114 research outputs found

    An innovative approach for energy generation from waves

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    Sustainable energy generation is becoming increasingly important due to the expected limitations in current energy resources and to reduce pollution. Wave energy generation has seen significant development in recent years. This paper describes an innovative system for generating energy from wave power. A complete description of the system is presented including the general concept, configurations, mechanical design, electrical system, simulation techniques and expected power output of the system. The results from the hydraulic linear wave simulator, using a real wave profiles captured at a location in the UK using an ultrasound system, it was seen that a ±0.8 m wave at 10 s time period, produced a conditioned power output of approximately 22 kW at optimum load conditions for the tested 3-phase 44 kW permanent magnet generator type STK500. The results indicate that this new technology could provide an efficient and low cost method of generating electricity from waves

    A statistical investigation of the rheological properties of magnesium phosphate cement

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    Magnesium phosphate cement (MPC) is a promising material applied for rapid patch repairing in civil engineering and waste immobilisation in nuclear industry. However, the rheological properties of this new binder material which highly affects its engineering application, is to be explored. The current work aims at investigating the rheological properties of MPC along 98 with determining the optimum conditions to obtain MPC materials with desirable rheological performances. The Response Surface Methodology (RSM) accompanied by Central Composite Design (CCD) were adopted to establish mathematical model describing the rheological characteristics of MPC in terms of yield stress (Pa) and plastic viscosity (Pa.s), as a function of three independent variables namely W/S ratio, M/P ratio and Borax dosage. The analysis of variance (ANOVA) was also conducted to assess the significance and adequacy of the regression models attained. The results showed that the M/P ratio and Borax dosage could affect significantly the yield stress of MPC, while W/S ratio was the significant coefficient influencing the plastic viscosity. The numerical optimised values of the W/S ratio, M/P ratio and Borax dosage were 0.25, 8.97 and 0.17 respectively, and a MPC paste with desirable rheological characteristics (yield stress of 0.40 Pa and plastic viscosity of 0.93 Pa.s) can be obtained. Further experiments will be carried out to verify the predicted optimum conditions and study the interactions between the factors in relation to the responses

    Immobilisation of caesium in magnesium phosphate-based blends

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    Disposal of Caesium (Cs) by incorporating it into host matrices has been proved as a promising concept. Even though Portland cement (PC) based systems can be used to encapsulate low (LLW) or intermediate level waste (ILW), they are not efficient for immobilising Cs due to the very high water-solubility of Cs. Magnesium phosphate cement (MPC), a chemically bonded ceramic consists of struvite families produced by the acid based reactions between dead-burnt magnesium oxide (MgO) and phosphates (e.g., KH2PO4), can be a potential candidate for hosting Cs, since it has been reported that Cs can be incorporated in the Kstruvite structures by substituting potassium (K) to form (K,Cs)-struvite. However, the acid-based reaction to form MPC under ambient temperature between magnesium oxide (MgO) and phosphates (e.g., KH2PO4) is violent and exothermic, which raises concerns about industrial application of MPC in real world. In this work, ground-granulated blast-furnace slag (GGBS) and pulverised fuel ash were used to replace MPC in order to reduce the heat released. The feasibility of MPC, as well as MPC-based blends, i.e. GGBS-MPC or PFAMPC matrices, for immobilising Cs was assessed by their leaching behaviour at the ages of 3d, 7d and 28d. In addition, two typical PC based systems currently used in nuclear waste immobilisation, i.e., pure PC and PC-GGBS (1:9) mixes, were also produced and tested as controls. The results indicated that all the MPC mixes, including pure MPC, GGBS-MPC and PFA-MPC, demonstrated superb capability for immobilising Cs, with the immobilisation rates achieved more than 99.5% at all curing age investigated. Compared to the traditional PC and PC/GGBS mixes, the MPC mixes nearly doubled the Cs immobilisation rate, which is rather encouraging

    Efficacy, Safety, and Durability of Voretigene Neparvovec-rzyl in RPE65 Mutation–Associated Inherited Retinal Dystrophy: Results of Phase 1 and 3 Trials

