A case study of using cosmic ray muons to monitor supercritical CO2 migration in geological formations

In carbon dioxide (CO2) geological storage, the monitoring of the injected CO2 migration in underground storage is essential to understanding storage process and ensuring storage safety. An effective monitoring system will be required for decades into the future during storage phase to indicate the location where the injected fluids have extended to. A novel radiographic probing technique using naturally occurring cosmic ray muon radiations was introduced in recent years as a promising continuous and cost-effective candidate method. This method utilizes the ability of different materials to attenuate muons as the detection property. The feasibility of this technique still needs to be investigated in terms of higher simulation accuracy, the intrinsic spatial resolution, and response sensitivity for storage with impurities. In this study, simulations are performed to understand the sensitivity of this method in responding to the presence of the injected fluids in saline aquifer formations. The energy spectrum of the cosmic ray muons for different zenith angles at sea level is sampled according to the modified Gaisser’s formula. The muon propagation process has been simulated with high fidelity by detailed description of different materials involved in the deployed geological model. The muon attenuation along different paths carries information on the interior of a monitored region and the muon scattering effect may lower the accuracy to locate the fluids. The intrinsic spatial resolution of this method is thus analyzed and found to be at a scale of several meters. This method aims to provide the basis for understanding the injected fluids behavior. The simulations show that the method is feasible and the injected fluids in saline aquifers can be identified with a high sensitivity

A study of using cosmic-ray muon radiography to detect CO2 leakage from a primary storage into geological formations

In CO2 geological sequestration, a combination of monitoring techniques needs to be in place to timely detect possible CO2 leakage from a primary storage along unanticipated pathways to shallower formations. This research aims to methodologically investigate the feasibility of a novel radiographic technique, i.e. cosmic-ray muon radiography, as a complementary continuous monitoring method. As an example, this method was tested on a geological model to monitor CO2 leakage into upper freshwater aquifers. The effectiveness of the method was preliminarily established by high-fidelity simulations, including the sensitivity for responding to CO2 leakage and the spatial resolution that can be achieved by the method. The simulation results indicate an increase of penetrating flux of the cosmic-ray muons with the increase of CO2 leakage in the monitored aquifers. The sensitivity tends to be higher in monitoring leakage taking place in shallower depths. At depths of about 200 m, the detectable CO2 can be as low as 3 % measured in volume fraction with a relatively high confidence level. The spatial resolution can be achieved within a range from 10 to 20 m for measurements at depths of no more than 520 m, demonstrating the effectiveness of the method

vONTSS: vMF based semi-supervised neural topic modeling with optimal transport

Recently, Neural Topic Models (NTM), inspired by variational autoencoders, have attracted a lot of research interest; however, these methods have limited applications in the real world due to the challenge of incorporating human knowledge. This work presents a semi-supervised neural topic modeling method, vONTSS, which uses von Mises-Fisher (vMF) based variational autoencoders and optimal transport. When a few keywords per topic are provided, vONTSS in the semi-supervised setting generates potential topics and optimizes topic-keyword quality and topic classification. Experiments show that vONTSS outperforms existing semi-supervised topic modeling methods in classification accuracy and diversity. vONTSS also supports unsupervised topic modeling. Quantitative and qualitative experiments show that vONTSS in the unsupervised setting outperforms recent NTMs on multiple aspects: vONTSS discovers highly clustered and coherent topics on benchmark datasets. It is also much faster than the state-of-the-art weakly supervised text classification method while achieving similar classification performance. We further prove the equivalence of optimal transport loss and cross-entropy loss at the global minimum.Comment: 24 pages, 12 figures, ACL findings 202

Improved production of a recombinant lipase expressed in and its application for conversion of microalgae oil to biodiesel

Part 2: Trust and PrivacyInternational audienceTrust and privacy have been widely studied as key issues and success factors for e-commerce. The advent of m-commerce calls for revisiting these concepts and re-examining their antecedents in the mobile context. This paper attempts a comparative approach to the issues of trust and privacy in e-commerce and m-commerce. It investigates how trust and privacy are differentiated with the shift from the context of e-commerce to the context of m-commerce. Our analysis is supported by the results of an exploratory qualitative study in m-commerce

Fund for Shared Insight: Media Analysis

Fund for Shared Insight ("Shared Insight") is a collaborative effort among fundersthat pools financial and other resources to make grants to improve philanthropy. Shared Insight believes philanthropy can have a greater social and environmental impact if foundations and nonprofits listen to the people they seek to help, act on what they hear, and openly share what they learn.Related to feedback loops, Shared Insight's work is focused on increasingthe extent to which foundations listen to others—especially the people they seek to help—and respond to their expressed interests. When Shared Insight talks about "the people they seek to help," they are referring to the individuals who receive programs and services from nonprofit organizations; for example, the students served by charter schools, the recently released prisoners benefiting from job-training services, and the low-income first-time mothers participating in prenatal through birth programs.Over the next three years, Shared Insight would hope to see changes in the amount and kind of discourse in the field related tobeneficiary feedback loops. In the summer of 2015, one year since the launch of the collaborative, ORS Impact repeated a media analysis of relevant blogs, periodicals, and reports. The following memo outlines changes in the amount and kind of discourse in the field around feedback loops compared to the year before Shared Insight launched. We raise a few observations and considerations. More detailed methodological notes follow

