Feasibility of using distributed chemical sensing for CO2 leakage monitoring

The feasibility study focused on the development of new fiber for distributed chemical sensing (DCS) that will allow direct detection of CO2 leakages in the environment. This is particularly important for monitoring well integrity for carbon capture and storage (CCS), to provide early warning for an incoming well failure and potential CO2 leaking through it. We proposed using optical spectroscopy in optical fiber for direct detection of CO2. The main approach is based on Raman interrogation within gas-filled Holey Fibers (HoFs), so that the location and concentration of the gases would be provided simultaneously via backscattering. Additionally, Infrared (IR) Absorption Spectroscopy could also be used, and the architecture would be more discrete since interleaving with standard solid core fibers and Fiber Bragg Grating (FBG) sections is required to enable reflection to the I/O controls. The possible Raman length or the IR numbers of sections would be defined based on signal to noise ratio. The optical spectroscopy methodology would overcome current roadblocks to CCS, as fiber optics will allow for CO2 (and other gases) detection in wells with direct in-situ measurements of concentration along with other important parameters such as temperature and pressure as the baseline of environment background. We were able to assess commercially available IR/Raman hollow core fiber and demonstrated detection of CO2 through them in our controlled environment setups. We have also established the ability of drilling precisely with pulsed femtoseconds (fs)-lasers side holes to enable penetration of CO2 into the hollow core fiber and reduce diffusion rates. Open joint collars were also explored having a double functionality: splicing to solid core fiber critical for field deployment and creating gas ingress locations. Both diffusion-only and pressurized fiber systems have been constructed following numerical simulations in COMSOL based semi-hybrid optical /fluido-dynamics models. FBGs have been identified, procured, and characterized but not yet integrated. Along the work we leveraged internal modeling/design, photonics/laser characterization, optical fiber fabrication, and AM lab capabilities to design, develop and test in-house components or assemblies. Our results indicate the critical potential that the HoF would have in the direct detection of CO2 downhole

TRA of DigiMon components

The DigiMon project aims to develop an affordable, flexible, societally embedded and smart monitoring system for industrial scale subsurface CO2 storage. For this purpose, the DigiMon system is to combine various types of measurements in integrated workflows. In this report, we describe the process of conducting the Technology Readiness Assessment (TRA) of various measurement techniques. We report on the identification, description and assessment of these measurement techniques as Critical Technology Elements (CTEs) being part of the DigiMon system

Editorial Nanomaterials for Optical Sensing and Sensors: Plasmonics, Raman, and Optofluidics

To date, environmental and healthcare problems have become the most important and challenging issues globally. Demands for fast and low-cost sensing methods and devices for environment monitoring This special issue contains 6 articles which cover the academic fields of environmental science, materials science, life science, nanotechnology, optics, physics, and chemistry. In the research article "Investigation of the Validity of the Universal Scaling Law on Linear Chains of Silver Nanoparticles," M. Alsawafta et al. examined (the generalization of) the universal scaling behavior for spherical silver nanoparticles arranged in finite linear chains (eight nanoparticles) and embedded in different host media. The results of simulation show that the plasmon ruler equation can be successfully extended to represent the fractional plasmon shift of many interacting nanoparticles. The decay length and the mount of the fractional shift of the silver linear chains strongly depend on the polarization state of the incident polarization. The LM exhibits a significant shift of the plasmon resonance (indicated by the value of ) as compared to that of the TM. This can be explained by the fact that the enhancement of the local field under parallel polarization is more pronounced. On the other hand, the decay of the TM shows a strong dependency on the dielectric function of the surrounding medium. It decays twice faster than the LM, as the host medium becomes denser. In the research article "Focused Ion Beam Assisted Interface Detection for Fabricating Functional Plasmonic Nanostructures," H. Wang et al. proposed the FIB-assisted interface detection and successfully carried out it using the sampleabsorbed current as the detection signal, and the patterning depth control for the plasmonic structure fabrication was achieved through controlling machining time or ion dose using the EPM. Material-dependent currents were measured through the EPM signal curves, and the quantitative models for the sample-absorbed currents and the ion beam current were also developed. In the research article "Immobilization Techniques and Integrated Signal Enhancement for POC Nanocolor Microfluidic Devices," M. Schlauf et al. reported the development of a silver enhancement technology that operates even in the presence of high chloride concentrations as it may be encountered in biologic samples. The silver enhancement reagents may be integrated into the microfluidic assay platform to be released upon sample addition. Hereby a highly sensitive onestep-assay can be realized. M. Schlauf et al. also demonstrated that adsorptive immobilization via a cationic polymeric interlayer is a competitive and fast technique for the binding of the capture protein streptavidin onto planar SiO 2 -surfaces such as REA biochips. In the research article "Investigating the Fabrication Imperfections of Plasmonic Nanohole Arrays and its Effect on the Optical Transmission Spectra," A. M. Mahros et al. investigated the extraordinary optical transmission spectra of thin gold films perforated with imperfect nano hole arrays using the finite difference time domain (FDTD) method. Exponential shapes for the nanohole sidewalls are used. The investigation of transmission spectra of imperfect nanohole arrays has not previously been demonstrated. It was found that the asymmetry between the two openings of the circular nanoholes or bending to their sidewalls strongly modifies both of the intensity and resonance positions of the transmission spectra. Furthermore, the results of this study assist in explaining the technicality of extraordinary optical transmission phenomenon and why some experimental results on transmission differ from those expected. In the research article "FRET-Based Detection of Enzymatic Reaction of Botulinum on Microfluidic Device," Y. M. Bae et al. implemented a microfluidic device to detect the enzymatic reaction of botulinum toxin A (BTA) using Förster resonance energy transfer (FRET). The microfluidic device comprised a main channel having two loading zones, a reaction chamber, and a side channel perpendicular to the main channel. The reaction chamber defined by weir in the main channel was packed with microbeads. The movement of the peptide substrate and the BTA in the microfluidic device was controlled by electrophoresis, and the enzymatic reaction of the BTA was detected through the changes of the fluorescence intensity in the reaction chamber. As a result, it was observed that the enzymatic reaction was affected by the electric voltage applied for the movement of the BTA and the peptide and improved by packing the microbeads in the reaction chamber. The microfluidic device provides with the tool to investigate the proteolysis of the substrate by the BTA. In the research article "Molecular Logic Computation with Debugging Method," X. Liu et al. considered constructing full adder and serial binary adder, using the new concept of seesaw gate. The simulation of the full add preformed properly as designed; however, unexpected exception is noted in the simulation of the serial binary adder. To identify and address the exception, they propose a new method for debugging the molecular circuit. The main idea for this method is to add fan-outs to monitor the circuit in a reverse stepwise manner. These fan-outs are fluorescent signals that can obtain the real-time concentration of the target molecule. By analyzing the monitoring result, the exception can be identified and located. In this paper, examples of XOR and serial binary adder circuits are described to prove the practicability and validity of the molecular circuit debugging method

