4,533,802 research outputs found
Observations of the December 13 and 14, 2006, Solar Particle Events in the 80 MeV/n - 3 GeV/n range from space with PAMELA detector
We present the space spectrometer PAMELA observations of proton and helium
fluxes during the December 13 and 14, 2006 solar particle events. This is the
first direct measurement of the solar energetic particles in space with a
single instrument in the energy range from 80 MeV/n up to 3
GeV/n. In the event of December 13 measured energy spectra of solar protons and
helium were compared with results obtained by neutron monitors and other
detectors. Our measurements show a spectral behaviour different from those
derived from the neutron monitor network. No satisfactory analytical fitting
was found for the energy spectra. During the first hours of the December 13
event solar energetic particles spectra were close to the exponential form
demonstrating rather significant temporal evolution. Solar He with energy up to
~1 GeV/n was recorded on December 13. In the event of December 14 energy of
solar protons reached ~600 MeV whereas maximum energy of He was below 100
MeV/n. The spectra were slightly bended in the lower energy range and preserved
their form during the second event. Difference in the particle flux appearance
and temporal evolution in these two events may argue for a special conditions
leading to acceleration of solar particles up to relativistic energies.Comment: Accepted for publication on Astrophysical journa
Buried-Anode Technology Leads to Advanced Lithium Batteries
A technology developed at the National Renewable Energy Laboratory has sparked a start-up company that has attracted funding from the Advanced Projects Research Agency-Energy (ARPA-E). Planar Energy, Inc. has licensed NREL\u27s buried-anode technology and put it to work in solid-state lithium batteries. The company claims its large-format batteries can achieve triple the performance of today\u27s lithium-ion batteries at half the cost, and if so, they could provide a significant boost to the emerging market for electric and plug-in hybrid vehicles
Laboratory Investigation of Skid Resistance for Steel Slag Utilization as Chip Seal
Slag as waste material of steel-making process has similar characteristics with aggregate that has been widely used in pavement construction. The use of slag as chip seal aggregate to provide skid resistance needs to be analyzed. In this laboratory study, the chip seal samples are made using steel slag and natural aggregate. The bonding materials used are asphalt and epoxy resin. Skid resistance tests for all chip seal samples and also hot rolled sheet pavement without chip seal application are performed using the Portable British Pendulum Tester. The results show the variations of chip seal aggregate weight are inconsistent. The natural aggregate used as chip seal material could produce high skid resistance value of 10.3% higher than that using steel slag. Also the skid resistance of chip seal with the ALD 3 mm are not significantly different with that of ALD 6 mm. Similar results occur on the skid resistance of chip seals using epoxy resin and asphalt
Neural Network Control of a Laboratory Magnetic Levitator
Magnetic levitation (maglev) systems are nowadays employed in applications ranging from non-contact
bearings and vibration isolation of sensitive machinery to high-speed passenger trains. In this chapter
a mathematical model of a laboratory maglev system was derived using the Lagrangian approach. A
linear pole-placement controller was designed on the basis of specifications on peak overshoot and
settling time. A 3-layer feed-forward Artificial Neural Network (ANN) controller comprising 3-input
nodes, a 5-neuron hidden layer, and 1-neuron output layer was trained using the linear state feedback
controller with a random reference signal. Simulations to investigate the robustness of the ANN control
scheme with respect to parameter variations, reference step input magnitude variations, and sinusoidal
input tracking were carried out using SIMULINK. The obtained simulation results show that the ANN
controller is robust with respect to good positioning accuracy
Evaluation of the Microbiological Quality of Water for Consumption at the Ocean Sky Garment Manufacturing Facilities
This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide. Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.FLA_Water_Testing_Ocean_Sky.pdf: 190 downloads, before Oct. 1, 2020
Analysis of Chemical Laboratory Management at SMAN 55 Jakarta
An understanding of laboratory management is highly important to be owned by parties related to the laboratory, both directly and indirectly. Laboratories must be managed and utilized properly, because chemical laboratories are one type of laboratory that is considered quite dangerous in the context of carrying out education, research, and / or community service. This study aims to describe the management of a chemical laboratory using qualitative descriptive research methods. Research subjects were the principal, vice chairman of the curriculum, chair of the laboratory, and teachers in the field of chemistry studies. Data collection techniques are observation, interviews, and documentation. The results of the research are: 1) Planning of chemical laboratory work program has been prepared and standardized by the head of the laboratory, 2) Organizing the laboratory structurally already exists, 3) Organizing by the principal involving all those involved in laboratory management, 4) The implementation of the program is suitable with the plan of the work program, 5) Supervision and evaluation of the principal must still be carried out intensively. In other words, laboratory management at SMA 55 Jakarta has been well organized
Laboratory Characterization and Astrophysical Detection of Vibrationally Excited States of Vinyl Cyanide in Orion-KL
New laboratory data of CHCHCN (vinyl cyanide) in its ground and
vibrationally excited states at the microwave to THz domain allow searching for
these excited state transitions in the Orion-KL line survey.
Frequency-modulated spectrometers combined into a single broadband 50-1900 GHz
spectrum provided measurements of CHCHCN covering a spectral range of
18-1893 GHz, whose assignments was confirmed by Stark modulation spectra in the
18-40 GHz region and by ab-initio anharmonic force field calculations. For
analyzing the emission lines of CHCHCN species detected in Orion-KL we used
the excitation and radiative transfer code (MADEX) at LTE conditions. The
rotational transitions of the ground state of this molecule emerge from four
cloud components of hot core nature which trace the physical and chemical
conditions of high mass star forming regions in the Orion-KL Nebula. The total
column density of CHCHCN in the ground state is (3.00.9)x10
cm. We report on the first interstellar detection of transitions in the
v10=1/(v11=1,v15=1) dyad in space, and in the v11=2 and v11=3 states in
Orion-KL. The lowest energy vibrationally excited states of vinyl cyanide such
as v11=1 (at 328.5 K), v15=1 (at 478.6 K), v11=2 (at 657.8 K), the
v10=1/(v11=1,v15=1) dyad (at 806.4/809.9 K), and v11=3 (at 987.9 K) are
populated under warm and dense conditions, so they probe the hottest parts of
the Orion-KL source. Column density and rotational and vibrational temperatures
for CHCHCN in their ground and excited states, as well as for the
isotopologues, have been constrained by means of a sample of more than 1000
lines in this survey. Moreover, we present the detection of methyl isocyanide
(CHNC) for the first time in Orion-KL and a tentative detection of vinyl
isocyanide (CHCHNC) and give column density ratios between the cyanide and
isocyanide isomers.Comment: 46 pages, 22 figures, 14 tables, 9 online table
Stable transport in proton driven Fast Ignition
Proton beam transport in the context of proton driven Fast Ignition is
usually assumed to be stable due to protons high inertia, but an analytical
analysis of the process is still lacking. The stability of a charge and current
neutralized proton beam passing through a plasma is therefore conducted here,
for typical proton driven Fast Ignition parameters. In the cold regime, two
fast growing Buneman-like modes are found, with an inverse growth-rate much
smaller than the beam time-of-flight to the target core. The stability issue is
thus not so obvious, and Kinetic effects are investigated. One unstable mode is
found stabilized by the background plasma protons and electrons temperatures.
The second mode is also damped, providing the proton beam thermal spread is
larger than 10 keV. In Fusion conditions, the beam propagation should
therefore be stable.Comment: Submitted to Po
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