ABSTRACT
With the outbreak of COVID-19, disinfection protection has become a necessary measure to prevent infection. As a new type of disinfectant, potassium peroxymonosulfate compound salt (PMS) has the advantages of good bactericidal effect, non-toxicity, high safety and stability. However, the current PMS products with irregular particle shapes lead to poor flowability, high hygroscopicity, poor stability of reactive oxygen species (ROS) and serious caking problems. In this work, an agglomeration-dissolution mechanism was designed to prepare spherical PMS particles with large size (>300 mm) and high sphericity (up to 90%), effectively addressing the above problems. Shaping (dissolution and abrasion) is the key to improving sphericity, which is mainly controlled by the design of the heating mode, residence time and stirring rate. Compared with the irregular PMS particles, the large spherical particles present better flowability (angle of repose decreased by 35.80%, Carr's index decreased by 64.29%, Hausner's ratio decreased by 19.14%), lower hygroscopicity (decreased by 38.0%), lower caking ratio (decreased by 84.50%), and higher stability (the monthly loss of ROS was reduced by 61.68%). The agglomeration -dissolution mechanism demonstrates the crystallization, agglomeration, dissolution and abrasion pro-cess of inorganic salt crystals, providing an opportunity to prepare high-end inorganic crystal materials with high-quality morphologies.(c) 2022 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.
ABSTRACT
With the outbreak of COVID-19, disinfection protection has become a necessary measure to prevent infection. As a new type of disinfectant, potassium peroxymonosulfate compound salt (PMS) has the advantages of good bactericidal effect, non-toxicity, high safety and stability. However, the current PMS products with irregular particle shapes lead to poor flowability, high hygroscopicity, poor stability of reactive oxygen species (ROS) and serious caking problems. In this work, an agglomeration-dissolution mechanism was designed to prepare spherical PMS particles with large size (>300 μm) and high sphericity (up to 90%), effectively addressing the above problems. Shaping (dissolution and abrasion) is the key to improving sphericity, which is mainly controlled by the design of the heating mode, residence time and stirring rate. Compared with the irregular PMS particles, the large spherical particles present better flowability (angle of repose decreased by 35.80%, Carr's index decreased by 64.29%, Hausner's ratio decreased by 19.14%), lower hygroscopicity (decreased by 38.0%), lower caking ratio (decreased by 84.50%), and higher stability (the monthly loss of ROS was reduced by 61.68%). The agglomeration-dissolution mechanism demonstrates the crystallization, agglomeration, dissolution and abrasion process of inorganic salt crystals, providing an opportunity to prepare high-end inorganic crystal materials with high-quality morphologies. © 2022 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences
ABSTRACT
The study of information spreading is important and necessary, especially during the Coronavirus, when plenty of opinions aroused in the Chinese Sina-microblog. On the basis of previous studies, we propose a comprehensive susceptible-reading-forwarding-immune (SRFI) model with considering user active search. We establish differential equations introducing average active reading rate to describe the multi-information propagation process. By using typical event about COVID-19 during the outbreak of public opinion to carry out the numerical fitting experiment to estimate model parameters, fit real data, and analyze the calculated information transmission indexes, we verify the validity of the model. We analyze the sensitivity of multiple parameters to multi-information transmission index based on reading and forwarding and the effect of average active reading rate to show the influence of the new parameter on multi-information transmission. In addition, to compare the predictive ability of the previous model with our new model, we use the early prediction method. Result shows that our new model can forecast the process of multi-information transmission faster and more exactly. The conclusions above indicate that the role of user active search is not negligible and the I-SRFI model can help us design effective communication strategies for rapid implementation of public health interventions. © 2022 IEEE.
ABSTRACT
After the outbreak of the COVID-19 pandemic, social media platforms offer an essential channel for the public to obtain and discuss the latest development of the epidemic situation and vaccine research. On the Chinese Sina Microblog, which is one of the most popular social platforms in China, two unique interaction mechanisms promote the change of the intensity and breadth of online information propagation, namely 'commenting' and 'forwarding'. Based on that, we propose a Susceptible-Commenting-Forwarding-Immune (SCFI) dynamic model and use the actual public opinion event on the Chinese Sina Microblog to adopt a data-model dual-drive research approach. We focus on the differences between the influence of 'commenting community' and 'forwarding community' on the promotion of information propagation, which is conducive to grasping the law of public opinion propagation. Our experimental results show that the multiple interactive mechanisms can particularly affect public opinion propagation. Our conclusions can contribute to designing effective communication strategies for governments and related agencies to guide public opinion in response to public health emergencies. © 2022 IEEE.
ABSTRACT
Purpose/Objective(s): To develop a tutoring program to help physician and physics residents to learn pancreas stereotactic body radiation therapy (SBRT) treatment planning via carefully collected cases and a series of specially designed knowledge models as teaching aid. Such programs are especially important during the Covid pandemic when most traditional hands-on medical teaching had to be moved online and asynchronous. Materials/Methods: The pilot tutoring program was composed of 5 teaching cases (1 benchmark case and 4 teaching cases), an interactive knowledge module (IKM) and a performance grading system. The tutoring program started with the benchmark case completed by each trainee independently to benchmark the baseline skill level. This same case was re-tested to evaluate the performance and clinical planning readiness after the trainee completes the tutoring program. 4 teaching cases were included: simple (1), intermediate (2) and complex (1). All 5 cases have simultaneous integrated boost prescription of 25Gy to the elective volume and 33Gy to the gross tumor volume. The IKM included a dose-volume prediction knowledge model for pancreas SBRT and is integrated via a graphic user interface in the treatment planning system. The trainee can seek reference and guidance from the IKM during learning – mimicking the hands-on tutoring of human expert. The grading system summarize the plan quality by weighing key dosimetric endpoints and their relative importance. Grade point average (GPA) was introduced to qualitatively appraise the plan quality into A, B and C (within 3%, 3-10% and > 10% difference of clinical plan score, corresponding to 4, 3, 2 point respectively). 5 trainees with minimum planning experience completed the teaching course. Results: Trainees achieved an average of 65.1% of total points (3.6 GPA) with 84 minutes planning time for the benchmark case pre-teaching, and improved to an average of 75.7% (4.2 GPA) using 48 minutes post-teaching. The clinical plan scored 72.7% of total points. All trainees improved their teaching plans’ scores after taking the virtual tutoring program. Post-teaching, all trainees received the GPA of A (clinical quality level) on the benchmark case planning. The total teaching time for each trainee ranged between 5 and 7 hours. Conclusion: The tutoring program with knowledge support modules provides encouraging learning outcomes in pancreas SBRT planning for inexperienced planners. This AI-enabled virtual teaching tool could provide valuable addition to the traditional human resource heavy in-person teaching of IMRT and SBRT treatment planning.
ABSTRACT
Aviation is the backbone of our modern society. In 2019, around 4.5 billion passengers travelled through the air. However, at the same time, aviation was also responsible for around 5% of anthropogenic causes of global warming. The impact of the COVID-19 pandemic on the aviation sector in the short term is clearly very high, but the long-term effects are still unknown. However, with the increase in global GDP, the number of travelers is expected to increase between three-to four-fold by the middle of this century. While other sectors of transportation are making steady progress in decarbonizing, aviation is falling behind. This paper explores some of the various options for energy carriers in aviation and particularly highlights the possibilities and challenges of using cryogenic fuels/energy carriers such as liquid hydrogen (LH2) and liquefied natural gas (LNG). © 2020 by the authors. Licensee MDPI, Basel, Switzerland.