Water Absorption and Diffusion in Hollow Glass Microsphere Filled Epoxy Syntactic Foams

2010 ◽  
Vol 143-144 ◽  
pp. 370-374
Author(s):  
Xiao Man Liu ◽  
Chang Jun He ◽  
Hui Jian Li ◽  
Hai Yan Peng

The durability is very important in the research and application of polymers and their composites under different environmental conditions. The study of durability of patical filled epoxy resins had absorpted more attension in recently years, and the study of moisture absorption or water diffusion was almost along with the material manufacture. In the present work, the water sorption behavior in a series of different content hollow particle filled syntactic foams was studied by gravimetric measurements. The fashion factors on water sorption were discussed, and the change of density of syntactic foams on the subject was put forward.

This volume centres on a clock, known as Clock B, built in the mid-1970s that achieved considerable acclaim after an extraordinary performance in a 2015 peer-reviewed public trial at the Royal Observatory, Greenwich. The clock was built according to an understanding of John Harrison’s unique theoretical approach to making precision pendulum clocks, which defies the standard approaches to making accurate clocks. The clock represents the culmination of over forty years of collaborative research into Harrison’s writing on the subject, which is scattered across a number of manuscripts and a book, printed shortly before his death. Ostensibly, Harrison set out to describe how to make his precision pendulum clock, but it is a mixture of his peripheral interests. Horological information is almost completely lost among vitriolic sentiments relating to his experiences with the Board of Longitude. However, as one reviewer surmised: ‘we are sorry to say that the public will be disappointed’ and another concluded that ‘it can only be excused by superannuated dotage’. The chapters provides contextual history and documentation of the analysis and decoding of the cryptic written descriptions. It presents this in parallel to the modern horological story of making, finishing, and adjusting Clock B; the process of testing, using electronic equipment to monitor the its performance and reaction to changes in environmental conditions, and, indeed, the mechanics behind the various compensating features of the design.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 98 ◽  
Author(s):  
Yi Cui ◽  
Shuyi Gao ◽  
Ruiyun Zhang ◽  
Longdi Cheng ◽  
Jianyong Yu

The aim of this paper is to study the hygroscopic behavior of hygroscopic exothermic fiber-based materials and to obtain a better understanding of the thermal performance of these fibers during the moisture absorption process. The temperature distribution of different kinds of hygroscopic exothermic fibers in the process of moisture absorption, observed by infrared camera, demonstrated two types of heating performance of these fibers, which might be related to its hygroscopic behavior. Based on the sorption isotherms, a Guggenheim-Anderson-de Boer (GAB) multi-layer adsorption model was selected as the optimal moisture absorption fitting model to describe the moisture absorption process of these fibers, which illustrated that water sorption capacity and the water–fiber/water–water interaction had a significant influence on its heating performance. The net isosteric heats of sorption decreased with an increase of moisture content, which further explained the main factor affecting the heat dissipation of fibers under different moisture contents. The state of adsorbed water and water vapor interaction on the fiber surface were studied by simultaneous thermal analysis (TGA-DSC) measurement. The percentage of bound and unbound water formation at low and high humidity had a profound effect on the thermal performance of fibers. It can therefore be concluded that the content of tightly bound water a strong water–fiber interaction was the main factor affecting the heating performance of fibers at low moisture content, and the content of loosely bound water reflected that water sorption capacity was the main factor affecting the heating performance of fibers at high moisture content. This was further proven by the heat of desorption.


Desalination ◽  
2006 ◽  
Vol 193 (1-3) ◽  
pp. 398-404 ◽  
Author(s):  
M.G. De Angelis ◽  
S. Lodge ◽  
M. Giacinti Baschetti ◽  
G.C. Sarti ◽  
F. Doghieri ◽  
...  

2011 ◽  
Vol 289 (2) ◽  
pp. 479-487 ◽  
Author(s):  
Shouwei Zhang ◽  
Haihong Niu ◽  
Zhiqiang Guo ◽  
Zhesheng Chen ◽  
Haiping Wang ◽  
...  

2021 ◽  
Vol 132 ◽  
pp. 7-18
Author(s):  
Norbert Chamier-Gliszczyński ◽  
Jerzy Fiuk

The article introduces a short outline of the concept of a scientific approach to the subject of search and rescue. Next, the model presents the mapping of selected assets with an indication of the assets essential for the rescue operation's configuration critical to the system. The crucial elements of the rescue operation that must be included in the model are: determining the location of the sought entity, environmental conditions during the rescue operation, survival conditions at the crash site, available assets (e.g. helicopters, described in the system model), the structure of the necessary commands to manage a rescue operation.


Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1049
Author(s):  
Raj Kumar Arya ◽  
Devyani Thapliyal ◽  
Jyoti Sharma ◽  
George D. Verros

For the past few decades, researchers have been intrigued by glassy polymers, which have applications ranging from gas separations to corrosion protection to drug delivery systems. The techniques employed to examine the sorption and diffusion of small molecules in glassy polymers are the subject of this review. Diffusion models in glassy polymers are regulated by Fickian and non-Fickian diffusion, with non-Fickian diffusion being more prevalent. The characteristics of glassy polymers are determined by sorption isotherms, and different models have been proposed in the literature to explain sorption in glassy polymers over the last few years. This review also includes the applications of glassy polymers. Despite having many applications, current researchers still have difficulty in implementing coating challenges due to issues such as physical ageing, brittleness, etc., which are briefly discussed in the review.


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