Carbon capture in the cement industry: technologies, progress, and retrofitting

Several different carbon-capture technologies have been proposed for use in the cement industry. This paper reviews their attributes, the progress that has been made toward their commercialization, and the major challenges facing their retrofitting to existing cement plants. A technology readiness level (TRL) scale for carbon capture in the cement industry is developed. For application at cement plants, partial oxy-fuel combustion, amine scrubbing, and calcium looping are the most developed (TRL 6 being the pilot system demonstrated in relevant environment), followed by direct capture (TRL 4–5 being the component and system validation at lab-scale in a relevant environment) and full oxy-fuel combustion (TRL 4 being the component and system validation at lab-scale in a lab environment). Our review suggests that advancing to TRL 7 (demonstration in plant environment) seems to be a challenge for the industry, representing a major step up from TRL 6. The important attributes that a cement plant must have to be “carbon-capture ready” for each capture technology selection is evaluated. Common requirements are space around the preheater and precalciner section, access to CO2 transport infrastructure, and a retrofittable preheater tower. Evidence from the electricity generation sector suggests that carbon capture readiness is not always cost-effective. The similar durations of cement-plant renovation and capture-plant construction suggests that synchronizing these two actions may save considerable time and money

STRATEGY MANAGEMENT IN A MULTI-AGENT SYSTEM USING NEURAL NETWORKS FOR INDUCTIVE AND EXPERIENCE-BASED LEARNING

Intelligent agents and multi-agent systems prove to be a promising paradigm for solving problems in a distributed, cooperative way. Neural networks are a classical solution for ensuring the learning ability of agents. In this paper, we analyse a multi-agent system where agents use different training algorithms and different topologies for their neural networks, which they use to solve classification and regression problems provided by a user. Out of the three training algorithms under investigation, Backpropagation, Quickprop and Rprop, the first demonstrates inferior performance to the other two when considered in isolation. However, by optimizing the strategy of accepting or rejecting tasks, Backpropagation agents succeed in outperforming the other types of agents in terms of the total utility gained. This strategy is learned also with a neural network, by processing the results of past experiences. Therefore, we show a way in which agents can use neural network models for both external purposes and internal ones.agents, learning, neural networks, strategy management multi-agent system.

A proposed therapeutic algorithm for colorectal cancer prevention, based on endoscopic polypectomies in patients with multiple colonic polyps

Introduction. Results from single medical centers having large numbers of patients with multiple colonic polyps that have undergone colonoscopy management are rare. Material and method. The present study is based on 2,000 cases enrolled during 2009 and 2017, including patients that underwent colonoscopy for various reasons in the Department for Upper and Lower Endoscopy of Witting Clinical Hospital, Bucharest, Romania. Results. Of the 2,000 patients examined during 2009 - 2017, 594 tumor formations were detected; 148 (24.9%) patients had colorectal malignancies, and 446 (75%) polypoid formations in 313 patients who had one or more colon polyps were found. Discussions. After performing statistical analyses on several general parameters (such as age, sex, overall clinical outcome of the patient) and polyp-related characteristics (such as: dimensions, location, histological type), we developed a stepwise algorithm for clinical management (with endoscopic polypectomy) of patients with multiple polyposis, with the goal of reducing unnecessary colorectal surgeries. Conclusions. We believe that this type of stepwise algorithm-based approach in the clinical management of patients with multiple polyposis can lead to a substantial decrease in unnecessary colectomies (no matter the approach, via laparotomy or laparoscopic procedures), with the accompanying benefit of avoiding the complications and negative long-life impact that they impose

Supersymmetric Canonical Commutation Relations

We present unitarily represented supersymmetric canonical commutation relations which are subsequently used to canonically quantize massive and massless chiral,antichiral and vector fields. The massless fields, especially the vector one, show new facets which do not appear in the non superymmetric case. Our tool is the supersymmetric positivity induced by the Hilbert-Krein structure of the superspace.Comment: 14 page

The prevalence of high dysplastic colonic adenomatous polyps in a 3 year endoscopic retrospective study from a single clinical center

Introduction: Many colon neoplastic tumors come from the malignancy of adenomatous polyps (70%-90%) that were not timely diagnosed in order to be resected. Materials and Methods: We conducted a retrospective study regarding the incidence of adenomatous polyps during 1.000 consecutive colonoscopies performed in our Upper and Lower Digestive Endoscopy Laboratory during a three-year period. Results: During these colonoscopies, some targeted polyps were biopsied or completely removed and the samples had been sent to a complete anatomopathological examination. Taking into consideration the results, the polyps were classified after the histological type and the form of dysplasia, in order to determine the polyp forms that present a high risk of malignancy. Conclusion: Given the rather high frequency of malignant polyps discovered during our study, we highly recommend colonoscopy as a method of choice for routine monitoring of selected cases