Seismic behavior of steel-reinforced high-strength concrete composite beams with bonded tendons

To study the seismic behavior of steel-reinforced high-strength concrete composite beams with bonded tendons (PSRHSCBs) under low cyclic loading, 13 PSRHSCBs were designed with the main parameters of the span-to-height ratio of beams (L/H), the cubic strength of concrete (fcu), the eccentricity of H-shaped steel (eH), the volume stirrup ratio (pv), the longitudinal reinforcement ratio (p), and the tension control stress of tendons(σcon). Using the simplified bilinear constitutive model of steel and the nonlinear constitutive model of high-strength concrete, and introducing plastic damage of concrete, fine finite element models were established with ABAQUS software. 11 similar test specimens were conducted by above modeling method, by comparing existing test curves and numerical simulation curves, both of them match well, which verified the validity of the modeling method. Subsequently, parameter analysis for 13 PSRHSCB specimens was performed, and the influence regularity of different parameters on the seismic behavior of this kind of composite beams was obtained. The results show that hysteretic curves of this kind of composite beams are full, and the failure mode is manifested as bending failure. The ultimate load, the energy dissipation capacity and the ductility coefficient of specimens can be improved significantly by increasing pv, on the contrary, the energy dissipation capacity and the ductility coefficient decrease gradually by increasing fcu. The stiffness degradation of specimens significantly slows down with the increasing of L/H and σcon, and the decreasing of eH. Finally, the trilinear skeleton curve model and the restoring force model are established by statistical regression, and the corresponding seismic design suggestions are given, and these can provide theoretical support for the seismic design of such composite beams in actual engineering

Effect of mangrove species on removal of tetrabromobisphenol A from contaminated sediments

Abstract(#br)The increase levels of tetrabromobisphenol A (TBBPA) in mangrove wetlands is of concern due to its potential toxic impacts on ecosystem. A 93-day greenhouse pot experiment was conducted to investigate the effects of mangrove plants, A. marina and K. obovata , on TBBPA degradation in sediment and to reveal the associated contributing factor(s) for its degradation. Results show that both mangrove species could uptake, translocate, and accumulate TBBPA from mangrove sediments. Compared to the unplanted sediment, urease and dehydrogenase activity as well as total bacterial abundance increased significantly ( p < 0.05) in the sediment planted with mangrove plants, especially for K. obovata . In the mangrove-planted sediment, the Anaerolineae genus was the dominant bacteria, which has been reported to enhance TBBPA dissipation, and its abundance increased significantly in the sediment at early stage (0–35 day) of the greenhouse experiment. Compared to A. marina -planted sediment, higher enrichment of Geobater, Pseudomonas, Flavobacterium, Azoarcus , all of which could stimulate TBBPA degradation, was observed for the K. obovata -planted sediment during the 93-day growth period. Our mass balance result has suggested that plant-induced TBBPA degradation in the mangrove sediment is largely due to elevated microbial activities and total bacterial abundance in the rhizosphere, rather than plant uptake. In addition, different TBBPA removal efficiencies were observed in the sediments planted with different mangrove species. This study has demonstrated that K. obovata is a more suitable mangrove species than A. marina when used for remediation of TBBPA-contaminated sediment

Resveratrol reduces the inflammatory response in adipose tissue and improves adipose insulin signaling in high-fat diet-fed mice

Background Obesity-induced glucose metabolism disorder is associated with chronic, low-grade, systemic inflammation and is considered a risk factor for diabetes and metabolic syndrome. Resveratrol (RES), a natural anti-inflammatory compound, is observed to improve glucose tolerance and insulin sensitivity in obese rodents and humans. This study aimed to test the effects of RES administration on insulin signaling and the inflammatory response in visceral white adipose tissue (WAT) caused by a high-fat diet (HFD) in mice. Methods A total of 40 wild-type C57BL/6 male mice were divided into four groups (10 in each group): the standard chow diet (STD) group was fed a STD; the HFD group was fed a HFD; and the HFD-RES/L and HFD-RES/H groups were fed a HFD plus RES (200 and 400 mg/kg/day, respectively). The L and H in RES/L and RES/H stand for low and high, respectively. Glucose tolerance, insulin sensitivity, circulating inflammatory biomarkers and lipid profile were determined. Quantitative PCR and Western blot were used to determine the expression of CC-chemokine receptor 2 (CCR2), other inflammation markers, glucose transporter 4 (GLUT4), insulin receptor substrate 1 (IRS-1) and pAkt/Akt and to assess targets of interest involving glucose metabolism and inflammation in visceral WAT. Results HFD increased the levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol and proinflammatory cytokines in serum, decreased the high-density lipoprotein cholesterol level in serum, and induced insulin resistance and WAT inflammation in mice. However, RES treatment alleviated insulin resistance, increased the expressions of pAkt, GLUT4 and IRS-1 in WAT, and decreased serum proinflammatory cytokine levels, macrophage infiltration and CCR2 expression in WAT. Conclusion Our results indicated that WAT CCR2 may play a vital role in macrophage infiltration and the inflammatory response during the development of insulin resistance in HFD-induced obesity. These data suggested that administration of RES offers protection against abnormal glucose metabolism and inflammatory adaptations in visceral WAT in mice with HFD-induced obesity