Al2O3 influence on structural, elastic, thermal properties of Yb3+ doped Ba–La-tellurite glass: Evidence of reduction in self-radiation trapping at 1μm emission

Ba–La-tellurite glasses doped with Yb3+ ions have been prepared through melt quenching technique by modifying their composition with the inclusion of varied concentration of Al2O3 to elucidate its effects on glass structural, elastic, thermal properties and Yb3+ ion NIR luminescence performance. The FTIR spectral analysis indicates Al2O3 addition is promoting the conversion of BOs from NBOs which have been generated during the process of depolymerisation of main glass forming TeO4 units. The elastic properties of the glass revealed an improved rigidity of the glass network on addition of Al2O3. In concurrence to this, differential thermal analysis showed an increase in glass transition temperature with improved thermal stability factor. Also, Yb3+ fluorescence dynamics demonstrated that, Al2O3 inclusion helps in restraining the detrimental radiation trapping of ∼1 μm emission

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Not AvailableAim:To assess the impact of different carbon sources on growth performance of grey mullet, Mugil cephalus fry in biofloc based culture system during nursery rearing phase. Methodology:The experimental trial was carried out for 60 days using three carbon sources, cassava, jaggery and barley in triplicate following a Completely Randomized Design. The carbon nitrogen ratio (C:N) in the systems were maintained at 15:1. Grey mullet fry (0.91g) were stocked @ of 1 fry -1 10 l and were fed with pelleted feed (35% crude protein) @ 4% of fish body weight thrice daily. Results:Significantly higher (P<0.05) growth performance, in terms -1 of Specfic Growth Rate (3.78 % day ) with lower Feed Conversion Ratio (1.35) were found in barley based biofloc group. Similarly, enhanced digestive enzyme activity in terms of amylase (8.78 Unit -1 -1 -1 -1 mg protein min ), lipase (2.77 Unit mg protein min ) and protease -1 -1 (4.22 Unit mg protein min ) were found in barley based biofloc group. Non- specific immune parameters such as lysozyme, respiratory burst activity and myeloperoxidase activity were significantly higher in barley based treatment group followed by jaggery and cassava based treatment groups. Likewise, stress indicators in serum and antioxidant status in liver were found to be lower in barley based treatment compared to cassava and jaggery based treatment groups. Interpretation: Rearing of Mugil cephalus in biofloc culture system is practicable; however, the carbon source required for biofloc production could be barley, compared to cassava and jaggery, in order to achieve maximum growth and to reduce the stressNot Availabl

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Not AvailableA 60- day experiment was conducted to evaluate the effect of biofloc on growth per-formance and physiological responses of grey mullet (Mugil cephalus). Grey mullet fry (average body weight of 0.91 ± 0.01 g) were stocked in biofloc treatment (BFT) and clear water (CW) control in triplicates. Grey mullet reared in biofloc- based units attained significantly better (p < 0.05) performance in terms of final body weight (FBW) (5.98 ± 0.08 g), specific growth rate (SGR) (3.15 ± 0.05), percentage weight gain (PWG) (560.7 ± 18.7) and survival (80.00 ± 3.8) with lower feed conversion ratio (FCR) (1.65 ± 0.04) and higher protein efficiency ratio (PER) (1.74 ± 0.04). The proximate analysis of the carcass showed better crude protein and crude lipid values in grey mullet reared in BFT than CW. In line with the growth performance, signifi-cantly higher activities of digestive enzyme such as, amylase (7.46 ± 0.28 U mg pro-tein−1), lipase (1.55 ± 0.07 U mg protein−1) and protease (2.91 ± 0.25 U mg protein−1) were found in the fish reared in BFT. Similarly, significantly higher serum protein (3.60 ± 0.46 mg ml−1), serum albumin (2.69 ± 0.30 mg ml−1), NBT (0.45 ± 0.02) and myeloperoxidase activity (0.98 ± 0.02) were found in fish reared in BFT compared to CW. There were no significant differences in stress indicators like serum cortisol and serum glucose of fish between the two groups, but lower values were observed in BFT. The results of this study demonstrated that biofloc- based culture system is ef-fective in improving nursery rearing of M. cephalus by enhancing growth performance, digestive enzyme activity, immune status and reduced stress response.Not Availabl

novel Gd 3+ -doped silica-based optical fiber material for dosimetry in proton therapy

International audienceOptical fibers hold promise for accurate dosimetry in small field proton therapy due to their superior spatial resolution and the lack of significant Cerenkov contamination in proton beams. One known drawback for most scintillation detectors is signal quenching in areas of high linear energy transfer, as is the case in the Bragg peak region of a proton beam. In this study, we investigated the potential of innovative optical fiber bulk materials using the sol-gel technique for dosimetry in proton therapy. This type of glass is made of amorphous silica (SiO 2) and is doped with Gd 3+ ions and possesses very interesting light emission properties with a luminescence band around 314 nm when exposed to protons. The fibers were manufactured at the University of Lille and tested at the TRIUMF Proton Therapy facility with 8.2-62.9 MeV protons and 2-6 nA of extracted beam current. Dose-rate dependence and quenching were measured and compared to other silica-based fibers also made by sol-gel techniques and doped with Ce 3+ and cu +. The three fibers present strong luminescence in the UV (Gd) or visible (Cu,Ce) under irradiation, with the emission intensities related directly to the proton flux. In addition, the 0.5 mm diameter Gd 3+-doped fiber shows superior resolution of the Bragg peak, indicating significantly reduced quenching in comparison to the Ce 3+ and cu + fibers with a Birks' constant, k B , of (0.0162 ± 0.0003) cm/MeV in comparison to (0.0333 ± 0.0006) cm/MeV and (0.0352 ± 0.0003) cm/MeV, respectively. To our knowledge, this is the first report of such an interesting k B for a silica-based optical fiber material, showing clearly that this fiber presents lower quenching than common plastic scintillators. This result demonstrates the high potential of this inorganic fiber material for proton therapy dosimetry