Analysis of Advanced Research Methods of Cement-Based Materials

2014 ◽  
Vol 633 ◽  
pp. 494-497
Author(s):  
Yan Zheng ◽  
Su Ping Cui ◽  
Ya Li Wang ◽  
Zi Ming Wang ◽  
Qian Jin Mao

The hydration of cement is known to be a complex phenomenon. Although the broad pattern of reactions and microstructural development are known, a number of important questions remain unanswered. How to select the proper techniques is what the research people think of for now. This paper reviewed the domestic and international research progress and presented the advantages and disadvantages of these methods and the application prospects. Nuclear magnetic resonance spectroscopy (NMR), nanoindentation and electron microscopy techniques of cements were expounded in detail. Furthermore, through analyzing the results obtained by different research methods, the paper predicted the development prospect of advanced testing method of cement-based materials.

2020 ◽  
Vol 13 (3) ◽  
pp. 230-241
Author(s):  
Ye Dai ◽  
Hui-Bing Zhang ◽  
Yun-Shan Qi

Background: Valves are an important part of nuclear power plants and are the control equipment used in nuclear power plants. It can change the cross-section of the passage and the flow direction of the medium and has the functions of diversion, cutoff, overflow, and the like. Due to the earthquake, the valve leaks, which will cause a major nuclear accident, endangering people's lives and safety. Objective: The purpose of this study is to synthesize the existing valve devices, summarize and analyze the advantages and disadvantages of various devices from many literatures and patents, and solve some problems of existing valves. Methods: This article summarizes various patents of nuclear-grade valve devices and recent research progress. From the valve structure device, transmission device, a detection device, and finally to the valve test, the advantages and disadvantages of the valve are comprehensively analyzed. Results: By summarizing the characteristics of a large number of valve devices, and analyzing some problems existing in the valves, the outlook for the research and design of nuclear power valves was made, and the planning of the national nuclear power strategic goals and energy security were planned. Conclusion: Valve damage can cause serious safety accidents. The most common is valve leakage. Therefore, the safety and reliability of valves must be taken seriously. By improving the transmission of the valve, the problems of complicated valve structure and high cost are solved.


2020 ◽  
Vol 9 (1) ◽  
pp. 303-322 ◽  
Author(s):  
Zhifang Zhao ◽  
Tianqi Qi ◽  
Wei Zhou ◽  
David Hui ◽  
Cong Xiao ◽  
...  

AbstractThe behavior of cement-based materials is manipulated by chemical and physical processes at the nanolevel. Therefore, the application of nanomaterials in civil engineering to develop nano-modified cement-based materials is a promising research. In recent decades, a large number of researchers have tried to improve the properties of cement-based materials by employing various nanomaterials and to characterize the mechanism of nano-strengthening. In this study, the state of the art progress of nano-modified cement-based materials is systematically reviewed and summarized. First, this study reviews the basic properties and dispersion methods of nanomaterials commonly used in cement-based materials, including carbon nanotubes, carbon nanofibers, graphene, graphene oxide, nano-silica, nano-calcium carbonate, nano-calcium silicate hydrate, etc. Then the research progress on nano-engineered cementitious composites is reviewed from the view of accelerating cement hydration, reinforcing mechanical properties, and improving durability. In addition, the market and applications of nanomaterials for cement-based materials are briefly discussed, and the cost is creatively summarized through market survey. Finally, this study also summarizes the existing problems in current research and provides future perspectives accordingly.


Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Michela Relucenti ◽  
Giuseppe Familiari ◽  
Orlando Donfrancesco ◽  
Maurizio Taurino ◽  
Xiaobo Li ◽  
...  

Several imaging methodologies have been used in biofilm studies, contributing to deepening the knowledge on their structure. This review illustrates the most widely used microscopy techniques in biofilm investigations, focusing on traditional and innovative scanning electron microscopy techniques such as scanning electron microscopy (SEM), variable pressure SEM (VP-SEM), environmental SEM (ESEM), and the more recent ambiental SEM (ASEM), ending with the cutting edge Cryo-SEM and focused ion beam SEM (FIB SEM), highlighting the pros and cons of several methods with particular emphasis on conventional SEM and VP-SEM. As each technique has its own advantages and disadvantages, the choice of the most appropriate method must be done carefully, based on the specific aim of the study. The evaluation of the drug effects on biofilm requires imaging methods that show the most detailed ultrastructural features of the biofilm. In this kind of research, the use of scanning electron microscopy with customized protocols such as osmium tetroxide (OsO4), ruthenium red (RR), tannic acid (TA) staining, and ionic liquid (IL) treatment is unrivalled for its image quality, magnification, resolution, minimal sample loss, and actual sample structure preservation. The combined use of innovative SEM protocols and 3-D image analysis software will allow for quantitative data from SEM images to be extracted; in this way, data from images of samples that have undergone different antibiofilm treatments can be compared.


