3,220 research outputs found
Validation Methods Research for Fault-Tolerant Avionics and Control Systems Sub-Working Group Meeting. CARE 3 peer review
A computer aided reliability estimation procedure (CARE 3), developed to model the behavior of ultrareliable systems required by flight-critical avionics and control systems, is evaluated. The mathematical models, numerical method, and fault-tolerant architecture modeling requirements are examined, and the testing and characterization procedures are discussed. Recommendations aimed at enhancing CARE 3 are presented; in particular, the need for a better exposition of the method and the user interface is emphasized
Validation Methods Research for Fault-Tolerant Avionics and Control Systems: Working Group Meeting, 2
The validation process comprises the activities required to insure the agreement of system realization with system specification. A preliminary validation methodology for fault tolerant systems documented. A general framework for a validation methodology is presented along with a set of specific tasks intended for the validation of two specimen system, SIFT and FTMP. Two major areas of research are identified. First, are those activities required to support the ongoing development of the validation process itself, and second, are those activities required to support the design, development, and understanding of fault tolerant systems
Combined Effect of Multistage Processing and Treatment Methods on the Physical, Chemical, and Microstructure Properties of Recycled Concrete Aggregates
This research aims to examine the effects of multi-stage processing on reducing the old cement fractions and enhancing the quality of CRA (concrete recycled aggregate). The investigation involves the use of demolished concrete debris and subsequent treatments in both single and multi-stage processes. The recycled aggregates (RA) were obtained using a multi-stage jaw crushing process followed by utilising natural aggregate, untreated RA, RA treated with hydrochloric acid and sodium silicate immersion (single stage treatment) and RA treated with mechanical scrubbing and sodium silicate immersion in two separate stages (multi-stage treatment). The subsequent phase of the experimental inquiry involves assessing the physical attributes of both treated and untreated RA. This is followed by conducting microstructural examinations utilising techniques such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry-differential thermal analysis (TG-DTA). The findings indicate that employing a two-step process, involving mechanical abrasion followed by immersion in sodium silicate, yields high-quality CRA. This conclusion is reinforced by the favourable physical performance observed. The water absorption values of CRA were lowered by 78% through single-stage treatments such as immersion in hydrochloric acid. The similar treatment is found to show densest concrete with Ca/Si ratio reduced to around 81% to that of untreated CRA. Additionally, for single stage treated CRA samples, microstructural study using FTIR verified the creation of additional hydration products, whereas for two stages treated CRA specimens, TGA analysis demonstrated the formation of stable CSH. According to the findings, it is advised to use a multi-stage process of jaw crushing, then treating it with mechanical abrasion and sodium silicate. This has the ability to improve the physical, chemical, and microstructural properties of CRA
Generation and Dispersion of Total Suspended Particulate Matter Due to Mining Activities in an Indian Opencast Coal Project
Evaluation of standardisation parameters and antioxidant activity of Bergenia ligulata
Berginia ligulata is one of the prominent ayurvedic herb for acute and chronic urinary tract infection [UTI].The present study highlighted the botanical as well as phytochemical studies including parameters such as macroscopic, physiochemical, evaluation and preliminary phytochemical studies of roots. On physiochemical analysis it was found that the powder was soluble in methanol, ethanol and water. It was insoluble in petroleum ether. On phytochemical analysis of aqueous and chloroform extract, it contains alkaloids, Saponin and Flavonoid
Time Dependent Cosmologies and Their Duals
We construct a family of solutions in IIB supergravity theory. These are time
dependent or depend on a light-like coordinate and can be thought of as
deformations of AdS_5 x S^5. Several of the solutions have singularities. The
light-like solutions preserve 8 supersymmetries. We argue that these solutions
are dual to the N=4 gauge theory in a 3+1 dimensional spacetime with a metric
and a gauge coupling that is varying with time or the light-like direction
respectively. This identification allows us to map the question of singularity
resolution to the dual gauge theory.Comment: 13 pages REVTeX and AMSLaTeX. v2: corrected typos and made some
clarifications; reference added; v3: more clarifications, references adde
SPECTROPHOTOMETRIC METHOD FOR THE ESTIMATION OF TOTAL ALKALOIDS IN THE TINOSPORA CORDIFOLIA M. AND ITS HERBAL FORMULATIONS
Objective: A simple spectrophotometric method was developed for the estimation of total alkaloids in Tinospora cordifolia M. and its formulations.Methods: The method based on the formation of yellow colored complex by reaction between bromocresol green (BCG) and alkaloids in medicinal plants. A yellow colored complex forms is easily extractable by chloroform at pH 4.7.Results: The method was linear in concentration range of 2-10 μg/ml with λmax at 415 nm. The LOD and LOQ were found to be 0.215 and 0.652 respectively. The intra-day and inter-day precision and accuracy were within the acceptable criteria (relative standard deviation<2.0% and accuracy within 100±2%). Conclusion: The developed method is simple, precise and accurate and can be adopted for the routine quality control and standardization of plant materials containing alkaloids and its pharmaceutical products.Â
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