Radio-frequency spectrum coding in ultra-long fibre laser based cryptography

We propose a new approach for secret key exchange involving the variation of the cavity length of an ultra-long fibre laser. The scheme is based on the realisation that the free spectral range of the laser cavity can be used as an information carrier. We present a proof-of-principle demonstration of this new concept using a 50-km-long fibre laser to link two users, both of whom can randomly add an extra 1-km-long fibre segment

Spatiotemporal Nonlinear Beam Shaping

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Genome-wide association and Mendelian randomisation analysis provide insights into the pathogenesis of heart failure

Heart failure (HF) is a leading cause of morbidity and mortality worldwide. A small proportion of HF cases are attributable to monogenic cardiomyopathies and existing genome-wide association studies (GWAS) have yielded only limited insights, leaving the observed heritability of HF largely unexplained. We report results from a GWAS meta-analysis of HF comprising 47,309 cases and 930,014 controls. Twelve independent variants at 11 genomic loci are associated with HF, all of which demonstrate one or more associations with coronary artery disease (CAD), atrial fibrillation, or reduced left ventricular function, suggesting shared genetic aetiology. Functional analysis of non-CAD-associated loci implicate genes involved in cardiac development (MYOZ1, SYNPO2L), protein homoeostasis (BAG3), and cellular senescence (CDKN1A). Mendelian randomisation analysis supports causal roles for several HF risk factors, and demonstrates CAD-independent effects for atrial fibrillation, body mass index, and hypertension. These findings extend our knowledge of the pathways underlying HF and may inform new therapeutic strategies

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Development of an efficient nano-fluid cooling/preheating system for PV-RO water desalination pilot plant

YesIn order to improve the performance of the reverse osmosis (RO) desalination plant powered by photovoltaic (PV), two cooling systems were proposed in this study to cool the PV and preheating the RO feed water as well. In the cooling design (1), the cooling fluid flows in direct contact with the back surface of the PV through channels of half circular cross-sections. While in the design (2), it flows through channels of squar cross-sections fixed on the PV back surface. Two nano-fluids were also tested as cooling fluid: H2O/CuO and H2O/Al2O3, in addition to distilled water for the purpose of comparison. The effect of changing the weight concentration of the nano-fluid (0.05, 0.1, and 0.15%) on the PV performance was also investigated. The results showed that the PV integrated with the cooling design (1) achieves better performance compared to design (2) at all studied cooling fluids. The improvements in the electric efficiency of the PV integrated with design (1) reached 39.5, 34.8 and 27.3 % when CuO and Al2O3 nano-fluids and distilled water were used as cooling fluid, respectively, compared to the uncooled PV. Based on the obtained experimental results, the PV integrated with design (1) was selected to power the RO with H2O/CuO nano-fluid of weight concentration 0.15% and flow rate 0.15 kg/s being used as the coolant. The RO powered by the improved PV was tested at different salinities of brackish water when the preheating technique was implemented. The results showed that the proposed PV-RO desalination system produces 366 l/day when brackish water of salinity 3000 ppm was used.The full text will be available 12 months after online publication

Broadband light generation in PPLN crystal and its interplay with spatial nonlinear effects

International audienceWe study spatio-temporal nonlinear dynamics in periodically-poled lithium niobate crystal. We discuss broadband conversion via cascading second harmonic generation in self-defocusing and self-focusing regime. Measurements well agree with simulations

Thermal performance investigation of double pass-finned plate solar air heater

In this paper, the double pass-finned plate solar air heater was investigated theoretically and experimentally. An analytical model for the air heater was presented. Numerical calculations had been performed under Tanta (latitude, 30° 47'N and longitude, 31°E) prevailing weather conditions. The theoretical predictions indicated that the agreement with the measured performance is fairly good. Comparisons between the measured outlet temperatures of flowing air, temperature of the absorber plate and output power of the double pass-finned and v-corrugated plate solar air heaters were also presented. The effect of mass flow rates of air on pressure drop, thermal and thermohydraulic efficiencies of the double pass-finned and v-corrugated plate solar air heaters were also investigated. The results showed that the double pass v-corrugated plate solar air heater is 9.3-11.9% more efficient compared to the double pass-finned plate solar air heater. It was also indicated that the peak values of the thermohydraulic efficiencies of the double pass-finned and v-corrugated plate solar air heaters were obtained when the mass flow rates of the flowing air equal 0.0125 and 0.0225 kg/s, respectively.Solar air heaters Double pass Fins Thermal performance Thermohydraulic efficiency

BALADE - Balayage autonome pour détection électromagnétique

International audienc