633 research outputs found

    SEU Performance of TAG Based Flip Flops

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    We describe heavy ion test results for two new SEU tolerant latches based on transition nand gates, one for single rail asynchronous and the other for dual rail synchronous designs, implemented in AMI 0.5microprocess

    La expansión del quejigo (Quercus faginea) en el Prepirineo Aragonés durante la segunda mitad del siglo XX

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    The expansion of Quercus faginea Lam. -due to a decrease in human pressure- was investigated in seven municipalities of the Aragón’s Pre-Pyrenees over the second half of the twentieth century. The rural emigration that occurred in this area since 1960s has generated a massive abandonment of agricultural lands and a decrease in livestock pressure. As a result, some abandoned fields have been colonized by Q. faginea; specially, in the municipalities that have known a marked decrease in the numbers of farmers and livestock. With the continued decrease of human pressure in the territory, it is expected that Q. faginea will colonize new areas during the next years as a result of secondary succession.Se investigó la expansión de Quercus faginea Lam. (quejigo) debida a la disminución de la presión antrópica en siete municipios del Prepirineo Aragonés durante la segunda mitad del siglo XX. La emigración rural que ha ocurrido en esta zona a partir de los años sesenta ha producido un abandono masivo de las tierras agrícolas junto con la disminución de la presión pastoral. Como resultado algunos de los campos abandonados han sido colonizados por el quejigo, sobre todo en los municipios con una disminución notable en el número de agricultores y cabezas de ganado. Se espera que, con la continua disminución de la presión humana en el territorio, los quejigares colonicen nuevas áreas en los próximos años como resultado de la sucesión secundaria

    The Effectiveness of TAG or Guard-Gates in SET Suppression Using Delay and Dual-Rail Configurations at 0.35 microns

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    Design options for decreasing the susceptibility of integrated circuits to Single Event Upset (SEU) fall into two categories: (1) increasing the critical charge to cause an upset at a particular node, and (2) employing redundancy to mask or correct errors. With decreasing device sizes on an Integrated Circuit (IC), the amount of charge required to represent a logic state has steadily reduced. Critical charge methods such as increasing drive strength or increasing the time required to change state as in capacitive or resistive hardening or delay based approaches extract a steadily increasing penalty as a percentage of device resources and performance. Dual redundancy is commonly assumed only to provide error detection with Triple Modular Redundancy (TMR) required for correction, but less well known methods employ dual redundancy to achieve full error correction by voting two inputs with a prior state to resolve ambiguity. This requires special circuits such as the Whitaker latch [1], or the guard-gate [2] which some of us have called a Transition AND Gate (TAG) [3]. A 2-input guard gate is shown in Figure 1. It is similar to a Muller Completion Element [4] and relies on capacitance at node "out" to retain the prior state when inputs disagree, while eliminating any output buffer which would be susceptible to radiation strikes. This paper experimentally compares delay based and dual rail flip-flop designs wherein both types of circuits employ guard-gates to optimize layout and performance, and draws conclusions about design criteria and suitability of each option. In both cases a design goal is protection against Single Event Transients (SET) in combinational logic as well as SEU in the storage elements. For the delay based design, it is also a goal to allow asynchronous clear or preset inputs on the storage elements, which are often not available in radiation tolerant designs

    Phonon dispersion and electron-phonon interaction for YBa_2Cu_3O_7 from first-principles calculations

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    We present a first principles investigation of the lattice dynamics and electron-phonon coupling of the high-T_c superconductor YBa_2Cu_3O_7 within the framework of density functional perturbation theory using a mixed-basis pseudopotential method. The calculated phonon dispersion curves are in excellent agreement with Raman, infrared and neutron data. Calculation of the Eliashberg function alpha^2F leads to a small electron-phonon coupling lambda=0.27 in disagreement with earlier approximate treatments. Our calculations strongly support the view that conventional electron-phonon coupling is not an important contribution to superconductivity in high-T_c materials.Comment: 4 pages, 4 figure

    Diel turbidity cycles in a headwater stream: evidence of nocturnal bioturbation?

