Quantum fluctuations in the phase and amplitude quadratures of light set limitations on the sensitivity of modern optical instruments. The sensitivity of the interferometric gravitational wave ...detectors, such as the Advanced Laser Interferometer Gravitational wave Observatory (LIGO), is limited by quantum shot noise, quantum radiation pressure noise, and a set of classical noises. We show how the quantum properties of light can be used to distinguish these noises using correlation techniques. Particularly, in the first part of the paper we show estimations of the coating thermal noise and gas phase noise, hidden below the quantum shot noise in the Advanced LIGO sensitivity curve. We also make projections on the observatory sensitivity during the next science runs. In the second part of the paper we discuss the correlation technique that reveals the quantum radiation pressure noise from the background of classical noises and shot noise. We apply this technique to the Advanced LIGO data, collected during the first science run, and experimentally estimate the quantum correlations and quantum radiation pressure noise in the interferometer for the first time.
Isolating ground-based interferometric gravitational wave observatories from environmental disturbances is one of the great challenges of the advanced detector era. In order to directly observe ...gravitational waves, the detector components and test masses must be highly inertially decoupled from the ground motion not only to sense the faint strain of space-time induced by gravitational waves, but also to maintain the resonance of the very sensitive 4 km interferometers. This article presents the seismic isolation instrumentation and strategy developed for Advanced LIGO interferometers. It reviews over a decade of research on active isolation in the context of gravitational wave detection, and presents the performance recently achieved with the Advanced LIGO observatory. Lastly, it discusses prospects for future developments in active seismic isolation and the anticipated benefits to astrophysical gravitational wave searches. Beyond gravitational wave research, the goal of this article is to provide detailed isolation strategy guidelines for sensitive ground-based physics experiments that may benefit from similar levels of inertial isolation.
Aerobic granular sludge is a promising process for nutrient removal in wastewater treatment. In this work, for the first time, biologically induced precipitation of phosphorus as hydroxyl-apatite (Ca
...5(PO
4)
3(OH)) in the core of granules is demonstrated by direct spectral and optical analysis: Raman spectroscopy, Energy dispersive X-ray (EDX) coupled with Scanning Electron Microscopy (SEM), and X-ray diffraction analysis are performed simultaneously on aerobic granules cultivated in a batch airlift reactor for 500 days. Results reveal the presence of mineral clusters in the core of granules, concentrating all the calcium and considerable amounts of phosphorus. Hydroxyapatite appears as the major mineral, whereas other minor minerals could be transiently produced but not appreciably accumulated. Biologically induced precipitation was responsible for 45% of the overall P removal in the operating conditions tested, with pH varying from 7.8 to 8.8. Major factors influencing this phenomenon (pH, anaerobic phosphate release, nitrification denitrification) need to be investigated as it is an interesting way to immobilize phosphorus in a stable and valuable product.
► Aerobic granulation process in SBR was studied for COD, N and P removal. ► Hydroxyapatite inside bio-aggregates was demonstrated by RAMAN, SEM-EDX and XRD. ► Biological Induced Precipitation coupled with EBPR implies P-removal efficiency. ► Operating conditions are the key factors influencing this process. ► Advantages: valuable subproducts, high efficiencies, low SVI, high stabilized MLTSS.
Access to critical metals required for high-performance technologies, particularly, the light rare earth elements (REEs = La, Ce, Nd, Pr), has become a major challenge for import-dependent economies ...such as the European Union. In this regard, the recycling of spent nickel metal hydride (Ni-MH) batteries by hydrometallurgical processes can serve as an attractive secondary source of REEs. In such processes, precipitation of REEs from pregnant leach solutions (PLS) in sulfate media using Na2SO4 is often reported. However, little consideration is given as to whether and how sodium ions influence the precipitation efficiency and selectivity. This work focuses on a better understanding of the precipitation process by coupling pilot-scale (2 L) experiments on industrially sourced PLS containing 50 g/L of Ni and 17 g/L of REEs, with thermodynamic modeling, to assess the influence of temperature (25 °C < T < 60 °C) and the Na/REEs molar ratio (0.8:1 < Na/REEs < 3.2:1). Equilibria calculations were performed using OLI Systems Inc. software whose database covers rare earth sulfate compound properties and an accurate description of the aqueous electrolytes. Highly selective precipitation was obtained at 60 °C and for a Na/REEs molar ratio of 4:1. A lanthanide-alkali solid solution was identified by multianalytical characterization.
This work proposes a review of the various unit operations described in the literature for the specific recycling of nickel metal hydride batteries, with a large focus on the chemical reactions and ...processes. After a brief presentation of the characteristics of spent nickel metal hydride batteries and their composition, this review first describes the physical pretreatment methods, followed by the main principles and challenges of element separation by pyrometallurgy. Then, the main steps of hydrometallurgical processes (leaching, selective precipitation, solvent extraction, electrowinning) are analyzed, focusing on explaining the main difficulties and the most promising solutions. In addition, when available, recent thermodynamic models have been used to calculate equilibria for both pyrometallurgical and hydrometallurgical systems, with a view to provide elements of understanding in the choice of operating conditions for unit operations.
•Spent nickel metal hydride batteries are secondary source of nickel and rare earths.•Efficient element separation remains a challenge due to the battery complexity.•Conventional pyrometallurgical routes and alternative thermal treatment are reviewed.•Hydrometallurgical operations (leaching and separation methods) are reviewed.•Recent thermodynamic models are powerful tools to better understand these processes.
