1,579 research outputs found
Dvali-Gabadadze-Porrati Cosmology in Bianchi I brane
The dynamics of Dvali-Gabadadze-Porrati Cosmology (DGP) braneworld with an
anisotropic brane is studied. The Friedmann equations and their solutions are
obtained for two branches of anisotropic DGP model. The late time behavior in
DGP cosmology is examined in the presence of anisotropy which shows that
universe enters a self-accelerating phase much later compared to the isotropic
case. The acceleration conditions and slow-roll conditions for inflation are
obtained
Comparative analysis of reliability models of a cable plant portraying summer and winter operating strategy
Optimization of hot press forging parameters in direct recycling of aluminium chip (AA 6061)
This study introduces a new approach of direct recycling using the hot press forging process that eliminates the two intermediate processes of cold-compact and pre-heating. This method leads to low energy consumption without intervening the metallurgical processes. In this study, the optimum of machined chips from high speed milling is recycled by hot press forging. The mechanical properties and surface integrity of the different chips were investigated. The performance of recycled aluminium AA 6061 chips in the mechanical and physical properties were compared with the original aluminium billet. Response surface methodology (RSM) was used to develop mathematical model of the effects on pre-compaction cycle, holding time and suitable pressure significant to the process. It is hoped that, utilization of primary metal could be fully utilized by direct recycling technique (hot press forging) introduced in this study and at the same time developing a sustainable manufacturing process technology for future needs
A Study of Affordable Roofing Systems with Composite Slab
Affordable housing is a term used to describe dwelling units whose total housing cost are deemed affordable to a group of people within a specified income range. Structural roofing system contribute substantially to cost of construction of housing unit in normal situation, hence any savings attained in roofing system will reduce the cost of construction of housing unit. In the study undertaken, the roofing system consists of primary beams and secondary beams perpendicular to each other. The infill proposed is a composite slab panel consisting of decking sheets, galvanized iron(G.I) sheets of trapezoidal and corrugated cross section at bottom with a layer of concrete above it. The rectangular composite panelsconsidered in the study have a least width of 0.5m and 0.75m with an aspect ratio varying from 1.00 to 2.00. The rectangular composite panels are designed using M20 grade concrete and reinforcing steel of yield strength 415 N/mm2. The cost analysis is made for the roofing system and the proposed roofing system indicates a cost reduction 40% when compared to a conventional reinforced concrete (RCC) slab of same size. The weight of the beam systems and the panels are found to be relatively less and can handled easily by two to five masons thus reducing the labour cost. The beam systems and panels are precasted and can be easily placed thus eliminating need of shuttering, leading to faster construction of slab. The proposed roofing system is cost effective with a greater speed of construction compared to conventional roofing system
DEVELOPMENT AND VALIDATION OF STABILITY INDICATING RP-HPLC METHOD FOR THE SIMULTANEOUS ESTIMATION OF ALISKIREN HEMIFUMARATE AND VALSARTAN IN BULK AND PHARMACEUTICAL DOSAGE FORM
Objective: A new, simple, selective, and reproducible stability indicating reversed - phase high performance liquid chromatography method for thesimultaneous estimation of Aliskiren (ALN) Hemifumarate and Valsartan (VLN) in bulk drug, and tablet dosage form was developed and validated asper ICH guidelines.Methods: The chromatographic separation was performed using a nucleosil C - 18 column and the analytes were detected by a malondialdehyde - 2010photodiode array detector. The mobile phase composed of methanol: potassium dihydrogen ortho phosphate buffer (adjusted to pH 3 withorthophosphoric acid). The flow rate was set at 1 ml/minutes, and the detection was carried out at 225 nm.Results: ALN Hemifumarate and VLN showed a retention time of 3.84 and 5.96 minutes, respectively. The linear dynamic range was found to be5-50 mcg/ml and 5-30 mcg/ml with a co-relation co-efficient of 0.992 and 0.985 for ALN and VLN, respectively, with mean percentage recoveries of99.95% and 99.25%. The results were validated and were found to successfully obey the parameters as per ICH guidelines.Conclusion: Hence, the method can be successfully applied for routine quality control analysis and stability studies for both ALN Hemifumarate andVLN in bulk and tablet dosage form as per regulatory requirements.Keywords: Aliskiren Hemifumarate, Valsartan, Reversed-phase high performance liquid chromatography, Stress degradation study, ICH guidelines
Bulk scalar field in DGP braneworld cosmology
We investigated the effects of bulk scalar field in the braneworld
cosmological scenario. The Friedmann equations and acceleration condition in
presence of the bulk scalar field for a zero tension brane and cosmological
constant are studied. In DGP model the effective Einstein equation on the brane
is obtained with bulk scalar field. The rescaled bulk scalar field on the brane
in the DGP model behaves as an effective four dimensional field, thus standard
type cosmology is recovered. In present study of the DGP model, the late-time
accelerating phase of the universe can be explained .Comment: 10 pages, to appear in JCA
New approach to time domain classification of broadband noise in gravitational wave data
Transient broadband noise in gravitational wave (GW) detectors-also known as noise triggers (referred to as triggers for brevity)-can often be a deterrant to the efficiency with which astrophysical search pipelines detect sources. It is important to understand their instrumental or environmental origin so that they could be eliminated or accounted for in the data. Since the number of triggers is large, data mining approaches such as clustering and classification are useful tools for this task. Classification of triggers based on a handful of discrete properties has been done in the past. A rich information content is available in the waveform or \ shape\ of the triggers that has had a rather restricted exploration so far. This paper presents a new way to classify triggers deriving information from both trigger waveforms as well as their discrete physical properties, using a sequential combination of the longest common subsequence (LCSS) and LCSS coupled with Fast Time Series Evaluation (FTSE) for waveform classification, and the multidimensional hierarchical classification (MHC) analysis for the grouping based on physical properties. A generalized k-means algorithm is used with the LCSS (and LCSS+FTSE) for clustering the triggers using a validity measure to determine the correct number of clusters in absence of any prior knowledge. The results have been demonstrated by simulations and by application to a segment of real LIGO data from the sixth science run. © 2012 American Physical Society
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