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    Purpose: A small number of recent studies have linked daily cycles in stream turbidity to nocturnal bioturbation by aquatic fauna, principally crayfish, and demonstrated this process can significantly impact upon water quality under baseflow conditions. Adding to this limited body of research, we use high-resolution water quality monitoring data to investigate evidence of diel turbidity cycles in a lowland, headwater stream with a known signal crayfish (Pacifastacus leniusculus) population and explore a range of potential causal mechanisms. Materials and methods: Automatic bankside monitoring stations measured turbidity and other water quality parameters at 30-min resolution at three locations on the River Blackwater, Norfolk, UK during 2013. Specifically, we focused on two 20-day periods of baseflow conditions during January and April 2013 which displayed turbidity trends typical of winter and spring seasons, respectively. The turbidity time-series, which were smoothed with 6.5 hour Savitzky-Golay filters to highlight diel trends, were correlated against temperature, stage, dissolved oxygen and pH to assess the importance of abiotic influences on turbidity. Turbidity was also calibrated against suspended particulate matter (SPM) over a wide range of values via linear regression. Results and discussion: Pronounced diel turbidity cycles were found at two of the three sites under baseflow conditions during April. Spring night-time turbidity values consistently peaked between 21:00 and 04:00 with values increasing by ~10 nephelometric turbidity units (NTU) compared with the lowest recorded daytime values which occurred between 10:00 and 14:00. This translated into statistically significant increases in median midnight SPM concentration of up to 76% compared with midday, with night-time (18:00 – 05:30) SPM loads also up to 30% higher than that recorded during the daytime (06:00 – 17:30). Relating turbidity to other water quality parameters exhibiting diel cycles revealed there to be neither any correlation that might indicate a causal link, nor any obvious mechanistic connections to explain the temporal turbidity trends. Diel turbidity cycles were less prominent at all sites during the winter. Conclusions: Considering the seasonality and timing of elevated turbidity, visual observations of crayfish activity, and an absence of mechanistic connections with other water quality parameters, the results presented here are consistent with the hypothesis that nocturnal bioturbation is responsible for generating diel turbidity cycles under baseflow conditions in headwater streams. However, further research in a variety of fluvial environments is required to better assess the spatial extent, importance and causal mechanisms of this phenomenon

    Measurement of CNGS muon neutrino speed with Borexino

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    We have measured the speed of muon neutrinos with the Borexino detector using short-bunch CNGS beams. The final result for the difference in time-of-flight between a =17 GeV muon neutrino and a particle moving at the speed of light in vacuum is {\delta}t = 0.8 \pm 0.7stat \pm 2.9sys ns, well consistent with zero.Comment: 6 pages, 5 figure

    Safety and efficacy of Axtra® PHY 20000 TPT2 (6‐phytase) as a feed additive for poultry and porcine species

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    Axtra\uae PHY 20000 TPT2 is a solid preparation that contains a 6-phytase produced with a genetically modified strain of Trichoderma reesei. The production strain and its recombinant DNA were not detected in Axtra\uae PHY 20000 TPT2. From the results obtained in tolerance studies, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive is safe for the target species at 2,000 FTU/kg feed. The studies provided to address the safety for the consumer were performed with the fermentation product that is used to formulate the additive and the results do not indicate any reason for concern for consumer safety arising from the use of the product as a feed additive. The studies provided to address the safety for the user were performed with the fermentation product that is used to formulate the additive and have been assessed in a previous opinion. Considering the results of those studies and the substances used during the formulation of Axtra\uae PHY 20000 TPT2, this formulation is not considered a dermal sensitiser. However, it should be considered a potential irritant to skin, eyes and the respiratory tract, and owing to the nature of the active substance, it should be considered a potential respiratory sensitiser. However, the exposure by inhalation is expected to be negligible. No risks to the environment are expected from the use of Axtra\uae PHY 20000 TPT2 as a feed additive. Based on the results of efficacy studies, the Panel concluded that the additive has the potential to be efficacious at 250 FTU/kg feed

