306,757 research outputs found
Effect of Diethylenetriamine and Triethylamine sensitization on the critical diameter of Nitromethane
In this work, the critical diameter for detonation was measured for Nitromethane (NM) sensitized with two different amines: Diethylenetriamine (DETA) and Triethylamine (TEA). The critical diameter in glass and polyvinylchloride tubes is found to decrease rapidly as the amount of sensitizer is increased, then increase past a critical amount of sensitizer. Thus the critical diameter reaches a minimum at a critical concentration of sensitizer. It was also found that the critical diameter is lower with DETA than with TEA
Thermal Model and Optimization of a Large Crystal Detector using a Metallic Magnetic Calorimeter
We established a simple thermal model of the heat flow in a large crystal
detector designed for a neutrinoless double beta decay experiment. The detector
is composed of a CaMoO crystal and a metallic magnetic calorimeter (MMC).
The thermal connection between the absorber and the sensor consists of a gold
film evaporated on the crystal surface and gold bonding wires attached to this
film and the MMC sensor. The model describes athermal and thermal processes of
heat flow to the gold film. A successive experiment based on optimization
calculations of the area and thickness of the gold film showed a significant
improvement in the size and rise-time of the measured signals
Bioaffinity detection of pathogens on surfaces
The demand for improved technologies capable of rapidly detecting pathogens with high sensitivity and selectivity in complex environments continues to be a significant challenge that helps drive the development of new analytical techniques. Surface-based detection platforms are particularly attractive as multiple bioaffinity interactions between different targets and corresponding probe molecules can be monitored simultaneously in a single measurement. Furthermore, the possibilities for developing new signal transduction mechanisms alongside novel signal amplification strategies aremuchmore varied. In this article, we describe some of the latest advances in the use of surface bioaffinity detection of pathogens. Three major sections will be discussed: (i) a brief overview on the choice of probe molecules such as antibodies, proteins and aptamers specific to pathogens and surface attachment chemistries to immobilize those probes onto various substrates, (ii) highlighting examples among the current generation of surface biosensors, and (iii) exploring emerging technologies that are highly promising and likely to form the basis of the next generation of pathogenic sensors
Third-order Intermodulation Reduction in Mobile Power Amplifiers by the First Stage Bias Control
In this paper, the third order intermodulation distortion (IMD3) of three-stage power amplifier (PA) is analyzed using the Volterra series. The analysis explains how the total IMD3 of the three-stage power amplifier can be reduced by the first-stage bias condition. The three-stage PA, which is fabricated using InGaP/GaAs hetero-junction bipolar transistor (HBT), operates with an optimized first driver stage bias for higher P1dB and good gain flatness. The power amplifier has been designed for 1626.5 MHz~1660.5 MHz satellite mobile communications. With Ï/4 DQPSK modulation signals, this PA can deliver a highly linear output power of 33 dBm from 3.6V supply voltage. At 33 dBm output power, it shows a gain of 31.9 dB, a power-added efficiency (PAE) of 39.8%, an adjacent channel power ratio (ACPR) of -28.2 dBc at a 31.25 KHz offset frequency
Variable dimension automatic synthesis programs (VASP)
Variable dimension FORTRAN 4 version of the Automatic Synthesis Program (ASP) compensates for limitations within the program itself. Improvements are versatile programming language, convenient input/output format, new subprograms, variable dimensioning, and efficient storage
New Limits on Interactions between Weakly Interacting Massive Particles and Nucleons Obtained with CsI(Tl) Crystal Detectors
New limits are presented on the cross section for Weakly Interacting Massive
Particle (WIMP) nucleon scattering in the KIMS CsI(T) detector array at the
Yangyang Underground Laboratory. The exposure used for these results is 24524.3
kg\cdotdays. Nuclei recoiling from WIMP interactions are identified by a pulse
shape discrimination method. A low energy background due to alpha emitters on
the crystal surfaces is identified and taken into account in the analysis. The
detected numbers of nuclear recoils are consistent with zero and 90% confidence
level upper limits on the WIMP interaction rates are set for electron
equivalent energies from 3 keV to 11 keV. The 90% upper limit of NR event rate
for 3.6-5.8 keV corresponding to 2-4 keV in NaI(T) is 0.0098 counts/kg/keV/day
which is below the annual modulation amplitude reported by DAMA. This is
incompatible with interpretations that enhance the modulation amplitude such as
inelastic dark matter models. We establish the most stringent cross section
limits on spin-dependent WIMP-proton elastic scattering for the WIMP masses
greater than 20 GeV/c2.Comment: 5 pages, 6 figure
Delivering knowledge in the field: A telecommunications service provision and maintenance case
This paper proposes a novel approach to providing knowledge management services in a business
process wherein field engineers are the main process actors, providing and maintaining
telecommunications services. Cooperating multi-agents play a central role for the provision of
knowledge management services by integrating heterogeneous systems to collect related knowledge
for the execution of mobile tasks. The proposed system is expected to increase both the performance of
the mobile workforce and customer satisfaction by supporting and encouraging knowledge sharing
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