica Napus L.) (United States)

    Cao, Hongxin; Zhang, Chunlei; Li, Guangming; Zhang, Baojun; Zhao, Suolao; Wang, Baoqing; Jin, Zhiqing; Zhu, Dawei; Zhu, Juanjuan; Wei, Xiufang

    The objectives of developing optimum leaf area index dynamic models for rape (OLAIDM) was to develop Rape Cultivation Simulation-Optimization- Decision Making System(Rape-CSODS) , to design its planting , to regulate and control its growth and development, and to fulfill its high yield, good quality, high benefits and standard production eventually. The OLAIDM were developed based on field experiments with 3 cultivars, 6 sowing dates, 2 types of plant pattern and 4 sites from 2002 to 2007 in middle and lower valley of Yangtze river in China and relative data from references of rape researches, employed ideas of R/WCSODS (Rice/Wheat Cultivation Simulation- Optimization-Decision Making System), and in the same time, the OLAIMR and its parameters also were assessed, calibrated and tested. The average absolute deviation(de), correlation coefficients(r) and the standard errors of their absolute deviation(Sde) of between the observed and simulated values for LAI of two cultivars in Wuhan and Nanjing were -0.03~0.1533, 0.9707~0.9997 and0.1332~0.4032, respectively. 1:1 line of them were in Fig. 1 to 4. Multi-factors such as the ramification types, cultivars, and light et al. were taken into account in this study, therefore, the OLAIDM with general adaptability, clear yield aim, mechanism, and dynamic characteristic can simulate optimum LAI dynamic for rape under different sites, cultivars and ramification types, and yielding levels.


    African Journals Online (AJOL)

    A REVIEW OF LITERATURE: RAPE AND COMMUNICATION MEDIA. STRATEGIES IN NIGERIA. *Omolola Tosan AKINWOLE. **Osakue Stevenson OMOERA. Abstract. Using historical-analytic methodology, this article reviews literature on rape and the ... The third assumption is the linguistic representation postulation. This.

  8. Gate induced superconductivity in layered material based electronic double layer field effect transistors

    NARCIS (Netherlands)

    Ye, J. T.; Inoue, S.; Kobayashi, K.; Kasahara, Y.; Yuan, H. T.; Shimotani, H.; Iwasa, Y.


    Applying the principle of field effect transistor to layered materials provides new opportunities to manipulate their electronic properties for interesting sciences and applications. Novel gate dielectrics like electronic double layer (EDL) formed by ionic liquids are demonstrated to achieve an

  9. Shortening of the development cycle in winter rape (Brassica napus var. oleifera L. by grafting nonvernalized scions on generative stock

    Directory of Open Access Journals (Sweden)

    Franciszek Dubert


    Full Text Available The conditions were investigated under which the development cycle in winter rape could be markedly reduced by grafting. Scions from non vernalized seedlings were grafted onto stock plants beginning their generative phase. Winter rape plants vernalized under natural field conditions and spring rape plants in the initial generative phase were used as stock. Best results were obtained by grafting scions from plants at the stage of 4 leaves, i.e. after 3 weeks of growth, onto winter rape stock. With such scions the effectiveness of graftings was high and seed crops were obtained 170 days earlier than under natural field conditions of growth and 80 days earlier than under artificial conditions. Scions grafted onto winter rape stock produced more siliques than those on spring rape. Grafting of scions after cutting off their apical meristems allowed formation of side shoots and consequently resulted in higher yields of siliques; the formation of siliques, however, was delayed by about 10 days as compared to grafts with apical meristems.

  10. Thermal electron acceleration by localized bursts of electric field in the radiation belts (United States)

    Artemyev, A. V.; Agapitov, O. V.; Mozer, F.; Krasnoselskikh, V.


    In this paper we investigate the resonant interaction of thermal ˜10-100 eV electrons with a burst of electrostatic field that results in electron acceleration to kilovolt energies. This single burst contains a large parallel electric field of one sign and a much smaller, longer-lasting parallel field of the opposite sign. The Van Allen Probe spacecraft often observes clusters of spatially localized bursts in the Earth's outer radiation belts. These structures propagate mostly away from the geomagnetic equator and share properties of soliton-like nonlinear electron acoustic waves: a velocity of propagation is about the thermal velocity of cold electrons (˜3000-10,000 km/s), and a spatial scale of electric field localization along the field lines is about the Debye radius of hot electrons (˜5-30 km). We model the nonlinear resonant interaction of these electric field structures and cold background electrons.

  11. Religious Affiliation, Religiosity, Gender, and Rape Myth Acceptance: Feminist Theory and Rape Culture. (United States)

    Barnett, Michael D; Sligar, Kylie B; Wang, Chiachih D C


    Rape myths are false beliefs about rape, rape victims, and rapists, often prejudicial and stereotypical. Guided by feminist theory and available empirical research, this study aimed to examine the influences of gender, religious affiliation, and religiosity on rape myth acceptance of U.S. emerging adults. A sample of 653 university students aged 18 to 30 years were recruited from a large public university in the southern United States to complete the research questionnaires. Results indicated that individuals who identified as Roman Catholic or Protestant endorsed higher levels of rape myth acceptance than their atheist or agnostic counterparts. Men were found more likely to ascribe to rape myths than their female counterparts. Religiosity was positively associated with rape myth acceptance, even after controlling the effect of conservative political ideology. No significant interaction was found between gender and religious affiliation or gender and religiosity. Limitations, future research directions, and implications of the findings are discussed from the perspective of feminist theory. © The Author(s) 2016.

  12. Second-order Dirac equation of graphene electrons in an electromagnetic field and their novel spin


    Luo, Ji


    The second-order Dirac equation (DE) and its velocity operator of graphene electrons in an electromagnetic field are obtained according to tight-binding k.p method. With extra terms included, they demonstrate the motion of graphene electrons more completely through a more complete Ehrenfest theorem and present finer properties of graphene electrons. Eigen-energy given by the second-order DE for field-free graphene indicates that extra terms may affect the trembling motion of graphene electron...

  13. Energy modulation of nonrelativistic electrons in an optical near field on a metal microslit


    R., Ishikawa; Jongsuck, Bae; K., Mizuno


    Energy modulation of nonrelativistic electrons with a laser beam using a metal microslit as an interaction circuit has been investigated. An optical near field is induced in the proximity of the microslit by illumination of the laser beam. The electrons passing close to the slit are accelerated or decelerated by an evanescent wave contained in the near field whose phase velocity is equal to the velocity of the electrons. The electron-evanescent wave interaction in the microslit has been analy...

  14. Rape survivor care crisis – mines the worst?

    African Journals Online (AJOL)

    The dire need for better healthcare worker training in rape forensics and safe survivor care has never been better illustrated than by the horrifying rape statistics Médecins. Sans Frontières (MSF) presented last month from the platinum-mining boom town of. Rustenburg. Promising to increase its rape survivor care and ...

  15. Exposure to Pornography and Acceptance of Rape Myths. (United States)

    Allen, Mike; And Others


    Summarizes the literature examining the association between acceptance of rape myths and exposure to pornography. States that nonexperimental methodology shows that exposure to pornography does not increase rape myth acceptance, while experimental studies show that exposure to pornography increases rape myth acceptance. Concludes that experimental…

  16. Working Together To Change the Rape and Violence Culture. (United States)

    Abrams, Julie M.; And Others

    This publication is a collection of 20 supporting documents for a conference program, "Working Together To Change the Rape and Violence Culture." Contents include: (1) "Presenter Contact Information"; (2) "Characteristics of Rape-Prone versus Rape-Free Cultures"; (3) "Dater's Bill of Rights"; (4)…

  17. 77 FR 30871 - Implementing the Prison Rape Elimination Act (United States)


    ... May 23, 2012 Part VI The President Memorandum of May 17, 2012--Implementing the Prison Rape... 3-- #0;The President ] Memorandum of May 17, 2012 Implementing the Prison Rape Elimination Act... assault on human dignity and an affront to American values. The Prison Rape Elimination Act of 2003 (PREA...

  18. 42 CFR 50.306 - Rape and incest. (United States)


    ... 42 Public Health 1 2010-10-01 2010-10-01 false Rape and incest. 50.306 Section 50.306 Public... § 50.306 Rape and incest. Federal financial participation is available in expenditures for medical procedures performed upon a victim of rape or incest if the program or project has received signed...

  19. Rape Myth Acceptance, Sexual Trauma History, and Posttraumatic Stress Disorder (United States)

    Baugher, Shannon N.; Elhai, Jon D.; Monroe, James R.; Gray, Matt J.


    The prediction of false rape-related beliefs (rape myth acceptance [RMA]) was examined using the Illinois Rape Myth Acceptance Scale (Payne, Lonsway, & Fitzgerald, 1999) among a nonclinical sample of 258 male and female college students. Predictor variables included measures of attitudes toward women, gender role identity (GRI), sexual trauma…

  20. Theoretical Consideration of Forcible Rape: A Critical Analysis. (United States)

    Clagett, Arthur F.


    Examined differences in hypothetical apperceptive fantasies of committing forcible rape, which are held by male subjects, as compared with the hypothetical apperceptive fantasies of being forcibly raped, held by the female subjects. Developed a critical analysis of social and cross-cultural variables affecting rape. (Author/ABL)

  1. An Empirical Investigation of Campus Demographics and Reported Rapes (United States)

    Wiersma-Mosley, Jacquelyn D.; Jozkowski, Kristen N.; Martinez, Taylor


    Objective: Rape on college campuses continues to be a pervasive public health issue with approximately 11% of women experiencing rape while in college. As such, it is important to examine factors unique to college campuses that influence the occurrences of rape. Methods: Using data from 1,423 four-year universities (public and private with at…


    African Journals Online (AJOL)

    the child after collecting same willingly give in for it with the adult, it is said to be rape as well. ... in their teens, while others are matured adults (Obasi, 2007). ... Christian teen girls are no less likely to become victims of the rape". Rape cases are not limited to Nigeria alone. Other countries of the globe have their own side of ...

  3. Counting the countless – rape victimisation during the Rwandan Genocide

    NARCIS (Netherlands)

    Bijleveld, C.C.J.H.; Morssinkhof, A.; Smeulers, A.L.


    Rape is regularly committed during a period of collective violence such as war. The article discusses the Rwandan genocide during which rape was used with the deliberate intent to destroy in whole or in part the Tutsi community. Rape is not often studied in such particular contexts, so little is

  4. Race and Rape: The Black Woman as Legitimate Victim. (United States)

    Williams, Linda Meyer

    Scientific investigations of the relationship between race and rape have been flawed by the acceptance of official statistics and have been influenced by prevailing myths about rape and race. This paper proposes a theoretical framework for understanding rape and race. The thesis is presented that only the black victim of sexual assault is viewed…

  5. A Snapshot of Serial Rape: An Investigation of Criminal Sophistication and Use of Force on Victim Injury and Severity of the Assault. (United States)

    de Heer, Brooke


    Prior research on rapes reported to law enforcement has identified criminal sophistication and the use of force against the victim as possible unique identifiers to serial rape versus one-time rape. This study sought to contribute to the current literature on reported serial rape by investigating how the level of criminal sophistication of the rapist and use of force used were associated with two important outcomes of rape: victim injury and overall severity of the assault. In addition, it was evaluated whether rapist and victim ethnicity affected these relationships. A nation-wide sample of serial rape cases reported to law enforcement collected by the Federal Bureau of Investigation (FBI) was analyzed (108 rapists, 543 victims). Results indicated that serial rapists typically used a limited amount of force against the victim and displayed a high degree of criminal sophistication. In addition, the more criminally sophisticated the perpetrator was, the more sexual acts he performed on his victim. Finally, rapes between a White rapist and White victim were found to exhibit higher levels of criminal sophistication and were more severe in terms of number and types of sexual acts committed. These findings provide a more in-depth understanding of serial rape that can inform both academics and practitioners in the field about contributors to victim injury and severity of the assault. © The Author(s) 2014.

  6. Improved Visualization of Vertebrate Nuclear Pore Complexes by Field Emission Scanning Electron Microscopy

    National Research Council Canada - National Science Library

    Shaulov, Lihi; Harel, Amnon


    Field emission scanning electron microscopy (FESEM) can provide high-resolution three-dimensional surface imaging of many biological structures, including nuclear envelopes and nuclear pore complexes (NPCs...

  7. Electronically Steerable Antennas with Panoramic Scan Field of View Project (United States)

    National Aeronautics and Space Administration — Electronically steerable antennas are key to effective radio transmission at millimeter-wave frequencies. To enable communication with rovers, robots, EVA...

  8. Resisting rape: the effects of victim self-protection on rape completion and injury. (United States)

    Tark, Jongyeon; Kleck, Gary


    The impact of victim resistance on rape completion and injury was examined utilizing a large probability sample of sexual assault incidents, derived from the National Crime Victimization Survey (1992-2002), and taking into account whether harm to the victim followed or preceded self-protection (SP) actions. Additional injuries besides rape, particularly serious injuries, following victim resistance are rare. Results indicate that most SP actions, both forceful and nonforceful, reduce the risk of rape completion, and do not significantly affect the risk of additional injury.

  9. The Psychology of the Politics of Rape: Political Ideology, Moral Foundations, and Attitudes Toward Rape. (United States)

    Barnett, Michael D; Hilz, Emily N


    Previous research has found that conservatives and liberals emphasize different moral foundations. The purpose of these two studies was to investigate whether moral foundations mediate the relationship between political ideology and attitudes toward rape among U.S. college students. In Study 1, moral foundations fully mediated the relationship between political ideology and rape myth acceptance. Study 2 generally replicated the results of Study 1, with binding foundations demonstrating the most consistent mediating effects. These results suggest that individual differences in moral decision-making may explain the relationship between political ideology and attitudes toward rape.

  10. Thermal electron acceleration by electric field spikes in the outer radiation belt: generation of field-aligned pitch angle distributions (United States)

    Vasko, I.; Agapitov, O. V.; Mozer, F.; Artemyev, A.


    Van Allen Probes observations in the outer radiation belt have demonstrated an abundance non-linear electrostatic stucture called Time Domain Structures (TDS). One of the type of TDS is electrostatic electron-acoustic double layers (DL). Observed DLs are frequently accompanied by field-aligned (bi-directional) pitch angle distributions (PAD) of electrons with energies from hundred eVs up to several keV (rarely up to tens of keV). We perform numerical simulations of the DL interaction with thermal electrons making use of the test particle approach. DL parameters assumed in the simulations are adopted from observations. We show that DLs accelerate thermal electrons parallel to the magnetic field via the electrostatic Fermi mechanism, i.e. due to reflections from DL potential humps. Due to this interaction some fraction of electrons is scattered into the loss cone. The electron energy gain is larger for larger DL scalar potential amplitudes and higher propagation velocities. In addition to the Fermi mechanism electrons can be trapped by DLs in their generation region and accelerated due to transport to higher latitudes. Both mechanisms result in formation of field-aligned PADs for electrons with energies comparable to those found in observations. The Fermi mechanism provides field-aligned PADs for PADs to higher energy electrons.

  11. Large-scale monitoring of effects of clothianidin-dressed oilseed rape seeds on pollinating insects in Northern Germany: effects on honey bees (Apis mellifera). (United States)

    Rolke, Daniel; Fuchs, Stefan; Grünewald, Bernd; Gao, Zhenglei; Blenau, Wolfgang


    Possible effects of clothianidin seed-treated oilseed rape on honey bee colonies were investigated in a large-scale monitoring project in Northern Germany, where oilseed rape usually comprises 25-33 % of the arable land. For both reference and test sites, six study locations were selected and eight honey bee hives were placed at each location. At each site, three locations were directly adjacent to oilseed rape fields and three locations were situated 400 m away from the nearest oilseed rape field. Thus, 96 hives were exposed to fully flowering oilseed rape crops. Colony sizes and weights, the amount of honey harvested, and infection with parasites and diseases were monitored between April and September 2014. The percentage of oilseed rape pollen was determined in pollen and honey samples. After oilseed rape flowering, the hives were transferred to an extensive isolated area for post-exposure monitoring. Total numbers of adult bees and brood cells showed seasonal fluctuations, and there were no significant differences between the sites. The honey, which was extracted at the end of the exposure phase, contained 62.0-83.5 % oilseed rape pollen. Varroa destructor infestation was low during most of the course of the study but increased at the end of the study due to flumethrin resistance in the mite populations. In summary, honey bee colonies foraging in clothianidin seed-treated oilseed rape did not show any detrimental symptoms as compared to colonies foraging in clothianidin-free oilseed rape. Development of colony strength, brood success as well as honey yield and pathogen infection were not significantly affected by clothianidin seed-treatment during this study.

  12. Nonlinear evolution of electron shear flow instabilities in the presence of an external guide magnetic field

    CERN Document Server

    Jain, Neeraj


    The dissipation mechanism by which the magnetic field reconnects in the presence of an external (guide) magnetic field in the direction of the main current is not well understood. In thin electron current sheets (ECS) (thickness ~ an electron inertial length) formed in collisionless magnetic reconnection, electron shear flow instabilities (ESFI) are potential candidates for providing an anomalous dissipation mechanism which can break the frozen-in condition of the magnetic field affecting the structure and rate of reconnection. We investigate the evolution of ESFI in guide field magnetic reconnection. The properties of the resulting plasma turbulence and their dependence on the strength of the guide field are studied. Utilizing 3-D electron-magnetohydrodynamic simulations of ECS we show that, unlike the case of ECS self-consistently embedded in anti-parallel magnetic fields, the evolution of thin ECS in the presence of a guide field (equal to the asymptotic value of the reconnecting magnetic field or larger) ...

  13. Quantum control via a genetic algorithm of the field ionization pathway of a Rydberg electron (United States)

    Gregoric, Vincent C.; Kang, Xinyue; Liu, Zhimin Cheryl; Rowley, Zoe A.; Carroll, Thomas J.; Noel, Michael W.


    Quantum control of the pathway along which a Rydberg electron field ionizes is experimentally and computationally demonstrated. Selective field ionization is typically done with a slowly rising electric field pulse. The (1/n*)4 scaling of the classical ionization threshold leads to a rough mapping between arrival time of the electron signal and principal quantum number of the Rydberg electron. This is complicated by the many avoided level crossings that the electron must traverse on the way to ionization, which in general leads to broadening of the time-resolved field ionization signal. In order to control the ionization pathway, thus directing the signal to the desired arrival time, a perturbing electric field produced by an arbitrary wave-form generator is added to a slowly rising electric field. A genetic algorithm evolves the perturbing field in an effort to achieve the target time-resolved field ionization signal.

  14. Rape trauma syndrome in the military courts. (United States)

    Young, S A


    The military courts have developed a rich case law tradition in the area of rape trauma syndrome testimony. These cases are particularly important in the context of a military that is both increasingly female and increasingly sensitive to mixed gender relationships. This article reviews the military court's approach to rape trauma testimony over the past 15 years. The author notes that military courts have been accepting of this testimony within certain well defined limits. The author analyzes the approach to testimony at one military medical center and offers a testimony model for the forensic psychiatrist who testifies in a military setting.

  15. Unstable plasma characteristics in mirror field electron cyclotron ...

    Indian Academy of Sciences (India)

    Electron cyclotron plasma reactor are prone to instabilities in specific input power [3–. 7] region (150–450 watts). ... Electron cyclotron resonance (ECR) plasma technology has become very important for fabrication of very large scale ... left hand polarized (LHP) wave. Shufflbotham and Thomson [4] observed several distinct.

  16. Perceptions of, and Assistance Provided to, a Hypothetical Rape Victim: Differences between Rape Disclosure Recipients and Nonrecipients (United States)

    Paul, Lisa A.; Kehn, Andre; Gray, Matt J.; Salapska-Gelleri, Joanna


    Objective: Undergraduate rape disclosure recipients' and nonrecipients' sociodemographic and life experience variables, attitudes towards rape, and responses to a hypothetical rape disclosure were compared to determine differences between them. Participants: One hundred ninety-two undergraduates at 3 universities participated in this online survey…

  17. Examining the Relationship between Male Rape Myth Acceptance, Female Rape Myth Acceptance, Victim Blame, Homophobia, Gender Roles, and Ambivalent Sexism (United States)

    Davies, Michelle; Gilston, Jennifer; Rogers, Paul


    The relationship between male rape myth acceptance, female rape myth acceptance, attitudes toward gay men, a series of gender role and sexism measures, victim blame and assault severity were investigated. It was predicted that men would display more negative, stereotypical attitudes than women and that male rape myth endorsement would be related…

  18. From the Gyration of Electrons to Cosmic Magnetic Fields (United States)

    Wang, Xia-Wei


    Employing Bohr's quantum theory, the author deduces three limits, which correspond to the magnetic fields of white dwarfs, neutron stars and the strongest in the universe. The author discusses the possible origins of magnetic fields due to collapse of stars, which produces a magnetic field of 10[superscript 8] T. Although the complete analysis…

  19. Lambs fed fresh winter forage rape (Brassica napus L.) emit less methane than those fed perennial ryegrass (Lolium perenne L.), and possible mechanisms behind the difference. (United States)

    Sun, Xuezhao; Henderson, Gemma; Cox, Faith; Molano, German; Harrison, Scott J; Luo, Dongwen; Janssen, Peter H; Pacheco, David


    The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems.

  20. Lambs fed fresh winter forage rape (Brassica napus L. emit less methane than those fed perennial ryegrass (Lolium perenne L., and possible mechanisms behind the difference.

    Directory of Open Access Journals (Sweden)

    Xuezhao Sun

    Full Text Available The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L. on methane yields (g methane per kg of feed dry matter intake, and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.. The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks. The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems.

  1. Electron-positron pair production by ultrarelativistic electrons in a soft photon field (United States)

    Mastichiadis, A.; Marscher, A. P.; Brecher, K.


    The fully differential cross section for photon-electron pair production is integrated numerically over phase space. Results are obtained for the astrophysically interesting case in which the interaction between an ultrarelativistic electron and a soft photon results in electron-positron pair production. The positron spectrum is a function of the energies of both the photon and the electron, as well as the angle of interaction. It is found that the energy at which the positron distribution peaks is inversely proportional to the photon energy and independent of the electron energy. The positron spectrum is integrated once more over initial electron energies for a power-law energy distribution of primary electrons. The same procedure is repeated for the recoil particle; it is shown that the peak of the recoil energy distribution depends linearly on the energy of the primary electron. Finally, semianalytical expressions are obtained for the energy losses of the primary electrons.

  2. Remote Estimation of Vegetation Fraction and Flower Fraction in Oilseed Rape with Unmanned Aerial Vehicle Data

    Directory of Open Access Journals (Sweden)

    Shenghui Fang


    Full Text Available This study developed an approach for remote estimation of Vegetation Fraction (VF and Flower Fraction (FF in oilseed rape, which is a crop species with conspicuous flowers during reproduction. Canopy reflectance in green, red, red edge and NIR bands was obtained by a camera system mounted on an unmanned aerial vehicle (UAV when oilseed rape was in the vegetative growth and flowering stage. The relationship of several widely-used Vegetation Indices (VI vs. VF was tested and found to be different in different phenology stages. At the same VF when oilseed rape was flowering, canopy reflectance increased in all bands, and the tested VI decreased. Therefore, two algorithms to estimate VF were calibrated respectively, one for samples during vegetative growth and the other for samples during flowering stage. The results showed that the Visible Atmospherically Resistant Index (VARIgreen worked most accurately for estimating VF in flower-free samples with an Root Mean Square Error (RMSE of 3.56%, while the Enhanced Vegetation Index (EVI2 was the best in flower-containing samples with an RMSE of 5.65%. Based on reflectance in green and NIR bands, a technique was developed to identify whether a sample contained flowers and then to choose automatically the appropriate algorithm for its VF estimation. During the flowering season, we also explored the potential of using canopy reflectance or VIs to estimate FF in oilseed rape. No significant correlation was observed between VI and FF when soil was visible in the sensor’s field of view. Reflectance at 550 nm worked well for FF estimation with coefficient of determination (R2 above 0.6. Our model was validated in oilseed rape planted under different nitrogen fertilization applications and in different phenology stages. The results showed that it was able to predict VF and FF accurately in oilseed rape with RMSE below 6%.

  3. Quantum Solids of Two Dimensional Electrons in Magnetic Fields (United States)


    skyrmions , in the electron crystal. Investigating tilting (B||) effect on the resonance around ν=1 would be potentially illuminating17. So far we have...substitution of e by e/3 implies the fpk for FWC may be much higher than fpk for electron WC 16A skyrmion can effective reverses several spins by modulating...the spin in a more continuous (and spatially-extended) way and saves exchange energy against Zeeman energy. Skyrmions are thought to be generally less

  4. Incapacitated rape and alcohol use: a prospective analysis. (United States)

    Kaysen, Debra; Neighbors, Clayton; Martell, Joel; Fossos, Nicole; Larimer, Mary E


    This study examined timing of alcohol-related sexual assaults (incapacitated rape) in relation to both alcohol consumption and alcohol-related negative consequences. The sample was drawn from a randomly selected pool of college students across three campuses (n=1238) followed over a three year time period. 91% of students never experienced an incapacitated rape, 2% reported an incapacitated rape prior to the first assessment point (n=30), and 6% reported one over the course of the study (n=76). Results indicated that incapacitated rape was associated with higher alcohol use and more negative consequences in the years prior to the assault. Incapacitated rape was also associated with higher alcohol use and more negative consequences during the year in which the rape took place and subsequent years, with highest rates measured for the year of the rape. These results suggest alcohol use can function as both risk factor and consequence of sexual victimization.

  5. The Martian Dust Devil Electron Avalanche: Laboratory Measurements of the E-Field Fortifying Effects of Dust-Electron Absorption (United States)

    Farrell, W. M.; McLain, J. L.; Collier, M. R.; Keller, J. W.


    Analogous to terrestrial dust devils, charged dust in Mars dust devils should become vertically stratified in the convective features, creating large scale E-fields. This E-field in a Martian-like atmosphere has been shown to stimulate the development of a Townsend discharge (electron avalanche) that acts to dissipate charge in regions where charge build-up occurs. While the stratification of the charged dust is a source of the electrical energy, the uncharged particulates in the dust population may absorb a portion of these avalanching electrons, thereby inhibiting dissipation and leading to the development of anomalously large E-field values. We performed a laboratory study that does indeed show the presence of enhanced E-field strengths between an anode and cathode when dust-absorbing filaments (acting as particulates) are placed in the avalanching electron flow. Further, the E-field threshold condition to create an impulsive spark discharge increases to larger values as more filaments are placed between the anode and cathode. We conclude that the spatially separated charged dust creates the charge centers and E-fields in a dust devil, but the under-charged portion of the population acts to reduce Townsend electron dissipation currents, further fortifying the development of larger-than-expected E-fields.

  6. The Martian dust devil electron avalanche: Laboratory measurements of the E-field fortifying effects of dust-electron absorption (United States)

    Farrell, W. M.; McLain, J. L.; Collier, M. R.; Keller, J. W.


    Analogous to terrestrial dust devils, charged dust in Mars dust devils should become vertically stratified in the convective features, creating large scale E-fields. This E-field in a Martian-like atmosphere has been shown to stimulate the development of a Townsend discharge (electron avalanche) that acts to dissipate charge in regions where charge build-up occurs. While the stratification of the charged dust is a source of the electrical energy, the uncharged particulates in the dust population may absorb a portion of these avalanching electrons, thereby inhibiting dissipation and leading to the development of anomalously large E-field values. We performed a laboratory study that does indeed show the presence of enhanced E-field strengths between an anode and cathode when dust-absorbing filaments (acting as particulates) are placed in the avalanching electron flow. Further, the E-field threshold condition to create an impulsive spark discharge increases to larger values as more filaments are placed between the anode and cathode. We conclude that the spatially separated charged dust creates the charge centers and E-fields in a dust devil, but the under-charged portion of the population acts to reduce Townsend electron dissipation currents, further fortifying the development of larger-than-expected E-fields.

  7. Electronic properties of zigzag and armchair graphene nanoribbons in the external electric and magnetic fields (United States)

    Afshari, F.; Ghaffarian, M.


    We explore, numerically, some electronic properties of zigzag and armchair graphene nanoribbons under the external perpendicular magnetic field and transverse electric field. Our results, in the magnetic field only, indicate that numerical Landau levels deviate from the Dirac Landau levels formula for higher levels and quantum Hall conductance curve of armchair nanoribbon shows oscillatory behavior in the high gate voltage. In the presence of transverse electric field only, it is shown that the electric dipole moment of zigzag nanoribbon increases abruptly versus the electric field in the range of low-intensity electric fields while for armchair nanoribbon this varies very slowly. This variation in stronger electric fields is staircase for armchair nanoribbon while it is smoothly for zigzag nanoribbon. In the presence of electric and magnetic fields, there are electrons and holes as charge carrier in the same proportions. Conducting electrons make a round current in the half of nanoribbons while conducting holes make a round current in the other half. Electronic vortices, which are static in the presence of magnetic field only, move along nanoribbons in the effect of the transverse electric field. By considering the curve of electric dipole moment versus the electric field, it is found that magnetic field increases the electric susceptibility of nanoribbons in the low-intensity electric fields substantially and creates considerable electric susceptibilities in several higher electric fields. So these indicate that the magnetic field increases the electric sensitivity of graphene nanoribbons.

  8. Electron-atom potential scattering assisted by a bichromatic elliptically polarized laser field (United States)

    Korajac, Arman; Habibović, Dino; Čerkić, Aner; Busuladžić, Mustafa; Milošević, Dejan B.


    Electron-atom potential scattering assisted by a bichromatic (two-component) elliptically polarized laser field is analyzed in the frame of the S-matrix theory. The second Born approximation is applied in the expansion of the S-matrix element. The first term in the expansion corresponds to the single scattering, while the second term in the expansion corresponds to the double scattering of electrons on atomic targets. The double scattering is possible in the presence of a laser field. The electron that has scattered on an atomic target may be driven back by the laser field and scatter again on the same atom. The double-scattered electrons may have considerably higher energies than those that scattered only once. We have investigated the dependence of the energy spectrum on various laser-field and incident electron parameters. The calculated electron energy spectra show the plateau-like structures with abrupt cutoffs. These cutoffs are explained by a classical analysis.

  9. Reader responses to literary depictions of rape

    NARCIS (Netherlands)

    E.M. Koopman (Emy); M. Hilscher (Michelle); G.C. Cupchik (Gerald)


    textabstractThis study explored reader responses to different literary depictions of rape. Four literary excerpts were used and divided as aesthetic versus nonaesthetic (style) and allusive versus explicit (detail). The general question was how readers would react to literary fragments depicting

  10. Ethical challenges when reading aesthetic rape scenes

    NARCIS (Netherlands)

    E.M. Koopman (Emy)


    textabstractBoth the issue of the ethics of representation and the issue of the ethics of reading are particularly important when it comes to representations of suffering and violence. This chapter addresses the ethics of representing and the ethics of reading rape, with a focus on the latter.

  11. Alcohol Consumption and Responsibility Judgment for Rape. (United States)

    Kreutzer, Jeffrey S.; And Others

    One explanation for the positive relationship between alcohol consumption and violent crime considers alcohol consumption to be a socially accepted excuse for otherwise inappropriate behaviors. A policy capturing methodology was used to examine judgments of responsibility for rape. Male (N=30) and female (N=66) undergraduates received 40 profiles…

  12. Taking a chance: Sex, alcohol & acquaintance rape

    DEFF Research Database (Denmark)

    Demant, Jakob; Heinskou, Marie Bruvik


    to grasp more of the complexities of the situation. By analyzing a single case of acquaintance rape and then reflect this case in the light of interviews on young people's drinking habits it is argued that the complexities within the analytical frame of chance is crucial in understanding reported...

  13. Random walk study of electron motion in helium in crossed electromagnetic fields (United States)

    Englert, G. W.


    Random walk theory, previously adapted to electron motion in the presence of an electric field, is extended to include a transverse magnetic field. In principle, the random walk approach avoids mathematical complexity and concomitant simplifying assumptions and permits determination of energy distributions and transport coefficients within the accuracy of available collisional cross section data. Application is made to a weakly ionized helium gas. Time of relaxation of electron energy distribution, determined by the random walk, is described by simple expressions based on energy exchange between the electron and an effective electric field. The restrictive effect of the magnetic field on electron motion, which increases the required number of collisions per walk to reach a terminal steady state condition, as well as the effect of the magnetic field on electron transport coefficients and mean energy can be quite adequately described by expressions involving only the Hall parameter.

  14. Scanning probe microscopy and field emission schemes for studying electron emission from polycrystalline diamond


    Chubenko, Oksana; Baturin, Stanislav S.; Baryshev, Sergey V.


    The letter introduces a diagram that rationalizes tunneling atomic force microscopy (TUNA) observations of electron emission from polycrystalline diamonds as described in recent publications. The direct observations of electron emission from grain boundary sites by TUNA could indeed be evidence of electrons originating from grain boundaries under external electric fields. At the same time, from the diagram it follows that TUNA and field emission schemes are complimentary rather than equivalen...

  15. Observation of Electron Bernstein Wave Heating in a Reversed Field Pinch (United States)

    Seltzman, A. H.; Anderson, J. K.; Diem, S. J.; Goetz, J. A.; Forest, C. B.


    The first observation of rf heating in a reversed field pinch (RFP) using the electron Bernstein wave (EBW) is demonstrated on the Madison Symmetric Torus. Propagation across and heating in a stochastic magnetic field is observed. Novel techniques are required to measure the suprathermal electron tail generated by EBW heating in the presence of intense Ohmic heating. rf-heated electrons directly probe the edge transport properties in the RFP; measured loss rates imply a large noncollisional radial diffusivity.

  16. Foldy–Wouthuysen transformation applied to the interaction of an electron with ultrafast electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Hinschberger, Y. [Institut de Physique et Chimie des Matériaux de Strasbourg, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2 (France); Hervieux, P.-A., E-mail: [Institut de Physique et Chimie des Matériaux de Strasbourg, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2 (France)


    By means of the Foldy–Wouthuysen transformation the nonrelativistic approximation of the external-electromagnetic-field Dirac equation to fifth order in powers of 1/m is obtained. Generalizing this result we postulate a general expression of the direct spin–field electronic Hamiltonian valid at any order in 1/m. -- Highlights: ► Coupling of an ultrafast electromagnetic field with the electron spin is investigated using a first-principles approach. ► May be involved in the coherent laser-induced demagnetization of ferromagnetic materials. ► A general expression of the direct spin–field electronic Hamiltonian is postulated.

  17. Rape Myths and the Cross-Cultural Adaptation of the Illinois Rape Myth Acceptance Scale in China. (United States)

    Xue, Jia; Fang, Gang; Huang, Hui; Cui, Naixue; Rhodes, Karin V; Gelles, Richard


    The study examines the similarities and differences between China and the United States with regard to rape myths. We assessed the individual level of rape myth acceptance among Chinese university students by adapting and translating a widely used measure of rape myth endorsement in the United States, the Illinois Rape Myth Acceptance (IRMA) scale. We assessed whether the IRMA scale would be an appropriate assessment of attitudes toward rape among young adults in China. The sample consisted of 975 Chinese university students enrolled in seven Chinese universities. We used explorative factor analysis to examine the factor structure of the Chinese translation of the IRMA scale. Results suggest that the IRMA scale requires some modification to be employed with young adults in China. Our analyses indicate that 20 items should be deleted, and a five-factor model is generated. We discuss relevant similarities and differences in the factor structure and item loadings between the Chinese Rape Myth Acceptance (CRMA) and the IRMA scales. A revised version of the IRMA, the CRMA, can be used as a resource in rape prevention services and rape victim support services. Future research in China that employs CRMA will allow researchers to examine whether individual's response to rape myth acceptance can predict rape potential and judgments of victim blaming and community members' acceptance of marital rape. © The Author(s) 2016.

