2,730 research outputs found
Negative Ion Production Rates In Rare Gas-Halide Lasers
This paper reports on dissociative electron attachment in F2, NF3, Cl2, and I2. The principle of the method is to produce a short burst of photoelectrons from a photocathode by means of light from an argon-fluoride laser. Subsequently, by studying the motion of electrons and negative ions in a constant electric field (E) region, information is obtained about drift velocities and effective attachment cross sections. Helium, argon, and nitrogen were used as buffer gases. Of particular interest is a very strong temperature dependence of the attachment coefficient in I2. Measurements were taken from 35 to 110°C, covering an E/N range of 1-50 Townsend. An explanation based on vibrational excitation is presented. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc
Temperature Dependence Of The Electron Attachment Coefficient In Iodine
The attachment coefficient for iodine in a (1% I2+99% N 2) mixture, 50 Torr total pressure, has been measured in an electron swarm experiment from 1 to 50 Townsends (1 Townsend=1Td=10-17 V cm2). As the temperature was increased from 35 to 110°C, the attachment coefficient increased for any E/N (electric field intensity/gas number density) values greater than 7 Td. These results are compared to other experimental data and an explanation for the temperature dependence, based on the population of upper vibrational states, is presented. © 1979 American Institute of Physics
Kekayaan Begonia Taman Nasional Gunung Halimun*[begonia Diversity in Gunung Halimun National Park]
Begonias arc unique due to asymmetric leaves, and they have large variation on their coloration and hairiness. The flower is unisexual, male and female flowers are in separate branches.The fruit with or without wings of different size and shape.Those unique characters attract them as ornamental plants, Mts. Halimun National Park has many species of wild Begonias which can be found on the forest floor.They grow in group and have essential role in mountainous forest ecosystem. Exploration for wild Begonia within forest around Cikaniki,Cirnarasa. Koridor Cianten, Gn, Botol, Gn. Bintang Gading, Gn. Sanggabuana will be presented in this paper
Electron Attachment In Dilute Fluorine-helium Mixtures
We have made an absolute determination of the electron attachment coefficient η (cm-1) in helium containing 0.1-1% fluorine covering an E/N range from 3Td-17Td. At an estimated average energy of 5 eV we find a rate coefficient equal to (7.5±1.5) x10-10 cm3/sec
Electron Drift Velocities In Helium-fluorine Gas Mixtures
Using a simple time-of-flight technique, we have measured the electron drift velocity in helium with 0.1-1% fluorine additive. Our results in a 0.1% mixture are in close agreement with data in pure helium. The measured drift velocity increases with increasing fluorine concentration. © 1978, American Institute of Physics. All rights reserved
IBM Watson Supporting Space Radiation
The NASA Human Research Program (HRP) Space Radiation (SR) Program Element has been working with IBM Watson Explorer (WEX) to create a tool that allows researchers to search the NASA SR-funded research corpus to help streamline research and maximize efficiency. The entire corpus of publications from research funded by the NASA SR Program Element has been ingested into WEX to allow for examination of: synergies across funded research areas, gaps in research, and collaboration opportunities. This information will be valuable to both scientists and managers as it will allow analysis related to specific scientific questions, inform key decisions and support cross validation of study results. NASA will also evaluate the potential to make WEX publicly available in order to facilitate proposal generation and to enhance collaborations within and across disciplines
Multitargeted anti-infective drugs : resilience to resistance in the antimicrobial resistance era
The standard drug discovery paradigm of single molecule - single biological target - single biological effect is perhaps particularly unsuitable for anti-infective drug discovery. This is due to the rapid evolution of resistance likely to be observed with single target drugs. Multi-targeted anti-infective drugs (MTAIDs) are likely to be superior due to their lower susceptibility to target-related resistance mechanisms. Strathclyde Minor Groove Binders (S-MGBs) are a class of compounds which have been developed by adopting the MTAID paradigm, and their effectiveness against a wide range of pathogenic organisms is discussed. The renaming of this class to Strathclyde Nucleic Acid Binders (SNABs) is also presented due to their likely targets including both DNA and RNA
Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling
Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have ex- plored its effects on knee frontal plane biomechanics during sta- tionary cycling. The purpose of this study was to examine the ef- fects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 par- ticipants (11 varus, 11 neutral, and 10 valgus alignment) per- formed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kine- matic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p \u3c 0.05). There were two different knee frontal plane loading patterns, in- ternal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95o (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling
- …