Project report on WP1 outcomes relevant to other WPs

This report summaries some of the key technologies that have been studied and developed through WP1 with the purpose of transferring these finding to other WPs in the DigiMon project. The objective of the DigiMon project is to develop an early-warning system for Carbon Capture and Storage (CCS) which utilises a broad range of sensor technologies including Distributed Acoustic Sensing (DAS). While the system is primarily focused on the CCS projects located in the shallow offshore environment of the North Sea, it is also intended to be adaptable to onshore settings. Some of the key areas that the systems will monitor include the movement of the plume within the reservoir, well integrity and CO2 leakage into the overburden. A combination of different methods will be adopted to monitor these key areas, which include active and passive seismics, gravimetry, temperature and chemical sensing. This report focuses on technology and methods which have been developed by the DigiMon project and is not intended as a technology review, which is instead the focus of the DigiMon deliverable 2.3 Technology Readiness Assessment

Critical technology elements (WP1)

The overall objective of the DigiMon project is to “accelerate the implementation of CCS by developing and demonstrating an affordable, flexible, societally embedded and smart Digital Monitoring early warning system”, for monitoring any CO2 storage reservoir and subsurface barrier system. Within the project the objective of WP1 was to develop individual technologies, data acquisition, analysis techniques and workflows in preparation for inclusion in the DigiMon system. The technologies and data processing techniques developed as part of WP1 include distributed fibre-optic sensing (DFOS) for seismic surveys and chemical sensing, 4D gravity and seafloor deformation measurements, a new seismic source and seismic monitoring survey design. For these technologies the key targets for WP1 were • Develop individual components of the system to raise individual technology readiness levels (TRLs), • Validate and optimise processing software for individual system components, • Develop an effective Distributed Acoustic Sensing (DAS) data interpretation workflow. This work was performed with the expected outcomes of • Raising the DAS TRL for passive seismic monitoring, • An assessment the feasibility of using Distributed Chemical Sensing (DCS) for CO2 detection, • Reducing the cost of 4D gravity and seafloor deformation measurements

The Halo Occupation Distribution of Active Galactic Nuclei

Using a fully cosmological hydrodynamic simulation that self-consistently incorporates the growth and feedback of supermassive black holes and the physics of galaxy formation, we examine the effects of environmental factors (e.g., local gas density, black hole feedback) on the halo occupation distribution of low luminosity active galactic nuclei (AGN). We decompose the mean occupation function into central and satellite contribution and compute the conditional luminosity functions (CLF). The CLF of the central AGN follows a log-normal distribution with the mean increasing and scatter decreasing with increasing redshifts. We analyze the light curves of individual AGN and show that the peak luminosity of the AGN has a tighter correlation with halo mass compared to instantaneous luminosity. We also compute the CLF of satellite AGN at a given central AGN luminosity. We do not see any significant correlation between the number of satellites with the luminosity of the central AGN at a fixed halo mass. We also show that for a sample of AGN with luminosity above 10^42 ergs/s the mean occupation function can be modeled as a softened step function for central AGN and a power law for the satellite population. The radial distribution of AGN inside halos follows a power law at all redshifts with a mean index of -2.33 +/- 0.08. Incorporating the environmental dependence of supermassive black hole accretion and feedback, our formalism provides a theoretical tool for interpreting current and future measurements of AGN clustering.Comment: 14 pages, 11 figures, 2 Tables (Matches the MNRAS accepted version

Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study

: The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p < 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)