    Safety and efficacy of a feed additive consisting of β-mannanase produced by Aspergillus niger CBS 120604 (Nutrixtend Optim) for use in all poultry for fattening (Kerry Ingredients & Flavours Ltd)

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    Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of a product containing beta-mannanase produced by a non-genetically modified strain of Aspergillus niger (CBS 120604). The commercial name is Nutrixtend Optim and it is intended to be used as a zootechnical feed additive for all poultry for fattening. Based on a tolerance trial in chickens for fattening and the no observed adverse effect level identified in a subchronic oral toxicity study in rats, the additive was considered safe for all poultry for fattening. The Panel concluded that the use of the product as a feed additive does not give rise to concerns for consumers and the environment. The additive is considered an irritant to skin and eyes and a dermal sensitiser. Due to the proteinaceous nature of the active substance, it is also considered a respiratory sensitiser. The Panel concludes that the additive has the potential to be efficacious as a zootechnical additive at the level of inclusion in feed of chickens for fattening of 30 U beta-mannanase/kg complete feed. This conclusion was extrapolated to all poultry for fattening. (c) 2023 European Food Safety Authority. EFSA Journal published by Wiley-VCH GmbH on behalf of European Food Safety Authority

    Identification of Specific Language Impairment in Multilingual Contexts: Preliminary Validation of a Short Parental Bilingual Questionnaire in Lebanon

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    Assessing children with Specific language Impairment (SLI) in multilingual contexts is challenging for speech language therapists given that language patterns in bilinguals and in children with SLI are often reported to be remarkably similar and that screening language tests are not standardized on bilingual populations. The present study aims to validate the use of a parental questionnaire focusing on early language development, the languages spoken by the child, the use of languages in his/her environment, and information on linguistic difficulties within the family, as a complement to language assessment in multilingual contexts. Thirty-three Lebanese/French bilingual children (12 with SLI and 21 with typical development) and their parents participated in this study in Lebanon. The parents were interviewed via the questionnaire while the children were administered standardized language tests in each language. Data analysis showed that the parents’ answers to the questionnaire were coherent throughout and that some variables of the questionnaire strongly discriminated between the two groups of children, in particular the age of the first words and first sentences. Moreover, although significant correlations were found with language test scores, the answers to the questionnaire allowed us to refine the interpretation of the performance on the standardized tests, thus demonstrating the value of the parental questionnaire as a complementary tool to clinical evaluation

    Safety and efficacy of l-tryptophan produced by fermentation with Escherichia coli KCCM 80135 for all animal species

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    Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on l-tryptophan produced by fermentation using Escherichia coli KCCM 80135 when used as a nutritional additive in feed and water for drinking for all animal species. The production strain and its recombinant DNA were not detected in the additive. l-Tryptophan produced by fermentation with E. coli KCCM 80135 does not raise any safety concern with regard to the genetic modification of the production strain. The use of l-tryptophan produced using E. coli KCCM 80135 in supplementing feed to compensate for tryptophan deficiency in feedingstuffs is safe for non-ruminant target species. Using unprotected forms of tryptophan in ruminants can be a risk. The use of l-tryptophan produced by fermentation using E. coli KCCM 80135 in animal nutrition presents no safety concerns to consumers of animal products. l-Tryptophan produced by E. coli KCCM 80135 is not toxic by inhalation. The additive is not an irritant to skin and eyes, and it is not a skin sensitiser. The additive under assessment is considered safe for the environment. It is regarded as an effective source of the amino acid l-tryptophan for all non-ruminant species. If the additive l-tryptophan is intended for use in ruminants, it should be protected from ruminal degradation
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