Behavior of the lean methane-air flame at zero-gravity

A special rig was designed and constructed to be compatible with the NASA Lewis Research Center Airborne Research Laboratory to allow the study of the effect of gravity on the behavior of lean limit in a standard 50.4 mm (2 in.) internal diameter tube when the mixtures are ignited at the open end and propagate towards the closed end of the tube. The lean limit at zero gravity was found to be 5.10% methane and the flame was found to extenguish in a manner previously observed for downward propagating flames at one g. It was observed that g-jitter could be maintained at less than + or 0.04 g on most zero g trajectories. All of propagating lean limit flames were found to be sporadically cellularly unstable at zero g. There was no observable correlation between the occurrence of g-jitter and the lean limit, average propagation speed of the flame through the tube or the occurrence of cellular instability

ICANOE - Imaging and Calorimetric Neutrino Oscillation Experiment

The main scientific goal of the ICANOE detector is the one of elucidating in a comprehensive way the pattern of neutrino masses and mixings, following the SuperKamiokande results and the observed solar neutrinos deficit. To achieve these goals, the experimental method is based upon the complementary and simultaneous detection of CERN beam (CNGS) and cosmic ray (CR) events. For the currently allowed values of the SuperKamiokande results, both CNGS and cosmic ray data will give independent measurements and provide a precise determination of the oscillation parameters.Comment: Talk given at the Workshop on the Next generation Nucleon decay and Neutrino detector (NNN99), September 23-25, 199

The Minimum Wage in America Will Current Legislation Really Help the Working Poor?

This same incentive is not present for players either already tied up in long-term contracts or those without enough major league service time to qualify for free-agent status. Were Finley\u27s plan adopted, this incentive would be present for all players in all seasons, instead of just the few hoping for lucrative contracts at the end of the year. While the competitive balance (and aggregate statistics) may not be effected, if work effort is indeed endogenous, overall effort (and hustle ) would likely be increased, and a finer product would be put on the field, potentially increasing attendance and thus revenues. Thus, this paper seeks to test whether the assertion that players perform better and expend more effort in their walk year is empirically observable. To do so, section II presents a model of the relationships between performance, effort and walk-year incentive, and reviews previous work done on similar topics. Section III discusses the relationship between performance and marginal revenue product. Section IV presents data and methodology, and section V states conclusions. Editor\u27s Note: Figures are missing from this article. We apologize for the inconvenience

Reframing the Opioid Epidemic as a National Emergency

On August 10, 2017 President Trump announced his intention to declare a national emergency following the recommendation of the White House Commission on Combating Drug Addiction and the Opioid Crisis. Opioid abuse is among the most consequential preventable public health threats facing the nation. More than 600,000 deaths have occurred to date, with 180,000 more predicted by 2020. Of the 20.5 million US residents 12 years or older with substance use disorders in 2015, 2 million were addicted to prescription pain relievers. A national emergency declaration authorizes public health powers, mobilizes resources, and facilitates innovative strategies to curb a rapidly escalating public health crisis

Fermi-Edge Superfluorescence from a Quantum-Degenerate Electron-Hole Gas

We report on the observation of spontaneous bursts of coherent radiation from a quantum-degenerate gas of nonequilibrium electron-hole pairs in semiconductor quantum wells. Unlike typical spontaneous emission from semiconductors, which occurs at the band edge, the observed emission occurs at the quasi-Fermi edge of the carrier distribution. As the carriers are consumed by recombination, the quasi-Fermi energy goes down toward the band edge, and we observe a continuously red-shifting streak. We interpret this emission as cooperative spontaneous recombination of electron-hole pairs, or superfluorescence, which is enhanced by Coulomb interactions near the Fermi edge. This novel many-body enhancement allows the magnitude of the spontaneously developed macroscopic polarization to exceed the maximum value for ordinary superfluorescence, making electron-hole superfluorescence even more "super" than atomic superfluorescence.Comment: 10 pages, 5 figure

High-temperature superconducting fault current microlimiters

High-temperature superconducting microbridges implemented with YBa(2)Cu(3)O(7-delta) thin-films are shown to be possible fault current limiters for microelectronic devices with some elements working at temperatures below the superconducting critical temperature and, simultaneously, under very low power conditions (below 1W). This is the case in the important applications of superconductors as SQUID based electronics, and technologies for communication or infrared detectors. In this paper it is shown that the good thermal behavior of these microlimiters allows working in a regime where even relatively small faults induce their transition to highly dissipative states, dramatically increasing their limitation efficiency. The conditions for optimal refrigeration and operation of these microlimiters are also proposed.Comment: 10 pages, 3 figures. LaTeX and EPS file

Detailed Modeling and Reliability Analysis of Fault-Tolerant Processor Arrays

Recent advances in VLSI/WSI technology have led to the design of processor arrays with a large number of processing elements confined in small areas. The use of redundancy to increase fault-tolerance has the effect of reducing the ratio of area dedicated to processing elements over the area occupied by other resources in the array. The assumption of fault-free hardware support (switches, buses, interconnection links, etc.,), leads at best to conservative reliability estimates. However, detailed modeling entails not only an explosive growth in the model state space but also a difficult model construction process. To address the latter problem, a systematic method to construct Markov models for the reliability evaluation of processor arrays is proposed. This method is based on the premise that the fault behavior of a processor array can be modeled by a Stochastic Petri Net (SPN). However, in order to obtain a more compact representation, a set of attributes is associated with each transition in the Petri net model. This representation is referred to as a Modified Stochastic Petri Net (MSPN) model. A MSPN allows the construction of the corresponding Markov model as the reachability graph is being generated. The Markov model generated can include the effect of failures of several different components of the array as well as the effect of a peculiar distribution of faults when the reconfiguration occurs. Specific reconfiguration schemes such as Successive Row Elimination (SRE), Alternate Row-Column Elimination (ARCE) and Direct Reconfiguration (DR), are analyze

EXTENT OF UTILIZATION OF PAPERLESS TECHNOLOGY: BASIS FOR A PROPOSED INTERVENTION PROGRAM

The purpose of this study was to assess the extent of utilization of paperless technology by the teachers in Bula District. The respondents of this study were the 204 teachers in the five different schools in Bula District namely: Bula Central Elementary School, Jose Divinagracia Elementary School, Dadiangas East Elementary School, Bula National School of Fisheries and Baluan National High School. A descriptive evaluative research design was utilized in this study. Based on the results of this study, it was revealed that the teachers have perceived that the utilization of paperless technology has been highly useful in grade management and test bank management; however, they found it moderately useful in user management. Nevertheless, the utilization of paperless technology by the teachers was highly recommended to utilized by the teachers. Finally, this study shows educators how paperless technology can reduce teacher workload, save money, and protect the environment while improving the teaching and learning process.  Article visualizations