A synoptic survey of Sudden Phase Anomalies (SPAs) observed in the phase variation measurements of 16 kHz VLF transmissions from Rugby (England) made at Visakhapatnam (India) has been carried out. These Sudden Ionospheric Disturbances caused during solar flares are examined in relation to flare time enhancements of X-ray radiation fluxes. It is found that nearly 81% of SPAs recorded have accompanying X-ray enhancements and in 80% of the cases H α flares and microwave bursts also occur concurrently. Using SPA magnitudes and flare time X-ray flux values, the threshold level of X-ray flux to induce an SPA has been estimated as 1.5 × 10 −3 ergs/cm 2 /s. In majority of the events, the change in reflection height during the flare is observed to be less than 4 kms. Other SPA characteristics like onset times, growth and relaxation times etc. have also been studied. These results are consistent with those obtained for other propagation paths.
The separation of H2S
from natural gas, biogas, and
coal gas is an essential process that requires large energy input
and high capital costs. We propose a new sorption-based process, which
can be coupled with the Claus desulfurization process to reduce sulfur
emissions. This new process is based on a new sorbent material consisting
of a specific composition of Cu, Mg, and Al oxides and exhibiting
superior sulfur capacity (∼7.5 mmol/g) at process conditions
compatible for integration with the Claus process. CuO is the active
sorbent component, which during H2S uptake is converted
to CuS and can be fully regenerated during cyclic operation. Al2O3 and small amounts of MgO are shown to be essential
components that contribute to sorbent activity and stability.
Fault modeling is an important step towards both understanding and validating the implemented system. The focus of the paper is to present a unified system fault modelling framework, including input related faults model based on system theory. The complex embedded system (CES) is modelled using sequence of communicating FSM (SCFSM) and the system faults are represented by two components of system fault vector -system behaviour fault vector and system communication fault vector. These two system fault vector components are related and are components of the "change parameter vector Θ", a general system level fault model based on Dynamic system theory. Input related faults are defined and their contribution is discussed. Faults propagation in mixed hardware software communication architecture is discussed, with the help of protocol example.
General TermsFault modeling and propagation, Embedded Systems development.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.