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    Purpose: To report the durability of voretigene neparvovec-rzyl (VN) adeno-associated viral vector–based gene therapy for RPE65 mutation–associated inherited retinal dystrophy (IRD), including results of a phase 1 follow-on study at year 4 and phase 3 study at year 2. Design: Open-label phase 1 follow-on clinical trial and open-label, randomized, controlled phase 3 clinical trial. Participants: Forty subjects who received 1.5×1011 vector genomes (vg) of VN per eye in at least 1 eye during the trials, including 11 phase 1 follow-on subjects and 29 phase 3 subjects (20 original intervention [OI] and 9 control/intervention [CI]). Methods: Subretinal injection of VN in the second eye of phase 1 follow-on subjects and in both eyes of phase 3 subjects. Main Outcome Measures: End points common to the phase 1 and phase 3 studies included change in performance on the Multi-Luminance Mobility Test (MLMT) within the illuminance range evaluated, full-field light sensitivity threshold (FST) testing, and best-corrected visual acuity (BCVA). Safety end points included adverse event reporting, ophthalmic examination, physical examination, and laboratory testing. Results: Mean (standard deviation) MLMT lux score change was 2.4 (1.3) at 4 years compared with 2.6 (1.6) at 1 year after administration in phase 1 follow-on subjects (n = 8), 1.9 (1.1) at 2 years, and 1.9 (1.0) at 1 year post-administration in OI subjects (n = 20), and 2.1 (1.6) at 1 year post-administration in CI subjects (n = 9). All 3 groups maintained an average improvement in FST, reflecting more than a 2 log10(cd.s/m2) improvement in light sensitivity at 1 year and subsequent available follow-up visits. The safety profile was consistent with vitrectomy and the subretinal injection procedure, and no deleterious immune responses occurred. Conclusions: After VN gene augmentation therapy, there was a favorable benefit-to-risk profile with similar improvement demonstrated in navigational ability and light sensitivity among 3 groups of subjects with RPE65 mutation–associated IRD, a degenerative disease that progresses to complete blindness. The safety profile is consistent with the administration procedure. These data suggest that this effect, which is nearly maximal by 30 days after VN administration, is durable for 4 years, with observation ongoing

    Whole-genome resequencing of two elite sires for the detection of haplotypes under selection in dairy cattle

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    Using a combination of whole-genome resequencing and high-density genotyping arrays, genome-wide haplotypes were reconstructed for two of the most important bulls in the history of the dairy cattle industry, Pawnee Farm Arlinda Chief (“Chief”) and his son Walkway Chief Mark (“Mark”), each accounting for ∼7% of all current genomes. We aligned 20.5 Gbp (∼7.3× coverage) and 37.9 Gbp (∼13.5× coverage) of the Chief and Mark genomic sequences, respectively. More than 1.3 million high-quality SNPs were detected in Chief and Mark sequences. The genome-wide haplotypes inherited by Mark from Chief were reconstructed using ∼1 million informative SNPs. Comparison of a set of 15,826 SNPs that overlapped in the sequence-based and BovineSNP50 SNPs showed the accuracy of the sequence-based haplotype reconstruction to be as high as 97%. By using the BovineSNP50 genotypes, the frequencies of Chief alleles on his two haplotypes then were determined in 1,149 of his descendants, and the distribution was compared with the frequencies that would be expected assuming no selection. We identified 49 chromosomal segments in which Chief alleles showed strong evidence of selection. Candidate polymorphisms for traits that have been under selection in the dairy cattle population then were identified by referencing Chief’s DNA sequence within these selected chromosome blocks. Eleven candidate genes were identified with functions related to milk-production, fertility, and disease-resistance traits. These data demonstrate that haplotype reconstruction of an ancestral proband by whole-genome resequencing in combination with high-density SNP genotyping of descendants can be used for rapid, genome-wide identification of the ancestor’s alleles that have been subjected to artificial selection
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