  18. Contact with Counter-Stereotypical Women Predicts Less Sexism, Less Rape Myth Acceptance, Less Intention to Rape (in Men) and Less Projected Enjoyment of Rape (in Women). (United States)

    Taschler, Miriam; West, Keon


    Intergroup contact-(positive) interactions with people from different social groups-is a widely researched and strongly supported prejudice-reducing mechanism shown to reduce prejudice against a wide variety of outgroups. However, no known previous research has investigated whether intergroup contact can also reduce sexism against women. Sexism has an array of negative outcomes. One of the most detrimental and violent ones is rape, which is both justified and downplayed by rape myth acceptance. We hypothesised that more frequent, higher quality contact with counter-stereotypical women would predict lower levels of sexism and thus less rape myth acceptance (in men) and less sexualised projected responses to rape (in women). Two studies using online surveys with community samples supported these hypotheses. In Study 1, 170 male participants who experienced more positive contact with counter-stereotypical women reported less intention to rape. Similarly, in Study 2, 280 female participants who experienced more positive contact with counter-stereotypical women reported less projected sexual arousal at the thought of being raped. Thus, the present research is the first known to show that contact could be a potential tool to combat sexism, rape myth acceptance, intentions to rape in men, and sexualisation of rape by women.

  19. Weevils of the genus Ceutorhynchus Germ associated with oilseed rape in northern Serbia

    Directory of Open Access Journals (Sweden)

    Ivan Sivčev


    Full Text Available Our research of the genus Ceutorhynchus associated with oilseed rape was conducted in northern parts of Serbia (Stari Žednik, Subotica. A specific assemblage of eight weevil species was found. The most numerous were stem weevils Ceutorhynchus napi with 81% of all trapped specimens, followed by C. pallidactylus with 18%. The remaining six weevil specimens were C. obstrictus, C.erysimi, C. minutus, C. picitarsis, C. sulcicollis and C. typhae, comprising 1% of all trapped insects. Stem weevils C. napi and C. pallidactylus began to immigrate into the oilseed rape fields in autumn, as early as November 10 (BBCH 17-18. The maximum flight was recorded at the beginning of oilseed rape stem elongation (BBCH 22-25 on March 23. A new generation of C. pallidactylus emerged from oilseed rape fields in June (BBCH 76-88, while individual specimens occurred during the autumn. The majority of C. napi emerged in March next year, sporadically until May 7. As a consequence of C. napi dominance insecticide treatment should be performed earlier than usual, i.e. when C. pallidactilus is the primary target.

  20. Electron transport in bulk GaN under ultrashort high-electric field transient (United States)

    Korotyeyev, V. V.; Kochelap, V. A.; Kim, K. W.


    We have investigated nonlinear electron transport in GaN induced by high-electric field transients by analyzing the temporal dependence of the electron drift velocity and temperature. For picosecond transients, our calculations have established that the electron dynamics retain almost all the features of the steady-state velocity-field characteristics including the portion with negative differential conductivity. It was also found that transient currents in GaN samples give rise to the THz re-emission effect—radiation of electromagnetic field, temporal and spectral properties of which directly relate to the velocity-field characteristics of the sample. The results clearly indicate that existing methods for the generation of high-electric field transients and subpicosecond signal measurements can be applied to the characterization of hot electron transport at ultrahigh fields while avoiding Joule self-heating, hot phonon accumulation and other undesirable effects.

  1. The Role of the Guide Field in Electron Acceleration during Magnetic Reconnection (United States)

    Dahlin, J.; Drake, J. F.; Swisdak, M.


    Magnetic reconnection is thought to be an important driver of energetic particles in a variety of astrophysical phenomena including solar flares and magnetospheric storms. Kinetic particle-in-cell (PIC) simulations of collisionless reconnection reveal that the efficiency of electron acceleration is highly sensitive to magnitude of the guide field (the magnetic field component perpendicular to the reconnection plane). In reconnection where the guide field is smaller than the reconnecting component, the dominant electron accelerator is a Fermi-type mechanism that preferentially energizes the most energetic particles. In strong guide field reconnection, the field-line contraction that drives the Fermi mechanism becomes weak. Instead, parallel electric fields are primarily responsible for driving electron heating but are ineffective in driving the energetic component of the spectrum. Three-dimensional simulations reveal that the stochastic magnetic field that develops during 3D guide field reconnection plays a vital role in particle acceleration and transport. In 2D systems electrons are trapped within stagnant magnetic island cores so that acceleration is suppressed, whereas in 3D the stochastic magnetic field enables energetic electrons to freely sample regions where energy release is taking place. In 3D systems with a weak guide field, however, transport is diminished and electron acceleration is suppressed as in the 2D case. These results suggest that the most efficient electron acceleration occur in reconnection with a moderate guide field (comparable to the reconnecting component) so that both (a) the Fermi mechanism is an efficient driver and (b) energetic electrons may freely access acceleration sites. This has important implications for understanding electron acceleration in solar flares and reconnection-driven dissipation in astrophysical turbulence.

  2. Influence of Magnetic Field Decay on Electron Capture in Magnetars ...

    Indian Academy of Sciences (India)

    Cooper & Kaplan (2010) proposed a new heating mechanism in magnetar crusts. They argued that the magnetic pressure is compa- rable to electron degeneracy pressure in the magnetar crust, and magnetic pressure partially supports the crust against gravity. When the magnetic pressure decreases and the crust shrinks, ...

  3. Unstable plasma characteristics in mirror field electron cyclotron ...

    Indian Academy of Sciences (India)

    Electron cyclotron plasma reactor are prone to instabilities in specific input power [3–7] region (150–450 watts). In this region power absorption by gas molecules in the cavity is very poor and enhanced input power gets reflected substantially without increasing ion density. There are abrupt changes in plasma characteristics ...

  4. Coronal Magnetic Field Lines and Electrons Associated with Type III ...

    Indian Academy of Sciences (India)

    We recently investigated some of the hitherto unreported observational characteristics of the low frequency (85–35 MHz) type III–V bursts from the Sun using radio spectropolarimeter observations. The quantitative estimates of the velocities of the electron streams associated with the above two types of bursts indicate that ...

  5. Quantum well electronic states in a tilted magnetic field (United States)

    Trallero-Giner, C.; Padilha, J. X.; Lopez-Richard, V.; Marques, G. E.; Castelano, L. K.


    We report the energy spectrum and the eigenstates of conduction and uncoupled valence bands of a quantum well under the influence of a tilted magnetic field. In the framework of the envelope approximation, we implement two analytical approaches to obtain the nontrivial solutions of the tilted magnetic field: (a) the Bubnov-Galerkin spectral method and b) the perturbation theory. We discuss the validity of each method for a broad range of magnetic field intensity and orientation as well as quantum well thickness. By estimating the accuracy of the perturbation method, we provide explicit analytical solutions for quantum wells in a tilted magnetic field configuration that can be employed to study several quantitative phenomena.

  6. Dynamical Mean Field Theory and Electronic Structure Calculations


    Chitra, R.; Kotliar, G.


    We formulate the dynamical mean field theory directly in the continuum. For a given definition of the local Green's function, we show the existence of a unique functional, whose stationary point gives the physical local Green's function of the solid. We present the diagrammatic rules to calculate it perturbatively in the interaction. Inspired by the success of dynamical mean field calculations for model Hamiltonian systems, we present approximations to the exact saddle point equations which m...

  7. Electron cyclotron maser instability (ECMI in strong magnetic guide field reconnection

    Directory of Open Access Journals (Sweden)

    R. A. Treumann


    Full Text Available The ECMI model of electromagnetic radiation from electron holes is shown to be applicable to spontaneous magnetic reconnection. We apply it to reconnection in strong current-aligned magnetic guide fields. Such guide fields participate only passively in reconnection, which occurs in the antiparallel components to both sides of the guide-field-aligned current sheets with current carried by kinetic Alfvén waves. Reconnection generates long (the order of hundreds of electron inertial scales electron exhaust regions at the reconnection site X point, which are extended perpendicular to the current and the guide fields. Exhausts contain a strongly density-depleted hot electron component and have properties similar to electron holes. Exhaust electron momentum space distributions are highly deformed, exhibiting steep gradients transverse to both the reconnecting and guide fields. Such properties suggest application of the ECMI mechanism with the fundamental ECMI X-mode emission beneath the nonrelativistic guide field cyclotron frequency in localized source regions. An outline of the mechanism and its prospects is given. Potential applications are the kilometric radiation (AKR in auroral physics, solar radio emissions during flares, planetary emissions and astrophysical scenarios (radiation from stars and compact objects involving the presence of strong magnetic fields and field-aligned currents. Drift of the exhausts along the guide field maps the local field and plasma properties. Escape of radiation from the exhaust and radiation source region still poses a problem. The mechanism can be studied in 2-D particle simulations of strong guide field reconnection which favours 2-D, mapping the deformation of the electron distribution perpendicular to the guide field, and using it in the numerical calculation of the ECMI growth rate. The mechanism suggests also that reconnection in general may become a source of the ECMI with or without guide fields. This is

  8. Modeling of electron cyclotron resonance acceleration in a stationary inhomogeneous magnetic field

    Directory of Open Access Journals (Sweden)

    Valeri D. Dougar-Jabon


    Full Text Available In this paper, the cyclotron autoresonance acceleration of electrons in a stationary inhomogeneous magnetic field is studied. The trajectory and energy of electrons are found through a numerical solution of the relativistic Newton-Lorentz equation by a finite difference method. The electrons move along a TE_{112} cylinder cavity in a steady-state magnetic field whose axis coincides with the cavity axis. The magnetic field profile is such that it keeps the phase difference between the electric microwave field and the electron velocity vector within the acceleration phase band. The microwaves amplitude of 6  kV/cm is used for numerical calculations. It is shown that an electron with an initial longitudinal energy of 8 keV can be accelerated up to 260 keV by 2.45 GHz microwaves at a distance of 17 cm.

  9. Dark-field electron holography for the measurement of geometric phase. (United States)

    Hÿtch, M J; Houdellier, F; Hüe, F; Snoeck, E


    The genesis, theoretical basis and practical application of the new electron holographic dark-field technique for mapping strain in nanostructures are presented. The development places geometric phase within a unified theoretical framework for phase measurements by electron holography. The total phase of the transmitted and diffracted beams is described as a sum of four contributions: crystalline, electrostatic, magnetic and geometric. Each contribution is outlined briefly and leads to the proposal to measure geometric phase by dark-field electron holography (DFEH). The experimental conditions, phase reconstruction and analysis are detailed for off-axis electron holography using examples from the field of semiconductors. A method for correcting for thickness variations will be proposed and demonstrated using the phase from the corresponding bright-field electron hologram. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Investigation of the Decelerating Field of an Electron Multiplier under Negative Ion Impact

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Kjeldgaard, K.


    The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions by ...... by a factor of 100. The secondary electron emission coefficient for the negative halogen ions relative to I− were measured on CuBe at the kinetic energies 1.0 and 1.5 keV.......The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions...

  11. Criminalizing rape within marriage: perspectives of Ghanaian university students. (United States)

    Adinkrah, Mensah


    Forcing sexual intercourse on an unwilling marital partner, or marital rape, is not a crime in many societies around the world, because of a marital exemption rule that prohibits the prosecution of husbands who rape their wives. Concurrently, marital rape is one of the least studied phenomena in sexual violence research. This is particularly true for societies in the non-Western world. The current study examined the general attitudes of a sample of university students in Ghana, a West African country, toward marital rape. Respondents were also asked whether an ongoing legislative effort to criminalize marital rape in the country was warranted. The results indicated strong opposition toward criminalization. The results also indicated no marked differences between male and female respondents in attitudes toward marital rape and the need for a legislative response to the phenomenon. Patriarchal ideologies such as wifely submission to the husband and an implicit duty to provide sex in marriage provided some of the justifications furnished for why marital rape should remain noncriminalized. Advocates of criminalization mentioned the social, physical, and psychological effects of rape and how the enactment of marital rape legislation and the imposition of severe criminal sanctions would help prevent the incidence of marital rape and other forms of violence against women in the society.

  12. Formation of field-reversed-configuration plasma with punctuated-betatron-orbit electrons. (United States)

    Welch, D R; Cohen, S A; Genoni, T C; Glasser, A H


    We describe ab initio, self-consistent, 3D, fully electromagnetic numerical simulations of current drive and field-reversed-configuration plasma formation by odd-parity rotating magnetic fields (RMF{o}). Magnetic-separatrix formation and field reversal are attained from an initial mirror configuration. A population of punctuated-betatron-orbit electrons, generated by the RMF{o}, carries the majority of the field-normal azimuthal electrical current responsible for field reversal. Appreciable current and plasma pressure exist outside the magnetic separatrix whose shape is modulated by the RMF{o} phase. The predicted plasma density and electron energy distribution compare favorably with RMF{o} experiments.

  13. Giant increase in cross-magnetic-field transport rate as an electron-positron plasma cools (United States)

    Aguirre, F. F.; Ordonez, C. A.


    An electron-positron plasma in thermal equilibrium within a uniform magnetic field is studied using a classical trajectory Monte Carlo simulation. The cross-magnetic-field single-particle diffusion coefficient is evaluated as a function of the magnetic field strength and plasma temperature. The transport rate is found to increase by many orders of magnitude as the plasma temperature is lowered, for a magnetic field strength of 1 T. The sharp dependence on temperature is due to electrons and positrons becoming temporarily correlated and drifting across the magnetic field before dissociating.

  14. Formation of Field-reversed-Configuration Plasma with Punctuated-betatron-orbit Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Welch, D. R.; Cohen, S. A.; Genoni, T. C.; Glasser, A. H.


    We describe ab initio, self-consistent, 3D, fully electromagnetic numerical simulations of current drive and field-reversed-configuration plasma formation by odd-parity rotating magnetic fields (RMFo). Magnetic-separatrix formation and field reversal are attained from an initial mirror configuration. A population of punctuated-betatron-orbit electrons, generated by the RMFo, carries the majority of the field-normal azimuthal electrical current responsible for field reversal. Appreciable current and plasma pressure exist outside the magnetic separatrix whose shape is modulated by the RMFo phase. The predicted plasma density and electron energy distribution compare favorably with RMFo experiments. __________________________________________________

  15. Estimating the Reliability of Electronic Parts in High Radiation Fields (United States)

    Everline, Chester; Clark, Karla; Man, Guy; Rasmussen, Robert; Johnston, Allan; Kohlhase, Charles; Paulos, Todd


    Radiation effects on materials and electronic parts constrain the lifetime of flight systems visiting Europa. Understanding mission lifetime limits is critical to the design and planning of such a mission. Therefore, the operational aspects of radiation dose are a mission success issue. To predict and manage mission lifetime in a high radiation environment, system engineers need capable tools to trade radiation design choices against system design and reliability, and science achievements. Conventional tools and approaches provided past missions with conservative designs without the ability to predict their lifetime beyond the baseline mission.This paper describes a more systematic approach to understanding spacecraft design margin, allowing better prediction of spacecraft lifetime. This is possible because of newly available electronic parts radiation effects statistics and an enhanced spacecraft system reliability methodology. This new approach can be used in conjunction with traditional approaches for mission design. This paper describes the fundamentals of the new methodology.

  16. Effect of upflowing field-aligned electron beams on the electron ...

    Indian Academy of Sciences (India)

    The dispersion relation D(ω, k) for electron cyclotron waves propagating parallel to Bo in the presence of upflowing FEBs could be taken as the sum of dispersion relations due to the main body of plasma Dm(ω, k) and upflowing. FEBs, Db(ω ..... into auroral zone increasing the population of energetic electrons which provide.

  17. Method of synthesizing small-diameter carbon nanotubes with electron field emission properties (United States)

    Liu, Jie (Inventor); Du, Chunsheng (Inventor); Qian, Cheng (Inventor); Gao, Bo (Inventor); Qiu, Qi (Inventor); Zhou, Otto Z. (Inventor)


    Carbon nanotube material having an outer diameter less than 10 nm and a number of walls less than ten are disclosed. Also disclosed are an electron field emission device including a substrate, an optionally layer of adhesion-promoting layer, and a layer of electron field emission material. The electron field emission material includes a carbon nanotube having a number of concentric graphene shells per tube of from two to ten, an outer diameter from 2 to 8 nm, and a nanotube length greater than 0.1 microns. One method to fabricate carbon nanotubes includes the steps of (a) producing a catalyst containing Fe and Mo supported on MgO powder, (b) using a mixture of hydrogen and carbon containing gas as precursors, and (c) heating the catalyst to a temperature above C. to produce a carbon nanotube. Another method of fabricating an electron field emission cathode includes the steps of (a) synthesizing electron field emission materials containing carbon nanotubes with a number of concentric graphene shells per tube from two to ten, an outer diameter of from 2 to 8 nm, and a length greater than 0.1 microns, (b) dispersing the electron field emission material in a suitable solvent, (c) depositing the electron field emission materials onto a substrate, and (d) annealing the substrate.

  18. Energy modulation of nonrelativistic electrons in an optical near field on a metal microslit (United States)

    Ishikawa, R.; Bae, J.; Mizuno, K.


    Energy modulation of nonrelativistic electrons with a laser beam using a metal microslit as an interaction circuit has been investigated. An optical near field is induced in the proximity of the microslit by illumination of the laser beam. The electrons passing close to the slit are accelerated or decelerated by an evanescent wave contained in the near field whose phase velocity is equal to the velocity of the electrons. The electron-evanescent wave interaction in the microslit has been analyzed theoretically and experimentally. The theory has predicted that electron energy can be modulated at optical frequencies. Experiments performed in the infrared region have verified theoretical predictions. The electron-energy changes of more than ±5 eV with a 10 kW CO2 laser pulse at the wavelength of 10.6 μm has been successfully observed for an electron beam with an energy of less than 80 keV.

  19. Classical understanding of electron vortex beams in a uniform magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yeong Deok [Department of Computer Science and Engineering, Woosuk University, Wanju, Cheonbuk, 565-701 (Korea, Republic of); Choi, Taeseung, E-mail: [Division of Applied Food System, College of Natural Science, Seoul Women' s University, Seoul 139-774 (Korea, Republic of); School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea, Republic of)


    Recently, interesting observations on electron vortex beams have been made. We propose a classical model that shows vortex-like motion due to suitably-synchronized motion of each electron's cyclotron motion in a uniform magnetic field. It is shown that some basic features of electron vortex beams in a uniform magnetic field, such as azimuthal currents, the relation between energy and kinetic angular momentum, and the parallel-axis theorem are understandable by using this classical model. We also show that the time-dependence of kinetic angular momentum of electron vortex beams could be understood as an effect of a specific nonuniform distribution of classical electrons. - Highlights: • A classical model for electron vortex beams is proposed. • The basic features of azimuthal currents could be understood by using this model. • The kinetic angular momentum of electron vortex beams is intuitively understandable.

  20. Observation of the Avalanche of Runaway Electrons in Air in a Strong Electric Field (United States)

    Gurevich, A. V.; Mesyats, G. A.; Zybin, K. P.; Yalandin, M. I.; Reutova, A. G.; Shpak, V. G.; Shunailov, S. A.


    The generation of an avalanche of runaway electrons is demonstrated for the first time in a laboratory experiment. Two flows of runaway electrons are formed sequentially in an extended air discharge gap at the stage of delay of a pulsed breakdown. The first, picosecond, runaway electron flow is emitted in the cathode region where the field is enhanced. Being accelerated in the gap, this beam generates electrons due to impact ionization. These secondary electrons form a delayed avalanche of runaway electrons if the field is strong enough. The properties of the avalanche correspond to the existing notions about the runaway breakdown in air. The measured current of the avalanche exceeds up to an order the current of the initiating electron beam.

  1. Combined influence of azimuthal and axial magnetic fields on resonant electron acceleration in plasma (United States)

    Singh, Arvinder; Rajput, Jyoti; Kant, Niti


    Resonant enhancement in electron acceleration due to a circularly polarized laser pulse in plasma, under the combined influence of external azimuthal and axial magnetic fields, is studied. We have investigated direct electron acceleration in plasma by employing a relativistic single particle simulation. The plasma is magnetized with an azimuthal magnetic field applied in the perpendicular plane and an axial magnetic field applied along the direction of laser beam propagation. Resonance takes place between electron and electric field of the laser pulse for the optimum value of the combined magnetic field, which supports electron acceleration to higher energies, up to the betatron resonance point. The optimum value of these magnetic fields is highly sensitive to laser initial intensity and laser initial spot size. The effects of laser intensity, initial spot size, and laser pulse duration are taken into consideration in optimizing the magnetic field for efficient electron acceleration. Higher electron energy gain, of the order of GeV, is observed by employing terawatt circularly polarized laser pulses in plasma under the influence of combined magnetic field of about 10 MG.

  2. Laser-sub-cycle two-dimensional electron momentum mapping using orthogonal two-color fields

    CERN Document Server

    Zhang, Li; Roither, Stefan; Kartashov, Daniil; Wang, YanLan; Wang, ChuanLiang; Schöffler, Markus; Shafir, Dror; Corkum, Paul; Baltuška, Andrius; Ivanov, Igor; Kheifets, Anatoli; Liu, XiaoJun; Staudte, André; Kitzler, Markus


    The two-dimensional sub-cycle-time to electron momentum mapping provided by orthogonal two-color laser fields is applied to photoelectron spectroscopy. Using neon as the example we gain experimental access to the dynamics of emitted electron wave packets in electron momenta spectra measured by coincidence momentum imaging. We demonstrate the opportunities provided by this time-to-momentum mapping by investigating the influence of the parent ion on the emitted electrons on laser-sub-cycle times. It is found that depending on their sub-cycle birth time the trajectories of photoelectrons are affected differently by the ion's Coulomb field.

  3. Modeling electron transport in the presence of electric and magnetic fields.

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Wesley C.; Drumm, Clifton Russell; Pautz, Shawn D.; Turner, C. David


    This report describes the theoretical background on modeling electron transport in the presence of electric and magnetic fields by incorporating the effects of the Lorentz force on electron motion into the Boltzmann transport equation. Electromagnetic fields alter the electron energy and trajectory continuously, and these effects can be characterized mathematically by differential operators in terms of electron energy and direction. Numerical solution techniques, based on the discrete-ordinates and finite-element methods, are developed and implemented in an existing radiation transport code, SCEPTRE.

  4. Sexual violence in the protracted conflict of DRC programming for rape survivors in South Kivu

    Directory of Open Access Journals (Sweden)

    Schmitz K Peter


    Full Text Available Abstract Background Despite international acknowledgement of the linkages between sexual violence and conflict, reliable data on its prevalence, the circumstances, characteristics of perpetrators, and physical or mental health impacts is rare. Among the conflicts that have been associated with widespread sexual violence has been the one in the Democratic Republic of the Congo (DRC. Methods From 2003 till to date Malteser International has run a medico-social support programme for rape survivors in South Kivu province, DRC. In the context of this programme, a host of data was collected. We present these data and discuss the findings within the frame of available literature. Results Malteser International registered 20,517 female rape survivors in the three year period 2005–2007. Women of all ages have been targeted by sexual violence and only few of those – and many of them only after several years – sought medical care and psychological help. Sexual violence in the DRC frequently led to social, especially familial, exclusion. Members of military and paramilitary groups were identified as the main perpetrators of sexual violence. Conclusion We have documented that in the DRC conflict sexual violence has been – and continues to be – highly prevalent in a wide area in the East of the country. Humanitarian programming in this field is challenging due to the multiple needs of rape survivors. The easily accessible, integrated medical and psycho-social care that the programme offered apparently responded to the needs of many rape survivors in this area.

  5. Early osmotic adjustment responses in drought-resistant and drought-sensitive oilseed rape. (United States)

    Hatzig, Sarah; Zaharia, L Irina; Abrams, Suzanne; Hohmann, Marie; Legoahec, Laurie; Bouchereau, Alain; Nesi, Nathalie; Snowdon, Rod J


    The impact of osmotic stress on growth, physiology, and metabolism of winter oilseed rape (Brassica napus L.) was investigated by detailed analysis of biomass traits, hormone metabolites and osmolytes in two genetically unrelated drought-tolerant genotypes and two unrelated drought-sensitive genotypes. Seedlings were grown in vitro under controlled conditions and osmotic stress was simulated by applying a gradual treatment with polyethylene glycol (PEG 6000), followed by hypo-osmotic treatment of variants used for metabolite determination. The results provide a basis for the identification of reliable selection criteria for drought resistance in oilseed rape. The in vitro cultivation system established during this study enabled effective discrimination of early osmotic stress responses between drought-resistant and -susceptible oilseed rape genotypes that also show large differences in relative seed yield under drought conditions in the field. Clear physiological and metabolic differences were observed between the drought-resistant and drought-sensitive genotypes, suggesting that osmotic adjustment is a key component of drought response in oilseed rape. Unexpectedly, however, the drought-resistant genotypes did not show typical hormonal adjustment and osmolyte accumulation, suggesting that they possess alternative physiological mechanisms enabling avoidance of stress symptoms. © 2014 Institute of Botany, Chinese Academy of Sciences.

  6. Modal description of longitudinal space-charge fields in pulse-driven free-electron devices

    Directory of Open Access Journals (Sweden)

    Yu. Lurie


    Full Text Available In pulsed-beam free-electron devices, longitudinal space-charge fields result in collective effects leading to an expansion of short electron bunches along their trajectory. This effect restricts an application of intense ultrashort electron pulses in free-electron radiation sources. A careful theoretical treatment is required in order to achieve an accurate description of the self-fields and the resulted electron beam dynamics. In this paper, longitudinal space-charge fields are considered in the framework of a three-dimensional, space-frequency approach. The model is based on the expansion of the total electromagnetic field (including self-fields in terms of transverse eigenmodes of the (cold cavity, in which the field is excited and propagates. The electromagnetic field, originally obtained in the model as a solution of the wave equation, is shown to satisfy also Gauss’s law. We applied the theory to derive an analytical expression for the longitudinal electric field of a pointlike charge, moving along a waveguide at a constant velocity. This enables consideration and study of the role played by different terms of the resulted expressions, such as components arising from forward and backward waves, propagating waves, and under cutoff frequencies, and so on. Possible simplifications in evaluation of longitudinal space-charge fields are discussed.

  7. Energetic electron-bunch generation in a phase-locked longitudinal laser electric field. (United States)

    Xiao, K D; Huang, T W; Ju, L B; Li, R; Yang, S L; Yang, Y C; Wu, S Z; Zhang, H; Qiao, B; Ruan, S C; Zhou, C T; He, X T


    Energetic electron acceleration processes in a plasma hollow tube irradiated by an ultraintense laser pulse are investigated. It is found that the longitudinal component of the laser field is much enhanced when a linear polarized Gaussian laser pulse propagates through the plasma tube. This longitudinal field is of π/2 phase shift relative to the transverse electric field and has a π phase interval between its upper and lower parts. The electrons in the plasma tube are first pulled out by the transverse electric field and then trapped by the longitudinal electric field. The trapped electrons can further be accelerated to higher energy in the presence of the longitudinal electric field. This acceleration mechanism is clearly illustrated by both particle-in-cell simulations and single particle modelings.

  8. Electron cyclotron resonance heating by magnetic filter field in a negative hydrogen ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, June Young, E-mail:; Cho, Won-Hwi; Dang, Jeong-Jeung; Chung, Kyoung-Jae, E-mail:; Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)


    The influence of magnetic filter field on plasma properties in the heating region has been investigated in a planar-type inductively coupled radio-frequency (RF) H{sup −} ion source. Besides filtering high energy electrons near the extraction region, the magnetic filter field is clearly observed to increase the electron temperature in the heating region at low pressure discharge. With increasing the operating pressure, enhancement of electron temperature in the heating region is reduced. The possibility of electron cyclotron resonance (ECR) heating in the heating region due to stray magnetic field generated by a filter magnet located at the extraction region is examined. It is found that ECR heating by RF wave field in the discharge region, where the strength of an axial magnetic field is approximately ∼4.8 G, can effectively heat low energy electrons. Depletion of low energy electrons in the electron energy distribution function measured at the heating region supports the occurrence of ECR heating. The present study suggests that addition of axial magnetic field as small as several G by an external electromagnet or permanent magnets can greatly increase the generation of highly ro-vibrationally excited hydrogen molecules in the heating region, thus improving the performance of H{sup −} ion generation in volume-produced negative hydrogen ion sources.

  9. Strain fields and electronic structure of antiferromagnetic CrN (United States)

    Rojas, Tomas; Ulloa, Sergio E.


    We present a theoretical analysis of the role that strain plays on the electronic structure of chromium nitride (CrN) crystals. We use local spin-density approximation + U calculations to study the elastic constants, deformation potentials, and strain dependence of electron and hole masses near the fundamental gap. We consider the lowest energy antiferromagnetic models believed to describe CrN at low temperatures, and apply strain along different directions. We find relatively large deformation potentials for all models, and find increasing gaps for tensile strain along most directions. Most interestingly, we find that compressive strains should be able to close the relatively small indirect gap (≃100 meV) at moderate amplitudes ≃1.3 % . We also find large and anisotropic changes in the effective masses with strain, with principal axes closely related to the magnetic ordering of neighboring layers in the antiferromagnet. It would be interesting to consider the role that these effects may have on typical film growth on different substrates, and the possibility of monitoring optical and transport properties of thin films as strain is applied.

  10. Features of electron-phonon interactions in nanotubes with chiral symmetry in magnetic field

    CERN Document Server

    Kibis, O V


    Interaction of the electrons with acoustic phonons in the nanotube with chiral symmetry by availability of the magnetic field, parallel to the nanotube axis, is considered. It is shown that the electron energy spectrum is asymmetric relative to the electron wave vector inversion and for that reason the electron-phonon interaction appears to be different for similar phonons with mutually contrary directions of the wave vector. This phenomenon leads to origination of the electromotive force by the spatially uniform electron gas heating and to appearance of the quadrupole component in the nanotube volt-ampere characteristics

  11. Electron-magnetohydrodynamic simulations of electron scale current sheet dynamics in the Vineta.II guide field reconnection experiment (United States)

    Jain, Neeraj; von Stechow, Adrian; Muñoz, Patricio A.; Büchner, Jörg; Grulke, Olaf; Klinger, Thomas


    Three dimensional electron-magnetohydrodynamic (EMHD) simulations of electron current sheet dynamics in a background of stationary and unmagnetized ions and the subsequent generation of electromagnetic fluctuations are carried out. The physical parameters and initial magnetic configuration in the simulations are chosen to be similar to those in the Vineta.II magnetic reconnection experiment. Consistent with the experimental results, our 3D EMHD simulations show the formation of an elongated electron scale current sheet together with the excitation of electromagnetic fluctuations within this sheet. The fluctuations in the simulations are generated by an electron shear flow instability growing on the in-plane (perpendicular to the direction of the main current in the sheet) electron shear flow (or current) developed during the current sheet evolution. Similar to the experiments, the magnetic field fluctuations perpendicular to the guide magnetic field exhibit a broadband frequency spectrum following a power law and a positive correlation with the axial current density. Although the experimental results show that ions influence the spectral properties of the fluctuations, the simulations suggest that the electron dynamics, even in the absence of ion motion, primarily determines the formation of the current sheet and the generation of electromagnetic fluctuations observed in the experiments.

  12. One-electron singular spectral features of the 1D Hubbard model at finite magnetic field

    Directory of Open Access Journals (Sweden)

    J.M.P. Carmelo


    Full Text Available The momentum, electronic density, spin density, and interaction dependences of the exponents that control the (k,ω-plane singular features of the σ=↑,↓ one-electron spectral functions of the 1D Hubbard model at finite magnetic field are studied. The usual half-filling concepts of one-electron lower Hubbard band and upper Hubbard band are defined in terms of the rotated electrons associated with the model Bethe-ansatz solution for all electronic density and spin density values and the whole finite repulsion range. Such rotated electrons are the link of the non-perturbative relation between the electrons and the pseudofermions. Our results further clarify the microscopic processes through which the pseudofermion dynamical theory accounts for the one-electron matrix elements between the ground state and excited energy eigenstates.

  13. On non-local electron heat conduction: effects of geometry and magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Soboleva, T.K. [UNAM, Mexico D.F., Mexico and Kurchatov Institute, Moscow (Russian Federation); Krasheninnikov, S.I. [University of California at San Diego, La Jolla (United States); Catto, P.J. [PSFC, Massachusetts Institute of Technology, Cambridge (United States)


    Self-similar 3D solutions of electron kinetic equation are obtained that can be used for benchmarking both reduced models and codes. It is demonstrated that the geometry (e. g. slab vs spherical) can be an important ingredient in describing non-local electron heat transport. The self-similar variable approach is extended to include the effects of the magnetic field on the kinetics of electron transport. It is found that magnetic field is not as important for the far tail of electron distribution function as one might think. Therefore, suppression of electron heat flux by magnetic field effects in inertial confinement fusion (ICF) studies may need to be reconsidered. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Exploring different explanatory psychological models of perpetrators of rape



    M.A. Without prejudice to race or culture, rape is the hurt of both males and females of all ages. Rape can be one of the most devastating emotional events in a person’s life, the effects of which are entrenched for life (Rozee & Koss, 2001). Motives underscoring the need to commit rape have received much attention in the literature. Evolutionary theorists such as Thornhill and Palmer (2000) report that sexual needs and reproduction are the primary motivational factors. Feminist theorists ...

  15. Immunolabeling for scanning electron microscopy (SEM) and field emission SEM. (United States)

    Goldberg, Martin W


    Scanning electron microscopy (SEM) is a high resolution surface imaging technique. Many biological process and structures occur at surfaces and if antibodies are available, their components can be located within the surface structure. This is usually done in a similar way to immuno-fluorescence, using an unconjugated primary antibody followed by a tagged secondary antibody against the primary. In this case the tag is usually a colloidal gold particle instead of a fluorophore. Therefore it is quite straightforward to adapt an immuno-fluorescence procedure for SEM, as long as certain precautions are followed, as discussed here. Progressing from immuno-fluorescence, which essentially only indicates the position of a protein within the volume of a cell, to immuno-SEM, puts the labeling into the context of cellular structures. The principles and practices of sample preparation, labeling and imaging are described here.

  16. Communicating/Muting Date Rape: A Co-Cultural Theoretical Analysis of Communication Factors Related to Rape Culture on a College Campus (United States)

    Burnett, Ann; Mattern, Jody L.; Herakova, Liliana L.; Kahl, David H., Jr.; Tobola, Cloy; Bornsen, Susan E.


    Previous studies suggest that college campuses foster a rape culture in which date rape (most commonly, rape of women) is an accepted part of campus activity (Buchwald, Fletcher, & Roth, 1993; Sanday, 2007). In focus groups at a Midwestern university, researchers asked students about rape as they experienced it or knew about it on campus. The…

  17. The effects of transverse magnetic field and local electronic interaction on thermoelectric properties of monolayer graphene (United States)

    Rezania, Hamed; Azizi, Farshad


    We study the effects of a transverse magnetic field and electron doping on the thermoelectric properties of monolayer graphene in the context of Hubbard model at the antiferromagnetic sector. In particular, the temperature dependence of thermal conductivity and Seebeck coefficient has been investigated. Mean field approximation has been employed in order to obtain the electronic spectrum of the system in the presence of local electron-electron interaction. Our results show the peak in thermal conductivity moves to higher temperatures with increase of both chemical potential and Hubbard parameter. Moreover the increase of magnetic field leads to shift of peak in temperature dependence of thermal conductivity to higher temperatures. Finally the behavior of Seebeck coefficient in terms of temperature has been studied and the effects of magnetic field and Hubbard parameter on this coefficient have been investigated in details.

