Detecting the cosmic gravitational wave background with the Big Bang Observer
CLASSICAL AND QUANTUM GRAVITY
Authors: Corbin, V; Cornish, NJ
Abstract
The detection of the cosmic microwave background radiation (CMB) was one of the most important cosmological discoveries of the last century. With the development of interferometric gravitational wave detectors, we may be in a position to detect the gravitational equivalent of the CMB; in this century. The cosmic gravitational background (CGB) is likely to be isotropic and stochastic, making it difficult to distinguish from instrument noise. The contribution from the CGB can be isolated by cross-correlating the signals from two or more independent detectors. Here we extend previous studies that considered the cross -correlation of two Michelson channels by calculating the optimal signal-to-noise ratio that can be achieved by combining the full set of interferometry variables that are available with a six link triangular interferometer. In contrast to the two channel case, we find that the relative orientation of a pair of coplanar detectors does not affect the signal-to-noise ratio. We apply our results to the detector design described in the Big Bang Observer (BBO) mission concept study and find that the BBO could detect a background with Omega(gw) > 2.2 x 10(-17).
Biocompatible Gels of Chitosan-Buriti Oil for Potential Wound Healing Applications
MATERIALS
Authors: Goncalves Ferreira, Maria Onaira; Lima, Idglan Sa; Ribeiro, Alessandra Braga; Lobo, Anderson O.; Rizzo, Marcia S.; Osajima, Josy Anteveli; Estevinho, Leticia Miranda; Silva-Filho, Edson C.
Abstract
The buriti oil (Mauritia flexuosa L.) can be associated with polymeric matrices for biomedical applications. This study aimed to evaluate the effect of chitosan gel (CG) associated with buriti oil (CGB) as a healing agent. The fatty acids and volatile compounds composition of buriti oil were performed and the composite gels were characterized using FTIR and thermal analysis. Biological tests including antimicrobial, antioxidant, anti-inflammatory and healing effects were also investigated. Buriti oil is composed of oleic and palmitic acids, and the main volatile compounds were identified. The buriti oil did not show antimicrobial activity, on the other hand, the composite gel (chitosan and oil) proved to be efficient against Staphylococcus aureus and Klebsiella pneumonia at the 10 mg/mL. Similar behavior was observed for antioxidant activity, determined by the beta-carotene bleaching assay, composite gels presenting higher activity and buriti oil showed anti-inflammatory activity, which may be related to the inhibition of the release of free radicals. Regarding wound healing performed using in vivo testing, the composite gel (CGB) was found to promote faster and complete wound retraction. The results indicated that the gel chitosan-buriti oil has a set of properties that improve its antibacterial, antioxidant and healing action, suggesting that this material can be used to treat skin lesions.