Author(s):  
Yan Zhang ◽  
YuanBo Bi ◽  
JianPing Zhou ◽  
DaQian Sun ◽  
HongMei Li

Abstract As two important industrial manufacturing materials, titanium alloys and stainless steel have their own advantages and disadvantages in terms of physical, chemical, and mechanical properties. The field of materials manufacturing has witnessed efforts to develop technical processes that can properly combine these two alloy types, aiming to effectively use their respective advantages. The welding technology for Ti alloy and stainless steel, as a research topic with broad prospects, is comprehensively and deeply analyzed in this review. The current research progress in this field was analyzed from different process perspectives such as fusion welding, brazing, diffusion welding, friction welding, explosive welding and vacuum hot-rolling welding. The results of the review showed that the greatest challenges of fusion welding are low ductility of the material, high residual stress, high cooling rate, and the formation of numerous brittle Ti-Fe intermetallics. By using appropriate intermediate materials between these two materials, the residual stress and brittle intermetallics near the interface of the transition joint can be minimised by solving the thermal expansion mismatch, reducing the bonding temperature and pressure, and suppressing the diffusion of elements such as Ti and Fe.


2012 ◽  
Vol 531-532 ◽  
pp. 485-489
Author(s):  
Chao Ding ◽  
Li Bao An ◽  
Xiao Xia Yang ◽  
Yan Yan Liu

Carbon nanotubes (CNTs) have drawn extensive research interest for a variety of applications in single electron transistors, field emission displays, interconnects, sensors, energy storage, composites, and many others due to their excellent electrical, mechanical, and thermal properties. One requirement for many of these applications is the need to integrate CNTs into various devices or circuits as functional components and different manipulation methods have been developed. This paper addresses the assembly of CNTs by dielectrophoresis (DEP) and reviews recent research progress of controlled assembly of CNTs. Totally six approaches are introduced in which different techniques including impedance measurement, optical induced DEP, floating electrode DEP, self-limiting resistor, fluidic assisted deposition, and real-time gap impedance monitoring of DEP are respectively used to control the yield of the DEP process. The advantages and disadvantages of these methods are analysed. The purpose is to help automating the DEP process of CNTs and other one-dimensional nanomaterials by presenting these advanced control techniques.


2021 ◽  
Vol 7 (2) ◽  
pp. 70-78
Author(s):  
Oleksandr Telcharov ◽  

The article presents the psychological analysis of the implicit mind theory and its research methods. The main problems of empirical research in psychology are briefly described. The main problems of research of the mind theory are highlighted; and the status of this phenomenon’s in scientific psychology is defined. The implicit mind theory is defined as a psychological quality expressed in the ability to explain and attribute mental states – beliefs, desires, emotions, knowledge, etc. – to themselves and others; as well as understanding that others have different beliefs, desires, intentions, and attitudes. Current difficulties in the research on the implicit mind theory are described. Age-related features of formation of the implicit mind theory are depicted. The latest scientific studies on the implicit mind theory are highlighted. Biological correlates of the theory are shown. It is also described that in the case of an alcohol addiction, certain brain areas that are known to be neurological correlates of the implicit mind theory are damaged. The main research methods, which are separated into three groups, are highlighted. The first group includes methods that study the implicit mind theory using behavioural experiment with special tasks. The second group includes methods that use semi-structured interview. The third group includes methods where respondents are asked to identify an emotion or an affective state of another person based on the visual stimuli (photo, picture etc.).The main methods of research of this psychological phenomenon, features, procedure, advantages, and disadvantages are described in detail. The most appropriate methods to examine addicts’ implicit mind theory are proposed. The procedure of investigation and psychological assessment of the implicit mind theory for people dependent on psychoactive substances is offered.


2021 ◽  
Vol XXVIII (2) ◽  
pp. 103-111
Author(s):  
Ion Rusu ◽  
◽  
Ion Cretu ◽  

This paper deals with the need to determine the technical condition of strategic buildings, blocks of flats, which are in a precarious condition as well as engineering networks located within the Ungheni district. The article refers to the real present situation of buildings and housing stock from Ungheni municipality, including their periods of commissioning. Current research methods of buildings are exposed, being listed their advantages and disadvantages.


2016 ◽  
pp. 200-220
Author(s):  
Anne-Kirstine Dyrvig

Evaluation of projects on integrated eCare is key to implementation and widespread use. The evaluation must, though, be thorough and include research methods from multiple different research traditions simultaneously. This implies a necessity of knowledge from all research paradigms and understanding of proper reporting. In this chapter, guidance for evaluation of integrated eCare is provided, along with discussions of advantages and disadvantages related to certain decisions that must be made during the research process. As an aid for understanding, real-life examples of evaluation are provided to illustrate challenges and possible solutions throughout the chapter.


Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 981 ◽  
Author(s):  
Zexuan Wang ◽  
Kunfeng Zhao ◽  
Bei Xiao ◽  
Peng Gao ◽  
Dannong He ◽  
...  

Monolithic catalysts have great industrial application prospects compared to powdered catalysts due to their low pressure drop, the high efficiency of mass and heat transfer, and recyclability. Deposition of active phases on the monolithic carriers dramatically increases the utilization rate and has been attracting continuous attention. In this paper, we reviewed the traditional (impregnation, coating, and spraying) and novel (hydrothermal and electrodeposition) strategies of surface deposition integration, analyzed the advantages and disadvantages of both ways, and then prospected the possible directions for future development of integration technologies.


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