  18. Electrons acceleration in a TE 113 cylindrical cavity affected by a static inhomogeneous magnetic field (United States)

    E Vergara, V.; González, J. D.; Beltrán, J. R.; Orozco, E. A.


    The relativistic dynamics of an electron accelerated in a cylindrical cavity mode TE 113 in the presence of a static inhomogeneous magnetic field is studied. This type of acceleration is known as Spatial AutoResonance Acceleration (SARA). The magnetic field profile is such that it keeps the phase difference between the electric microwave field and the electron velocity vector within the acceleration phase band. We study the dynamic of the electron through simulations of the relativistic Newton-Lorentz equation. Numerical experiments with TE 113 cylindrical microwave fields of a frequency of 2.45GHz and an amplitude of the order of 7kV/cm show that it is possible accelerate the electrons up to energies of the order of 300keV. This energy is about of 30% higher than those obtained in previous studies by using the TE 112 mode.

  19. Rape: Past and present legal regulation

    Directory of Open Access Journals (Sweden)

    Đapović Lasta S.


    Full Text Available Rape was identified as a criminal act in the earliest known legal writings, Hamurabi's legal code (cir. 2000 BC. In the Balkans, in the Middle Ages, rape was always punished in one way or another, in the statutes of the Adriatic maritime towns, which were under the rule of the Nemanjić state or the West. All categories of women, even prostitutes and slaves, were protected by law from sexual violence in many statutes. Also in Dušan's legal code the regulation is found, severely punishing rapists. Laws following the Second Serbian Uprising, also provide severe punishment for sexual violence, especially towards women but also male minors. Legal and court practice, following the Second World War, indicate that the protection of women from sexual violence is completely inadequate and this at a time when women had achieved equal rights with men in many spheres of life. World events at the end of the 20th century: collapse of the Soviet Union: as well as the happenings in this region,: war, ethnic and religious conflicts resulted in massive rape of women, opening of brothels, trading women and family violence. Non state organizations, mainly women in expert associations, invest great effort to rectify this very unsatisfactory situation. They exert pressure for change in the law and in court practice, by which women would have more effective defense against sexual violence, as well as organized assistance for women victims of traffic, and warning of the possible danger.

  20. Tunable-frequency high-field electron paramagnetic resonance (United States)

    Krzystek, J.; Zvyagin, S. A.; Ozarowski, Andrew; Trofimenko, S.; Telser, Joshua


    A tunable-frequency methodology based on backward wave oscillator sources in high-frequency and -field EPR (HFEPR) is described. This methodology is illustrated by an application to three non-Kramers transition metal ion complexes and one Kramers ion complex. The complexes are of: Ni(II) ( S = 1) as found in dichlorobistriphenylphosphanenickel(II), Mn(III) ( S = 2) as found in mesotetrasulfonatoporphyrinatomanganese(III) chloride, Fe(II) ( S = 2) as found in ferrous sulfate tetrahydrate, and Co(II) ( S = 3/2) as found in azido(tris(3- tert-butylpyrazol-1-yl)hydroborate)cobalt(II). The above Ni(II) and Mn(III) complexes have been studied before by HFEPR using the multifrequency methodology based on Gunn oscillator sources, but not by the present method, while the Fe(II) and Co(II) complexes presented here have not been studied by any form of HFEPR. Highly accurate spin Hamiltonian parameters can be obtained by the experimental methodology described here, in combination with automated fitting procedures. This method is particularly successful in determining g-matrix parameters, which are very difficult to extract for high-spin systems from single frequency (or a very limited set of multi-frequency) HFEPR spectra, but is also able to deliver equally accurate values of the zero-field splitting tensor. The experimental methods involve either conventional magnetic field modulation or an optical modulation of the sub-THz wave beam. The relative merits of these and other experimental methods are discussed.

  1. Generation of a spin-polarized electron beam by multipole magnetic fields. (United States)

    Karimi, Ebrahim; Grillo, Vincenzo; Boyd, Robert W; Santamato, Enrico


    The propagation of an electron beam in the presence of transverse magnetic fields possessing integer topological charges is presented. The spin-magnetic interaction introduces a nonuniform spin precession of the electrons that gains a space-variant geometrical phase in the transverse plane proportional to the field's topological charge, whose handedness depends on the input electron's spin state. A combination of our proposed device with an electron orbital angular momentum sorter can be utilized as a spin-filter of electron beams in a mid-energy range. We examine these two different configurations of a partial spin-filter generator numerically. The results of this analysis could prove useful in the design of an improved electron microscope. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Field-emission cathode gating for rf electron guns


    Lewellen, J. W.; J. Noonan


    We present a novel method of combining the most desirable characteristics of thermionic-cathode and photocathode rf guns, using a field-emission cathode and multiple rf frequencies. Simulations indicate that extremely low-emittance beams (on the order of 2 nm normalized emittance) at moderate beam currents (1 mA) and beam energies of ∼2  MeV can be obtained using this technique. The resulting gun design promises to be useful as a driver source for a number of applications, including high-volt...

  3. Thermionic field emission of electrons from the paraboloidal metal micropoint (United States)

    Petrin, A. B.


    The problem of determining the emission current as a function of voltage, radius of the micropoint curvature, and the distance between the micropoint and a conducting plane is considered on the basis of the theoretical method developed for determining the electric field in the vicinity of a paraboloidal micropoint near a plane metal surface. The universal current-voltage characteristics for a copper micropoint, which are considered for various distances between the micropoint and the plane, can be used for obtaining quantitative estimates of currents in various physics problems.

  4. Ethanol production from rape straw: Part of an oilseed rape biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Arvaniti, E.


    Agricultural residues from rapeseed biodiesel industry (rapeseed cake, rape straw, crude glycerol), which represent the 82%wt. of the oilseed rape, currently have only low-grade applications in the market. For this, a scenario was built on exploiting qualities of rapeseed biodiesel residues for forming added-value products, and expanding and upgrading an existing biodiesel plant, to an oilseed rape biorefinery by 2020 in European ground. Selection of products was based on a technological feasibility study given the time frame, while priority was given to Low-Value-High-Volume readily marketed products, like production of energy and feed. Products selected except rapeseed biodiesel, were ethanol, biogas, enzymes energy, chemical building blocks, and superior quality animal fodder. The production lines were analyzed and prospects for 2020 were projected on a critical basis. Particular merit was given to two products, ethanol from cellulose, and cellulolytic enzymes from rape straw. Cellulosic ethanol from rape straw was optimized for all production steps, i.e. for thermo-chemical pretreatment, enzyme hydrolysis, and fermentation of C6 sugars. Thermo-chemical pretreatment was studied with Wet oxidation technique at different conditions of temperature, reaction time, and oxygen pressure, but also factors like pre-soaking straw in warm water, or recycling liquid were also studied. Wet oxidation has been extensively tested in the past for different substrates, and gives promising results with indicators that are important for cellulosic ethanol production; C6 sugars recovery, high digestibility for enzymes, and limited formed degradation products. Here, optimal pretreatment conditions for rape straw were first presoaking rape straw at 80 deg. C for 20 minutes, and then wet-oxidize with 12 bar of oxygen at 205 deg. C for 3 minutes. Recovery of cellulose and hemicellulose under these conditions was 105% and 106% respectively, while recovery of lignin was 86%. When this

  5. Ending Rape in War: How Far Have We Come?

    Directory of Open Access Journals (Sweden)

    Lucy Fiske


    Full Text Available The rape of women has for centuries been an endemic feature of war, yet perpetrators largely go unpunished. Women were sanctioned as the spoils of war in biblical times and more recently it has been claimed that it is more dangerous to be a woman than a soldier in modern conflict. Nevertheless, until the establishment of the ad hoc International Criminal Tribunals for Rwanda and the former Yugoslavia – there was very little concern regarding the need to address the rape of women in conflict. This paper briefly maps historical attitudes towards rape in war, outlines some analyses and explanations of why rape in war occurs and finally turns more substantively to recent efforts by the international community to prosecute rape as a war crime and a crime against humanity. We argue, that while commendable in some ways, contemporary approaches to rape in war risk reinforcing aspects of women’s status which contribute to the targeting of women for rape and continue to displace women from the centre to the margins in debates and practices surrounding rape in both war and peace time.  We conclude by arguing that criminal prosecutions alone are insufficient and that, if we are to end the rape of women and girls in war (and peace we need a radical restructuring of gender relations across every sphere of social and political life.

  6. Reactions to rape: a military forensic psychiatrist's perspective. (United States)

    Ritchie, E C


    Accusations of rape or sexual harassment are currently very high-profile in the military. This article discusses rape allegations in the military legal system from a psychiatric perspective. The original definition of "rape trauma syndrome" and subsequent psychiatric thinking about the diagnosis are briefly outlined. Common reactions seen in military victims in this era are described. A prototypical military case is presented. An adequate evaluation of an alleged victim is outlined. Credentials and preparation of an expert witness are also briefly discussed, with cautions about the use of expert testimony in cases of alleged sexual assault and rape trauma syndrome.

  7. Neutrino production of electron-positron pairs in a moderately strong magnetic field (United States)

    Kuznetsov, A. V.; Rumyantsev, D. A.; Savin, V. N.


    Neutrino production of electron-positron pairs via the processes v\\bar v → e - e + and ν → νe - e + in a moderately strong magnetic field is investigated. Under these conditions electrons and positrons can be produced in the states corresponding to excited Landau levels. The results can be used for calculating the efficiency of the electron-positron plasma production by neutrinos in the conditions of the accretion disk around a Kerr black hole.

  8. A simple model for atomic layer doped field-effect transistor (ALD-FET) electronic states

    Energy Technology Data Exchange (ETDEWEB)

    Mora R, M.E. [Centro de Investigaciones en Optica, Unidad Aguascalientes. Juan de Montoro 207, Zona Centro, 20000 Aguascalientes (Mexico); Gaggero S, L.M. [Escuela de Fisica, Universidad Autonoma de Zacatecas, Av. Preparatoria 301, 98060 Zacatecas (Mexico)


    We propose a simple potential model based on the Thomas-Fermi approximation to reproduce the main properties of the electronic structure of an atomic layer doped field effect transistor. Preliminary numerical results for a Si-based ALD-FET justify why bound electronic states are not observed in the experiment. (Author)

  9. Thermodynamics of Two-Dimensional Electron Gas in a Magnetic Field

    Directory of Open Access Journals (Sweden)

    V. I. Nizhankovskii


    Full Text Available Change of the chemical potential of electrons in a GaAs-AlGa1−As heterojunction was measured in magnetic fields up to 6.5 T at several temperatures from 2.17 to 12.3 K. A thermodynamic equation of state of two-dimensional electron gas well describes the experimental results.

  10. Study of electric fields parallel to the magnetic lines of force using artificially injected energetic electrons (United States)

    Wilhelm, K.; Bernstein, W.; Whalen, B. A.


    Electron beam experiments using rocket-borne instrumentation will be discussed. The observations indicate that reflections of energetic electrons may occur at possible electric field configurations parallel to the direction of the magnetic lines of force in an altitude range of several thousand kilometers above the ionosphere.

  11. Modulation of Electronic and Optical Anisotropy Properties of ML-GaS by Vertical Electric Field (United States)

    Guo, Fei; Wu, Yaping; Wu, Zhiming; Ke, Congming; Zhou, Changjie; Chen, Ting; Li, Heng; Zhang, Chunmiao; Fu, Mingming; Kang, Junyong


    We investigate the electric-field-dependent optical properties and electronic behaviors of GaS monolayer by using the first-principles calculations. A reversal of the dipole transition from E//c to E⊥c anisotropy is found with a critical external electric field of about 5 V/nm. Decomposed projected band contributions exhibit asymmetric electronic structures in GaS interlayers under the external electric field, which explains the evolution of the absorption preference. Spatial distribution of the partial charge and charge density difference reveal that the strikingly reversed optical anisotropy in GaS ML is closely linked to the additional crystal field originated from the external electric field. These results pave the way for experimental research and provide a new perspective for the application of the monolayer GaS-based two-dimensional electronic and optoelectronic devices.

  12. Effect of magnetic field on electron spectrum in spherical nano-structures

    Directory of Open Access Journals (Sweden)

    V. Holovatsky


    Full Text Available The influence of the magnetic field on energy spectrum and wave functions of electron in spherical nano-structures such as single quantum dot and spherical layer is investigated. It is shown that the magnetic field takes off the spectrum degeneration with respect to the magnetic quantum number. Increasing magnetic field induction entails the monotonous character of electron energy for the states with m ≥ 0 and non-monotonous one for the states with m < 0. The electron wave functions of the ground and few excited states are studied considering the influence of the magnetic field. It is shown that 1s and 1p states are degenerated in the spherical layer driven by the strong magnetic field. In the limit case, the series of size-quantized levels produce the Landau levels which are typical for the bulk crystals.

  13. Hormones and Pod Development in Oilseed Rape (Brassica napus) 1 (United States)

    de Bouille, Pierre; Sotta, Bruno; Miginiac, Emile; Merrien, André


    The endogenous levels of several plant growth substances (indole acetic acid, IAA; abscisic acid, ABA; zeatin, Z; zeatin riboside, [9R]Z; isopentenyladenine, iP; and isopentenyladenosine, [9R]iP were measured during pod development of field grown oilseed Rape (Brassica napus L. var oleifera cv Bienvenu) with high performance liquid chromatography and immunoenzymic (enzyme-linked immunosorbent assay, ELISA) techniques. Results show that pod development is characterized by high levels of Z and [9R]Z in 3 day old fruits and of IAA on the fourth day. During pod maturation, initially a significant increase of IAA and cytokinins was observed, followed by a progressive rise of ABA levels and a concomitant decline of IAA and cytokinin (except iP) levels. The relationship between hormone levels and development, especially pod number, seed number per pod, and seed weight determination, will be discussed. PMID:16666891

  14. Characterisation of MFM tip stray fields using Lorentz electron tomography

    CERN Document Server

    Scott, J


    considered, as is a possible improved design of DPC detector. distribution a tomographic method must be used. The collection and calibration of the tomographic data series is discussed, including the special sample mounting methods required. To understand the principles behind MFM, the theory behind atomic force microscopy (AFM) is discussed at length in Chapter 3. The extension of AFM to MFM is covered, and the simple point charge analysis of the MFM imaging process is reviewed. A more sophisticated analysis is then presented, based on the knowledge of the MFM point- response function. It is demonstrated that in some cases, the magnetic charge distribution of a samples can be extracted provided that the response function of the MFM tip (related directly to the stray field distribution from the tip) is known. Finally, some specialised MFM techniques are briefly reviewed. In Chapter 4, prototype tips (produced at Sheffield University) coated with a low-coercivity amorphous ferromagnetic alloy (METGLAS 2605SC) ...

  15. Magnetic field amplification in electron phase-space holes and related effects

    Directory of Open Access Journals (Sweden)

    R. A. Treumann


    Full Text Available Three-dimensional electron phase-space holes are shown to have positive charges on the plasma background, which produce a radial electric field and force the trapped electron component into an azimuthal drift. In this way electron holes generate magnetic fields in the hole. We solve the cylindrical hole model exactly for the hole charge, electric potential and magnetic field. In electron holes, the magnetic field is amplified on the flux tube of the hole; equivalently, in ion holes the field would be decreased. The flux tube adjacent to the electron hole is magnetically depleted by the external hole dipole field. This causes magnetic filamentation. It is also shown that holes are massive objects, each carrying a finite magnetic moment. Binary magnetic dipole interaction of these moments will cause alignment of the holes into chains along the magnetic field or, in the three-dimensional case, produce a magnetic fabric in the volume of hole formation. Since holes, in addition to being carriers of charges and magnetic moments, also have finite masses, they behave like quasi-particles, performing E × B, magnetic field, and diamagnetic drifts. In an inhomogeneous magnetic field, their magnetic moments experience torque, which causes nutation of the hole around the direction of the magnetic field, presumably giving rise to low frequency magnetic modulations like pulsations. A gas of many such holes may allow for a kinetic description, in which holes undergo binary dipole interactions. This resembles the polymeric behaviour. Both magnetic field generation and magnetic structure formation are of interest in auroral, solar coronal and shock physics, in particular in the problem of magnetic field filamentation in relativistic foreshocks and cosmic ray acceleration.

  16. Magnetic-field generation and electron-collimation analysis for propagating fast electron beams in overdense plasmas. (United States)

    Cai, Hong-Bo; Zhu, Shao-Ping; Chen, Mo; Wu, Si-Zhong; He, X T; Mima, Kunioki


    An analytical fluid model is proposed for artificially collimating fast electron beams produced in the interaction of ultraintense laser pulses with specially engineered low-density-core-high-density-cladding structure targets. Since this theory clearly predicts the characteristics of the spontaneously generated magnetic field and its dependence on the plasma parameters of the targets transporting fast electrons, it is of substantial relevance to the target design for fast ignition. The theory also reveals that the rapid changing of the flow velocity of the background electrons in a transverse direction (perpendicular to the flow velocity) caused by the density jump dominates the generation of a spontaneous interface magnetic field for these kinds of targets. It is found that the spontaneously generated magnetic field reaches as high as 100 MG, which is large enough to collimate fast electron transport in overdense plasmas. This theory is also supported by numerical simulations performed using a two-dimensional particle-in-cell code. It is found that the simulation results agree well with the theoretical analysis.

  17. Multi-field electron emission pattern of 2D emitter: Illustrated with graphene (United States)

    Luo, Ma; Li, Zhibing


    The mechanism of laser-assisted multi-field electron emission of two-dimensional emitters is investigated theoretically. The process is basically a cold field electron emission but having more controllable components: a uniform electric field controls the emission potential barrier, a magnetic field controls the quantum states of the emitter, while an optical field controls electron populations of specified quantum states. It provides a highly orientational vacuum electron line source whose divergence angle over the beam plane is inversely proportional to square root of the emitter height. Calculations are carried out for graphene with the armchair emission edge, as a concrete example. The rate equation incorporating the optical excitation, phonon scattering, and thermal relaxation is solved in the quasi-equilibrium approximation for electron population in the bands. The far-field emission patterns, that inherit the features of the Landau bands, are obtained. It is found that the optical field generates a characteristic structure at one wing of the emission pattern.

  18. Meteorological and landscape influences on pollen beetle immigration into oilseed rape crops. (United States)

    Skellern, Matthew P; Welham, Sue J; Watts, Nigel P; Cook, Samantha M


    Heavy reliance on pesticide inputs to maintain crop yields has been an important aspect of agricultural intensification. Insecticide use has had detrimental impacts on pollinators and natural pest control agents, contributing to a decline in associated ecosystem services, and has also led to resistance development in pest populations. Throughout Europe, in oilseed rape (Brassica napus L.) crops, prophylactic use of insecticides against pollen beetles (Meligethes aeneus F. also known as Brassicogethes aeneus) has led to such issues, and there is an urgent need to develop more sustainable pest management practices for the crop. Although advice is available to oilseed rape growers regarding control thresholds, it may not be adhered to due to the expense of pollen beetle monitoring relative to the inexpensive cost of pyrethroid insecticides. Thus, the key to reducing prophylactic insecticide applications may lie with improved, less labour intensive methods of pollen beetle monitoring. For these to be realized, a better understanding is needed of the effects of agri-landscape features and meteorological conditions on pollen beetle immigration into the crop. In this study, based on data from four years of pollen beetle monitoring on a total of 41 field sites, we model the effects of meteorological (wind speed and direction, rainfall and accumulated temperature) and landscape (areas of woodland, residential gardens, the current and previous seasons' oilseed rape crops, and lengths of hedgerows and treelines) variables on directional sticky trap catches, at both the single trap and field scales. Meteorological variables, particularly accumulated temperature and wind speed were more important than landscape variables in predicting the abundance of pollen beetles immigrating into OSR fields. Sticky traps that were facing downwind caught more beetles than those that were facing across-wind or upwind; this is the first study to show at a landscape-scale, direct evidence for

  19. Comparison between 3D conventional techniques, field-in-field and electronic tissue compensation for mantle fields planning; Comparacao entre tecnica 3D convencional, field-in-field e compensacao eletronica para planejamento de manto

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Lais P.; Silva, Leonardo P.; Trindade, Cassia; Garcia, Paulo L.; Santos, Maira R.; Batista, Delano V.S., E-mail: [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil)


    External radiotherapy treatment for Hodgkin's lymphoma over diaphragm region requires large radiation fields with protections applied to larynx, humerus head and lungs. The size and shape of the field, which covers different depths, make it difficult to distribute a homogeneous dose. Techniques such as field-in-field and electronic tissue compensation may be used to make dose homogeneous and compensate the obliquity from the tissue. Three types of planning were performed for diagnose of nodular sclerosis Hodgkin's lymphoma: one plan with two fields, AP-PA (AP plan), another with four fields field-in- field (FF plan), and a third one with two fields and electronic tissue compensation (ETC plan). Results showed better gradient, cover of PTV and dose distribution for the ETC plan, besides the advantage from this technique of does not require protection blocks. In the meanwhile, AP and FF plans require simpler dosimetry and fewer MU. Related to the uniformity of dose distribution, AP plan showed hot areas in the neck region, FF plan showed hot areas in the shoulder region and ETC plan showed most uniform distribution without hot areas. The electronic tissue compensation is a useful tool for large and shaped fields as the mantle field, however higher MU and complex dosimetry should be taken in account. (author)

  20. Perceptions of stranger and acquaintance rape: the role of benevolent and hostile sexism in victim blame and rape proclivity. (United States)

    Abrams, Dominic; Viki, G Tendayi; Masser, Barbara; Bohner, Gerd


    In Studies 1 and 2, after reading an acquaintance-rape but not a stranger-rape scenario, higher benevolent sexist but not hostile sexist participants blamed the victim significantly more. In Study 2, higher hostile sexist but not benevolent sexist male participants showed significantly greater proclivity to commit acquaintance (but not stranger) rape. Studies 3 and 4 supported the hypothesis that the effects of benevolent sexism and hostile sexism are mediated by different perceptions of the victim, as behaving inappropriately and as really wanting sex with the rapist. These findings show that benevolent sexism and hostile sexism underpin different assumptions about women that generate sexist reactions toward rape victims.

  1. Electron Beam Dose Distribution in the Presence of Non-Uniform Magnetic Field


    Mohamad Javad Tahmasebi-Birgani; Mohamad Reza Bayatiani; Fatemeh Seif; Mansur Zabihzadeh; Hojatolah Shahbazian


    Introduction Magnetic fields are capable of altering the trajectory of electron beams andcan be used in radiation therapy.Theaim of this study was to produce regions with dose enhancement and reduction in the medium. Materials and Methods The NdFeB permanent magnets were arranged on the electron applicator in several configurations. Then, after the passage of the electron beams (9 and 15 MeV Varian 2100C/D) through the non-uniform magnetic field, the Percentage Depth Dose(PDDs) on central axi...

  2. High field electron transport in indium gallium nitride and indium aluminium nitride (United States)

    Masyukov, N. A.; Dmitriev, A. V.


    In this paper, we study theoretically the hot electron transport in two nitride semiconductor solid solutions, InxGa1-xN and InxAl1-xN, in the electric fields up to 30 kV/cm. We calculate the electron drift velocity field dependence at 77 and 300 K for the bulk samples with the electron concentration of 1 × 1018 and 1 × 1019 cm-3 and alloy composition x = 0, 0.25, 0.5, 0.75, and 1.

  3. Nitrogen plasma formation through terahertz-induced ultrafast electron field emission

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Zalkovskij, Maksim; Strikwerda, Andrew


    . Terahertz (THz) radiation, commonly understood to be nonionizing due to its low photon energy, is here shown to produce electron field emission. We demonstrate that a carrier-envelope phase-stable single-cycle optical field at THz frequencies interacting with a metallic microantenna can generate...... and accelerate ultrashort and ultrabright electron bunches into free space, and we use these electrons to excite and ionize ambient nitrogen molecules near the antenna. The associated UV emission from the gas forms a novel THz wave detector, which, in contrast with conventional photon-counting or heat...

  4. Acceleration of electrons by high intensity laser radiation in a magnetic field


    Melikian, Robert


    We consider the acceleration of electrons in vacuum by means of the circularly-polirized electromagnetic wave, propagating along a magnetic field. We show that the electron energy growth, when using ultra-short and ultra-intense laser pulses (10 ps, 10^{18} Bm/cm^2, CO_{2} laser) in the presence of a magnetic field, may reach up to the value 2,1 Gev. The growth of the electron energy is shown to increase proportionally with the increase of the laser intensity and the initial energy of the ele...

  5. Enhanced performance of thermal-assisted electron field emission based on barium oxide nanowire

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Yunkang [Department of Mathematics and Physics, Nanjing Institute of technology, Nanjing, 211167 (China); Chen, Jing, E-mail: [School of Electronic Science & Engineering, Southeast University, Nanjing, 210096 (China); Zhang, Yuning; Zhang, Xiaobing; Lei, Wei; Di, Yunsong [School of Electronic Science & Engineering, Southeast University, Nanjing, 210096 (China); Zhang, Zichen, E-mail: [Integrated system for Laser applications Group, Institute of Microelectronics of Chinese Academy of Sciences, 100029, Beijing (China)


    Highlights: • A possible mechanism for thermal-assisted electric field was demonstrated. • A new path for the architecture of the novel nanomaterial and methodology for its potential application in the field emission device area was provided. • The turn-on field, the threshold field and the field emission current density were largely related to the temperature of the cathode. • The relationship between the work function of emitter material and the temperature of emitter was found. - Abstract: In this paper, thermal-assisted field emission properties of barium oxide (BaO) nanowire synthesized by a chemical bath deposition method were investigated. The morphology and composition of BaO nanowire were characterized by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SED), X-ray diffraction (XRD), and energy dispersive X-ray spectrometer (EDX) respectively. The turn-on field, threshold field and the emission current density could be affected relatively due to the thermal-assisted effect when the electric field was applied, in the meanwhile, the turn-on field for BaO nanowire was measured to be decreased from 1.12 V/μm to 0.66 V/μm when the temperature was raised from 293 K to 593 K, whereas for the threshold field was found to decrease from 3.64 V/μm to 2.12 V/μm. The improved performance was demonstrated due to the reduced work function of the BaO nanowire as the agitation temperature increasing, leading to the higher probability of electrons tunneling through the energy barrier and enhancement of the field emission properties of BaO emitters.

  6. Effect of electric fields generated by microactuators on the imaging in electron microscopy

    NARCIS (Netherlands)

    Vermeer, Rolf; Woldering, L.A.; Abelmann, Leon


    In this paper we are investigating the potential to employ small devices in crucial areas with limited volumes in electron microscopes. We present the analysis of the electric fields that are present in an electrostatically actuated micro electro mechanical systems (MEMS) device. The electric fields

  7. Focusing of intensive electron beams in helix TWT with PPM focusing system with nonsinusoidal field

    Directory of Open Access Journals (Sweden)

    Chasnyk V. I.


    Full Text Available Experimental results on beam transmission of intensive electron beams in high-voltage TWT with PPM focusing system with nonsinusoidal field at great values of magnetic field parameter α are presented. It is shown, that at 1,01,4, which correspond to the second region of stability, conductance is 82% in statics and 75% in dynamics.

  8. Enhanced electron field emission from carbon nanotubes irradiated by energetic C ions. (United States)

    Sun, Peng-Cheng; Deng, Jian-Hua; Cheng, Guo-An; Zheng, Rui-Ting; Ping, Zhao-Xia


    The field emission performance and structure of the vertically aligned multi-walled carbon nanotube arrays irradiated by energetic C ion with average energy of 40 keV have been investigated. During energetic C ion irradiation, the curves of emission current density versus the applied field of samples shift firstly to low applied fields when the irradiation doses are less than 9.6 x 10(16) cm(-2), and further increase of dose makes the curves reversing to a high applied field, which shows that high dose irradiation in carbon nanotube arrays makes their field emission performance worse. After energetic ion irradiation with a dose of 9.6 x 1016 cm(-2), the turn-on electric field and the threshold electric field of samples decreased from 0.80 and 1.13 V/microm to 0.67 and 0.98 V/microm respectively. Structural analysis of scanning electron microscopy, transmission electron microscopy and Raman spectroscopy indicates that the amorphous carbon nanowire/carbon nanotube hetero nano-structures have been fabricated in the C ion irradiated carbon nanotubes. The enhancement of electron field emission is due to the formation of amorphous carbon nanowires at the tip of carbon nanotube arrays, which is an electron emitting material with low work function.

  9. Experimental verification of the role of electron pressure in fast magnetic reconnection with a guide field (United States)

    Fox, W.


    Magnetic reconnection enables explosive conversion of magnetic field energy to plasma kinetic energy in space and laboratory plasmas. In many reconnecting plasmas in space, solar, and laboratory plasmas, reconnection proceeds in the presence of a finite guide field (GF) such that the magnetic field lines meet at an angle less than 180°, and in magnetic fusion devices the guide field can be the largest component of the field. We report detailed laboratory observations of the structure of reconnection current sheets in a two-fluid plasma regime with a guide magnetic field. We observe and quantitatively analyze the quadrupolar electron pressure variation in the ion-diffusion region, as originally predicted by extended magnetohydrodynamics simulations. The projection of the electron pressure gradient parallel to the magnetic field contributes significantly to balancing the parallel electric field, and the results demonstrate how parallel and perpendicular force balance are coupled in guide field reconnection and confirm basic theoretical models of the importance of electron pressure gradients for obtaining fast magnetic reconnection. I discuss connections to observations of reconnection with finite guide field by spacecraft missions, and implications for two-fluid reconnection in magnetic fusion devices.

  10. Mean field ring polymer molecular dynamics for electronically nonadiabatic reaction rates. (United States)

    Duke, Jessica Ryan; Ananth, Nandini


    We present a mean field ring polymer molecular dynamics method to calculate the rate of electron transfer (ET) in multi-state, multi-electron condensed-phase processes. Our approach involves calculating a transition state theory (TST) estimate to the rate using an exact path integral in discrete electronic states and continuous Cartesian nuclear coordinates. A dynamic recrossing correction to the TST rate is then obtained from real-time dynamics simulations using mean field ring polymer molecular dynamics. We employ two different reaction coordinates in our simulations and show that, despite the use of mean field dynamics, the use of an accurate dividing surface to compute TST rates allows us to achieve remarkable agreement with Fermi's golden rule rates for nonadiabatic ET in the normal regime of Marcus theory. Further, we show that using a reaction coordinate based on electronic state populations allows us to capture the turnover in rates for ET in the Marcus inverted regime.

  11. Electron Raman scattering in a double quantum well tuned by an external nonresonant intense laser field (United States)

    Tiutiunnyk, A.; Mora-Ramos, M. E.; Morales, A. L.; Duque, C. M.; Restrepo, R. L.; Ungan, F.; Martínez-Orozco, J. C.; Kasapoglu, E.; Duque, C. A.


    In this work we shall present a study of inelastic light scattering involving inter-subband electron transitions in coupled GaAs-(Ga,Al)As quantum wells. Calculations include the electron related Raman differential cross section and Raman gain. The effects of an external nonresonant intense laser field are used in order to tune these output properties. The confined electron states will be described by means of a diagonalization procedure within the effective mass and parabolic band approximations. It is shown that the application of the intense laser field can produce values of the intersubband electron Raman gain above 400 cm-1. The system proposed here is an alternative choice for the development of AlxGa1-xAs semiconductor laser diodes that can be tuned via an external nonresonant intense laser field.

  12. Developing field emission electron sources based on ultrananocrystalline diamond for accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Baryshev, Sergey V.; Jing, Chunguang; Qiu, Jiaqi; Antipov, Sergey; Jabotinski, Vadim; Shao, Jiahang; Gai, Wei; Sumant, Anirudha V.


    Radiofrequency (RF) electron guns work by establishing an RF electromagnetic field inside a cavity having conducting walls. Electrons from a cathode are generated in the injector and immediately become accelerated by the RF electric field, and exit the gun as a series of electron bunches. Finding simple solutions for electron injection is a long standing problem. While energies of 30-50 MeV are achievable in linear accelerators (linacs), finding an electron source able to survive under MW electric loads and provide an average current of 1-10 mA is important. Meeting these requirements would open various linac applications for industry. The natural way to simplify and integrate RF injector architectures with the electron source would be to place the source directly into the RF cavity with no need for additional heaters/lasers. Euclid TechLabs in collaboration with Argonne National Lab are prototyping a family of highly effective field emission electron sources based on a nitrogen-incorporated ultrananocrystalline diamond ((N)UNCD) platform. Determined metrics suggest that our emitters are emissive enough to meet requirements for magnetized cooling at electron-ion colliders, linac-based radioisotope production and X-ray sterilization, and others.

  13. Relativistic quantum dynamics in strong fields: Photon emission from heavy, few-electron ions

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsche, S. [Kassel Univ. (Germany). Inst. fuer Physik; Indelicato, P. [Lab. Kastler Brossel, Ecole Normale Superieure et Universite Pierre et Marie Curie, Paris (France); Stoehlker, T. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik


    Recent progress in the study of the photon emission from highly-charged heavy ions is reviewed. These investigations show that high-Z ions provide a unique tool for improving the understanding of the electron-electron and electron-photon interaction in the presence of strong fields. Apart from the bound-state transitions, which are accurately described in the framework of quantum electrodynamics, much information has been obtained also from the radiative capture of (quasi-) free electrons by high-Z ions. Many features in the observed spectra hereby confirm the inherently relativistic behavior of even the simplest compound quantum systems in nature. (orig.)

  14. Spin polarized electron-positron pair production via elliptical polarized laser fields

    CERN Document Server

    Wöllert, Anton; Keitel, Christoph H


    We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.

  15. Ultrafast electron field emission from gold resonant antennas studied by two terahertz pulse experiments

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Zalkovskij, Maksim; Strikwerda, Andrew C.


    Summary form only given. Ultrafast electron field emission from gold resonant antennas induced by strong terahertz (THz) transient is investigated using two THz pulse experiments. It is shown that UV emission from nitrogen plasma generated by liberated electrons is a good indication of the local...... electric field at the antenna tip. Using this method resonant properties of antennas fabricated on high resistivity silicon are investigated in the strong field regime. Decrease of antenna Q-factor due to ultrafast carrier multiplication in the substrate is observed....

  16. Experimental Development of Low-emittance Field-emission Electron Sources

    Energy Technology Data Exchange (ETDEWEB)

    Lueangaranwong, A. [Northern Illinois Univ., DeKalb, IL (United States). Northern Illinois Center for Accelerator & Detector Development; Buzzard, C. [Northern Illinois Univ., DeKalb, IL (United States); Divan, R. [Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials; Korampally, V. [Northern Illinois Univ., DeKalb, IL (United States); Piot, P. [Northern Illinois Univ., DeKalb, IL (United States). Northern Illinois Center for Accelerator & Detector Development; Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)


    Field emission electron sources are capable of extreme brightness when excited by static or time-dependent electro- magnetic fields. We are currently developing a cathode test stand operating in DC mode with possibility to trigger the emission using ultra-short (~ 100-fs) laser pulses. This contribution describes the status of an experiment to investigate field-emission using cathodes under development at NIU in collaboration with the Argonne’s Center for Nanoscale Materials.