Understanding how life began is one of the most fascinating problems to solve. By approaching this enigma from a chemistry perspective, the goal is to define what series of chemical reactions could ...lead to the synthesis of nucleotides, amino acids, lipids, and other cellular components from simple feedstocks under prebiotically plausible conditions. It is well established that evolution of life involved RNA which plays central roles in both inheritance and catalysis. In this review, we present historically important and recently published articles aimed at understanding the emergence of RNA nucleosides and nucleotides on the early Earth.
In this work, we propose the combination of small-angle X-ray scattering (SAXS) and high throughput, droplet based microfluidics as a powerful tool to investigate macromolecular interactions, ...directly related to protein solubility. For this purpose, a robust and low cost microfluidic platform was fabricated for achieving the mixing of proteins, crystallization reagents, and buffer in nanoliter volumes and the subsequent generation of nanodroplets by means of a two phase flow. The protein samples are compartmentalized inside droplets, each one acting as an isolated microreactor. Hence their physicochemical conditions (concentration, pH, etc.) can be finely tuned without cross-contamination, allowing the screening of a huge number of saturation conditions with a small amount of biological material. The droplet flow is synchronized with synchrotron radiation SAXS measurements to probe protein interactions while minimizing radiation damage. To this end, the experimental setup was tested with rasburicase (known to be very sensitive to denaturation), proving the structural stability of the protein in the droplets and the absence of radiation damage. Subsequently weak interaction variations as a function of protein saturation was studied for the model protein lysozime. The second virial coefficients (A2) were determined from the X-ray structure factors extrapolated to the origin. A2 obtained values were found to be in good agreement with data previously reported in literature but using only a few milligrams of protein. The experimental results presented here highlight the interest and convenience of using this methodology as a promising and potential candidate for studying protein interactions for the construction of phase diagrams.
Phosphorous (P) is an essential element and plays a key role for life on Earth. It stiffens the bone structure, is a major component of DNA and is involved in the metabolism of living cells. One of ...the most widely known metabolic processes is photosynthesis, which, amongst many other things, fuels the growth of plants. Modern agriculture uses fertilizers to supply plants with additional phosphorous in order to support photosynthesis and maximize yields. Still today, the primary source for fertilizers is phosphate rock, the supply of which is finite and estimated to be depleted within in the next century. In recent years, several techniques were developed to recycle phosphorous and prevent future scarcity of this vital element. This study examines a method to recover P from nutrient-rich wastewater streams by crystallizing struvite (MgNH4PO4·6H2O). A low-grade magnesium oxide, a by-product of the magnesite industry, is added to the effluent to precipitate struvite. Precipitation was investigated in terms of the amount of magnesia added, and its influence on crystallization kinetics and the resulting particle morphologies and sizes. The amount of magnesia determines the supersaturation of the solution by fixing the pH and the chemical potential of magnesium ions in solution, thereby inducing crystallization. Here, the use of an MgO suspension couples the struvite precipitation to a prior MgO dissolution step. This step is controlled by surface reaction and it is assumed that the suspended particles facilitate heterogeneous nucleation. Apparently, the amount of magnesia solids has a strong influence and precipitation mainly occurs around the MgO particles.
•A dense MgO suspension is suitable as a precursor.•The preparation of the suspension hydrates more than 99% of the initial MgO.•The use of MgO is beneficial to the phosphorous recovery rate.•Precipitation is highly influenced by the chemistry around the suspended particles.
Lipid-conjugated small-interfering RNAs (siRNAs) exhibit accumulation and gene silencing in extrahepatic tissues, providing an opportunity to expand therapeutic siRNA utility beyond the liver. ...Chemically engineering lipids may further improve siRNA delivery and efficacy, but the relationship between lipid structure/configuration and siRNA pharmacodynamics is unclear. Here, we synthesized a panel of mono-, di-, and tri-meric fatty acid-conjugated siRNAs to systematically evaluate the impact of fatty acid structure and valency on siRNA clearance, distribution, and efficacy. Fatty acid valency significantly altered the physicochemical properties of conjugated siRNAs, including hydrophobicity and micelle formation, which affected distribution. Trivalent lipid-conjugated siRNAs were predominantly retained at the site of injection with minimal systemic exposure, whereas monovalent lipid-conjugated siRNAs were quickly released into the circulation and accumulated primarily in kidney. Divalent lipid-conjugated siRNAs showed intermediate behavior, and preferentially accumulated in liver with functional distribution to lung, heart, and fat. The chemical structure of the conjugate, rather than overall physicochemical properties (i.e. hydrophobicity), predicted the degree of extrahepatic tissue accumulation necessary for productive gene silencing. Our findings will inform chemical engineering strategies for enhancing the extrahepatic delivery of lipophilic siRNAs.
Calcium carbonate scaling in industrial cooling circuits is a serious problem limiting the efficiency of heat exchanges. One preventive treatment consists in injecting an inhibitor polymeric additive ...in the circulating water. This work focuses on scaling experiments carried out in pilot plants, with and without additives, and simulated by using the CooliSS software (Cooling circuit Simulation Software) developed by EDF company. A local inhibition law of CaCO3 crystal growth describing the adsorption of additives was found and implemented to calculate the global variation of calcium in the pilot plant. A small quantity of additive rapidly results in a decrease of the calcium deposit. The presence of suspended solids in water decreases the global inhibition by adsorption on other solids than calcite (illite and SiO2). It was shown that the efficiency factors (inhibition ratios) depend on the nature of the surface (material) and on the presence of suspended particles in the cooling water.
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