  17. In situ electromagnetic field diagnostics with an electron plasma in a Penning-Malmberg trap

    CERN Document Server

    Amole, C; Baquero-Ruiz, M.; Bertsche, W.; Butler, E.; Capra, A.; Cesar, C.L.; Charlton, M.; Deller, A.; Evetts, N.; Eriksson, S.; Fajans, J.; Friesen, T.; Fujiwara, M.C.; Gill, D.R.; Gutierrez, A.; Hangst, J.S.; Hardy, W.N.; Hayden, M.E.; Isaac, C.A.; Jonsell, S.; Kurchaninov, L.; Little, A.; Madsen, N.; McKenna, J.T.K.; Menary, S.; Napoli, S.C.; Olchanski, K.; Olin, A.; Pusa, P.; Rasmussen, C.; Robicheaux, F.; Sarid, E.; Silveira, D.M.; So, C.; Stracka, S.; Tharp, T.; Thompson, R.I.; van der Werf, D.P.; Wurtele, J.S.


    We demonstrate a novel detection method for the cyclotron resonance frequency of an electron plasma in a Penning-Malmberg trap. With this technique, the electron plasma is used as an in situ diagnostic tool for measurement of the static magnetic field and the microwave electric field in the trap. The cyclotron motion of the electron plasma is excited by microwave radiation and the temperature change of the plasma is measured non-destructively by monitoring the plasma's quadrupole mode frequency. The spatially-resolved microwave electric field strength can be inferred from the plasma temperature change and the magnetic field is found through the cyclotron resonance frequency. These measurements were used extensively in the recently reported demonstration of resonant quantum interactions with antihydrogen.

  18. Schrödinger Theory of Electrons in Electromagnetic Fields: New Perspectives

    Directory of Open Access Journals (Sweden)

    Viraht Sahni


    Full Text Available The Schrödinger theory of electrons in an external electromagnetic field is described from the new perspective of the individual electron. The perspective is arrived at via the time-dependent “Quantal Newtonian” law (or differential virial theorem. (The time-independent law, a special case, provides a similar description of stationary-state theory. These laws are in terms of “classical” fields whose sources are quantal expectations of Hermitian operators taken with respect to the wave function. The laws reveal the following physics: (a in addition to the external field, each electron experiences an internal field whose components are representative of a specific property of the system such as the correlations due to the Pauli exclusion principle and Coulomb repulsion, the electron density, kinetic effects, and an internal magnetic field component. The response of the electron is described by the current density field; (b the scalar potential energy of an electron is the work done in a conservative field. It is thus path-independent. The conservative field is the sum of the internal and Lorentz fields. Hence, the potential is inherently related to the properties of the system, and its constituent property-related components known. As the sources of the fields are functionals of the wave function, so are the respective fields, and, therefore, the scalar potential is a known functional of the wave function; (c as such, the system Hamiltonian is a known functional of the wave function. This reveals the intrinsic self-consistent nature of the Schrödinger equation, thereby providing a path for the determination of the exact wave functions and energies of the system; (d with the Schrödinger equation written in self-consistent form, the Hamiltonian now admits via the Lorentz field a new term that explicitly involves the external magnetic field. The new understandings are explicated for the stationary state case by application to two quantum

  19. Evaluation of nine genotypes of oilseed rape (Brassica napus L.) for larval infestation and performance of rape stem weevil (Ceutorhynchus napi Gyll.). (United States)

    Schaefer, Heike L; Brandes, Haiko; Ulber, Bernd; Becker, Heiko C; Vidal, Stefan


    The rape stem weevil, Ceutorhynchus napi Gyll., is a serious pest of winter oilseed rape (Brassica napus L.) crops in Europe causing severe yield loss. In currently used oilseed rape cultivars no resistance to C. napi has been identified. Resynthesized lines of B. napus have potential to broaden the genetic variability and may improve resistance to insect pests. In this study, the susceptibility to C. napi of three cultivars, one breeding line and five resynthesized lines of oilseed rape was compared in a semi-field plot experiment under multi-choice conditions. Plant acceptance for oviposition was estimated by counting the number of C. napi larvae in stems. The larval instar index and the dry body mass were assessed as indicators of larval performance. The extent of larval feeding within stems was determined by the stem injury coefficient. Morphological stem traits and stem contents of glucosinolates were assessed as potential mediators of resistance. The resynthesized line S30 had significantly fewer larvae than the cultivars Express617 and Visby and the resynthesized lines L122 and L16. The low level of larval infestation in S30 was associated with a low larval instar and stem injury index. Low numbers of larvae were not correlated with the length or diameter of stems, and the level of stem glucosinolates. As indicated by the low larval infestation and slow larval development the resistance of S30 to C. napi is based on both antixenotic and antibiotic properties of the genotypes. The resynthesized line S30 should therefore be introduced into B. napus breeding programs to enhance resistance against C. napi.

  20. Evaluation of nine genotypes of oilseed rape (Brassica napus L. for larval infestation and performance of rape stem weevil (Ceutorhynchus napi Gyll..

    Directory of Open Access Journals (Sweden)

    Heike L Schaefer

    Full Text Available The rape stem weevil, Ceutorhynchus napi Gyll., is a serious pest of winter oilseed rape (Brassica napus L. crops in Europe causing severe yield loss. In currently used oilseed rape cultivars no resistance to C. napi has been identified. Resynthesized lines of B. napus have potential to broaden the genetic variability and may improve resistance to insect pests. In this study, the susceptibility to C. napi of three cultivars, one breeding line and five resynthesized lines of oilseed rape was compared in a semi-field plot experiment under multi-choice conditions. Plant acceptance for oviposition was estimated by counting the number of C. napi larvae in stems. The larval instar index and the dry body mass were assessed as indicators of larval performance. The extent of larval feeding within stems was determined by the stem injury coefficient. Morphological stem traits and stem contents of glucosinolates were assessed as potential mediators of resistance. The resynthesized line S30 had significantly fewer larvae than the cultivars Express617 and Visby and the resynthesized lines L122 and L16. The low level of larval infestation in S30 was associated with a low larval instar and stem injury index. Low numbers of larvae were not correlated with the length or diameter of stems, and the level of stem glucosinolates. As indicated by the low larval infestation and slow larval development the resistance of S30 to C. napi is based on both antixenotic and antibiotic properties of the genotypes. The resynthesized line S30 should therefore be introduced into B. napus breeding programs to enhance resistance against C. napi.

  1. Female University Student and Staff Perceptions of Rape (United States)

    Herman, Michele H.; Sedlacek, William E.


    This study explores the fears of potential rape victims and the amount of information about rape and self-defense that such women possess. Many dimensions were found to explain the variability of responses among female members of the campus community. Suggestions for programs were offered. (Author/PC)

  2. "Corrective rape" of lesbians in the era of transformative ...

    African Journals Online (AJOL)

    There have been numerous incidents of “corrective” rape of lesbians in recent years. This article examines the adequacy of the existing South African legal framework to deal with incidents of “corrective” rape against the background of transformative constitutionalism. The various definitions of transformative ...

  3. Date rape among undergraduates in southwestern Nigeria federal ...

    African Journals Online (AJOL)

    Correlational survey design was adopted to examine the extent to which attitude towards date rape is associated with the respondents' emotional empathy, beliefs in rape myths and gender. Simple random sampling technique was adopted at three stages to draw one thousand two hundred and sixteen undergraduates ...

  4. Knowledge and Perceptions of Date Rape among Female ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    (Afr J Reprod Health 2013; 17[3]: 137-148). Keywords: Female undergraduate students, Date rape perception, Date rape-related knowledge. Introduction. Violence against women is a pervasive human rights abuse worldwide1,2. It is any act that results in, or may result in, physical, sexual or psychological harm or suffering ...

  5. Rape Myth Beliefs and Bystander Attitudes among Incoming College Students (United States)

    McMahon, Sarah


    Objective: The bystander approach to rape prevention is gaining popularity on college campuses, although research is limited. This study explored bystander attitudes and their relationship with rape myths in a sample of college students. Participants: Surveys from 2,338 incoming undergraduate students at a large, northeastern university were…

  6. The Experience of Male Rape in Non-Institutionalised Settings

    African Journals Online (AJOL)


    medical and psychological requirements of rape and sexual assault victims .... and can entail a higher degree of psychological manipulation rather ..... and happiness. Conclusion and Future Research. Among the primary observations evident in the descriptions obtained in this study is that the rape has tremendous power in ...

  7. A review of literature: rape and communication media strategies in ...

    African Journals Online (AJOL)

    Using historical-analytic methodology, this article reviews literature on rape and the communication strategies that can be used to address rape issues in Nigeria. In doing this, it critically engages communication theories as they apply to some communication media strategies that have been/can be deployed to redress the ...

  8. Rape Prevention with College Men: Evaluating Risk Status (United States)

    Stephens, Kari A.; George, William H.


    This study evaluates the effectiveness of a theoretically based rape prevention intervention with college men who were at high or low risk to perpetrate sexually coercive behavior. Participants (N = 146) are randomly assigned to the intervention or control group. Outcomes include rape myth acceptance, victim empathy, attraction to sexual…

  9. Understanding the innermost nature of genocidal rape: A community ...

    African Journals Online (AJOL)

    This article shows that existing explanations of wartime rapes that are the biosocial, cultural and war strategy approaches do not capture sufficiently the innermost nature of genocidal rape. It proposes a new theoretical framework, the community-based approach, and confronts its premises with the real-life experiences of ...

  10. Genotypic variation of rape in phosphorus uptake from sparingly ...

    African Journals Online (AJOL)



    Feb 14, 2012 ... were investigated to elucidate the contributions of root morphology and organic acids exudation to P uptake by rape from ... experiments, the activation capacity of insoluble Fe-P and Al-P of organic acids secreted by different rape genotypes roots ..... root morphology, root exudates, root architecture and.


    African Journals Online (AJOL)

    Fr. Ikenga

    connection is one which takes place otherwise than between husband and wife. A lot of issues arise ... It can therefore be said that rape is any sexual contact that is accompanied by penetration of whatever orifice of .... through its lens to look also at the Nigerian society which encourages offences of rape. It is a statement of ...

  12. [Rape: a social problem and a public health issue]. (United States)

    Piet, Emmanuelle


    The French legal definition of rape was somewhat vague until the 1970s. In December 1980, the increased awareness created by the feminist movement led to a precise legal definition and to the possibility for self-help groups to participate in legal actions. In 1985, a telephone helpline was created after several rapes were following several rapes committed in public. Since 1986, more than 39 000 women have called this hotline. Other recent studies confirm the frequency of rape. Major advances have been made in recent years, in terms of justice for minors who are victims of rape (lengthening of the statutory limitation on sexual crimes) and healthcare provision (opening of refuges, medical-legal consultations, victim management centers, greater awareness among healthcare professionals, etc.). Women need to be better informed of the frequency of rape, its legal implications, rapists' strategies, mental disorders, and the physical (especially gynecological) repercussions of rape. Women must also be aware that the rapist is the only guilty party. Finally, a multidisciplinary strategy is needed, notably involving self-help associations and hospital units that deal with rape victims.

  13. Acquaintance Rape on Campus: The Problem, the Victims, and Prevention. (United States)

    Neff, Laurie


    Asserts that, although providing educational programs and materials on acquaintance rape and prevention strategies is important, attention must also be given to victims. Discusses recognition of stress response pattern of victims suffering from Rape Trauma Syndrome and provision of appropriate referral and support services. Includes selected list…

  14. The emergency management of a rape case in a nutshell ...

    African Journals Online (AJOL)

    The management of a rape case in the emergency department is shrouded in an unacceptable level of lack of confidence. Since South Africa has a high incidence of rape, the contribution of health practitioners in addressing the crime successfully is essential. The medical management of such cases carries a high level of ...

  15. Rape, sexual politics and the construction of manhood among the ...

    African Journals Online (AJOL)

    Pascah Mungwini

    198). Burgess and Holmstrom (1974), in their analysis of the rape trauma syndrome, characterized rape as an act of violence which uses sex as a weapon. As will be highlighted below, the construction of Shona masculinity presents the male in contraposition to the female, thus attributing the active role to the male and the.

  16. Perception of Rape Amongst Secondary School Students In Port ...

    African Journals Online (AJOL)

    Alasia Datonye

    Background: Rape in children is a significant public health problem and represents the least reported but most devastating major form of child abuse all over the world. It occurs when one person does not fully and freely consent to sexual intercourse. This study seeks to evaluate the perception of rape among secondary ...

  17. Attitudes toward rape among Nigerian young adults: the role of ...

    African Journals Online (AJOL)

    Three hypotheses were tested with the independent group t-test. Attitudes of young adults toward rape was found to be different based on gender and parental family structure; male young adults had more positive attitudes toward rape than their female counterparts (t = 2.02, df = 318, p < .05); youth from polygamous family ...

  18. Psycho-legal challenges facing the mentally retarded rape victim

    African Journals Online (AJOL)


    Sep 3, 2011 ... against women and children is rife in South Africa, the country has been branded the 'rape capital of the world'. ... the criminal justice system, have regarded people with mental retardation as unreliable witnesses. ..... Another important role player in this legal battle is the police. If a rape survivor with mental ...

  19. The Influence of Rape Myth Acceptance and Situational Factors in ...

    African Journals Online (AJOL)

    Through mixed-method victimisation surveys that covered four universities in Lagos and Ogun states, involving 206 respondents and 12 in-depth interviewees, the study found that emotions and societal perception of rape are strong factors in determining personal conception and description of rape-like experiences.

  20. Simultaneous Bright-Field and Dark-Field Scanning Transmission Electron Microscopy in Scanning Electron Microscopy: A New Approach for Analyzing Polymer System Morphology (United States)

    Patel, Binay S.

    Scanning transmission electron microscopy in scanning electron microscopy (STEM-IN-SEM) is a convenient technique for polymer characterization. Utilizing the lower accelerating voltages, larger field of view and, exclusion of post-specimen projection lens in an SEM; STEM-IN-SEM has shown results comparable to transmission electron microscopy (TEM) observation of polymer morphology. Various specimen-holder geometries and detector arrangements have been used for bright field (BF) STEM-IN-SEM imaging. To further the characterization potential of STEM-IN-SEM a new specimen holder has been developed to facilitate simultaneous BF and dark field (DF) STEM-IN-SEM imaging. A new specimen holder and a new microscope configuration were designed for this new imaging technique. BF and DF signals were maximized for optimal STEM-IN-SEM imaging. BF signal intensities were found to be twice as large as DF signal intensities. BF and DF STEM-IN-SEM imaging spatial resolutions are limited to 1.8 nm and approximately 5 nm, respectively. Simultaneous BF & DF STEM-IN-SEM imaging is applicable to both industrial and academic research environments. Examples of commodity and engineering polymer morphology characterization are provided. Results are comparable to TEM observation and may serve as a suitable precursor to STEM characterization of polymer systems. Finally, future developments of various accessories for this technique are discussed.

  1. Spectrum of fast electrons in a dense gas in the presence of a nonuniform pulsed field (United States)

    Tkachev, A. N.; Yakovlenko, S. I.


    The problems of gas preionization in discharges related to laser physics are considered. The propagation of fast electrons injected from the cathode in the presence of a nonuniform nonstationary field and the motion of multiplying electrons at the edge of the avalanche in the presence of a nonuniform nonstationary field are simulated. The effect of the voltage pulse steepness and the field nonuniformity on the mean propagation velocity of fast electrons and their energy distribution is demonstrated. At certain combinations of the voltage pulse rise time and amplitude and at a certain time interval, the center of gravity of the electron cloud can move in the opposite direction relative to the direction of force acting upon electrons. It is also demonstrated that the number of hard particles (and, hence, the hard component of the x-ray bremsstrahlung) increases with both an increase in the voltage amplitude and a decrease in the pulse rise time. For nonoptimal conditions of the picosecond voltage pulse, an assumption is formulated: an electron beam in gas is formed due to the electrons at the edge of the avalanche rather than the background multiplication wave approaching the anode.

  2. Are pesticide residues in honey related to oilseed rape treatments? (United States)

    Karise, Reet; Raimets, Risto; Bartkevics, Vadims; Pugajeva, Iveta; Pihlik, Priit; Keres, Indrek; Williams, Ingrid H; Viinalass, Haldja; Mänd, Marika


    Pesticide treatments before and during the flowering of honey bee forage crops may lead to residues in honey. In northern regions oilseed rape belongs to the main forage crops that is mostly cultivated by means of intensive agriculture, including several pesticide treatments. However, in addition to the focal forage crops, pesticides from non-forage crops can spread to wild flowers around fields, and thus the residues in honey would reflect the whole range of pesticides used in the agricultural landscape. The aim of our study was to clarify which currently used pesticides are present in honey gathered from heterogeneous agricultural landscapes after the end of flowering of oilseed crops. Honey samples (N = 33) were collected from beehives of Estonia during 2013 and 2014, and analysed for residues of 47 currently used agricultural pesticides using the multiresidue method with HPLC-MS/MS and GC-MS and a single residue method for glyphosate, aminopyralid and clopyralid. Residues of eight different active ingredients with representatives from all three basic pesticide classes were determined. Although no correlation was detected between the cumulative amount of pesticide residues and percent of oilseed crops in the foraging territory, most of the residues are those allowed for oilseed rape treatments. Among all pesticides, herbicide residues prevailed in 2013 but not in 2014. Despite the relatively small agricultural impact of Estonia, the detected levels of pesticide residues sometimes exceeded maximum residue level; however, these concentrations do not pose a health risk to consumers, also acute toxicity to honey bees would be very unlikely. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Suspects in criminal investigations of rape

    Directory of Open Access Journals (Sweden)

    Marinković Darko


    Full Text Available Investigations of sexual assaults mostly focus on victims and their credibility, which may cause lack of firm evidence in relation to suspects. Given the fact that the criminal offence of rape is characterised by a high incidence of false reports and accusations, frequently indicating specific persons as the perpetrators, certain caution is necessary in the investigation in order to avoid false accusations and/or convictions. As regards the personality of the rapist and motives for committing a forcible sexual act, certain types or rather certain categories of perpetrators can be distinguished, although it should be noted that a large number of rapists do not belong to one category only, but rather combine characteristics of several different types. During a criminal investigation it is of vital importance to differentiate between a rape as a surprise attack and a rape as abuse of trust, as they are compatible with the nature of the suspect's defence. The suspect shall be subjected to a forensic examination in the course of the investigation in order to find traces which prove vaginal, anal or oral penetration, coerced sexual intercourse and identity of the rapist. While conducting an interrogation of a suspected rapist, a crime investigating officer shall use either factual or emotional approach to his interviewee, depending on his psychological and motivational characteristics. In this regard, the factual approach is believed to be more efficient with anger rapists and sadistic rapists, whereas the compassionate approach gives good results with the gentlemen-rapists and partly with the power asserting rapists.

  4. SU-E-T-432: Field Size Influence On the Electron and Photon Spectra Within Small MV Field Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Benmakhlouf, H; Andreo, P [Department of Medical Physics, Karolinska University Hospital, Stockholm and Department of Physics, Medical Radiation Physics, Stockholm University (Sweden)


    Purpose: To investigate the influence of photon field size on the electron and photon fluence spectra in the active volume of small field detectors. Methods: The PENELOPE MC system based usercode PenEasy was used to calculate the material influence on the spectra by scoring the differential fluence in inserts of silicon, carbon, phosphorus and aluminium having 3 mm diameter and height. The spectra were then calculated inside the active volume of eleven detectors (ion chambers and solid-state detectors) whose geometry was simulated with great detail. The inserts/detectors were placed at 10 cm depth in a 30 cm x 30 cm x 30 cm water phantom and irradiated with 2.5 MeV photons and Varian Clinac 6 MV beams of small, medium and large size. Results: For all configurations, photon spectra in the scoring volume were similar to that in a small water volume except for additional characteristic x-ray peaks resulting from the material itself and from the materials surrounding the detectors (i.e. high-Z shielding the silicon). Electron fluence calculated in the inserts were up to 60% larger than in water; the difference increased with material density and decreasing field size. MC-calculated doses were compared to analytically determined collision kerma and restricted cema (cut-off=15keV). For the inserts, with large and medium fields K-col agreed with MC-dose, but K-col overestimated the dose for small fields due to lack of lateral CPE. For the detectors, up to 15% differences between K-col and the MC-dose were found. For all configurations the C-delta and MC-dose agreed within ±2%. Conclusion: The most relevant findings were that shielding affects substantially the photon spectra and material conditions the electron spectra, their field size dependence varying with the geometry configuration. These affect the values of factors entering into relative dosimetry.

  5. Giving birth with rape in one's past: a qualitative study. (United States)

    Halvorsen, Lotta; Nerum, Hilde; Oian, Pål; Sørlie, Tore


    Rape is one of the most traumatizing violations a woman can be subjected to, and leads to extensive health problems, predominantly psychological ones. A large proportion of women develop a form of posttraumatic stress termed Rape Trauma Syndrome. A previous study by our research group has shown that women with a history of rape far more often had an operative delivery in their first birth and those who gave birth vaginally had second stages twice as long as women with no history of sexual assault. The aim of this study is to examine and illuminate how women previously subjected to rape experience giving birth for the first time and their advice on the kind of birth care they regard as good for women with a history of rape. A semi-structured interview with 10 women, who had been exposed to rape before their first childbirth. Data on the birth experience were analyzed by qualitative content analysis. The main theme was "being back in the rape" with two categories: "reactivation of the rape during labor," with subcategories "struggle," "surrender," and "escape" and "re-traumatization after birth," with the subcategories "objectified," "dirtied," and "alienated body." A rape trauma can be reactivated during the first childbirth regardless of mode of delivery. After birth, the women found themselves re-traumatized with the feeling of being dirtied, alienated, and reduced to just a body that another body is to come out of. Birth attendants should acknowledge that the common measures and procedures used during normal birth or cesarean section can contribute to a reactivation of the rape trauma. © 2013, Copyright the Authors Journal compilation © 2013, Wiley Periodicals, Inc.

  6. Imposed magnetic field and hot electron propagation in inertial fusion hohlraums (United States)

    Strozzi, David J.; Perkins, L. J.; Marinak, M. M.; Larson, D. J.; Koning, J. M.; Logan, B. G.


    > . The field's main hydrodynamic effect is to significantly reduce electron thermal conduction perpendicular to the field. This results in hotter and less dense plasma on the equator between the capsule and hohlraum wall. The inner laser beams experience less inverse bremsstrahlung absorption before reaching the wall. The X-ray drive is thus stronger from the equator with the imposed field. We study superthermal, or `hot', electron dynamics with the particle-in-cell code ZUMA, using plasma conditions from HYDRA. During the early-time laser picket, hot electrons based on two-plasmon decay in the laser entrance hole (Regan et al., Phys. Plasmas, vol. 17(2), 2010, 020703) are guided to the capsule by a 70 T field. Twelve times more energy deposits in the deuterium-tritium fuel. For plasma conditions early in peak laser power, we present mono-energetic test-case studies with ZUMA as well as sources based on inner-beam stimulated Raman scattering. The effect of the field on deuterium-tritium deposition depends strongly on the source location, namely whether hot electrons are generated on field lines that connect to the capsule.

  7. Hot electron reduction in two-plasmon-decay by magnetic fields (United States)

    Liu, Wenda; Ren, Chuang


    We performed PIC simulations on two-plasmon-decay (TPD) and associated hot electron generation under perpendicular magnetic fields of 10 and 100 T. TPD linear growth and saturation levels are not significantly changed. Hot electron generation is significantly reduced when B =100 T but not when B =10 T. The reduction is due to disruption of the staged acceleration of hot electron through their gyro-motion. The reduction affects the low-energy hot electrons more than high-energy ones. Magnetic field generation mechanisms in target corona will also be discussed. Work funded by DOE (DE-FC02-04ER54789, DE-SC0012316) and NSF (PHY-1314734).

  8. Charging and the cross-field discharge during electron accelerator operation on a rocket (United States)

    Kellogg, Paul J.; Monson, Steven J.


    Preliminary results are presented from experiments to study the neutralization processes around an electron beam emitting rocket. The rocket, SCEX II, was flown on January 31, 1987 from Alaska, with a payload consisting of two independent electron accelerators and two arms with conducting elements to act as Langmuir probes and to measure floating potentials. It was expected that electrons in the strong electric fields around the charged rocket would gain sufficient energy to ionize neutrals, producing ions which would be hurled outward at energies up to the rocket potential. Three hemispherical retarding potential analyzers were ejected from the main payload to measure these ions. The measurements show that fields sufficient to accelerate electrons to ionizing energies were present around the rocket.

  9. Energy Conversion Mechanism for Electron Perpendicular Energy in High Guide-Field Reconnection (United States)

    Guo, Xuehan; Horiuchi, Ritoku; Kaminou, Yasuhiro; Cheng, Frank; Ono, Yasushi


    The energy conversion mechanism for electron perpendicular energy, both the thermal and the kinetic energy, is investigated by means of two-dimensional, full-particle simulations in an open system. It is shown that electron perpendicular heating is mainly due to the breaking of magnetic moment conservation in separatrix region because the charge separation generates intense variation of electric field within the electron Larmor radius. Meanwhile, electron perpendicular acceleration takes place manly due to the polarization drift term as well as the curvature drift term of E . u⊥ in the downstream near the X-point. The enhanced electric field due to the charge separation there results in a significant effect of the polarization drift term on the dissipation of magnetic energy within the ion inertia length in the downstream. Japan Society for the Promotion of Science (JSPS) Fellows 15J03758.

  10. Direct Visualization of Local Electromagnetic Field Structures by Scanning Transmission Electron Microscopy. (United States)

    Shibata, Naoya; Findlay, Scott D; Matsumoto, Takao; Kohno, Yuji; Seki, Takehito; Sánchez-Santolino, Gabriel; Ikuhara, Yuichi


    The functional properties of materials and devices are critically determined by the electromagnetic field structures formed inside them, especially at nanointerface and surface regions, because such structures are strongly associated with the dynamics of electrons, holes and ions. To understand the fundamental origin of many exotic properties in modern materials and devices, it is essential to directly characterize local electromagnetic field structures at such defect regions, even down to atomic dimensions. In recent years, rapid progress in the development of high-speed area detectors for aberration-corrected scanning transmission electron microscopy (STEM) with sub-angstrom spatial resolution has opened new possibilities to directly image such electromagnetic field structures at very high-resolution. In this Account, we give an overview of our recent development of differential phase contrast (DPC) microscopy for aberration-corrected STEM and its application to many materials problems. In recent years, we have developed segmented-type STEM detectors which divide the detector plane into 16 segments and enable simultaneous imaging of 16 STEM images which are sensitive to the positions and angles of transmitted/scattered electrons on the detector plane. These detectors also have atomic-resolution imaging capability. Using these segmented-type STEM detectors, we show DPC STEM imaging to be a very powerful tool for directly imaging local electromagnetic field structures in materials and devices in real space. For example, DPC STEM can clearly visualize the local electric field variation due to the abrupt potential change across a p-n junction in a GaAs semiconductor, which cannot be observed by normal in-focus bright-field or annular type dark-field STEM imaging modes. DPC STEM is also very effective for imaging magnetic field structures in magnetic materials, such as magnetic domains and skyrmions. Moreover, real-time imaging of electromagnetic field structures can

  11. Electron beam relaxation in a beam-plasma discharge in crossed fields

    Energy Technology Data Exchange (ETDEWEB)

    Gadeev, K.K.; Erastov, E.M.; Ivanov, A.A.; Muksunov, A.M.; Nikiforov, V.A.; Severnyj, V.V.; Khripunov, B.I.; Shapkin, V.V. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii)

    Experimental investigation into production conditions of high- degree ionization plasma with an electron beam Usub(b)=5 kV, Isub(b)=0.7 A in crypton n/sub 0/=3x10/sup 12/ cm/sup -3/ in crossed electric and magnetic fields is stated. It is shown that resonance electric field can lead both to starting up of volume discharge-under these conditions electron beam power dissipation sharply increases, and discharge breakdown. Power dissipation increases when incresing magnetic field intensity from 8 to 12 kGs. Dependence of electron beam power dissipation on a longitudinal size of working volume has been investigated. A minimum length of the beam and gas interaction range, at which generation of volume discharge is still possible, has been determined. The data obtained can be useful during construction of a plasma centrifuge on the basis of beam-plasma discharge.

  12. Singlet triplet transition of a two-electron quantum ring in magnetic and electric fields (United States)

    Malet, F.; Pi, M.; Serra, Ll.; Lipparini, E.


    We present an exact numerical calculation of the spin phase diagram of a two-electron quantum ring as a function of an applied in-plane electric field E and a perpendicular magnetic field B. In general, large E and B favour, respectively, singlet and triplet states. At low fields, however, the spin phase diagram shows singlet-triplet oscillations and the formation of spin islands surrounded by the complementary phase. Calculations of the density dipole excitation spectrum as a function of the electric field are also reported.

  13. Modelling coronal electron density and temperature profiles based on solar magnetic field observations (United States)

    Rodríguez Gómez, J. M.; Antunes Vieira, L. E.; Dal Lago, A.; Palacios, J.; Balmaceda, L. A.; Stekel, T.


    The density and temperature profiles in the solar corona are complex to describe, the observational diagnostics is not easy. Here we present a physics-based model to reconstruct the evolution of the electron density and temperature in the solar corona based on the configuration of the magnetic field imprinted on the solar surface. The structure of the coronal magnetic field is estimated from Potential Field Source Surface (PFSS) based on magnetic field from both observational synoptic charts and a magnetic flux transport model. We use an emission model based on the ionization equilibrium and coronal abundances from CHIANTI atomic database 8.0. The preliminary results are discussed in details.

  14. Electric-field-induced interferometric resonance of a one-dimensional spin-orbit-coupled electron


    Jingtao Fan; Yuansen Chen; Gang Chen; Liantuan Xiao; Suotang Jia; Franco Nori


    The efficient control of electron spins is of crucial importance for spintronics, quantum metrology, and quantum information processing. We theoretically formulate an electric mechanism to probe the electron spin dynamics, by focusing on a one-dimensional spin-orbit-coupled nanowire quantum dot. Owing to the existence of spin-orbit coupling and a pulsed electric field, different spin-orbit states are shown to interfere with each other, generating intriguing interference-resonant patterns. We ...

  15. Late Adolescents' Perspectives on Marital Rape: The Impact of Gender and Fraternity/Sorority Membership. (United States)

    Auster, Carol J.; Leone, Janel M.


    Examined attitudes toward marital rape-in particular, the impact of gender and fraternity/sorority membership on respondents' views regarding marital rape versus rape by a stranger, as well as feelings about actions that a victim of marital rape may take. While fraternity and nonfraternity men showed significant differences in responses, sorority…

  16. Date Rape: Its Relationship to Trauma Symptoms and Sexual Self-Esteem. (United States)

    Shapiro, Brenda L.; Schwarz, J. Conrad


    Extends previous research on date rape by assessing trauma symptoms and sexual self-esteem among college women who had, or who had not, been raped. Results indicate that rape victims had significantly more trauma symptoms and lower sexual self-esteem compared to other women, thus suggesting date rape's significant consequences. (RJM)

  17. Mapping Above-Ground Biomass of Winter Oilseed Rape Using High Spatial Resolution Satellite Data at Parcel Scale under Waterlogging Conditions

    Directory of Open Access Journals (Sweden)

    Jiahui Han


    Full Text Available Oilseed rape (Brassica napus L. is one of the three most important oil crops in China, and is regarded as a drought-tolerant oilseed crop. However, it is commonly sensitive to waterlogging, which usually refers to an adverse environment that limits crop development. Moreover, crop growth and soil irrigation can be monitored at a regional level using remote sensing data. High spatial resolution optical satellite sensors are very useful to capture and resist unfavorable field conditions at the sub-field scale. In this study, four different optical sensors, i.e., Pleiades-1A, Worldview-2, Worldview-3, and SPOT-6, were used to estimate the dry above-ground biomass (AGB of oilseed rape and track the seasonal growth dynamics. In addition, three different soil water content field experiments were carried out at different oilseed rape growth stages from November 2014 to May 2015 in Northern Zhejiang province, China. As a significant indicator of crop productivity, AGB was measured during the seasonal growth stages of the oilseed rape at the experimental plots. Several representative vegetation indices (VIs obtained from multiple satellite sensors were compared with the simultaneously-collected oilseed rape AGB. Results showed that the estimation model using the normalized difference vegetation index (NDVI with a power regression model performed best through the seasonal growth dynamics, with the highest coefficient of determination (R2 = 0.77, the smallest root mean square error (RMSE = 104.64 g/m2, and the relative RMSE (rRMSE = 21%. It is concluded that the use of selected VIs and high spatial multiple satellite data can significantly estimate AGB during the winter oilseed rape growth stages, and can be applied to map the variability of winter oilseed rape at the sub-field level under different waterlogging conditions, which is very promising in the application of agricultural irrigation and precision agriculture.

  18. Widespread rape does not directly appear to increase the overall HIV prevalence in conflict-affected countries: so now what?

    Directory of Open Access Journals (Sweden)

    Mills Edward


    Full Text Available Abstract Background Sub-Saharan Africa (SSA is severely affected by HIV/AIDS and conflict. Sexual violence as a weapon of war has been associated with concerns about heightened HIV incidence among women. Widespread rape by combatants has been documented in Burundi, Sierra Leone, Rwanda, Democratic Republic of Congo, Liberia, Sudan and Uganda. To examine the assertion that widespread rape may not directly increase HIV prevalence at the population level, we built a model to determine the potential impact of varying scenarios of widespread rape on HIV prevalence in the above seven African countries. Discussion Our findings show that even in the most extreme situations, where 15% of the female population was raped, where HIV prevalence among assailants was 8 times the country population prevalence, and where the HIV transmission rate was highest at 4 times the average high rate, widespread rape increased the absolute HIV prevalence of these countries by only 0.023%. These projections support the finding that widespread rape in conflict-affected countries in SSA has not incurred a major direct population-level change in HIV prevalence. However, this must not be interpreted to say that widespread rape does not pose serious problems to women's acquisition of HIV on an individual basis or in specific settings. Furthermore, direct and indirect consequences of sexual violence, such as physical and psychosocial trauma, unwanted pregnancies, and stigma and discrimination cannot be understated. Summary The conclusions of this article do not significantly change current practices in the field from an operational perspective. Proper care and treatment must be provided to every survivor of rape regardless of the epidemiological effects of HIV transmission at the population level. Sexual violence must be treated as a protection issue and not solely a reproductive health and psychosocial issue. It is worth publishing data and conclusions that could be

  19. Theory and computation of few-electron atoms in intense laser fields

    CERN Document Server

    Moore, L


    experimental peak laser intensity measurement. At 780 nm preliminary results of a comparable calculation of double-ionization are given. In anticipation of a high intensity, high frequency radiation source becoming available in Germany by 2003, a calculation at 14 nm has also been performed. Momentum distributions have revealed the new process of double-electron above threshold ionization. In this process both electrons absorb excess photons during double-ionization. The study of the helium atom-exposed to an intense laser field forms the topic of this thesis. In the context of laser-atom interactions, a laser is said to be intense if the force it exerts on an electron in an atomic orbital is comparable to the force experienced by that electron due to the binding atomic potential. The electronic response of the helium atom to an intense laser field is governed by the interactions of the two electrons between themselves, with the nucleus and with the field. The problem therefore is the fundamental three-body p...

  20. Electron impact ionization in the Martian atmosphere: Interplay between scattering and crustal magnetic field effects (United States)

    Lillis, Robert J.; Fang, Xiaohua


    Precipitating electrons are typically the dominant source of energy input into Mars' nighttime upper atmosphere, with consequences for atmospheric and ionospheric structure, composition, chemistry, and electrodynamics. Mars' spatially heterogeneous crustal magnetic fields affect the fluxes of precipitating electrons, via both the magnetic mirror force and Gauss' law of conservation of magnetic flux. We use a kinetic electron transport model to examine ionization rate profiles that result from the combination of these magnetic effects and elastic and inelastic scattering by atmospheric neutrals. Specifically, we calculate ionization rates as a function of altitude, crustal magnetic field strength, and the initial energy and pitch angle of the precipitating electrons, covering the relevant ranges of these parameters. Several complex behaviors are exhibited, including bifurcating ionization peaks with distinct characteristics and energy-dependent and crustal field strength-dependent increases in ionization with decreasing pitch angle. Elucidating such behavior is important for understanding the effect of Mars' unique crustal fields on the Mars upper atmosphere and ionosphere, both to predict the consequences of measured electron precipitation and to enable, for the first time, downward coupling of global plasma models with thermosphere-ionosphere models.

  1. Dynamical characteristics of Rydberg electrons released by a weak electric field

    CERN Document Server

    Diesen, Elias; Richter, Martin; Kunitski, Maksim; Dörner, Reinhard; Rost, Jan M


    The dynamics of ultra-slow electrons in the combined potential of an ionic core and a static electric field is discussed. With state-of-the-art detection it is possible to create such electrons through strong intense-field photo-absorption and to detect them via high-resolution time-of-flight spectroscopy despite their very low kinetic energy. The characteristic feature of their momentum spectrum, which emerges at the same position for different laser orientations, is derived and could be revealed experimentally with an energy resolution of the order of 1meV.

  2. Imaging the atomic orbitals of carbon atomic chains with field-emission electron microscopy (United States)

    Mikhailovskij, I. M.; Sadanov, E. V.; Mazilova, T. I.; Ksenofontov, V. A.; Velicodnaja, O. A.


    A recently developed high-field technique of atomic chains preparation has made it possible to attain the ultrahigh resolution of field-emission electron microscopy (FEEM), which can be used to direct imaging the intra-atomic electronic structure. By applying cryogenic FEEM, we are able to resolve the spatial configuration of atomic orbitals, which correspond to quantized states of the end atom in free-standing carbon atomic chains. Knowledge of the intra-atomic structure will make it possible to visualize generic aspects of quantum mechanics and also lead to approaches for a wide range of nanotechnological applications.

  3. Chirped Auger electron emission due to field-assisted post-collision interaction

    Directory of Open Access Journals (Sweden)

    Bonitz M.


    Full Text Available We have investigated the Auger decay in the temporal domain by applying a terahertz streaking light field. Xenon and krypton atoms were studied by implementing the free-electron laser in Hamburg (FLASH as well as a source of high-order harmonic radiation combined with terahertz pulses from an optical rectification source. The observed linewidth asymmetries in the streaked spectra suggest a chirped Auger electron emission which is understood in terms of field-assisted post-collision interaction. The experimentally obtained results agree well with model calculations.

  4. Measurements of hot electrons in the Extrap T1 reversed-field pinch (United States)

    Welander, A.; Bergsåker, H.


    The presence of an anisotropic energetic electron population in the edge region is a characteristic feature of reversed-field pinch (RFP) plasmas. In the Extrap T1 RFP, the anisotropic, parallel heat flux in the edge region measured by calorimetry was typically several hundred 0741-3335/40/2/011/img1. To gain more insight into the origin of the hot electron component and to achieve time resolution of the hot electron flow during the discharge, a target probe with a soft x-ray monitor was designed, calibrated and implemented. The x-ray emission from the target was measured with a surface barrier detector covered with a set of different x-ray filters to achieve energy resolution. A calibration in the range 0.5-2 keV electron energy was performed on the same target and detector assembly using a 0741-3335/40/2/011/img2 cathode electron gun. The calibration data are interpolated and extrapolated numerically. A directional asymmetry of more than a factor of 100 for the higher energy electrons is observed. The hot electrons are estimated to constitute 10% of the total electron density at the edge and their energy distribution is approximated by a half-Maxwellian with a temperature slightly higher than the central electron temperature. Scalings with plasma current, as well as correlations with local 0741-3335/40/2/011/img3 measurements and radial dependences, are presented.

  5. Analytic description of elastic electron-atom scattering in an elliptically polarized laser field (United States)

    Flegel, A. V.; Frolov, M. V.; Manakov, N. L.; Starace, Anthony F.; Zheltukhin, A. N.


    An analytic description of laser-assisted electron-atom scattering (LAES) in an elliptically polarized field is presented using time-dependent effective range (TDER) theory to treat both electron-laser and electron-atom interactions nonperturbatively. Closed-form formulas describing plateau features in LAES spectra are derived quantum mechanically in the low-frequency limit. These formulas provide an analytic explanation for key features of the LAES differential cross section. For the low-energy region of the LAES spectrum, our result generalizes the Kroll-Watson formula to the case of elliptic polarization. For the high-energy (rescattering) plateau in the LAES spectrum, our result generalizes prior results for a linearly polarized field valid for the high-energy end of the rescattering plateau [Flegel , J. Phys. BJPAPEH0953-407510.1088/0953-4075/42/24/241002 42, 241002 (2009)] and confirms the factorization of the LAES cross section into three factors: two field-free elastic electron-atom scattering cross sections (with laser-modified momenta) and a laser field-dependent factor (insensitive to the scattering potential) describing the laser-driven motion of the electron in the elliptically polarized field. We present also approximate analytic expressions for the exact TDER LAES amplitude that are valid over the entire rescattering plateau and reduce to the three-factor form in the plateau cutoff region. The theory is illustrated for the cases of e-H scattering in a CO2-laser field and e-F scattering in a midinfrared laser field of wavelength λ=3.5μm, for which the analytic results are shown to be in good agreement with exact numerical TDER results.

  6. New Statistical Multiparticle Approach to the Acceleration of Electrons by the Ion Field in Plasmas

    Directory of Open Access Journals (Sweden)

    Eugene Oks


    Full Text Available The phenomenon of the acceleration of the (perturbing electrons by the ion field (AEIF significantly reduces Stark widths and shifts in plasmas of relatively high densities and/or relatively low temperature. Our previous analytical calculations of the AEIF were based on the dynamical treatment: the starting point was the ion-microfield-caused changes of the trajectories and velocities of individual perturbing electrons. In the current paper, we employ a statistical approach: the starting point is the electron velocity distribution function modified by the ion microfield. The latter had been calculated by Romanovsky and Ebeling in the multiparticle description of the ion microfield. The result shows again the reduction of the electron Stark broadening. Thus two totally different analytical approaches (dynamical and statistical agree with each other and therefore disprove the corresponding recent fully-numerical simulations by Stambulchik et al. that claimed an increase of the electron Stark broadening.

  7. Field Distribution of a Planar Electrostatic Wiggler and Modulation Effect on the Motion of Relativistic Electrons (United States)

    Zhang, Shi-Chang


    A planar electrostatic wiggler is formed by two parallel metallic plates, where the upper-plate is corrugated with sinusoidal ripples and connected to a negative voltage and the lower-plate is smooth and grounded. The field distribution is mathematically derived in detail. It is demonstrated that this planar electrostatic wiggler can efficiently modulate the motion of relativistic electrons just as a magneto-static wiggler does in a free-electron laser. Results obtained here will provide basis to analyze the amplification mechanism of a fast wave by a relativistic electron beam in a planar electrostatic wiggler.

  8. Cathodoluminescence-activated nanoimaging: noninvasive near-field optical microscopy in an electron microscope. (United States)

    Bischak, Connor G; Hetherington, Craig L; Wang, Zhe; Precht, Jake T; Kaz, David M; Schlom, Darrell G; Ginsberg, Naomi S


    We demonstrate a new nanoimaging platform in which optical excitations generated by a low-energy electron beam in an ultrathin scintillator are used as a noninvasive, near-field optical scanning probe of an underlying sample. We obtain optical images of Al nanostructures with 46 nm resolution and validate the noninvasiveness of this approach by imaging a conjugated polymer film otherwise incompatible with electron microscopy due to electron-induced damage. The high resolution, speed, and noninvasiveness of this "cathodoluminescence-activated" platform also show promise for super-resolution bioimaging.

  9. On the electric breakdown field of the mesosphere and the influence of electron detachment

    DEFF Research Database (Denmark)

    Neubert, Torsten; Chanrion, Olivier Arnaud


    It has been suggested recently that electron associative detachment from negative atomic oxygen ions provides an additional source of free electrons in electric discharges of the mesosphere, the sprites, and gigantic jets. Here we study attachment under some simplifying assumptions and show...... for electron avalanches to grow. Detachment is likely to affect the conductivity of streamer filaments and other long-lasting space charge structures like gigantic jets or the ionization state of the mesosphere when illuminated by thunderstorm fields. Detachment by itself does not directly affect small...

  10. Electromagnetic microwaves in metal films with electron-phonon interaction and a dc magnetic field

    DEFF Research Database (Denmark)

    Hasselberg, L.E.


    A quantum-mechanical treatment of electromagnetic microwaves is performed for a metal film. The directions of the exterior ac and dc fields are taken to be arbitrary and boundary conditions for the electrons are assumed to be specular. The relation between the current and the electromagnetic fiel...... in the transmission spectrum can perhaps be obtained by assuming a finite Debye temperature and specular reflections of the electrons at the boundary surfaces. A sharp peak entirely caused by the finite electron-phonon interaction is also discussed....

  11. Free-Free Transitions in the Presence of Laser Fields at Very Low Incident Electron Energy (United States)

    Bhatia, A. K.; Sinha, Chandana


    We study the free-free transition in electron-hydrogenic systems in ground state in presence of an external laser field at very loud incident energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen to be monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser in a nonperturbative manner by choosing a Volkov wave function for it. The scattering weave function for the electron is solved numerically by taking into account the effect of the electron exchange, short-range as well as of the long-range interactions to get the S and P wave phase shifts while for the higher angular momentum phase shifts the exchange approximation has only been considered. We calculate the laser assisted differential cross sections (LADCS) for the aforesaid free-free transition process for single photon absorption/emission. The laser intensity is chosen to be much less than the atomic field intensity. A strong suppression is noted in the LADCS as compared to the field free (FF) cross sections. Unlike the FF ones, the LADCS exhibit some oscillations having a distinct maximum at a low value of the scattering angle depending on the laser parameters as well as on the incident energies.

  12. Characterization of fast photoelectron packets in weak and strong laser fields in ultrafast electron microscopy. (United States)

    Plemmons, Dayne A; Tae Park, Sang; Zewail, Ahmed H; Flannigan, David J


    The development of ultrafast electron microscopy (UEM) and variants thereof (e.g., photon-induced near-field electron microscopy, PINEM) has made it possible to image atomic-scale dynamics on the femtosecond timescale. Accessing the femtosecond regime with UEM currently relies on the generation of photoelectrons with an ultrafast laser pulse and operation in a stroboscopic pump-probe fashion. With this approach, temporal resolution is limited mainly by the durations of the pump laser pulse and probe electron packet. The ability to accurately determine the duration of the electron packets, and thus the instrument response function, is critically important for interpretation of dynamics occurring near the temporal resolution limit, in addition to quantifying the effects of the imaging mode. Here, we describe a technique for in situ characterization of ultrashort electron packets that makes use of coupling with photons in the evanescent near-field of the specimen. We show that within the weakly-interacting (i.e., low laser fluence) regime, the zero-loss peak temporal cross-section is precisely the convolution of electron packet and photon pulse profiles. Beyond this regime, we outline the effects of non-linear processes and show that temporal cross-sections of high-order peaks explicitly reveal the electron packet profile, while use of the zero-loss peak becomes increasingly unreliable. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Locally Resolved Electron Emission Area and Unified View of Field Emission from Ultrananocrystalline Diamond Films

    Energy Technology Data Exchange (ETDEWEB)

    Chubenko, Oksana [Department of Physics, The George Washington University, 725 21st Street NW, Washington, D.C. 20052, United States; Euclid TechLabs, 365 Remington Boulevard, Bolingbrook, Illinois 60440, United States; Baturin, Stanislav S. [PSD Enrico; Kovi, Kiran K. [Euclid TechLabs, 365 Remington Boulevard, Bolingbrook, Illinois 60440, United States; Sumant, Anirudha V. [Center for Nanoscale Materials, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States; Baryshev, Sergey V. [Euclid TechLabs, 365 Remington Boulevard, Bolingbrook, Illinois 60440, United States


    One of the common problems in case of field emission from polycrystalline diamond films, which typically have uniform surface morphology, is uncertainty in determining exact location of electron emission sites across the surface. Although several studies have suggested that grain boundaries are the main electron emission source, it is not particularly clear what makes some sites emit more than the others. It is also practically unclear how one could quantify the actual electron emission area and therefore field emission current per unit area. In this paper we study the effect of actual, locally resolved, field emission (FE) area on electron emission characteristics of uniform planar highly conductive nitrogen-incorporated ultrananocrystalline diamond ((N)UNCD) field emitters. It was routinely found that field emission from as-grown planar (N)UNCD films is always confined to a counted number of discrete emitting centers across the surface which varied in size and electron emissivity. It was established that the actual FE area critically depends on the applied electric field, as well as that the actual FE area and the overall electron emissivity improve with sp2 fraction present in the film irrespectively of the original substrate roughness and morphology. To quantify the actual FE area and its dependence on the applied electric field, imaging experiments were carried out in a vacuum system in a parallel-plate configuration with a specialty anode phosphor screen. Electron emission micrographs were taken concurrently with I-V characteristics measurements. In addition, a novel automated image processing algorithm was developed to process extensive imaging datasets and calculate emission area per image. By doing so, it was determined that the emitting area was always significantly smaller than the FE cathode surface area. Namely, the actual FE area would change from 5×10-3 % to 1.5 % of the total cathode area with the applied electric field increased. Finally and most

  14. Field electron emission from hydrogen plasma treated nano-ZnO thin films. (United States)

    Wang, Xiao-Ping; Liu, Xin-Xin; Wang, Li-Jun; Li, Huai-Hui; Mei, Cui-Yu; Liu, Xiao-Fei; Can, Yang


    A nano-Zno films are deposited on the Mo film/ceramic substrates by using the electron beam vapor deposition technique. Then a hydrogen plasma treated method is used to improve the characteristics of ZnO thin films by microwave plasma chemical vapor deposition system. Effects of process parameters on morphologies and structures of the ZnO thin films are detected and analysed by field emission scanning electron microscopy, X-ray diffraction spectrum and energy dispersive spectrum. The experimental result indicates that the hydrogen plasma treated techniques can essentially reduce the surface resistance and improve the field emission current density of the nano-ZnO thin films. For the hydrogen plasma treated sample, its field emission current density can increased more than three times at 2.2 V/microm electric field condition.

  15. Effect of electron-to-ion mass ratio on radial electric field generation in tokamak (United States)

    Li, Zhenqian; Dong, Jiaqi; Sheng, Zhengmao; Yu, M. Y.; Wang, Weixing


    Generation of coherent radial electric fields in plasma by drift-wave turbulence driven by plasma inhomogeneities is ab initio studied using gyro-kinetic particle simulation for conditions of operational tokamaks. In particular, the effect of the electron-to-ion mass ratio ɛ on the entire evolution of the plasma is considered. It is found that the electric field can be increased, and the turbulence-induced particle transport reduced, by making ɛ smaller, in agreement with many existing experimental observations.

  16. Electron spin resonance study of the demagnetization fields of the ferromagnetic and paramagnetic films

    Directory of Open Access Journals (Sweden)

    I.I. Gimazov, Yu.I. Talanov


    Full Text Available The results of the electron spin resonance study of the La1-xCaxMnO3 manganite and the diphenyl-picrylhydrazyl thin films for the magnetic field parallel and perpendicular to plane of the films are presented. The temperature dependence of the demagnetizing field is obtained. The parameters of the Curie-Weiss law are estimated for the paramagnetic thin film.

  17. A review of electron bombardment thruster systems/spacecraft field and particle interfaces (United States)

    Byers, D. C.


    This paper collates and summarizes information on the field and particle interfaces of electron bombardment ion thruster systems. Major areas discussed are the nonpropellant particles, neutral propellant, ion beam, low energy plasma, and fields. Spacecraft functions and subsystems reviewed are solar arrays, thermal control systems, optical sensors, communications, science, structures and materials, and potential control. An appendix is included to facilitate identification of specific interaction areas.

  18. Rape-accepting attitudes of university undergraduate students. (United States)

    Talbot, Kimberly K; Neill, Karen S; Rankin, Linda L


    The College Date Rape Attitudes Survey and the Attitudes Toward Women Scale were used in a cross-sectional study to assess rape-accepting attitudes of a convenience sample of 1602 university undergraduate students using a survey distributed online. The findings evidenced that males and individuals with more traditional gender role beliefs had attitudes more accepting of rape than the females and individuals who had more egalitarian gender role beliefs. Respondents who personally knew a rape survivor had attitudes less accepting of rape than those respondents who did not know a survivor. These findings support a continuing need to address rape myths in sexual violence prevention programming. The sexual assault nurse examiner (SANE-A) has an important role in prevention services to educate and build awareness of rape myths both on campus and through community-based efforts to reach this high risk population. Further, the SANE can build important linkages between the college campus and the healthcare setting to support the provision of effective intervention services and improved outcomes in victims of sexual violence. © 2010 International Association of Forensic Nurses.

  19. Genocide Rape Trauma Management: An Integrated Framework for Supporting Survivors. (United States)

    Mukamana, Donatilla; Brysiewicz, Petra; Collins, Anthony; Rosa, William


    During the 1994 Rwandan genocide, rape was widely used as a strategic weapon against Tutsi women. More than 20 years later, many of these women are still suffering devastating psychological, social, and physical effects of these experiences and remain in need of effective interventions that address their complex trauma. This article develops the theory of genocide rape trauma management as a conceptual framework for promoting the holistic health and recovery of female genocide rape survivors. A qualitative study using grounded theory explored the lived experiences of genocide rape survivors and led to the development of this model. The need for a contextually appropriate model is highlighted, with historical and current data regarding the Rwandan context and the experiences of genocide rape survivors. The research details the complex dynamics of emotional, physical, existential, and psychosocial sequelae related to genocide rape trauma, and how these interact with both local community and broader political attitudes toward survivors, as well as the serious interrelated economic challenges and limitations in current public health and welfare services. The research demonstrates the necessary elements of a holistic approach encompassing a synergistic combination of skilled psychological care, self-help strategies, collaborative support groups, community education, social reintegration, advocacy, accessible medical care, and economic empowerment. These interacting elements form the basis of the theory of genocide rape trauma management, offering an encompassing integrated framework that can be adapted to, and evaluated in, other similar contexts.

  20. Kinetic Alfven Waves Carrying Intense Field Aligned Currents: Particle Trapping and Electron Acceleration (United States)

    Rankin, R.; Artemyev, A.


    It is now common knowledge that dispersive scale Alfvén waves can drive parallel electron acceleration [Lotko et al., JGR, 1998; Samson et al., Ann. Geophys., 2003; Wygant et al., JGR, 2002] and transverse ion energization in the auroral zone and inner magnetosphere [Johnson and Cheng, JGR, 2001; Chaston et al., 2004]. In this paper we show that relatively low energy electrons (plasma sheet electrons with energies ranging up to ˜100 eV) can be accelerated very efficiently as they interact nonlinearly with kinetic Alfvén waves (KAWs) that carry intense field aligned currents from the equatorial plane toward the ionosphere in the inner magnetosphere. We propose a theoretical model describing electron trapping into an effective wave potential generated by parallel wave electric fields (with perpendicular wavelengths on the order of the ion gyro-radius) and the mirror force acting on electrons as they propagate along geomagnetic field lines. We demonstrate that waves with an electric potential amplitude between ~100 - 400 V can trap and accelerate electrons to energies approaching several keVs. Trapping acceleration corresponds to conservation of the electron magnetic moment and, thus, results in a significant decrease of the electron equatorial pitch-angle with time. Analytical and numerical estimates of the maximum energy and probability of trapping are presented. We discuss the application of the proposed model in light of recent observations of electromagnetic fluctuations in the inner magnetosphere that are present during periods of strong geomagnetic activity [Chaston et al., GRL, 2014; Califf et al., JGR, 2015].

  1. Attosecond Interference Induced by Coulomb-Field-Driven Transverse Backward-Scattering Electron Wave-Packets

    CERN Document Server

    Song, Xiaohong; Lin, Cheng; Sheng, Zhihao; Yu, Xianhuan; Yang, Weifeng; Hu, Shilin; Chen, Jing; Xu, SongPo; Chen, YongJu; Quan, Wei; Liu, XiaoJun


    A novel and universal interference structure is found in the photoelectron momentum distribution of atoms in intense infrared laser field. Theoretical analysis shows that this structure can be attributed to a new form of Coulomb-field-driven backward-scattering of photoelectrons in the direction perpendicular to the laser field, in contrast to the conventional rescattering along the laser polarization direction. This transverse backward-scattering process is closely related to a family of photoelectrons initially ionized within a time interval of less than 200 attosecond around the crest of the laser electric field. Those electrons, acquiring near-zero return energy in the laser field, will be pulled back solely by the ionic Coulomb field and backscattered in the transverse direction. Moreover, this rescattering process mainly occurs at the first or the second return times, giving rise to different phases of the photoelectrons. The interference between these photoelectrons leads to unique curved interference ...

  2. Ion sense of polarization of the electromagnetic wave field in the electron whistler frequency band

    Directory of Open Access Journals (Sweden)

    B. Lundin


    Full Text Available It is shown that the left-hand (or ion-type sense of polarization can appear in the field interference pattern of two plane electron whistler waves. Moreover, it is demonstrated that the ion-type polarized wave electric fields can be accompanied by the presence at the same observation point of electron-type polarized wave magnetic fields. The registration of ion-type polarized fields with frequencies between the highest ion gyrofrequency and the electron gyrofrequency in a cold, overdense plasma is a sufficient indication for the existence of an interference wave pattern, which can typically occur near artificial or natural reflecting magnetospheric plasma regions, inside waveguides (as in helicon discharges, for example, in fields resonantly emitted by beams of charged particles or, in principle, in some self-sustained, nonlinear wave field structures. A comparison with the conventional spectral matrix data processing approach is also presented in order to facilitate the calculations of the analyzed polarization parameters.Key words. Ionosphere (wave propagation Radio science (waves in plasma Space plasma physics (general or miscellaneous

  3. Ion sense of polarization of the electromagnetic wave field in the electron whistler frequency band

    Directory of Open Access Journals (Sweden)

    B. Lundin

    Full Text Available It is shown that the left-hand (or ion-type sense of polarization can appear in the field interference pattern of two plane electron whistler waves. Moreover, it is demonstrated that the ion-type polarized wave electric fields can be accompanied by the presence at the same observation point of electron-type polarized wave magnetic fields. The registration of ion-type polarized fields with frequencies between the highest ion gyrofrequency and the electron gyrofrequency in a cold, overdense plasma is a sufficient indication for the existence of an interference wave pattern, which can typically occur near artificial or natural reflecting magnetospheric plasma regions, inside waveguides (as in helicon discharges, for example, in fields resonantly emitted by beams of charged particles or, in principle, in some self-sustained, nonlinear wave field structures. A comparison with the conventional spectral matrix data processing approach is also presented in order to facilitate the calculations of the analyzed polarization parameters.

    Key words. Ionosphere (wave propagation Radio science (waves in plasma Space plasma physics (general or miscellaneous

  4. SEM technique for imaging and measuring electronic transport in nanocomposites based on electric field induced contrast (United States)

    Jesse, Stephen [Knoxville, TN; Geohegan, David B [Knoxville, TN; Guillorn, Michael [Brooktondale, NY


    Methods and apparatus are described for SEM imaging and measuring electronic transport in nanocomposites based on electric field induced contrast. A method includes mounting a sample onto a sample holder, the sample including a sample material; wire bonding leads from the sample holder onto the sample; placing the sample holder in a vacuum chamber of a scanning electron microscope; connecting leads from the sample holder to a power source located outside the vacuum chamber; controlling secondary electron emission from the sample by applying a predetermined voltage to the sample through the leads; and generating an image of the secondary electron emission from the sample. An apparatus includes a sample holder for a scanning electron microscope having an electrical interconnect and leads on top of the sample holder electrically connected to the electrical interconnect; a power source and a controller connected to the electrical interconnect for applying voltage to the sample holder to control the secondary electron emission from a sample mounted on the sample holder; and a computer coupled to a secondary electron detector to generate images of the secondary electron emission from the sample.

  5. Luminescent tracks of high-energy photoemitted electrons accelerated by plasmonic fields

    Directory of Open Access Journals (Sweden)

    Di Vece Marcel


    Full Text Available The emission of an electron from a metal nanostructure under illumination and its subsequent acceleration in a plasmonic field forms a platform to extend these phenomena to deposited nanoparticles, which can be studied by state-of-the-art confocal microscopy combined with femtosecond optical excitation. The emitted and accelerated electrons leave defect tracks in the immersion oil, which can be revealed by thermoluminescence. These photographic tracks are read out with the confocal microscope and have a maximum length of about 80 μm, which corresponds to a kinetic energy of about 100 keV. This energy is consistent with the energy provided by the intense laser pulse combined with plasmonic local field enhancement. The results are discussed within the context of the rescattering model by which electrons acquire more energy. The visualization of electron tracks originating from plasmonic field enhancement around a gold nanoparticle opens a new way to study with confocal microscopy both the plasmonic properties of metal nano objects as well as high energy electron interaction with matter.

  6. Chemical ionization mass spectrometry using carbon nanotube field emission electron sources. (United States)

    Radauscher, Erich J; Keil, Adam D; Wells, Mitch; Amsden, Jason J; Piascik, Jeffrey R; Parker, Charles B; Stoner, Brian R; Glass, Jeffrey T


    A novel chemical ionization (CI) source has been developed based on a carbon nanotube (CNT) field emission electron source. The CNT-based electron source was evaluated and compared with a standard filament thermionic electron source in a commercial explosives trace detection desktop mass spectrometer. This work demonstrates the first reported use of a CNT-based ion source capable of collecting CI mass spectra. Both positive and negative modes were investigated. Spectra were collected for a standard mass spectrometer calibration compound, perfluorotributylamine (PFTBA), as well as trace explosives including trinitrotoluene (TNT), Research Department explosive (RDX), and pentaerythritol tetranitrate (PETN). The electrical characteristics, lifetime at operating pressure, and power requirements of the CNT-based electron source are reported. The CNT field emission electron sources demonstrated an average lifetime of 320 h when operated in constant emission mode under elevated CI pressures. The ability of the CNT field emission source to cycle on and off can provide enhanced lifetime and reduced power consumption without sacrificing performance and detection capabilities. Graphical Abstract ᅟ.

  7. Field Emission Vacuum (FEV) Electronic Devices for Operation Above 500 Degrees Celsius (United States)

    Peltz, L.; Jones, W. M.; Frampton, R. V.; Keith, A. R.; Scherer, A.


    Boeing is teamed with Caltech to develop FEV (Field-Emission Vacuum) electronics. Our Boeing-Caltech team has recently begun work, under NASA ROSES C.24 HOTTech program, to demonstrate robust FEV operating at 500C, towards Venus surface missions.

  8. Synthesis of carbon nanofibres from waste chicken fat for field electron emission applications

    Energy Technology Data Exchange (ETDEWEB)

    Suriani, A.B., E-mail: [Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak 35900 (Malaysia); Department of Physics, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak 35900 (Malaysia); Dalila, A.R. [Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak 35900 (Malaysia); Department of Physics, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak 35900 (Malaysia); Mohamed, A.; Isa, I.M.; Kamari, A.; Hashim, N. [Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak 35900 (Malaysia); Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak 35900 (Malaysia); Soga, T.; Tanemura, M. [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan)


    Highlights: • Waste chicken fat is used as a starting material to produce CNFs via TCVD method. • High heating rate applied resulted in aggregation of catalyst particles. • Aggregated catalyst produced sea urchin-like CNFs with amorphous nature. • The as-grown CNFs presented a potential for field electron emission applications. - Abstract: Carbon nanofibres (CNFs) with sea urchin-like morphology were synthesised from waste chicken fat precursor via catalytic thermal chemical vapour deposition method at 750 °C. The CNFs showed amorphous structures under high-resolution transmission electron microscopy, micro-Raman spectroscopy and X-ray diffraction examination. X-ray photoelectron spectroscopy analysis confirmed that the core of the sea urchin-like CNFs was composed of Fe{sub 3}C formed within the first 20 min of synthesis time. The growth of amorphous CNFs from agglomerated Fe{sub 3}C particles was favourable due to the high heating rate applied during the synthesis. Field electron emission examination of the CNFs indicated turn-on and threshold field values of 5.4 and 6.6 V μm{sup −1} at current density of 1 and 10 μA cm{sup −2}, respectively. This study demonstrates that waste chicken fat, a low-cost and readily available resource, can be used as an inexpensive carbon source for the production of CNFs with a potential application in field electron emitters.

  9. Hot electrons injection in carbon nanotubes under the influence of quasi-static ac-field (United States)

    Amekpewu, M.; Mensah, S. Y.; Musah, R.; Mensah, N. G.; Abukari, S. S.; Dompreh, K. A.


    The theory of hot electrons injection in carbon nanotubes (CNTs) where both dc electric field (Ez), and a quasi-static ac field exist simultaneously (i.e. when the frequency ω of ac field is much less than the scattering frequency v (ω ⪡ v or ωτ ⪡ 1, v =τ-1) where τ is relaxation time) is studied. The investigation is done theoretically by solving semi-classical Boltzmann transport equation with and without the presence of the hot electrons source to derive the current densities. Plots of the normalized current density versus dc field (Ez) applied along the axis of the CNTs in the presence and absence of hot electrons reveal ohmic conductivity initially and finally negative differential conductivity (NDC) provided ωτ ⪡ 1 (i.e. quasi- static case). With strong enough axial injection of the hot electrons, there is a switch from NDC to positive differential conductivity (PDC) about Ez ≥ 75 kV / cm and Ez ≥ 140 kV / cm for a zigzag CNT and an armchair CNT respectively. Thus, the most important tough problem for NDC region which is the space charge instabilities can be suppressed due to the switch from the NDC behaviour to the PDC behaviour predicting a potential generation of terahertz radiations whose applications are relevance in current-day technology, industry, and research.

  10. Field ionization kinetic and electron impact studies of gas phase transition states - The cyclic bromonium ion (United States)

    Green, M. M.; Giguere, R. J.; Falick, A. M.; Aberth, W.; Burlingame, A. L.


    Cis- and trans-isomers of 4-t-butylcyclohexyl bromide were studied to determine the mechanism of cyclic bromonium ion formation. The field ionization kinetic and electron impact data indicate that the formation of the cyclic structure occurs simultaneously with loss of the neutral fragment. The data also show that little or no gas-phase cis-trans isomerization occurs.

  11. High-magnetic-field-assisted scattering of electrons with atomic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Ajoy [Laban Hrad Vidyapith, AD-369, Salt Lake City, Kolkata 700064 (India)


    We have investigated quantum mechanically the scattering of electrons off atomic hydrogen in a strong magnetic field. Elastic, inelastic, backward and total scattering cross sections are reported. Near-resonance behaviour of the system is analysed. Results are presented after evaluating and summing all-order Born series under suitable physical conditions.

  12. Electric field dependence of the electron mobility in bulk wurtzite ZnO

    Indian Academy of Sciences (India)

    ZnO) material is studied. The low-field electron mobility is calculated as a function of doping concentration and lattice temperature. The results show that above nearly 50 K the electrical conduction is governed by activation through the bulk ...

  13. Magnetoresistance of a two-dimensional electron gas in a random magnetic field

    DEFF Research Database (Denmark)

    Smith, Anders; Taboryski, Rafael Jozef; Hansen, Luise Theil


    We report magnetoresistance measurements on a two-dimensional electron gas made from a high-mobility GaAs/AlxGa1-xAs heterostructure, where the externally applied magnetic field was expelled from regions of the semiconductor by means of superconducting lead grains randomly distributed...

  14. Exact analytic solutions for a Dirac electron moving in graphene under magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Kuru, S [Department of Physics, Faculty of Science, Ankara University, 06100 Ankara (Turkey); Negro, J; Nieto, L M, E-mail:, E-mail: jnegro@fta.uva.e, E-mail: luismi@metodos.fam.cie.uva.e [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, E-47071 Valladolid (Spain)


    Exact analytical solutions for the bound states of a graphene Dirac electron in various magnetic fields with translational symmetry are obtained. In order to solve the time-independent Dirac-Weyl equation the factorization method used in supersymmetric quantum mechanics is adapted to this problem. The behavior of the discrete spectrum, probability and current densities are discussed.

  15. Exact analytic solutions for a Dirac electron moving in graphene under magnetic fields. (United States)

    Kuru, S; Negro, J; Nieto, L M


    Exact analytical solutions for the bound states of a graphene Dirac electron in various magnetic fields with translational symmetry are obtained. In order to solve the time-independent Dirac-Weyl equation the factorization method used in supersymmetric quantum mechanics is adapted to this problem. The behavior of the discrete spectrum, probability and current densities are discussed.

  16. Do electromagnetic fields interact with electrons in the Na,K-ATPase? (United States)

    Blank, Martin


    The effects of low frequency electric and magnetic fields on several biochemical systems, including the Na,K-ATPase, indicate that electromagnetic (EM) fields interact with electrons. The frequency optima for two enzymes in response to EM fields are very close to their turnover numbers, suggesting that these interactions directly affect reaction rates. Nevertheless, generally accepted ideas about Na,K-ATPase function and ion transport mechanisms do not consider interactions with electrons. To resolve the clash of paradigms, we hypothesize interaction with transient electrons and protons that arise from flickering of H-bonds in the hydrated protein. These transient charges in the enzyme could provide a trigger for the sequence of conformation changes that are part of the ion transport mechanism. If the distributions of transient electrons and protons in the membrane are affected by their concentration and the membrane potential, as expected from electric double layer theory, this can account for the different effects of low frequency electric and magnetic fields, as well as for the observation that membrane hyperpolarization reverses the ATPase reaction to generate ATP. Bioelectromagnetics (c) 2005 Wiley-Liss, Inc.

  17. ["Biastophilia"--rape as a form of paraphilia?]. (United States)

    Knecht, Thomas


    Rape is primarily regarded as a crime against sexual integrity. If rape is the only way for an individual to get sexual satisfaction, it meets the criteria of paraphilia, i.e. a disorder of sexual preference. The correct technical term is "biastophilia". The author investigates the evolutionary origins of this deviant form of copulation behavior, whose crucial characteristic is breaking the will of the sexual object. He shows that in a primeval environment this type of mating behavior may have been a promising strategy to pass on one's genes to the next generation. Thus, the behavioral pattern of raping had the chance to become widely spread in spite of its social undesirability.

  18. Gender-Blind Sexism and Rape Myth Acceptance. (United States)

    Stoll, Laurie Cooper; Lilley, Terry Glenn; Pinter, Kelly


    The purpose of this article is to explore whether gender-blind sexism, as an extension of Bonilla-Silva's racialized social system theory, is an appropriate theoretical framework for understanding the creation and continued prevalence of rape myth acceptance. Specifically, we hypothesize that individuals who hold attitudes consistent with the frames of gender-blind sexism are more likely to accept common rape myths. Data for this article come from an online survey administered to the entire undergraduate student body at a large Midwestern institution (N = 1,401). Regression analysis showed strong support for the effects of gender-blind sexism on rape myth acceptance. © The Author(s) 2016.

  19. Rape in South Africa: an invisible part of apartheid's legacy. (United States)

    Armstrong, S


    Male dominated power systems in South Africa coupled with a culture of aggression and domination have not allowed for the mainstream emergence of qualities such as trust, compassion, and gentleness, frequently associated with female virtues. Rape under such circumstances is the assertion of male power, and, as expected, the numbers of rape cases and other forms of gender violence have increased. Under an apartheid system, where only the rape of white women was prosecuted, and gender and race issues could diffuse the black struggle, there were difficulties in mobilizing support to end violence against black women. There was social acceptance that rape of black women was part of life. Police statistics on the incidence of rape were notoriously unreliable, because only a small percentage of cases are reported to police, and many women would be ashamed to admit to marital abuse, including rape. In women's groups, it was reported that 1 out of every 4 women had been raped, and raped at early ages, such as 14 years of age. In impoverished communities, there is widespread poverty, injustice, prejudice, alcohol abuse, and other conditions impacting on women. The rapists may be school classmates, or street fighters, or political activists. The sexual initiation of women worldwide and in South Africa frequently is accompanied by coercion. Abduction and forced sex is considered legitimate for young men, who believe that mental health is deleteriously affected by lack of sex. Girls may even be abducted from the classroom, as a way of preventing women's power and control over assets and resources and diminishing the potential threat to gender power relations. School girls who become pregnant are often forced to leave school. Victims of rape may be excluded from family life and forced to seek prostitution as a means of support. Rape is reportedly experienced among older women with bottles, tins, or other devices which inflict injury. Only rape with penal penetration is an

  20. Rape trauma syndrome: time to open the floodgates? (United States)

    Keogh, Andrew


    The conviction rate in rape cases remains remarkably low, leading many to believe a new approach is needed to prosecuting such crimes. Many important steps have been taken in relation to the collection and retention of evidence and the setting up of specialist rape prosecutors, but important evidential weaknesses remain present in the system alongside Victorian attitudes to sexual conduct. The British Home Office is currently consulting on a number of measures, including the admissibility of evidence showing the presence of rape trauma syndrome. This paper examines the history of this controversial evidential debate.

  1. Changing attitudes and perceptions of Hispanic men ages 18 to 25 about rape and rape prevention. (United States)

    Lawson, Sarah Lynn; Munoz-Rojas, Derby; Gutman, Lauren Samantha; Siman, Matilde Nathalia


    This exploratory study was designed to test the effectiveness of Foubert's intervention, The Men's Program, on a sample of 18- to 25-year-old Hispanic men who are not enrolled at a University or College. We explored participants' perceptions of, reactions to, and experience of the program. The information collected will be used to adapt the program to this specific population in order to increase cultural relevancy and specificity and create lasting attitudinal change. Three groups of six-eight Hispanic males (n = 22) were exposed to the intervention program. The Bystander Attitude Scale and the Rape Attitude and Beliefs Scale were administered as pre- and post-test measures. A short focus group was conducted to ask the men about their experience of the intervention. Analysis showed a significant increase in participants' willingness to intervene (p = 0.005) along with a decrease in rape myth acceptance in four of the five subscales (Justice p = 0.03; Status p = 0.004; Tactics p = 0.04; and Gender p = 0.002) after exposure to the intervention. Analysis of focus group material yielded several interesting themes about knowledge of rape, family and culture, perceptions of women, and the program material. This study showed promising change in attitudes about rape beliefs and bystander behaviors in Hispanic males exposed to an educational intervention. Through the information obtained, a cultural adaption from the analysis of the focus group data will be implemented during Phase 2 of the study. The adapted intervention will be tested before, after, and 1- and 3-months post-intervention to test whether the change in attitudes and behaviors are sustainable over time.

  2. Metal/Polymer Based Stretchable Antenna for Constant Frequency Far-Field Communication in Wearable Electronics

    KAUST Repository

    Hussain, Aftab M.


    Body integrated wearable electronics can be used for advanced health monitoring, security, and wellness. Due to the complex, asymmetric surface of human body and atypical motion such as stretching in elbow, finger joints, wrist, knee, ankle, etc. electronics integrated to body need to be physically flexible, conforming, and stretchable. In that context, state-of-the-art electronics are unusable due to their bulky, rigid, and brittle framework. Therefore, it is critical to develop stretchable electronics which can physically stretch to absorb the strain associated with body movements. While research in stretchable electronics has started to gain momentum, a stretchable antenna which can perform far-field communications and can operate at constant frequency, such that physical shape modulation will not compromise its functionality, is yet to be realized. Here, a stretchable antenna is shown, using a low-cost metal (copper) on flexible polymeric platform, which functions at constant frequency of 2.45 GHz, for far-field applications. While mounted on a stretchable fabric worn by a human subject, the fabricated antenna communicated at a distance of 80 m with 1.25 mW transmitted power. This work shows an integration strategy from compact antenna design to its practical experimentation for enhanced data communication capability in future generation wearable electronics.

  3. Study on magnetic field generation and electron collimation in overdense plasmas

    Directory of Open Access Journals (Sweden)

    Cai Hongbo


    Full Text Available An analytical fluid model is proposed for artificially collimating fast electron beams produced in interaction of ultraintense laser pulses with specially engineered sandwich structure targets. The theory reveals that in low-density-core structure targets, the magnetic field is generated by the rapid change of the flow velocity of the background electrons in transverse direction (perpendicular to the flow velocity caused by the density jump. It is found that the spontaneously generated magnetic field reaches as high as 100 MG, which is large enough to collimate fast electron transport in overdense plasmas. This theory is also supported by numerical simulations performed using a two-dimensional particle-in-cell code. It is found that the simulation results agree well with the theoretical analysis.

  4. Electron scattering filter design for a single field rotational total skin irradiation. (United States)

    Pham, Y T; Bubb, I F; Cramb, J A


    The aim of radiotherapy treatment of cutaneous T-cell lymphoma is to irradiate the skin with an appropriately homogeneous dose distribution up to a few millimetres in depth. This can be achieved by applying one of the total skin electron irradiation techniques. An aluminium/polystyrene foam electron scattering filter was designed so that the incident beam is broadened and degraded sufficiently to achieve a mean dose uniformity in a rectangular field of 180 cm height and 40 cm width. This paper reports on the development and construction of the electron scattering filter for use with a Varian 2100C accelerator, without MLCs, with a dose uniformity, over a useful field dimension of 180 cm height and 40 cm width, of +/- 7% about the mean, and an x-ray contamination of less than 2.4% beyond a depth of 3 cm.

  5. Research on Proximity Magnetic Field Influence in Measuring Error of Active Electronic Current Transformers

    Directory of Open Access Journals (Sweden)

    Wu Weijiang


    Full Text Available The principles of the active electronic current transformer (ECT are introduced, and the mechanism of how a proximity magnetic field can influence the measuring of errors is analyzed from the perspective of the sensor section of the ECT. The impacts on active ECTs created by three-phase proximity magnetic field with invariable distance and variable distance are simulated and analyzed. The theory and simulated analysis indicate that the active ECTs are sensitive to proximity magnetic field under certain conditions. According to simulated analysis, a product structural design and the location of transformers at substation sites are suggested for manufacturers and administration of power supply, respectively.

  6. Monte Carlo analysis of electronic noise in semiconductors under sub-terahertz cyclostationary mixed fields

    Energy Technology Data Exchange (ETDEWEB)

    Capizzo, M.C.; Persano Adorno, D.; Zarcone, M. [Dipartimento di Fisica e Tecnologie Relative, Viale delle Scienze, Ed. 18, 90128, Palermo (Italy)


    This paper reports the results of Monte Carlo simulations of electronic noise in a GaAs bulk driven by two mixed high-frequency large-amplitude periodic electric fields. Under these conditions, the system response shows some peculiarities in the noise performance, such as a resonant-like enhancement of the spectra near the two frequencies of the applied fields. The relations among the frequency response and the velocity fluctuations as a function of intensities and frequencies of the sub-terahertz mixed excitation fields have been investigated. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Media Re-victimization of Rape Victims in a Shame Culture? Exploring the Framing and Representation of Rape Cases in Nigerian Dailies

    National Research Council Canada - National Science Library

    Chinenye Nwabueze; Fidelis Oduah


      [...]India as a country has in recent time, continued to have its doses of not just rape cases but "gang raping" of powerless, defenseless and innocent women and girls by rapists and "the situation...

  8. Electronic Field Data Collection in Support of Satellite-Based Food Security Monitoring in Tanzania (United States)

    Nakalembe, C. L.; Dempewolf, J.; Justice, C. J.; Becker-Reshef, I.; Tumbo, S.; Maurice, S.; Mbilinyi, B.; Ibrahim, K.; Materu, S.


    In Tanzania agricultural extension agents traditionally collect field data on agriculture and food security on paper, covering most villages throughout the country. The process is expensive, slow and cumbersome and prone to data transcription errors when the data get entered at the district offices into electronic spreadsheets. Field data on the status and condition of agricultural crops, the population's nutritional status, food storage levels and other parameters are needed in near realtime for early warning to make critical but most importantly timely and appropriate decisions that are informed with verified data from the ground. With the ubiquitous distribution of cell phones, which are now used by the vast majority of the population in Tanzania including most farmers, new, efficient and cost-effective methods for field data collection have become available. Using smartphones and tablets data on crop conditions, pest and diseases, natural disasters and livelihoods can be collected and made available and easily accessible in near realtime. In this project we implemented a process for obtaining high quality electronic field data using the GeoODK application with a large network of field extension agents in Tanzania and Uganda. These efforts contribute to work being done on developing an advanced agriculture monitoring system for Tanzania, incorporating traditional data collection with satellite information and field data. The outcomes feed directly into the National Food Security Bulletin for Tanzania produced by the Ministry of Agriculture as well as a form a firm evidence base and field scale monitoring of the disaster risk financing in Uganda.

  9. Self-generated magnetic fields and electron transport in laser driven hohlraums (United States)

    Edwards, John; Alley, Ed; Hammer, Jim; Town, Richard; Haines, Malcolm


    It is well known that magnetic fields can be generated during the interaction of an intense laser beam with solid targets. The principle source of magnetic field from Ohm's law is the familiar grad(T)xgrad(n) term, which results in Megagauss fields for laser intensities typical of inertial fusion and other high energy density experiments. In a hohlraum the main consequence of this is to increase the electron temperature by x2 near the laser entrance holes because of reduced thermal conduction in the cross-field (axial) direction. Despite the "localizing" effect of the magnetic field on the electrons, it appears that the diffusion approximation for electron heat flow breaks down, with the departure becoming progressively worse as the laser power is increased. The results of Lasnex simulations are used to illustrate these effects for laser powers ranging from 10TW to 500TW which cover conditions from Nova to NIF. Potential knock on consequences for inertial fusion are discussed. -This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

  10. Experiments on penetration of a plasma with magnetized electrons across a magnetic field (United States)

    Cid, R. E.; Cohen, R. H.; Hooper, E. B.; Molvik, A. W.; Porter, G. D.; Ryutov, D. D.


    In a number of situations of practical interest, one has to deal with plasma flow past bodies whose size is much greater than the electron gyroradius but much smaller than the ion gyroradius (examples from two very different environments are: spaceraft in the geomagnetic field, and irregularities on the surface of divertor plates). The ions are then repelled from the region inaccessible for electrons by the ambipolar potential, and a shadow with a size much less than the ion gyro-radius is formed. We present a systematic experimental study of plasma penetration into such shadows across the magnetic field lines. The experiments are performed on the Bluebell device situated at LLNL. The flow of an Argon plasma with density up to 10^12 cm-3 and electron temperature 2-3 eV is collimated by holes with diameters from 0.5 to 2 cm made in a thin aluminum disk that intersepts the rest of the plasma. The magnetic field strength is in the range of a few tens of gauss. The plasma density distribution in the gradually expanding plasma jets behind the holes is measured by electrostatic probes. In order to eliminate direct electric contact with the upstream plasma (which is sometimes quite "noisy"), some of the holes are covered with fine metal meshes. We report on the measurements of the cross-field expansion rate of the jets vs. the plasma density, the density of the background gas, and the magnetic field intensity.

  11. The Effect of Magnetic Field Errors on Dynamical Friction in Electron Coolers

    CERN Document Server

    Bruhwiler, David L; Busby, Richard; Fedotov, Alexei V; Litvinenko, Vladimir N; Veitzer, Seth A


    A proposed luminosity upgrade to the Relativistic Heavy Ion Collider (RHIC) includes a novel electron cooling section,* which would use ~55 MeV electrons to cool fully-ionized 100 GeV/nucleon gold ions. A strong (1-5 T) solenoidal field will be used to magnetize the electrons and thus enhance the dynamical friction force on the ions. The physics of magnetized friction is being simulated for RHIC parameters, using the VORPAL code.** Most theoretical treatments for magnetized dynamical friction do not consider the effect of magnetic field errors, except in a parametric fashion.*** However, field errors can in some cases dramatically reduce the velocity drag and corresponding cooling rate. We present a simple analytical model for the magnetic field errors, which must be Lorentz transformed into the beam frame for use in our simulations. The simulated dynamical friction for the case of a perfect solenoidal field will be compared with results from this new model, for parameters relevant to RHIC.

  12. Spin dynamics in Kapitza-Dirac scattering of electrons from bichromatic laser fields

    CERN Document Server

    Dellweg, Matthias M; Müller, Carsten


    Kapitza-Dirac scattering of nonrelativistic electrons from counterpropagating bichromatic laser waves of linear polarization i s studied. The focus lies on the electronic spin dynamics in the Bragg regime when the laser fields possess a frequency ratio of two. To this end, the time-dependent Pauli equation is solved numerically, both in coordinate space and momentum space. Our numerical results are corroborated by analytical derivations. We demonstrate that, for certain incident electron momenta, the scattering crucially relies on the electron spin which undergo es characteristic Rabi-like oscillations. A parameter regime is identified where the Rabi oscillations reach maximum amplitude. We also briefly discuss spin-dependent Kapitza-Dirac scattering of protons.

  13. Effect of Resonant Helical Field (RHF) on Runaway Electrons in Tokamaks (United States)

    Ghanbari, M. R.; Ghoranneviss, M.; Ghanbari, K.; Elahi, A. Salar; Salem, M. K.; Mohammadi, S.; Arvin, R.


    The high energy current of runaway electrons during a major disruption in tokamak reactors can cause serious damage to the first wall of the reactor and reduce its life time. Therefore, finding a method to minimize runaway electron is much needed. Resonant helical field (RHF) is one of the methods for controlling the magnetohydrodynamic (MHD) activity. This paper attempts to examine the effect of RHF on the generation of runaway electrons. Main parameters such as plasma current, loop voltage, emitted hard X-ray intensity, MHD oscillation, Hα radiation and MHD activity modes, in the presence and absence of RHF (L = 2 and L = 3), were measured. The results show that applying this system can change runaway electrons generation.

  14. Meat and bone meal as nitrogen and phosphorus supplier to cereals and oilseed rape

    Directory of Open Access Journals (Sweden)

    Anna Nogalska


    Full Text Available The purpose of this study was to evaluate the effect of meat and bone meal (MBM on cultivation of winter triticale, winter oilseed rape, winter wheat and maize. The average annual yields and protein yield achieved in crop rotation were studied. The field trials were carried out in north-eastern Poland in 2006–2010. The factor was dose of MBM: 1.0, 1.5, 2.0 and 2.5 t ha-1 year-1 or 2.0, 3.0, 4.0 and 5.0 t ha-1 every other year. The four-year experiment has proven that MBM is a valuable nitrogen and phosphorus fertilizer in cultivation of cereals and oilseed rape. By amendment of the tested meal into the soil it produced crop yield and protein yield similar to that achieved by mineral fertilization. However, the crude fat yield of rape was significantly higher under the influence of all the MBM doses. The yield-stimulating effect of MBM did not depend on the frequency of its application; therefore it is more convenient to apply it once every two years. Increasing MBM from 1.5 to 2.5 t ha-1 did not significantly increase any of the four crop yields, therefore for soils that had satisfactory nutrients content, 1 or 1.5 t ha-1 MBM is enough and increasing MBM will only increase economic burden for farmers and environmental risks.

  15. Influence of top dressing on yield and seed quality components of oilseed rape

    Directory of Open Access Journals (Sweden)

    Vujaković Milka


    Full Text Available Oilseed rape is an agronomically important species grown for seed that contains 40-48% oil and 18-25% proteins. Oilseed rape has high demands for nitrogen. The research was performed on four varieties of oilseed rape (Banaćanka, Valeska, Slavica and Express developed at Institute of Field and Vegetable Crops in Novi Sad, during vegetative seasons 2007-2008 and 2008-2009. During vegetation, top dressing was applied with different amounts of KAN: control (0 kg N ha-1, 50 kg N ha-1, 100 kg N ha-1, 150 kg N ha-1 and the N quantity determination were performed applying the balancing method (also known as N-min method. Yield, 1000-seed weight, seed germination, oil and protein content were determined after harvest. Yield and seed germination depended on seed production year. 1000-seed weight depended on seed production year and genotype. Oil and protein content in seed depended on production year, genotype and amount of the N-fertilizer applied by top dressing.

  16. Using the GENESYS model quantifying the effect of cropping systems on gene escape from GM rape varieties to evaluate and design cropping systems

    Directory of Open Access Journals (Sweden)

    Colbach Nathalie


    Full Text Available Gene flow in rapeseed is a process taking place both in space and over the years and cannot be studied exclusively by field trials. Consequently, the GENESYS model was developed to quantify the effects of cropping systems on transgene escape from rapeseed crops to rapeseed volunteers in neighbour plots and in the subsequent crops. In the present work, this model was used to evaluate the risk of rape harvest contamination by extraneous genes in various farming systems in case of co-existing GM, conventional and organic crops. When 50 % of the rape varieties in the region were transgenic, the rate of GM seeds in non-GM crop harvests on farms with large fields was lower than the 0.9 % purity threshold proposed by the EC for rape crop production (food and feed harvests, but on farms with smaller fields, the threshold was exceeded. Harvest impurity increased in organic farms, mainly because of their small field size. The model was then used to evaluate the consequences of changes in farming practices and to identify those changes reducing harvest contamination. The effects of these changes depended on the field pattern and farming system. The most efficient practices in limiting harvest impurity comprised improved set-aside management by sowing a cover crop in spring on all set-aside fields in the region, permanently banning rape crops and set-aside around seed production fields and (for non-GM farmers clustering farm fields to reduce gene inflow from neighbour fields.

  17. Local-gauge finite-element method for electron waves in magnetic fields. (United States)

    Ueta, Tsuyoshi; Miyagawa, Yuu


    The finite-element method (FEM) has already been extended to analyze transport properties of electron waves of two-dimensional electron systems in magnetic fields. Although many researchers have created new formulations or improvements to this method, few have analyzed how this method is applied to realistic systems. The present paper suggests that conventional formulations of the FEM do not give accurate results for large systems or for strong magnetic fields; in addition, it suggests that the selected gauge significantly influences the numerical results. Furthermore, this paper proposes a conceptually different formulation of the FEM that solves the poor convergence problem. This formulation is simple: matrix elements are multiplied by the Peierls phase in the absence of a magnetic field. To show the advantages of this formulation, numerical examples are presented.

  18. Study on the Electronic Magnetic Field Oriented Control Based on D-axis Current

    Directory of Open Access Journals (Sweden)

    Hongyu Feng


    Full Text Available In order to improve the magnetic field orientation accuracy and system performance, the electronic field oriented control has been a hot research field of the induction motor speed control. Although the vector control of AC machines has many excellent properties, the researchers have been attempting to simplify the calculating steps and the structure of the control system to improve the accuracy of filed-oriented and the performance of AC machine drives. Based on the analysis of the conventional induction motor magnetic field oriented control, this paper puts forward a novel method of stator magnetic field orientation control. By analytical methods, the given current of d-axis can be calculated directly, and the stator flux can be controlled precisely. This method has a fast flux and torque response, and the control performance is unaffected by the rotor parameters.

  19. Transport properties of a two-dimensional electron gas due to a spatially random magnetic field (United States)

    Rushforth, A. W.; Gallagher, B. L.; Main, P. C.; Neumann, A. C.; Marrows, C. H.; Zoller, I.; Howson, M. A.; Hickey, B. J.; Henini, M.


    We have studied the magnetoresistance of a near-surface two-dimensional electron gas (2DEG) in the presence of a random magnetic field produced by CoPd multilayers deposited onto the surface of the heterostructure. This novel method allows us to switch the random field on and off by applying an external magnetic field and also to control the amplitude and correlation length of the random field by varying the growth parameters of the multilayers. The presence of the random field is confirmed by quenching of the Shubnikov-de Haas oscillations and we see an enhanced magnetoresistance which can be interpreted semi-classically. We also observe other unusual features which may be quantum in origin.

  20. Rape embryogenesis. V. Accumulation of lipid bodies

    Directory of Open Access Journals (Sweden)

    Teresa Tykarska


    Full Text Available In embryo of winter rape var. Górczański lipid bodies have been observed in the light microscope starting from two-celled proembryo. Their number and size increase in the course of embryogenesis, especially since greening of endosperm and embryo. Lipid bodies, either single or in clusters, are present in all embryo cells, the clusters occur in various parts of the cytoplasm. During embryo maturation lipid bodies move and locate in a number of layers by the cell wall. At the same time their appearance change. Typical storage lipids originate. Lipid bodies are unevenly distributed within the embryo: their number and size decrease along the embryo axis from its part below cotyledons towards root apex. Moreover, they are histologically diversified: the biggest are located in epidermis and cortex, whereas the smallest -in central cylinder. In columella there are fewest lipid bodies.

  1. Rape embryogenesis. III. Embryo development in time

    Directory of Open Access Journals (Sweden)

    Teresa Tykarska


    Full Text Available It was found that the growth curve of the rape embryo axis is of triple sigmoid type. Embryo growth occurs in 3 phases corresponding to 3 different periods of development. Phase I includes growth of the apical cell up to it's division into two layers of octants. Phase II comprises the increase of the spherical proembryo to the change of its symmetry from radial to bilateral. Phase III includes, growth of the embryo from the heart stage up to the end of embryogenesis. In each phase the relative growth rate increases drastically and then diminishes. The differences in growth intensity during the same phase are several-fold. The growth intensity maximum of the embryo axis occurs in phase II. The phasic growth intensity maxima occur: in phase I during apical cell elongation, :before its division, and in phases II and III in the periods of cell division ;growth in globular and torpedo-shaped -shaped embryos.

  2. [Anxiety and depression levels in rape offenders]. (United States)

    Herrera-Hernández, E; Marván, L; Saavedra, M; Contreras, C M


    Whether the active subject of rape possesses a particular personality trait is a much debated matter. It is an accepted fact that a small amount of rapists fall into the sadistic diagnostic category. Other psychopatologic traits likely to identify a rapist are, however, unknown. The present study was carried over at a jail near the city of Xalapa (Veracruz) Mexico. Hamilton, IDARE, and Zung scales, in their modified Spanish version were applied to a sample of imprisoned adult rapists. Compared to their control group (men serving sentences for other felonies), rapists scored higher in anxiety, and depression scales. In the light of these results, it is suggested that some rapists are likely to be anxious-depressive subjects that, after having "acquired" a sociopathic repertoire, offend other people in conditions of indefensiveness, contrary to depressive subjects who aggress themselves.

  3. Rape embryogenesis I. The proembryo development

    Directory of Open Access Journals (Sweden)

    Teresa Tykarska


    Full Text Available The development of the proembryo of rape Brassica napus L. from the zygote to the young embryo proper is described. A number of regularities were found in the direction, succession, and distribution of segmental and differentiating divisions of the proembryo. The direction of the divisions seems to foe determined by the direction of growth and the shape of the cells. The termyoung embryo proper is proposed to denote the globular embryo which already possesses separate plerome and periblem mother-cells and mother-cells of the iec layer and of clumella. The body of the embryo proper is derived from the apical cell ca which arose from the first division of the zygote and from the hypophysis - the only suspensor cell which closes the spheroid of the embryo. The development of the Brassica napus L. proembryo follows the sub-archetype Capsella bursa-pastoris in the IV megarchetype of Soueges.

  4. Investigation of the photodetached electronic wave packet dynamics in a magnetic field near a surface (United States)

    Chen, Zhaohang; Wang, Dehua; Cheng, Shaohao


    The electronic wave packet dynamics photodetached from H- ion in a magnetic field near an elastic surface has been studied by using the time-dependent perturbation theory combined with the semiclassical closed orbit theory for the first time. Firstly, we put forward an analytic formula for calculating the autocorrelation function of this system. Then we calculate and analyze the autocorrelation function in great detail. It is demonstrated that the quantum wave packet revival phenomenon is significant when the laser pulse width is far less than the period of the detached electron's closed orbit. As the pulse width is close to the period of the detached electron's closed orbit, the quantum wave packet revival phenomenon becomes weakened. When the laser pulse width is bigger than the period of the closed orbit of the detached electron, the adjacent revival peaks in the autocorrelation function begin to merge and the quantum revival phenomenon disappears. In addition, the magnetic field strength can also affect the autocorrelation function of this system. As the magnetic field strength is relatively small, the quantum wave packet revival phenomenon is weak. With the increase of the magnetic field strength, the number of the reviving peaks in the autocorrelation function becomes increased and the quantum wave packet revival phenomenon becomes significant. Therefore, we can control the quantum wave packet revival in the autocorrelation function of this system by changing the laser pulse width and the external magnetic field strength. This study can guide the future experimental research on the wave packet dynamics of atoms or ions in the external fields or surfaces.

  5. Effects of Electronic Quantum Interference, Photonic-Crystal Cavity, Longitudinal Field and Surface-Plasmon- Polariton for Optical Amplification

    National Research Council Canada - National Science Library

    Cardimona, David A; Alsing, Paul M; Huang, Danhong


    Some possibilities for coherent optical amplification of a normally-incident and weak radiation field are reviewed based on various physical mechanisms, such as electronic quantum interference induced...

  6. Electronic structure of four-coordinate C3v nickel(II) scorpionate complexes: investigation by high-frequency and -field electron paramagnetic resonance and electronic absorption spectroscopies. (United States)

    Desrochers, Patrick J; Telser, Joshua; Zvyagin, S A; Ozarowski, Andrew; Krzystek, J; Vicic, David A


    A series of complexes of formula TpNiX, where Tp*- = hydrotris(3,5-dimethylpyrazole)borate and X = Cl, Br, I, has been characterized by electronic absorption spectroscopy in the visible and near-infrared (NIR) region and by high-frequency and -field electron paramagnetic resonance (HFEPR) spectroscopy. The crystal structure of TpNiCl has been previously reported; that for TpNiBr is given here: space group = Pmc2(1), a = 13.209(2) A, b = 8.082(2) A, c = 17.639(4) A, alpha = beta = gamma = 90 degrees , Z = 4. TpNiX contains a four-coordinate nickel(II) ion (3d8) with approximate C3v point group symmetry about the metal and a resulting S = 1 high-spin ground state. As a consequence of sizable zero-field splitting (zfs), TpNiX complexes are "EPR silent" with use of conventional EPR; however, HFEPR allows observation of multiple transitions. Analysis of the resonance field versus the frequency dependence of these transitions allows extraction of the full set of spin Hamiltonian parameters. The axial zfs parameter for TpNiX displays pronounced halogen contributions down the series: D = +3.93(2), -11.43(3), -22.81(1) cm(-1), for X = Cl, Br, I, respectively. The magnitude and change in sign of D observed for TpNiX reflects the increasing bromine and iodine spin-orbit contributions facilitated by strong covalent interactions with nickel(II). These spin Hamiltonian parameters are combined with estimates of 3d energy levels based on the visible-NIR spectra to yield ligand-field parameters for these complexes following the angular overlap model (AOM). This description of electronic structure and bonding in a pseudotetrahedral nickel(II) complex can enhance the understanding of similar sites in metalloproteins, both native nickel enzymes and nickel-substituted zinc enzymes.

  7. Evolution of Rape Myths and Sexual Assaults in Newspaper Coverage

    Directory of Open Access Journals (Sweden)

    Yan-Wen Tsai


    Full Text Available The article presents an analysis of the coverage of three newspapers of rape in the daily Press in Taiwan. The idea that rape is a sexual rather than an aggressive act encourages people not to take it seriously as a crime-an attitude frequently revealed in comments by defense attorneys and newspaper. The authors’ investigated that the female victim who did not know most of her attackers will be portrayed as helpless and not responsible for her victimization. The newspapers sustained and reinforced the myths that a woman who is having consensual sex cannot be raped, and if so, she is held culpable and perceived as “asking for it.” A content analysis of newspapers’ headlines and coverage between 2002 and 2013 showed that more than 50% endorsed a rape myth.

  8. Party Rape, Nonconsensual Sex, and Affirmative Consent Policies

    National Research Council Canada - National Science Library

    Kelly Oliver


    ... of communication, the communication of pleasure. [...]given the increasingly slippery slope between sex and sexual assault, and uncertainty about what counts as rape, many women are subject to sexual aggression, even sexual assault, and are not...

  9. Electron Beam Dose Distribution in the Presence of Non-Uniform Magnetic Field

    Directory of Open Access Journals (Sweden)

    Mohamad Javad Tahmasebi-Birgani


    Full Text Available Introduction Magnetic fields are capable of altering the trajectory of electron beams andcan be used in radiation therapy.Theaim of this study was to produce regions with dose enhancement and reduction in the medium. Materials and Methods The NdFeB permanent magnets were arranged on the electron applicator in several configurations. Then, after the passage of the electron beams (9 and 15 MeV Varian 2100C/D through the non-uniform magnetic field, the Percentage Depth Dose(PDDs on central axis and dose profiles in three depths for each energy were measured in a 3D water phantom. Results For all magnet arrangements and for two different energies, the surface dose increment and shift in depth of maximum dose (dmax were observed. In addition, the pattern of dose distribution in buildup region was changed. Measurement of dose profile showed dose localization and spreading in some other regions. Conclusion The results of this study confirms that using magnetic field can alter the dose deposition patterns and as a result can produce dose enhancement as well as dose reduction in the medium using high-energy electron beams. These effects provide dose distribution with arbitrary shapes for use in radiation therapy.

  10. Experimental Investigation of Electron Cloud Containment in a Nonuniform Magnetic Field (United States)

    Eninger, J. E.


    Dense clouds of electrons were generated and studied in an axisymmetric, nonuniform magnetic field created by a short solenoid. The operation of the experiment was similar to that of a low-pressure (approximately 0.000001 Torr) magnetron discharge. Discharge current characteristics are presented as a function of pressure, magnetic field strength, voltage, and cathode end-plate location. The rotation of the electron cloud is determined from the frequency of diocotron waves. In the space charge saturated regime of operation, the cloud is found to rotate as a solid body with frequency close to V sub a/phi sub a where V sub a is the anode voltage and phi suba is the total magnetic flux. This result indicates that, in regions where electrons are present, the magnetic field lines are electrostatic equipotentials (E bar, B bar = 0). Equilibrium electron density distributions suggested by this conditions are integrated with respect to total ionizing power and are found consistent with measured discharge currents.

  11. Thirty per cent contrast in secondary-electron imaging by scanning field-emission microscopy. (United States)

    Zanin, D A; De Pietro, L G; Peter, Q; Kostanyan, A; Cabrera, H; Vindigni, A; Bähler, Th; Pescia, D; Ramsperger, U


    We perform scanning tunnelling microscopy (STM) in a regime where primary electrons are field-emitted from the tip and excite secondary electrons out of the target-the scanning field-emission microscopy regime (SFM). In the SFM mode, a secondary-electron contrast as high as 30% is observed when imaging a monoatomic step between a clean W(110)- and an Fe-covered W(110)-terrace. This is a figure of contrast comparable to STM. The apparent width of the monoatomic step attains the 1 nm mark, i.e. it is only marginally worse than the corresponding width observed in STM. The origin of the unexpected strong contrast in SFM is the material dependence of the secondary-electron yield and not the dependence of the transported current on the tip-target distance, typical of STM: accordingly, we expect that a technology combining STM and SFM will highlight complementary aspects of a surface while simultaneously making electrons, selected with nanometre spatial precision, available to a macroscopic environment for further processing.

  12. Hot Electron Propagation and Imposed Magnetic Field in Inertial Fusion Hohlraums

    CERN Document Server

    Strozzi, D J; Marinak, M M; Larson, D J; Koning, J M; Logan, B G


    Simulations with the radiation-hydrodynamics code HYDRA of a low-adiabat ignition design for the National Ignition Facility (NIF), with and without an imposed axial magnetic field, are presented. We also study superthermal, or "hot," electron dynamics with the hybrid-PIC code ZUMA, using plasma conditions from HYDRA. During the early-time laser picket, when hot electrons from the window are a concern, we find ~2E-3 of the hot electron energy in a source consistent with two-plasmon decay (80 keV temperature) in the laser entrance hole deposits in the deuterium-tritium (DT) fuel, while most of the energy deposits in the high-Z wall. A 70 Tesla field, which may improve capsule performance, magnetizes hot electrons in the hohlraum fill gas, guides them to the capsule, and increases the DT deposition 12x. Early in peak laser power, electrons with >125 keV reach the DT fuel, and those with ~185 keV deposit the largest fraction of their energy (13%) in DT. HYDRA magnetohydrodynamics (MHD) simulations with an initial...

  13. Modelling microscopic features of streamer encounters, electric fields, electron beams and X-ray bursts (United States)

    Koehn, C.; Kochkin, P.; Ebert, U.


    Thunderstorms emit terrestrial gamma-ray flashes (TGFs), beams of photons with quantum energies ofup to 40 MeV. Likewise electric discharges in the laboratory, mimicing lightning on a small spatial andenergetic scale, emit X-rays whose energies are limited by the available potential difference betweenthe two electrodes. For a maximal available difference of 1 MV and a gap distance of 1 m between the twoelectrodes, we will present the energy and spatial distribution of generated X-rays.For that we have followed the motion of preaccelerated, monoenergetic and monodirectional electronbeams with energies between 100 keV and the maximal available energy of 1 MeV for different electricfield configurations using a particle Monte Carlo code. Omitting any field, we present the subsequent energy and spatial distribution of X-raysand analyse how the photon number depends on the initial electron energy. Fig. 1 shows the position and energy of photons generated by Bremsstrahlung after 0.3 ns by beams of 500 000 electrons with initial energies of 1 MeV moving in the zdirection in STP air. The electrons have generated electron avalanches and all have cooleddown and attached to oxygen after 0.3 ns. Every cross represents one photon projected onto the xz plane; the photon energies Eγ are color coded. We see that photons with energies of approx. 1 MeV can be produced and that the high-energy tail of X-rays is beamedtowards the direction of the initial electron beam whereas low-energy photons show a more isotropicbehaviour. Analysing the cross sections of photons interacting with air we conclude that photons travelseveral meters in air and can reach detectors several meters from the position of the discharge. Byestimating the electric field ahead of the discharge corona and by simulating the motion of electronbeams in these fields, we exclude that electrons travel as far as photons and disturb the measured X-raysignal.

  14. Electron Cooling and Isotropization during Magnetotail Current Sheet Thinning: Implications for Parallel Electric Fields (United States)

    Lu, San; Artemyev, A. V.; Angelopoulos, V.


    Magnetotail current sheet thinning is a distinctive feature of substorm growth phase, during which magnetic energy is stored in the magnetospheric lobes. Investigation of charged particle dynamics in such thinning current sheets is believed to be important for understanding the substorm energy storage and the current sheet destabilization responsible for substorm expansion phase onset. We use Time History of Events and Macroscale Interactions during Substorms (THEMIS) B and C observations in 2008 and 2009 at 18 - 25 RE to show that during magnetotail current sheet thinning, the electron temperature decreases (cooling), and the parallel temperature decreases faster than the perpendicular temperature, leading to a decrease of the initially strong electron temperature anisotropy (isotropization). This isotropization cannot be explained by pure adiabatic cooling or by pitch angle scattering. We use test particle simulations to explore the mechanism responsible for the cooling and isotropization. We find that during the thinning, a fast decrease of a parallel electric field (directed toward the Earth) can speed up the electron parallel cooling, causing it to exceed the rate of perpendicular cooling, and thus lead to isotropization, consistent with observation. If the parallel electric field is too small or does not change fast enough, the electron parallel cooling is slower than the perpendicular cooling, so the parallel electron anisotropy grows, contrary to observation. The same isotropization can also be accomplished by an increasing parallel electric field directed toward the equatorial plane. Our study reveals the existence of a large-scale parallel electric field, which plays an important role in magnetotail particle dynamics during the current sheet thinning process.





    2014 ARDHIANSYAHAKSAN (B111 10105), dengan judul ???Analisis Kriminologis Terhadap Tindak Kejahatan Pemerkosaan Lelaki (Male Rape)???. Di bawah bimbingan bapak Prof. Dr. AndiSofyan, S.H., M.H., sebagai Pembimbing I dan bapak KaisaruddinKamaruddin, S.H., sebagai Pembimbing II. Tujuan dari penelitian ini adalah untuk mengetahui faktor penyebab terjadinya tindak kejahatan pemerkosaan lelaki (male rape) dan upaya yang dapat ...

  16. Stochastic Electron Acceleration by the Whistler Instability in a Growing Magnetic Field (United States)

    Riquelme, Mario; Osorio, Alvaro; Quataert, Eliot


    We use 2D particle-in-cell simulations to study the effect of the saturated whistler instability on the viscous heating and nonthermal acceleration of electrons in a shearing, collisionless plasma with a growing magnetic field, {\\boldsymbol{B}}. In this setup, an electron pressure anisotropy with {p}\\perp ,e> {p}| | ,e naturally arises due to the adiabatic invariance of the electron magnetic moment ({p}| | ,e and {p}\\perp ,e are the pressures parallel and perpendicular to {\\boldsymbol{B}}). If the anisotropy is large enough, then the whistler instability arises, efficiently scattering the electrons and limiting {{Δ }}{p}e (\\equiv {p}\\perp ,e-{p}| | ,e). In this context, {{Δ }}{p}e taps into the plasma velocity shear, producing electron heating by the so-called anisotropic viscosity. In our simulations, we permanently drive the growth of | {\\boldsymbol{B}}| by externally imposing a plasma shear, allowing us to self-consistently capture the long-term, saturated whistler instability evolution. We find that besides the viscous heating, the scattering by whistler modes can stochastically accelerate electrons to nonthermal energies. This acceleration is most prominent when initially {β }e∼ 1, gradually decreasing its efficiency for larger values of {β }e (\\equiv 8π {p}e/| {\\boldsymbol{B}}{| }2). If initially {β }e∼ 1, then the final electron energy distribution can be approximately described by a thermal component, plus a power-law tail with a spectral index of ∼3.7. In these cases, the nonthermal tail accounts for ∼ 5 % of the electrons and for ∼ 15 % of their kinetic energy. We discuss the implications of our results for electron heating and acceleration in low-collisionality astrophysical environments, such as low-luminosity accretion flows.

  17. Method to eliminate the impact of magnetic fields on the position of the electron beam during EBW (United States)

    Laptenok, V. D.; Druzhinina, A. A.; Murygin, A. V.; Seregin, Yu N.


    The paper presents the approximate formulas for calculating the deflection angle and the misalignment of the electron beam from the optical axis of the electron gun caused by the action of magnetic fields during the electron beam welding. Mathematical model of the effect of magnetic field induced by thermoelectric currents on the electron beam position in the process of electron beam welding of dissimilar materials is presented. The method of monitoring of the misalignment of the scanning electron beam and its mathematical model are proposed. Monitoring of the misalignment of the scanning electron beam is based on the processing of the signal of the collimated X-ray sensor directed to the optical axis of the electron gun by synchronous detection method. The method of compensation of the effect of magnetic fields by passing through the welded seam the currents which compensate thermoelectric currents is considered.

  18. Capture of electrons for acceleration in a betatron with time and spatial variation of the magnetic field (United States)

    Romanov, V. V.; Chakhlov, V. L.


    It is shown that an additional pulsed magnetic field superimposed on the primary magnetic field of a betatron leads to time and spatial variation of the resulting magnetic field in the working gap of the accelerator. A mathematical model is developed for the capture of electrons for betatron acceleration with the additional pulsed magnetic field. It is shown that the time and spatial variation of the magnetic field in the working gap of the accelerator during electron injection leads to an increase in the efficiency of their capture for acceleration. The method of calculation permits a direct modeling of the capture of electrons for acceleration to obtain the highest efficiency.

  19. Enhanced field electron emission of graphene sheets by CsI coating after electrophoretic deposition. (United States)

    Liu, Jianlong; Zeng, Baoqing; Wu, Zhe; Sun, Hao


    Because of the large quantities of edges, graphene can serve as an efficient edge emitter for field emission (FE). Cesium iodide (CsI) coating was promising to enhance the electron emission and utilized in FE applications. In this work, FE of graphene sheets after electrophoretic deposition (ED) was studied. Electron emission property of GS was obviously improved by coating with CsI. The turn-on field of GS decreased from 4.4 to 2.5 V/ μm; and threshold field decreased from 9 to 5.8 V/μm, respectively. This FE improvement must due to a higher effective density of emission site generated around the GS surface after coating. Scanning electron microscopy (SEM) and computation were taken to reveal the influence after coating. Investigations of CsI coated MWCNTs were also compared in order to better understand the origin of the low turn-on electric field obtained by GS. © 2012 American Chemical Society

  20. Foucault imaging and small-angle electron diffraction in controlled external magnetic fields. (United States)

    Nakajima, Hiroshi; Kotani, Atsuhiro; Harada, Ken; Ishii, Yui; Mori, Shigeo


    We report a method for acquiring Foucault images and small-angle electron diffraction patterns in external magnetic fields using a conventional transmission electron microscope without any modification. In the electron optical system that we have constructed, external magnetic fields parallel to the optical axis can be controlled using the objective lens pole piece under weak excitation conditions in the Foucault mode and the diffraction mode. We observe two ferromagnetic perovskite-type manganese oxides, La 0.7 Sr 0.3 MnO 3 (LSMO) and Nd 0.5 Sr 0.5 MnO 3 , in order to visualize magnetic domains and their magnetic responses to external magnetic fields. In rhombohedral-structured LSMO, pinning of magnetic domain walls at crystallographic twin boundaries was found to have a strong influence on the generation of new magnetic domains in external applied magnetic fields. © The Author 2016. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail:

  1. Advances in the field of single-particle cryo-electron microscopy over the last decade. (United States)

    Frank, Joachim


    In single-particle cryo-electron microscopy (cryo-EM), molecules suspended in a thin aqueous layer are rapidly frozen and imaged at cryogenic temperature in the transmission electron microscope. From the random projection views, a three-dimensional image is reconstructed, enabling the structure of the molecule to be obtained. In this article I discuss technological progress over the past decade, which has, in my own field of study, culminated in the determination of ribosome structure at 2.5-Å resolution. I also discuss likely future improvements in methodology.

  2. Electronic data capture platform for clinical research based on mobile phones and near field communication technology. (United States)

    Morak, Jürgen; Schwetz, Verena; Hayn, Dieter; Fruhwald, Friedrich; Schreier, Gunter


    Electronic data capture systems support data acquisition for clinical research and enable the evaluation of new investigational medical devices. In case of evaluating a device the most challenging part is the user interface i.e. the solution how to acquire the data within a clinical setting and to synchronize them with a web-based data centre. The aim of this paper is to describe the development of an electronic data capture system with a mobile data input solution based on mobile phones and Near Field Communication technology. This system was evaluated within a real clinical setting and demonstrated high usability, security and reliability.

  3. Electric-Field-Induced Nuclear Spin Resonance Mediated by Oscillating Electron Spin Domains in GaAs-Based Semiconductors


    Kumada, N.; Kamada, T.; Miyashita, S.; Hirayama, Y.; Fujisawa, T.


    We demonstrate an alternative nuclear spin resonance using radio frequency (RF) electric field (nuclear electric resonance: NER) instead of magnetic field. The NER is based on the electronic control of electron spins forming a domain structure. The RF electric field applied to a gate excites spatial oscillations of the domain walls and thus temporal oscillations of the hyperfine field to nuclear spins. The RF power and burst duration dependence of the NER spectrum provides insight into the in...

  4. Phenology of cabbage stem flea beetle (Psylliodes chrysocephala L in oilseed rape

    Directory of Open Access Journals (Sweden)

    Sivčev Lazar


    Full Text Available The cabbage stem flea beetle (Psylliodeschrysocephala (L. is an important pest of winter oilseed rape in Serbia. Beetles colonize oilseed rape in early October and are active in the field until first frost and wintertime. In autumn, adults can be seen laying eggs in the soil around plants. Larvae of P. chrysocephala developed intensively on leaf petioles in November, reaching their highest numbers at the end of the month. No infested plants were found in a conventional field, while 14.5% of all dissected leaf petioles were infested on an integrated field. On unprotected plants in an organic field, 76.0% of the plants were infested with larvae at the growth-stage BBCH 18-19, with 31.1% infested leaves on average. As a results, the number of plants was reduced by 51%, i.e. from 43.0/m2 recorded in the autumn to 22.0/m2 in the following spring. A new generation of P. chrysocephala beetles emerged from the soil in the first half of June and rapidly escaped the fields from almost dry plants. Our results showed that a part of the population stayed in aestivation and emerged in the following crop during the next season. On the following 5 March, 0.5 beetles/m2 were found in emergence cages in the organic field, while 0.81 beetles/m2 were found in the former trap crop.

  5. Electrons in strong electromagnetic fields: spin effects and radiation reaction (Conference Presentation) (United States)

    Bauke, Heiko; Wen, Meng; Keitel, Christoph H.


    Various different classical models of electrons including their spin degree of freedom are commonly applied to describe the coupled dynamics of relativistic electron motion and spin precession in strong electromagnetic fields. The spin dynamics is usually governed by the Thomas-Bargmann-Michel-Telegdi equation [1, 2] in these models, while the electron's orbital motion follows the (modified) Lorentz force and a spin-dependent Stern-Gerlach force. Various classical models can lead to different or even contradicting predictions how the spin degree of freedom modifies the electron's orbital motion when the electron moves in strong electromagnetic fields. This discrepancy is rooted in the model-specific energy dependency of the spin induced relativistic Stern-Gerlach force acting on the electron. The Frenkel model [3, 4] and the classical Foldy-Wouthuysen model 5 are compared exemplarily against each other and against the quantum mechanical Dirac equation in order to identify parameter regimes where these classical models make different predictions [6, 7]. Our theoretical results allow for experimental tests of these models. In the setup of the longitudinal Stern-Gerlach effect, the Frenkel model and classical Foldy-Wouthuysen model lead in the relativistic limit to qualitatively different spin effects on the electron trajectory. Furthermore, it is demonstrated that in tightly focused beams in the near infrared the effect of the Stern-Gerlach force of the Frenkel model becomes sufficiently large to be potentially detectable in an experiment. Among the classical spin models, the Frenkel model is certainly prominent for its long history and its wide application. Our results, however, suggest that the classical Foldy-Wouthuysen model is superior as it is qualitatively in better agreement with the quantum mechanical Dirac equation. In ultra strong laser setups at parameter regimes where effects of the Stern-Gerlach force become relevant also radiation reaction effects are

  6. Religiousness and Rape Myth Acceptance: Risk and Protective Effects. (United States)

    Ensz, Samantha; Jankowski, Peter J


    This study addressed the lack of research simultaneously examining multiple dimensions of religiousness when predicting rape myth acceptance, and extended prior findings of a mediating role for right-wing authoritarianism (i.e., uncritical submission to authority and aggressive attitude toward those who do not conform to social norms) in the association between religiousness and prejudice. The sample consisted of 99 undergraduate and graduate students ( M age = 31.87 years, 66.7% female, 80.82% White, and 93% Christian affiliated) from a religiously affiliated university in the Midwest United States. As hypothesized, dimensions of religiousness exhibited differential associations with rape myth acceptance. Religious motivation characterized by openness and exploration (i.e., quest religiousness) was a significant negative predictor of rape myth acceptance, directly, and indirectly through right-wing authoritarianism. In contrast, rigid adherence to religious beliefs, assumed to be "right" and absolutely true (i.e., religious fundamentalism), and extrinsically motivated religiousness each exhibited a positive association with rape myth acceptance through right-wing authoritarianism. In addition, internally motivated religiousness and religious fundamentalism each moderated the nonlinear effect for quest predicting rape myth acceptance. Findings suggest that uncritical religious and secular submission to external authorities or uncommitted and nonexploring religiousness may have increased the extent to which persons adhered to rape myths, whereas religious exploration was protective. Practical implications center on the need for socioculturally relevant prevention and intervention efforts with religious identifying college students.

  7. Women's erotic rape fantasies: an evaluation of theory and research. (United States)

    Critelli, Joseph W; Bivona, Jenny M


    This article is the first systematic review of the research literature on women's rape fantasies. Current research indicates that between 31% and 57% of women have fantasies in which they are forced into sex against their will, and for 9% to 17% of women these are a frequent or favorite fantasy experience. Erotic rape fantasies are paradoxical: they do not appear to make sense. Why would a person have an erotic and pleasurable fantasy about an event that, in real life, would be abhorrent and traumatic? In this article, the major theories of women's rape fantasies are evaluated both rationally and empirically. These theories explain rape fantasies in terms of masochism, sexual blame avoidance, openness to sexuality, sexual desirability, male rape culture, biological predisposition to surrender, sympathetic physiological activation, and adversary transformation. This article evaluates theory and research, makes provisional judgments as to which theories appear to be most viable, and begins the task of theoretical integration to arrive at a more complete and internally consistent explanation for why many women engage in erotic rape fantasies. Methodological critiques and programs for future research are presented throughout.

  8. Pulse shape optimization for electron-positron production in rotating fields (United States)

    Fillion-Gourdeau, François; Hebenstreit, Florian; Gagnon, Denis; MacLean, Steve


    We optimize the pulse shape and polarization of time-dependent electric fields to maximize the production of electron-positron pairs via strong field quantum electrodynamics processes. The pulse is parametrized in Fourier space by a B -spline polynomial basis, which results in a relatively low-dimensional parameter space while still allowing for a large number of electric field modes. The optimization is performed by using a parallel implementation of the differential evolution, one of the most efficient metaheuristic algorithms. The computational performance of the numerical method and the results on pair production are compared with a local multistart optimization algorithm. These techniques allow us to determine the pulse shape and field polarization that maximize the number of produced pairs in computationally accessible regimes.

  9. Electronic Field Guides and User Communities in the Eco-informatics Revolution

    Directory of Open Access Journals (Sweden)

    R. D. Stevenson


    Full Text Available The recognition that taxonomy is central to the conservation of biodiversity has reestablished the critical role of taxonomy in biology. However, many of the tools taxonomists produce for the identification and characterization of species, e.g., dichotomous keys, have been difficult to use and largely ignored by the general public in favor of field guides, which are essentially browsable picture guides. We review the role of field guides in species identification and discuss the application of a host of digital technologies to produce user-friendly tools for identification that are likely to greatly enhance species identification in the field by nonspecialists. We suggest that wider adoption of the citizen science model and the use of electronic field guides will enhance public understanding and participation in biodiversity monitoring.

  10. Metal-insulator transition of 2d electron gas in a random magnetic field

    CERN Document Server

    Wang, X R; Liu, D Z


    We study the metal-insulator transition of a two-dimensional electron gas in the presence of a random magnetic field from the localization property. The localization length is directly calculated using a transfer matrix technique and finite size scaling analysis. We argue that there is a metal-insulator transition in such a system and show strong numerical evidence that the system undergoes a disorder driven Kosterlitz-Thouless type metal-insulator transition. We will also discuss a mean field theory which maps the random field system into a two-dimensional XY-model. The vortex and antivortex excitations in the XY-model correspond to two different kinds of magnetic domains in the random field system.

  11. Density of one-particle states for 2-D electron gas in magnetic field

    Directory of Open Access Journals (Sweden)



    Full Text Available The density of states of a particle in a 2-D area is independent both of the energy and form of the area only at the region of large values of energy. If energy is small, the density of states in the rectangular potential well essentially depends on the form of the area. If the bottom of the potential well has a potential relief, it can define the small eigenvalues as the discrete levels. In this case, dimensions and form of the area would not have any importance. If the conservation of zero value of the angular momentum is taken into account, the effective one-particle Hamiltonian for the 2-D electron gas in the magnetic field in the circle is the Hamiltonian with the parabolic potential and the reflecting bounds. It is supposed that in the square, the Hamiltonian has the same view. The 2-D density of states in the square can be computed as the convolution of 1-D densities. The density of one-particle states for 2-D electron gas in the magnetic field is obtained. It consists of three regions. There is a discrete spectrum at the smallest energy. In the intervening region the density of states is the sum of the piecewise continuous function and the density of the discrete spectrum. At great energies, the density of states is a continuous function. The Fermi energy dependence on the magnetic field is obtained when the field is small and the Fermi energy is located in the region of continuous spectrum. The Fermi energy oscillates and in the average it increases proportionally to the square of the magnetic induction. Total energy of electron gas in magnetic field also oscillates and increases when the magnetic field increases monotonously.

  12. Langmuir wave electric fields induced by electron beams in the heliosphere (United States)

    Reid, Hamish A. S.; Kontar, Eduard P.


    Solar electron beams responsible for type III radio emission generate Langmuir waves as they propagate out from the Sun. The Langmuir waves are observed via in situ electric field measurements. These Langmuir waves are not smoothly distributed but occur in discrete clumps, commonly attributed to the turbulent nature of the solar wind electron density. Exactly how the density turbulence modulates the Langmuir wave electric fields is understood only qualitatively. Using weak turbulence simulations, we investigate how solar wind density turbulence changes the probability distribution functions, mean value and variance of the beam-driven electric field distributions. Simulations show rather complicated forms of the distribution that are dependent upon how the electric fields are sampled. Generally the higher magnitude of density fluctuations reduce the mean and increase the variance of the distribution in a consistent manor to the predictions from resonance broadening by density fluctuations. We also demonstrate how the properties of the electric field distribution should vary radially from the Sun to the Earth and provide a numerical prediction for the in situ measurements of the upcoming Solar Orbiter and Solar Probe Plus spacecraft.

  13. Integrated electronic transport and thermometry at milliKelvin temperatures and in strong magnetic fields. (United States)

    Samkharadze, N; Kumar, A; Manfra, M J; Pfeiffer, L N; West, K W; Csáthy, G A


    We fabricated a He-3 immersion cell for transport measurements of semiconductor nanostructures at ultra low temperatures and in strong magnetic fields. We have a new scheme of field-independent thermometry based on quartz tuning fork Helium-3 viscometry which monitors the local temperature of the sample's environment in real time. The operation and measurement circuitry of the quartz viscometer is described in detail. We provide evidence that the temperature of two-dimensional electron gas confined to a GaAs quantum well follows the temperature of the quartz viscometer down to 4 mK.

  14. Monte Carlo analysis of field-dependent electron avalanche coefficients in nitrogen at atmospheric pressure (United States)

    Nguyen, H. K.; Mankowski, J.; Dickens, J. C.; Neuber, A. A.; Joshi, R. P.


    Calculations of electron impact ionization of nitrogen gas at atmospheric pressure are presented based on the kinetic Monte Carlo technique. The emphasis is on energy partitioning between primary and secondary electrons, and three different energy sharing schemes have been evaluated. The ionization behavior is based on Wannier's classical treatment. Our Monte Carlo results for the field-dependent drift velocities match the available experimental data. More interestingly, the field-dependent first Townsend coefficient predicted by the Monte Carlo calculations is shown to be in close agreement with reported data for E/N values ranging as high as 4000 Td, only when a random assignment of excess energies between the primary and secondary particles is used.

  15. Annular dark-field scanning transmission electron microscopy (ADF-STEM) tomography of polymer systems. (United States)

    Lu, Kangbo; Sourty, Erwan; Loos, Joachim


    We have utilized bright-field conventional transmission electron microscopy tomography and annular dark-field scanning transmission electron microscopy (ADF-STEM) tomography to characterize a well-defined carbon black (CB)-filled polymer nanocomposite with known CB volume concentration. For both imaging methods, contrast can be generated between the CB and the surrounding polymer matrix. The involved contrast mechanisms, in particular for ADF-STEM, will be discussed in detail. The obtained volume reconstructions were analysed and the CB volume concentrations were carefully determined from the reconstructed data. For both imaging modes, the measured CB volume concentrations are substantially different and only quantification based on the ADF-STEM data revealed about the same value as the known CB loading. Moreover, when applying low-convergence angles for imaging ADF-STEM tomography, data can be obtained of micrometre-thick samples.

  16. Confinement of an electron in a non-homogeneous magnetic field: Integrable vs superintegrable quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Contreras-Astorga, A., E-mail: [Department of Mathematics and Actuarial Science, Indiana University Northwest, 3400 Broadway, Gary, IN 46408 (United States); Departamento de Física, Cinvestav, A.P. 14-740, 07000 México D.F. (Mexico); Negro, J., E-mail: [Departamento de Física Teórica, Atómica y Óptica and IMUVA, Universidad de Valladolid, E-47011 Valladolid (Spain); Tristao, S., E-mail: [Departamento de Física Teórica, Atómica y Óptica and IMUVA, Universidad de Valladolid, E-47011 Valladolid (Spain)


    This paper deals with the problem of an electron in a non-homogeneous magnetic field perpendicular to a plane. From the classical point of view this is an integrable, but not superintegrable, solvable system. In the quantum framework of the Dirac equation this integrable system is solvable too; the energy levels and wavefunctions of bound states, for its reduction to the plane, are computed. The effective one-dimensional matrix Hamiltonian is shown to belong to a shape-invariant hierarchy. Through this example we will shed some light on the specific properties of a quantum integrable system with respect to those characteristic of superintegrable systems. - Highlights: • The system: an electron in a non-homogeneous magnetic field. • This is a solvable integrable but not superintegrable system. • Solutions to the discrete Dirac spectrum are found. • The shape-invariance of Dirac matrix Hamiltonians is characterized. • Specific properties of integrable, not superintegrable, systems are analyzed.

  17. Neutrino decay to electron and W boson in a superstrong magnetic field in the Early Universe (United States)

    Kuznetsov, Alexander; Okrugin, Alexander; Shitova, Anastasiya


    An intense electromagnetic field makes possible the process of the neutrino decay into electron and W boson that is kinematically forbidden in a vacuum. The exact formula for the probability of ultra high energy neutrino decay in a superstrong magnetic field via the representation for the propagators of the charged particles expanded as sums over Landau levels is derived. The obtained function clarifies previously known approximate formula. The neutrino mean free path is estimated. It is shown, that the resonance peaks present in the decay width for certain neutrino energies correspond to the electron and the W boson creation at specific Landau levels. Some interesting possible manifestations of the process in the conditions of the Early Universe are briefly discussed.

  18. High Electron Confinement under High Electric Field in RF GaN-on-Silicon HEMTs

    Directory of Open Access Journals (Sweden)

    Farid Medjdoub


    Full Text Available We report on AlN/GaN high electron mobility transistors grown on silicon substrate with highly optimized electron confinement under a high electric field. The fabricated short devices (sub-10-nm barrier thickness with a gate length of 120 nm using gate-to-drain distances below 2 µm deliver a unique breakdown field close to 100 V/µm while offering high frequency performance. The low leakage current well below 1 µA/mm is achieved without using any gate dielectrics which typically degrade both the frequency performance and the device reliability. This achievement is mainly attributed to the optimization of material design and processing quality and paves the way for millimeter-wave devices operating at drain biases above 40 V, which would be only limited by the thermal dissipation.

  19. High-contrast en bloc staining of neuronal tissue for field emission scanning electron microscopy. (United States)

    Tapia, Juan Carlos; Kasthuri, Narayanan; Hayworth, Kenneth J; Schalek, Richard; Lichtman, Jeff W; Smith, Stephen J; Buchanan, JoAnn


    Conventional heavy metal poststaining methods on thin sections lend contrast but often cause contamination. To avoid this problem, we tested several en bloc staining techniques to contrast tissue in serial sections mounted on solid substrates for examination by field emission scanning electron microscopy (FESEM). Because FESEM section imaging requires that specimens have higher contrast and greater electrical conductivity than transmission electron microscopy (TEM) samples, our technique uses osmium impregnation (OTO) to make the samples conductive while heavily staining membranes for segmentation studies. Combining this step with other classic heavy metal en bloc stains, including uranyl acetate (UA), lead aspartate, copper sulfate and lead citrate, produced clean, highly contrasted TEM and scanning electron microscopy (SEM) samples of insect, fish and mammalian nervous systems. This protocol takes 7-15 d to prepare resin-embedded tissue, cut sections and produce serial section images.

  20. Imaging plant nuclei and membrane-associated cytoskeleton by field emission scanning electron microscopy. (United States)

    Fišerová, Jindřiška; Goldberg, Martin W


    Scanning electron microscopy (SEM) is a powerful technique that can image exposed surfaces in 3D. Modern scanning electron microscopes, with field emission electron sources and in-lens specimen chambers, achieve resolutions of better than 0.5 nm and thus offer views of ultrastructural details of subcellular structures or even macromolecular complexes. Obtaining a reliable image is, however, dependent on sample preparation methods that robustly but accurately preserve biological structures. In plants, exposing the object of interest may be difficult due to the existence of a cell wall. This protocol shows how to isolate plant nuclei for SEM imaging of the nuclear envelope and associated structures from both sides of the nuclear envelope in cultured cells as well as in leaf or root cells. Further, it provides a method for uncovering membrane-associated cytoskeletal structures.

  1. LASER-driven fast electron dynamics in gaseous media under the influence of large electric fields (United States)

    Batani, D.; Baton, S. D.; Manclossi, M.; Piazza, D.; Koenig, M.; Benuzzi-Mounaix, A.; Popescu, H.; Rousseaux, C.; Borghesi, M.; Cecchetti, C.; Schiavi, A.


    We present the results of experiments performed at the LULI laboratory, using the 100 TW laser facility, on the study of the propagation of fast electrons in gas targets. The implemented diagnostics included chirped shadowgraphy and proton imaging. Proton images showed the presence of very large fields in the gas (produced by charge separation). In turn, these imply a strong inhibition of propagation, and a slowing down of the fast electron cloud as it penetrates in the gas. Indeed chirped shadowgraphy images show a reduction in time of the velocity of the electron cloud from the initial value, of the order of a fraction of c, over a time scale of a few picoseconds.

  2. Evolution from perturbative to field-ionization regimes through electron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, P.; Mevel, E.; Breger, P.; Trainham, R.; Petite, G. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche sur l`Etat Condense, les Atomes et les Molecules; Migus, A.; Chambaret, J.P.; Antonetti, A. [Ecole Polytechnique, 91 - Palaiseau (France)


    A study of the electron energy spectra from rare gases ionization by intense femtosecond pulses allows to span the various ionization regimes in strong fields. Using 70 fs, 617 nm pulses, xenon, krypton and argon produce electron energy spectra characteristic of the perturbative regime i.e. dominated by resonances and Above-Threshold Ionization. However, for these atoms, ionization saturates at intensities lower than required for the onset of the tunneling regime. At the highest intensity, helium produces structureless electron energy spectra indicating a very fast ionization. However, the appearance intensity is already too high to observe the perturbative regime. With neon, only the ATI structure remains observable and it seems to stand at the border of the tunneling regime. This trend, from xenon to helium may be viewed as the typical behavior of an atom submitted to increasing intensities if it could be recorded without the limitations of the detection threshold and the saturation intensity. (author).

  3. Scientific Objectives of Electron Losses and Fields INvestigation Onboard Lomonosov Satellite (United States)

    Shprits, Y. Y.; Angelopoulos, V.; Russell, C. T.; Strangeway, R. J.; Runov, A.; Turner, D.; Caron, R.; Cruce, P.; Leneman, D.; Michaelis, I.; Petrov, V.; Panasyuk, M.; Yashin, I.; Drozdov, A.; Russell, C. L.; Kalegaev, V.; Nazarkov, I.; Clemmons, J. H.


    The objective of the Electron Losses and Fields INvestigation on board the Lomonosov satellite (ELFIN-L) project is to determine the energy spectrum of precipitating energetic electrons and ions and, together with other polar-orbiting and equatorial missions, to better understand the mechanisms responsible for scattering these particles into the atmosphere. This mission will provide detailed measurements of the radiation environment at low altitudes. The 400-500 km sun-synchronous orbit of Lomonosov is ideal for observing electrons and ions precipitating into the atmosphere. This mission provides a unique opportunity to test the instruments. Similar suite of instruments will be flown in the future NSF- and NASA-supported spinning CubeSat ELFIN satellites which will augment current measurements by providing detailed information on pitch-angle distributions of precipitating and trapped particles.

  4. Rape and child sexual abuse: what beliefs persist about motives, perpetrators, and survivors? (United States)

    McGee, Hannah; O'Higgins, Madeleine; Garavan, Rebecca; Conroy, Ronán


    Rape myths are prejudicial and stereotyped beliefs about rape which persist in society. They may have a significant impact on those affected by rape as well as the performance of legal and public participants in the justice system. Rape myths may differ over time and within different societies and cultural settings. Awareness of contemporary and local rape myths is necessary if they are to be successfully challenged through public campaigns and other means. This study sought to assess the prevalence of myths concerning rape and sexual abuse in a national population survey.

  5. Analysis of yield and plant traits of oilseed rape (Brassica napus L. cultivated in temperate region in light of the possibilities of sowing in arid areas

    Directory of Open Access Journals (Sweden)

    Tadeusz Zając


    Full Text Available This work is a review of selected literature on the species of Brassica with the greatest economic significance. Oilseed rape (Brassica napus ssp. oleifera currently ranks third worldwide among oilseed crops used for oil production and is the most important in the temperate zone. The manifold uses of rape include not only human consumption of oil, but also the use of post-extraction meal to feed livestock as well as industrial applications as a source of bioenergy or cellulose. The improvement in the economic position of rape among crop plants is also due to the doubling of its yield between 1970 and 2009; the average annual increase in seed yield worldwide was 27 kg ha−1 yr−1. The yield level in Europe exceeds the average yields achieved in the world, particularly in Asia. Recently, the cultivation of oilseed rape was started on a relatively large acreage in Iran where the yield amounted 2.1 t ha−1, exceeding the yields of China and India. In Poland, the acreage of oilseed rape cultivation between 1965 and 2013 increased 3–4 times, and during this period the annual increase in seed yield was 29 kg ha−1 yr−1. Under the field conditions of the temperate climate zone, winter oilseed rape yield is mainly determined by agro-climatic conditions during the growing period, the level of nitrogen fertilization, and the production potential of varieties, which is currently highest in hybrids. There is a noticeable tendency of hybrids towards formation of more siliques by individual oilseed plants. Different production categories of plants appear in a rape crop. Semi-dwarf varieties of winter rapeseed are distinguished by greater silique density, particularly on the main shoot. Moreover, these hybrids are characterized by faster growth of the root system, which enables them to take up nitrogen from the soil more efficiently.

  6. Mitigation of pattern sensitivity in full-field electronic dispersion compensation


    Zhao, Jian A.; McCarthy, Mary E.; Gunning, Paul; Ellis, Andrew D.


    We investigate the pattern-dependent decoding failures in full-field electronic dispersion compensation (EDC) by offline processing of experimental signals, and find that the performance of such an EDC receiver may be degraded by an isolated "1" bit surrounded by long strings of consecutive "0s". By reducing the probability of occurrence of this kind of isolated "1" and using a novel adaptive threshold decoding method, we greatly improve the compensation performance to achieve 10-Gb/s on-off ...

  7. Tunable superlattice amplifiers based on dynamics of miniband electrons in electric and magnetic fields


    Hyart, T. (Timo)


    Abstract The most important paradigms in quantum mechanics are probably a twolevel system, a harmonic oscillator and an ideal (infinite) periodic potential. The first two provide a starting point for understanding the phenomena in systems where the spectrum of energy levels is discrete, whereas the last one results in continuous energy bands. Here an attempt is made to study the dynamics of the electrons in a narrow miniband of a semiconductor superlattice under electric and magnetic field...

  8. Statistical simulation of the energy spectra of field-emission electrons (United States)

    Egorov, N. V.; Antonov, A. Yu.; Demchenko, N. S.


    Random energies of electrons that escape from the source in the course of field emission are simulated using energy spectra. A relationship of the random values of total energy and the energy related to the normal (with respect to surface) component of momentum is established. A family of quadrature formulas needed for the integration of the distribution density of particles is analyzed. A hypothesis on the compliance of selected random energies with desired distribution laws is statistically tested.

  9. Electron residual energy due to stochastic heating in field-ionized plasma

    CERN Document Server

    Khalilzadeh, Elnaz; Jahanpanah, Jafar; Chakhmachi, Amir; Yazdani, Elnaz


    The electron residual energy originated from the stochastic heating in under-dense field-ionized plasma is here investigated. The optical response of plasma is initially modeled by using the concept of two counter-propagating electromagnetic waves. The solution of motion equation of a single electron indicates that by including the ionization, the electron with higher residual energy compared to the case without ionization could be obtained. In agreement with chaotic nature of the motion, it is found that the electron residual energy will significantly be changed by applying a minor change to the initial conditions. Extensive kinetic 1D-3V particle-in-cell (PIC) simulations have been performed in order to resolve full plasma reactions. In this way, two different regimes of plasma behavior are observed by varying the pulse length. The results indicate that the amplitude of scattered fields in sufficient long pulse length is high enough to act as a second counter-propagating wave for triggering the stochastic e...

  10. Ion acceleration driven by a relativistic electron beam under a strong magnetic field (United States)

    Taguchi, Toshihiro; Antonsen, Thomas; Mima, Kunioki


    We have been investigating about an electron beam propagation under a strong magnetic field and found a very interesting phenomena. It is a generation of a large amplitude whistler wave, which is amplified by a nonlinear coupling of obliquely propagating circularly polarized waves. Since the previous work did not include ion motions, such a giant whistler wave mainly affects on beam electrons and they stagnate due to a large ponderomotive force of the electromagnetic wave. In order to investigate the influence of the strong wave on background ions, we have developed a new PIC code which has an open (upstream and downstream) boundaries. By using the new code, we have been studying the kinetic behavior of ions in a circumstance generating a large whistler wave. As a result, it is found that the electrostatic field induced by the stagnated beam electrons not only creates a density dip in the background electrons but also accelerates background ions. We will discuss the relation between the ion acceleration and a formation of a collisionless shock wave. This work was supported by a Grant-in-Aid for Scientific Research (B), 15H03758.

  11. Strain-induced modulation on phonon and electronic properties of suspended black phosphorus field effect transistor (United States)

    Zheng, Bo; Si, Naichao; Xie, Guoxin; Wang, Quan


    Black phosphorus has recently appeared as a promising two-dimensional material for applications in high performance nanoelectronics. Its single- and few-atomic layer forms in field-effect transistors have attracted a lot of attention due to the tunable bandgap (0.3-2.0 eV), high carrier mobility (1000 cm2 V-1 s-1) and decent on-off ratios (105). Here, we demonstrate a suspended black phosphorus field effect transistor (BP-FET) and utilize Raman spectroscope to characterize the strain on the effects of Raman phonon. We find that red shifts appear in all the three vibrational modes (Ag1 , B2g and Ag2) in different degrees. Among them, Ag1 mode is most sensitive to the tensile strain. We further investigate the electronic properties with a Cascade semi-automatic probe station. The linear relationships in the output curves indicate the contacts between black phosphorus and electrodes are ohmic contacts. The transfer characteristic curves declare the drain current modulation is ∼ 7.6 ×103 for the hole conduction and ∼57 for the electron conduction. Mobility of this device is found to be 347.5 cm2 V-1 s-1 and 4.9 cm2 V-1 s-1 for the hole and electron conduction, respectively. These results provide a theoretical basis for the coordination of high-performance black phosphorus electronic components.

  12. Guiding of relativistic electron beams in dense matter by longitudinally imposed strong magnetic fields

    CERN Document Server

    Bailly-Grandvaux, M; Bellei, C; Forestier-Colleoni, P; Fujioka, S; Giuffrida, L; Honrubia, J J; Batani, D; Bouillaud, R; Chevrot, M; Cross, J E; Crowston, R; Dorard, S; Dubois, J -L; Ehret, M; Gregori, G; Hulin, S; Kojima, S; Loyez, E; Marques, J -R; Morace, A; Nicolai, Ph; Roth, M; Sakata, S; Schaumann, G; Serres, F; Servel, J; Tikhonchuk, V T; Woolsey, N; Zhang, Z


    High-energy-density flows through dense matter are needed for effective progress in the production of laser-driven intense sources of energetic particles and radiation, in driving matter to extreme temperatures creating state regimes relevant for planetary or stellar science as yet inaccessible at the laboratory scale, or in achieving high-gain laser-driven thermonuclear fusion. When interacting at the surface of dense (opaque) targets, intense lasers accelerate relativistic electron beams which transport a significant fraction of the laser energy into the target depth. However, the overall laser-to-target coupling efficiency is impaired by the large divergence of the electron beam, intrinsic to the laser-plasma interaction. By imposing a longitudinal 600T laser-driven magnetic-field, our experimental results show guided >10MA-current of MeV-electrons in solid matter. Due to the applied magnetic field, the transported energy-density and the peak background electron temperature at the 60micron-thick targets re...

  13. Width dependent collisionless electron dynamics in the static fields of the shock ramp, 2, Phase space portrait

    Directory of Open Access Journals (Sweden)

    M. Gedalin


    Full Text Available We study numerically in detail the behaviour of electrons in the strongly inhomogeneous static magnetic and electric fields, which are typical for thin quasiperpendicular collisionless shocks. We pay particular attention to the dependence of the final electron velocities on their initial velocities, for different shock widths. Electrons are completely magnetized when the shock is wide, but become demagnetized, and the energies that they acquire rapidly increase with the steepening of the field structure. One of the clear manifestations of the electron demagnetization is the loss of even approximate one-to-one correspondence of the downstream perpendicular velocity to the upstream perpendicular velocity. Electron reflection occurs despite the large cross-shock potential which accelerates electrons along the magnetic field (the regime of complete magnetization or across the shock (strong demagnetization. The reflected ion fraction is sensitive to the potential, magnetic field jump, and ramp width.

  14. Electron field emission from freestanding Diamond nanomembranes and Application to time-of-flight mass spectrometry (United States)

    Kim, Hyunseok; Park, Jonghoo; Shin, Hyuncheol; Blick, Robert H.


    We introduce a prototype of a freestanding diamond nanomembrane for large protein detection in time-of-flight mass spectrometry. Doped diamond as a material for mass spectroscopy is extremely interesting due to its mechanical and electrical properties. The freestanding diamond nanomembranes we are able to fabricate have lateral extensions of 400 μm × 400 μm with a thickness of 100nm. We employ optical lithography and a Buffered Oxide Etch (BOE) of SiO2 followed by anisotropic etching of the substrate silicon using TMAH solution and finally removing SiO2. The electron field emission from the surface of the membrane is traced in the IV characteristics at room temperature. The membrane is then applied for detection of the large ionized proteins using time-of-flight mass spectrometry. Ion detection is demonstrated in our nanomembrane MALDI-TOF analysis of Insulin (5,735 Da). That is when the ions with a large kinetic energy bombard the nanomembrane, their energy is thermalized upon impact into phonons. The phonons give a thermal energy to the electrons with the membrane, which are then excited to higher energetic states. Given an extraction voltage this leads to electron field emission from the membrane which we labeled phonon-assisted field emission (PAFE). In other words, the MALDI mass spectra are obtained by exploiting ballistic phonon propagation and quasi-diffusive phonon propagation.

  15. Field-induced electron emission from nanoporous carbon of various types

    Directory of Open Access Journals (Sweden)

    Alexander V. Arkhipov


    Full Text Available The influence of fabrication technology on field electron emission properties of nanoporous carbon (NPC has been investigated. Samples of NPC derived from different carbides via chlorination at different temperatures demonstrated similar low-field emission ability with the threshold electric field strength of 2–3 V/μm. This property correlated with the presence of nanopores with the characteristic size of 0.5–1.2 nm determining high values of specific surface area (more than 800 m2/g of the material. In most cases, voltage–current characteristics of emission were approximately linear in Fowler–Nordheim (FN coordinates (excluding the low-current part near the emission threshold, but the plot slope angles were in notable disagreement with the known material morphology and electronic properties, and this could not be explained within the frames of FN emission theory. We suggest that the actual emission mechanism for NPC involves hot electrons generated at internal boundaries, and that emission centers may be associated with relatively large (20–100 nm onion-like particles observed in many microscopy images.

  16. Direct Nanoscale Sensing of the Internal Electric Field in Operating Semiconductor Devices Using Single Electron Spins. (United States)

    Iwasaki, Takayuki; Naruki, Wataru; Tahara, Kosuke; Makino, Toshiharu; Kato, Hiromitsu; Ogura, Masahiko; Takeuchi, Daisuke; Yamasaki, Satoshi; Hatano, Mutsuko


    The electric field inside semiconductor devices is a key physical parameter that determines the properties of the devices. However, techniques based on scanning probe microscopy are limited to sensing at the surface only. Here, we demonstrate the direct sensing of the internal electric field in diamond power devices using single nitrogen-vacancy (NV) centers. The NV center embedded inside the device acts as a nanoscale electric field sensor. We fabricated vertical diamond p-i-n diodes containing the single NV centers. By performing optically detected magnetic resonance measurements under reverse-biased conditions with an applied voltage of up to 150 V, we found a large splitting in the magnetic resonance frequencies. This indicated that the NV center senses the transverse electric field in the space-charge region formed in the i-layer. The experimentally obtained electric field values are in good agreement with those calculated by a device simulator. Furthermore, we demonstrate the sensing of the electric field in different directions by utilizing NV centers with different N-V axes. This direct and quantitative sensing method using an electron spin in a wide-band-gap material provides a way to monitor the electric field in operating semiconductor devices.

  17. Integration of magnetic field and electron reflection data to improve Mars internal magnetic field model definition at 185 km altitude (United States)

    Mozzoni, D. T.; Cain, J. C.; Lillis, R. J.


    Because no further projects are planned to better define the global magnetic field about Mars, it is important to utilize present the Mars Global Surveyor (MGS) Magnetometer/Electron Reflectometer (MAG/ER) data to its fullest. Challenges in deriving an accurate model include the fact that the mapping orbit of MGS was limited to two local times, and also had a narrow distribution of data ranging from only southern latitudes below 350 km to only northern latitudes over 400 km. The aerobraking and science phasing orbit data below 350 km down to near 100 km was nearly all on the sunlit side with its strong distortions from the solar wind and embedded ionospheric currents. The improvement reported herein is from the addition of the projected total field evaluated at 185 km above the areoid. These data are derived from extrapolation of the pitch angle distributions of ER data to the reflection altitudes and adjustment to a common data altitude. Crucial to this analysis is the angular distribution of the magnetic field itself below MGS. Thus it was an iterative process whereby the 185 km data sets were recalculated based on the last iterative solutions from the magnetic field models derived including these data. The statistical improvements at the ER mapped altitudes after 5 iterations was to reduce the initial 2.0 nT sigma differences with a Gaussian spread of 20 nT to 0.5 nT and a spread of 12 nT. Unfortunately, many areas of very high field especially provided no data as they were on closed field lines. However, the iterative solutions also improved the 185 km scalar maps significantly from the original based on linear field line estimates, up to several hundred nT. The next step planned is to utilize the concept suggested by Connerney to use along-track gradients, especially those at lowest altitudes on the dayside, to input to the model sets. Preliminary tests indicate the possibility of added improvements in the missing ER data areas once this technique is perfected.

  18. Electric field measurements on Cluster: comparing the double-probe and electron drift techniques

    Directory of Open Access Journals (Sweden)

    A. I. Eriksson


    Full Text Available The four Cluster satellites each carry two instruments designed for measuring the electric field: a double-probe instrument (EFW and an electron drift instrument (EDI. We compare data from the two instruments in a representative sample of plasma regions. The complementary merits and weaknesses of the two techniques are illustrated. EDI operations are confined to regions of magnetic fields above 30 nT and where wave activity and keV electron fluxes are not too high, while EFW can provide data everywhere, and can go far higher in sampling frequency than EDI. On the other hand, the EDI technique is immune to variations in the low energy plasma, while EFW sometimes detects significant nongeophysical electric fields, particularly in regions with drifting plasma, with ion energy (in eV below the spacecraft potential (in volts. We show that the polar cap is a particularly intricate region for the double-probe technique, where large nongeophysical fields regularly contaminate EFW measurments of the DC electric field. We present a model explaining this in terms of enhanced cold plasma wake effects appearing when the ion flow energy is higher than the thermal energy but below the spacecraft potential multiplied by the ion charge. We suggest that these conditions, which are typical of the polar wind and occur sporadically in other regions containing a significant low energy ion population, cause a large cold plasma wake behind the spacecraft, resulting in spurious electric fields in EFW data. This interpretation is supported by an analysis of the direction of the spurious electric field, and by showing that use of active potential control alleviates the situation.

  19. On the Production of Flat Electron Bunches for Laser Wake Field Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Kando, M.; Fukuda, Y.; Kotaki, H.; Koga, J.; Bulanov, S.V.; Tajima, T.; /JAERI, Kyoto; Chao, A.; Pitthan, R.; /SLAC; Schuler, K.-P.; /DESY; Zhidkov, A.G.; /CRIEPI, Tokyo; Nemoto, K.; /CRIEPI, Tokyo


    We suggest a novel method for injection of electrons into the acceleration phase of particle accelerators, producing low emittance beams appropriate even for the demanding high energy Linear Collider specifications. In this paper we work out the injection into the acceleration phase of the wake field in a plasma behind a high intensity laser pulse, taking advantage of the laser polarization and focusing. With the aid of catastrophe theory we categorize the injection dynamics. The scheme uses the structurally stable regime of transverse wake wave breaking, when electron trajectory self-intersection leads to the formation of a flat electron bunch. As shown in three-dimensional particle-in-cell simulations of the interaction of a laser pulse in a line-focus with an underdense plasma, the electrons, injected via the transverse wake wave breaking and accelerated by the wake wave, perform betatron oscillations with different amplitudes and frequencies along the two transverse coordinates. The polarization and focusing geometry lead to a way to produce relativistic electron bunches with asymmetric emittance (flat beam). An approach for generating flat laser accelerated ion beams is briefly discussed.

  20. Theory of Superthermal, Wide, Electron Phase-Space Holes and Bipolar Fields* (United States)

    Goldman, M. V.; Newman, D. L.


    Laboratory reconnection experiments [1] and recent magnetospheric spacecraft observations [2] are beginning to find bipolar fields with a spatial half-width equal to many Debye lengths (10 or more) traveling at high speeds (faster than the thermal velocity of the bulk of electrons). Electron phase-space hole solutions of the nonlinear Poisson-Vlasov equations (stationary in a frame co-moving with the hole) are constructed analytically with these properties by assuming there is secondary component of the electron distribution. This component can be a tail on the electron distribution or a beam. The hole velocity will be close to the velocity at the end of the tail or the velocity of the beam, provided the ions are moving with sufficient velocity in the frame of the hole. Vlasov simulations are used to study accessibility and stability of these solutions. * Work supported by DOE, NASA, and NSF [1]W. Fox, M. Porkolab, J. Egedal, N. Katz, A. Le, and A. Vrublevskis, "Observation of electron phase-space holes during magnetic reconnection in the Versatile Toroidal Facility," Abstract GP6.00029, 50th Annual Meeting of the Division of Plasma Physics, American Physical Society (Dallas, Nov.~2008). [2] R. E. Ergun and J. Tao, private communication.

  1. Nonadiabaticity of electron-tunneling-ionization processes in elliptical strong laser fields (United States)

    Cai, Jun; Chen, Yan-jun; Xia, Qin-zhi; Ye, Di-fa; Liu, Jie; Fu, Li-bin


    We theoretically investigate the electron-tunneling process for a helium atom irradiated by an elliptical strong laser field. The momentum distribution for an electron ionized during the cycle when the laser intensity reaches its maximum is captured, such that we can ignore the interference between the wave packets ionized in different laser cycles and precisely determine the center of the momentum distribution. The quantum mechanical prediction of the center position is further compared to the semiclassical single-trajectory simulation as well as the experimental data. We find that the electron momentums along the minor axis of the laser polarization show good agreement with the nonadiabatic semiclassical calculation for a wide range of laser intensities, indicating the existence of a nonzero lateral momentum when the electron exits the barrier. On the other hand, the offset angles obtained by our quantum mechanical approach for different laser intensities are larger than the nonadiabatic semiclassical results, indicating the importance of the quantum effects during the electron's under-the-barrier dynamics.

  2. Optical emission of graphene and electron-hole pair production induced by a strong terahertz field (United States)

    Oladyshkin, I. V.; Bodrov, S. B.; Sergeev, Yu. A.; Korytin, A. I.; Tokman, M. D.; Stepanov, A. N.


    We report on experimental observation of optical emission of graphene induced by an intense terahertz (THz) pulse. P-doped chemical-vapor-deposition graphene with an initial Fermi energy of about 200 meV was used; optical photons were detected in the 2.0-3.5 eV range. Emission started when the THz field amplitude exceeded 100 kV/cm. For the THz fields from 200 to 300 kV/cm, the temperature of optical radiation was constant, while the number of emitted photons increased by several dozen times. This fact clearly indicates multiplication of electron-hole pairs induced by an external field and not electron heating. The experimental data are in good agreement with the theory of Landau-Zener interband transitions. It is shown theoretically that Landau-Zener transitions are possible even in the case of heavily doped graphene because the strong THz field removes quasiparticles from the region of interband transitions for several femtoseconds, which cancels the Pauli blocking effect.

  3. Effect of undulator harmonics field on free-electron laser harmonic generation

    Directory of Open Access Journals (Sweden)

    Qika Jia


    Full Text Available The harmonics field effect of a planar undulator on free-electron laser (FEL harmonic generation has been analyzed. For both the linear case and the nonlinear case, the harmonic fraction of the radiation can be characterized by the coupling coefficients. The modification of the coupling coefficients is given when the third harmonics magnetic field component exists, thus the enhancement of the harmonic radiation can be predicted. The numerical results show that with the third harmonics magnetic field component that has the opposite sign to the fundamental, the intensity of third-harmonic radiation can be increased distinctly for both the small signal gain and the nonlinear harmonic generation. The increase is larger for the smaller undulator deflecting parameter.

  4. Plasma heating, electric fields and plasma flow by electron beam ionospheric injection (United States)

    Winckler, J. R.; Erickson, K. N.


    The electric fields and the floating potentials of a Plasma Diagnostics Payload (PDP) located near a powerful electron beam injected from a large sounding rocket into the auroral zone ionosphere have been studied. As the PDP drifted away from the beam laterally, it surveyed a region of hot plasma extending nearly to 60 m radius. Large polarization electric fields transverse to B were imbedded in this hot plasma, which displayed large ELF wave variations and also an average pattern which has led to a model of the plasma flow about the negative line potential of the beam resembling a hydrodynamic vortex in a uniform flow field. Most of the present results are derived from the ECHO 6 sounding rocket mission.

  5. Magnetic-field-driven electron transport in ferromagnetic/ insulator/semiconductor hybrid structures (United States)

    Volkov, N. V.; Tarasov, A. S.; Rautskii, M. V.; Lukyanenko, A. V.; Varnakov, S. N.; Ovchinnikov, S. G.


    Extremely large magnetotransport phenomena were found in the simple devices fabricated on base of the Me/SiO2/p-Si hybrid structures (where Me are Mn and Fe). These effects include gigantic magnetoimpedance (MI), dc magnetoresistance (MR) and the lateral magneto-photo-voltaic effect (LMPE). The MI and MR values exceed 106% in magnetic field about 0.2 T for Mn/SiO2/p-Si Schottky diode. LMPE observed in Fe/SiO2/p-Si lateral device reaches the value of 104% in a field of 1 T. We believe that in case with the Schottky diode MR and MI effects are originate from magnetic field influence on impact ionization process by two different ways. First, the trajectory of the electron is deflected by a magnetic field, which suppresses acquisition of kinetic energy and therefore impact ionization. Second, the magnetic field gives rise to shift of the acceptor energy levels in silicon to a higher energy. As a result, the activation energy for impact ionization significantly increases and consequently threshold voltage rises. Moreover, the second mechanism (acceptor level energy shifting in magnetic field) can be responsible for giant LMPE.

  6. Ireland: child rape case undermines abortion ban. (United States)


    Abortion has been illegal in Ireland since 1861. This position was written into the national Constitution in 1963 and reconfirmed by referendum in 1983. Contraception is also illegal in the country. The pregnancy of a 14-year old adolescent due to an alleged rape, however, has caused many in Ireland to voice their support for abortion in limited circumstances. Approximately 5000 pregnant women go from Ireland to the United Kingdom annually for abortions. This 14-year old youth also planned to make the crossing, but was blocked from leaving by the Irish police and later by an injunction of the Attorney-General. The Irish Supreme Court upheld the injunction even though the young woman was reportedly contemplating suicide. A national outcry ensued with thousands of demonstrators marching in Dublin to demand the availability of information on abortion and that Irish women be allowed to travel whenever and wherever they desire. 66% of respondents to recent public opinion polls favor abortion in certain circumstances. Ultimately, the Irish Supreme Court reversed their stance to allow pregnant Irish women to travel internationally and gave suicidal Irish women the right to abortions. These decisions were made shortly within the time frame needed for the young lady in question to received a legal abortion in the United Kingdom.

  7. Synthesis, structural, and field electron emission properties of quasi-aligned carbon nanotubes from gutter oil

    Energy Technology Data Exchange (ETDEWEB)

    Suriani, A.B., E-mail: [Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjung Malim, Perak (Malaysia); Department of Physics, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjung Malim, Perak (Malaysia); Dalila, A.R. [Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjung Malim, Perak (Malaysia); Department of Physics, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjung Malim, Perak (Malaysia); Mohamed, A. [Nanotechnology Research Centre, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjung Malim, Perak (Malaysia); Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjung Malim, Perak (Malaysia); Soga, T.; Tanemura, M. [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555 (Japan)


    Quasi-aligned carbon nanotubes (CNTs) have been successfully synthesised from the simple pyrolysis of gutter oil as starting material and ferrocene as a catalyst. The synthesis process was performed at synthesis and vaporisation temperatures of 800 and 250 °C, respectively, in a thermal chemical vapour deposition furnace. The CNTs synthesised using gutter oil have an overall diameter of about 30–50 nm, length of 30 μm, I{sub D}/I{sub G} ratio of 0.66, and purity of 81%, comparable to those obtained using conventional carbon sources. A field electron emission study of the CNTs exhibited a low turn-on and threshold field of 1.94 and 2.94 V μm{sup −1}, which corresponded to current densities of 100 μA cm{sup −2} and 1.0 mA cm{sup −2}, respectively which indicate that the CNTs synthesised are suitable candidates for use as field electron emitters. The synthesised CNTs from gutter oil also open up potential mass production applications in energy storage devices. This study demonstrates that gutter oil, a low-cost and readily available resource, can be used as an inexpensive carbon source for the mass production of CNTs. - Highlights: • Gutter oil was used as starting material to synthesise CNTs by TCVD method. • CNTs of good quality (I{sub D}/I{sub G} ∼ 0.66 and purity ∼ 81%) were successfully produced. • The synthesised CNTs show a potential for field electron emission application.

  8. Electron emission from conductors subjected to intense, short-pulse electric fields (United States)

    Scarpetti, R. D.; Goerz, D. A.; Bowen, P. R.; Hodgin, R. L.; Wong, K. C.; Champney, P. D'a.


    We studied electron emission from metal electrodes subjected to electric fields ranging from 0.5 to 2.5 MV/cm for pulse durations of 3 to 10 ns. We used two high-voltage pulsers for these tests; a 500 to 700 kV, 72 ohm pulser that generated a 3 ns Gaussian pulse; and a 2 MV, 60 ohm pulser that generated a 10 ns flat-top pulse with a 1-ns risetime. The high voltage levels allowed emission studies using electrode spacings of several millimeters to several centimeters. Our studies emphasized bare and anodized aluminum surface shaving surface finishes that ranged from rolled stock to machined finishes of 2 to 400 micron-in roughness. We also investigated polished stainless steel and brass. Emphasis was on first-shot performance with subsequent pulses applied to check for possible conditioning. The background pressure was typically .00005 Torr. Our studies showed that for 10 ns pulse lengths, anodized aluminum surfaces could hold off more than twice the electric field strength of bare aluminum surfaces without appreciable electron emission. Anodized surfaces performed well at 1.0 to 1.5 MV/cm, while bare surfaces emitted at 0.5 to 0.7 MV/cm. For the shorter, 3 ns pulse lengths, anodizing was less effective at improving suppression of electron emission, while surface finish became the important factor. Electrodes with surface finishes of 40 micro-in or better roughness performed well at field strengths of up to 2.4 MV/cm. The behavior of velvet cloth as an emitter was also investigated using the 3 ns pulser. We found that velvet would emit within 3 ns at field strengths approaching 100 kV/cm.

  9. Microwave spectroscopy of two-dimensional electrons in tilted magnetic field (United States)

    Zhu, Han

    A two-dimensional electron system in a perpendicular magnetic field exhibits a large family of phases with crystalline or partial crystalline order. These include the Wigner solid (WS) at small filling factor nu of the lowest Landau level (LL), WS formed of dilute quasiparticles near integer nu, and the bubble and the stripe phases in the third or higher LL's. These phases are pinned by sample disorder, and exhibit collective oscillation modes, or pinning modes, which give rise to resonances in microwave conductivity spectra, as found in previous studies. The resonances serve not only as evidence for the particular phases, but also as tools for probing charge ordering, dynamics, and disorder effects. This thesis presents our microwave spectroscopic study of these phases in the presence of an in-plane magnetic field, Bip, which can affect the electron orbitals and spins. We find that applying Bip expands the range of nu in which WS occurs in the lowest LL. In the second LL, near integer nu, applying Bip similarly expands the range of nu for the quasiparticle WS, accompanied by a significant increase in the pinning energy. The stripe phase shows a resonance only if measured with a microwave electric field polarized perpendicular to the stripes. The resonance polarization can switch in Bip, indicating reorientation of the stripes; the strength of the disorder pinning depends on B ip, and plays an important role in orienting the stripes. The bubble phase shows isotropic resonance at zero Bip; applying Bip isotropically shifts up the resonance frequency, and induces anisotropy in the resonance intensity. Because the experimental systems have finite layer thickness, we ascribe these effects to Bip altering the electron orbital wave functions, which changes electron-electron interaction and electron-disorder interaction. Applying Bip also increases the Zeeman gap, and affects the spin degree of freedom. We find the pinning-mode resonance frequency of the solid near nu = 1

  10. "Lucrece this night I must enjoy thee" : a narcissistic reading of The Rape of Lucrece

    National Research Council Canada - National Science Library

    Koketso, Daniel


    The circumstances under which acts of rape are committed, and the relationship between power and sexual aggression, may seem to be distinctly modern concerns, yet Shakespeare explores them in The Rape of Lucrece (1594...

  11. “You Have to Confess”: Rape and the Politics of Storytelling

    Directory of Open Access Journals (Sweden)

    Tara Roeder


    Full Text Available This article examines the discourse of rape in contemporary culture, paying special attention to the courtroom setting, where rape victims are often required to tell cohesive, linear narratives that underscore their blamelessness if they hope to be believed. Because of deeply entrenched cultural myths about rape, the type of story often required for the successful prosecution of perpetrators may require rape victims to construct narratives that do not accurately reflect their lived experience. Writers such as Susan Brison, Patricia Weaver Francisco, and Alice Sebold engage with the complex politics of rape and its telling in their memoirs. While constructing stories that will suffice in the courtroom setting remains an important task for many rape victims, such stories may ultimately have to be relinquished and rewritten in order to revise prevailing cultural perceptions of rape, its perpetrators, and its victims. The memoirs of rape survivors thus come to function as a different—and necessary—type of public testimony.

  12. Mutilating granuloma inguinale after rape A case report | O'Farrell ...

    African Journals Online (AJOL)

    Abstract. A woman with extensive mutilating lesions of genital granuloma inguinale following rape is described. As far as is known granuloma inguinale has not previously been reported in a rape victim.

  13. Free-Free Transitions in the Presence of Laser Fields and Debye Potential at Very Low Incident Electron Energies (United States)

    Bhatia, Anand


    We study the free-free transition in electron-helium ion in the ground state and embedded in a Debye potential in the presence of an external laser field at very low incident electron energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen as monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing Volkov wave function for it. The scattering wave function for the incident electron on the target embedded in a Debye potential is solved numerically by taking into account the effect of electron exchange. We calculate the laser-assisted differential and total cross sections for free-free transition for absorption/emission of a single photon or no photon exchange. The results will be presented at the conference.

  14. Helium like impurity in CdTe/ Cd1-xMnxTe semimagnetic semiconductors under magnetic field: Dimensionality effect on electron - Electron interaction (United States)

    Kalpana, Panneer Selvam; Jayakumar, Kalyanasundaram


    We study the effect of magnetic field on the Coulomb interaction between the two electrons confined inside a CdTe/Cd1-xMnxTe Quantum Well (QW), Quantum Well Wire (QWW) and Quantum Dot (QD) for the composition of Mn2+ ion, x = 0.3. The two particle Schrodinger equation has been solved using variational technique in the effective mass approximation. The results show that the applied magnetic field tremendously alters the Coulomb interaction of the electrons and their binding to the donor impurity by shrinking the spatial extension of the two particle wavefunction and leads to tunnelling through the barrier. The qualitative phenomenon involved in such variation of electron - electron interaction with the magnetic field has also been explained through the 3D - plot of the probability density function.

  15. Suspect aggression and victim resistance in multiple perpetrator rapes. (United States)

    Woodhams, Jessica; Cooke, Claire


    Several research studies have reported an elevated level of aggression in rapes committed by multiple perpetrators compared to rapes committed by lone suspects. Several factors that have been linked to elevated aggression in generic samples of rape were examined for the first time with a sample of multiple perpetrator rapes. Factors that might be associated with victim resistance were also investigated. Victim and offender characteristics, as well as the behaviors displayed by victims and offenders, were extracted from the police files of 89 multiple perpetrator stranger rapes perpetrated against female victims in the United Kingdom. These behaviors were rated for their level of suspect (non-sexual) aggression and victim resistance, respectively. Degree of victim resistance was significantly and positively associated with suspect aggression. Older victims were the recipients of significantly higher levels of suspect aggression. Victims who were incapacitated from drugs and/or alcohol were less likely to be the recipients of suspect aggression. Group leaders displayed more aggression towards the victim than the followers in the groups. The number of perpetrators was significantly related to the degree of resistance displayed by the victim with offences perpetrated by fewer suspects being characterized by more victim resistance. Research regarding cognitive appraisal during criminal interactions and the respective roles of offenders is referred to in considering these relationships.

  16. Quantitative atomic resolution mapping using high-angle annular dark field scanning transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Van Aert, S., E-mail: [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Verbeeck, J. [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Erni, R. [National Center for Electron Microscopy, Ernest Orlando Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 72R0150, Berkeley, CA 94720 (United States); Bals, S. [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Luysberg, M. [Institute of Solid State Research and Ernst Ruska Center for Microscopy and Spectroscopy with Electrons, Helmholtz Research Center Juelich, 52425 Juelich (Germany); Dyck, D. Van; Tendeloo, G. Van [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)


    A model-based method is proposed to relatively quantify the chemical composition of atomic columns using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images. The method is based on a quantification of the total intensity of the scattered electrons for the individual atomic columns using statistical parameter estimation theory. In order to apply this theory, a model is required describing the image contrast of the HAADF STEM images. Therefore, a simple, effective incoherent model has been assumed which takes the probe intensity profile into account. The scattered intensities can then be estimated by fitting this model to an experimental HAADF STEM image. These estimates are used as a performance measure to distinguish between different atomic column types and to identify the nature of unknown columns with good accuracy and precision using statistical hypothesis testing. The reliability of the method is supported by means of simulated HAADF STEM images as well as a combination of experimental images and electron energy-loss spectra. It is experimentally shown that statistically meaningful information on the composition of individual columns can be obtained even if the difference in averaged atomic number Z is only 3. Using this method, quantitative mapping at atomic resolution using HAADF STEM images only has become possible without the need of simultaneously recorded electron energy loss spectra.

  17. Atom-by-atom structural and chemical analysis by annular dark-field electron microscopy. (United States)

    Krivanek, Ondrej L; Chisholm, Matthew F; Nicolosi, Valeria; Pennycook, Timothy J; Corbin, George J; Dellby, Niklas; Murfitt, Matthew F; Own, Christopher S; Szilagyi, Zoltan S; Oxley, Mark P; Pantelides, Sokrates T; Pennycook, Stephen J


    Direct imaging and chemical identification of all the atoms in a material with unknown three-dimensional structure would constitute a very powerful general analysis tool. Transmission electron microscopy should in principle be able to fulfil this role, as many scientists including Feynman realized early on. It images matter with electrons that scatter strongly from individual atoms and whose wavelengths are about 50 times smaller than an atom. Recently the technique has advanced greatly owing to the introduction of aberration-corrected optics. However, neither electron microscopy nor any other experimental technique has yet been able to resolve and identify all the atoms in a non-periodic material consisting of several atomic species. Here we show that annular dark-field imaging in an aberration-corrected scanning transmission electron microscope optimized for low voltage operation can resolve and identify the chemical type of every atom in monolayer hexagonal boron nitride that contains substitutional defects. Three types of atomic substitutions were found and identified: carbon substituting for boron, carbon substituting for nitrogen, and oxygen substituting for nitrogen. The substitutions caused in-plane distortions in the boron nitride monolayer of about 0.1 A magnitude, which were directly resolved, and verified by density functional theory calculations. The results demonstrate that atom-by-atom structural and chemical analysis of all radiation-damage-resistant atoms present in, and on top of, ultra-thin sheets has now become possible.

  18. Generation and confinement of hot ions and electrons in a reversed-field pinch plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, B E; Almagri, A F; Anderson, J K; Caspary, K J; Clayton, D J; Den Hartog, D J; Ennis, D A; Fiksel, G; Gangadhara, S; Kumar, S; Magee, R M; O' Connell, R; Parke, E; Prager, S C; Reusch, J A; Sarff, J S; Stephens, H D [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Brower, D L; Ding, W X [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Craig, D, E-mail: bchapman@wisc.ed [Wheaton College, Wheaton, IL 60187 (United States)


    By manipulating magnetic reconnection in Madison Symmetric Torus (MST) discharges, we have generated and confined for the first time a reversed-field pinch (RFP) plasma with an ion temperature >1 keV and an electron temperature of 2 keV. This is achieved at a toroidal plasma current of about 0.5 MA, approaching MST's present maximum. The manipulation begins with intensification of discrete magnetic reconnection events, causing the ion temperature to increase to several kiloelectronvolts. The reconnection is then quickly suppressed with inductive current profile control, leading to capture of a portion of the added ion heat with improved ion energy confinement. Electron energy confinement is simultaneously improved, leading to a rapid ohmically driven increase in the electron temperature. A steep electron temperature gradient emerges in the outer region of the plasma, with a local thermal diffusivity of about 2 m{sup 2} s{sup -1}. The global energy confinement time reaches 12 ms, the largest value yet achieved in the RFP and which is roughly comparable to the H-mode scaling prediction for a tokamak with the same plasma current, density, heating power, size and shape.

  19. Electric field modulation of electronic structures in InSe and black phosphorus heterostructure (United States)

    Ding, Yi-min; Shi, Jun-jie; Zhang, Min; Xia, Congxin; Wu, Meng; Wang, Hui; Cen, Yu-lang; Pan, Shu-hang


    The electronic structures of InSe and black phosphorus (BP) heterostructure modulated by an external electric field (E⊥) have been investigated based on first-principles calculations. We find that InSe/BP has type II band offset with a direct band gap of 0.39 eV, and the electrons (holes) are spatially located in InSe (BP) layer. Meanwhile, the band structures of InSe/BP can be effectively modulated by E⊥. The band gap shows linear variation with E⊥ and its maximum of 0.69 eV is observed when E⊥ is 0.4 V / Å. The InSe/BP experiences a transition from semiconductor to metal with E⊥ of -0.6 and 0.8 V / Å. The band offsets are also modulated by E⊥, resulting in different spatial distribution of electron-hole pairs. Most importantly, the high carrier mobility can be preserved well under E⊥. Our results show that the novel InSe/BP heterostructure has great potential application in electronic and optoelectronic devices.

  20. Variability of the Magnetic Field Power Spectrum in the Solar Wind at Electron Scales (United States)

    Roberts, Owen Wyn; Alexandrova, O.; Kajdič, P.; Turc, L.; Perrone, D.; Escoubet, C. P.; Walsh, A.


    At electron scales, the power spectrum of solar-wind magnetic fluctuations can be highly variable and the dissipation mechanisms of the magnetic energy into the various particle species is under debate. In this paper, we investigate data from the Cluster mission’s STAFF Search Coil magnetometer when the level of turbulence is sufficiently high that the morphology of the power spectrum at electron scales can be investigated. The Cluster spacecraft sample a disturbed interval of plasma where two streams of solar wind interact. Meanwhile, several discontinuities (coherent structures) are seen in the large-scale magnetic field, while at small scales several intermittent bursts of wave activity (whistler waves) are present. Several different morphologies of the power spectrum can be identified: (1) two power laws separated by a break, (2) an exponential cutoff near the Taylor shifted electron scales, and (3) strong spectral knees at the Taylor shifted electron scales. These different morphologies are investigated by using wavelet coherence, showing that, in this interval, a clear break and strong spectral knees are features that are associated with sporadic quasi parallel propagating whistler waves, even for short times. On the other hand, when no signatures of whistler waves at ∼ 0.1{--}0.2{f}{ce} are present, a clear break is difficult to find and the spectrum is often more characteristic of a power law with an exponential cutoff.