Uniaxial Compressive Properties of Bismaleamid-coated Carbon Microballoons

2007 ◽  
Vol 43 (6) ◽  
pp. 417-429 ◽  
Author(s):  
K.B. Carlisle ◽  
K.K. Chawla ◽  
M. Koopman ◽  
G.M. Gladysz ◽  
M. Lewis
2022 ◽  
Vol 319 ◽  
pp. 126133
Author(s):  
Danna Wang ◽  
Xinyue Wang ◽  
Ashraf Ashour ◽  
Liangsheng Qiu ◽  
Baoguo Han

Author(s):  
E.T. O’Toole ◽  
G.P. Wray ◽  
J.R. Kremer ◽  
J.R. Mcintosh

Ultrarapid freezing and cryomicroscopy of frozen hydrated material makes it possible to visualize samples that have never been exposed to chemical fixatives, dehydration, or stains. In principle, freezing and cryoimaging methods avoid artifacts associated with chemical fixation and processing and allow one to visualize the specimen in a condition that is close to its native state. Here we describe a way to use a high voltage electron microscope (HVEM) for the cryoimaging of frozen hydrated PTK1 cells.PTK1 cells were cultured on formvar-coated, carbon stabilized gold grids. After three days in culture, the grids were removed from the culture medium and blotted in a humidity chamber at 35° C. In some instances, the grids were rinsed briefly in 0.16 M ammonium acetate buffer (pH 7.2) prior to blotting. After blotting, the grids were transferred to a plunging apparatus and plunged into liquid ethane held directly above its freezing point. The plunging apparatus consists of a vertical slide rail that guides the fall of a mounted pair of forceps that clamp the specimen. The forceps are surrounded by a plexiglass humidity chamber mounted over a dewar of liquid nitrogen containing an ethane chamber. After freezing, the samples were transferred to liquid nitrogen and viewed in a JEOL JEM 1000 equipped with a top entry cold stage designed and built by Mr. George Wray (Univ. Colorado). The samples were routinely exposed to electron doses of 1 e/Å2/sec, and viewed at a temperature of −150° C. A GATAN video system was used to enhance contrast and to estimate the correct amount of underfocus needed to obtain phase contrast at various magnifications. Low dose micrographs were taken using two second exposures of Kodak 4463 film. The state of the solid water in the specimen was determined by diffraction using a 30/μm field limiting aperture and a camera length of 1 meter.


1989 ◽  
Vol 02 (02) ◽  
pp. 59-66 ◽  
Author(s):  
G. J. Miller ◽  
Maron Calderwood Mays ◽  
L. Tilmant ◽  
P. A. Indelicato ◽  
M. S. Bloomberg

2019 ◽  
Vol 26 (4) ◽  
pp. 197-208
Author(s):  
Leo Gu Li ◽  
Albert Kwok Hung Kwan

Previous research studies have indicated that using fibres to improve crack resistance and applying expansive agent (EA) to compensate shrinkage are both effective methods to mitigate shrinkage cracking of concrete, and the additions of both fibres and EA can enhance the other performance attributes of concrete. In this study, an EA was added to fibre reinforced concrete (FRC) to produce concrete mixes with various water/binder (W/B) ratios, steel fibre (SF) contents and EA contents for testing of their workability and compressive properties. The test results showed that adding EA would slightly increase the superplasticiser (SP) demand and decrease the compressive strength, Young’s modulus and Poisson’s ratio, but significantly improve the toughness and specific toughness of the steel FRC produced. Such improvement in toughness may be attributed to the pre-stress of the concrete matrix and the confinement effect of the SFs due to the expansion of the concrete and the restraint of the SFs against such expansion.


2020 ◽  
Vol 35 (23-24) ◽  
pp. 3157-3169
Author(s):  
Qingyuan Xu ◽  
Shuguang Li ◽  
Runsheng Hu ◽  
Mengmeng Liu ◽  
Dong Wang ◽  
...  

Abstract


Author(s):  
Farid Triawan ◽  
Geraldy Cahya Denatra ◽  
Djati Wibowo Djamari

The study of a thin-walled column structure has gained much attention due to its potential in many engineering applications, such as the crash box of a car. A thin-walled square column usually exhibits high initial peak force, which may become very dangerous to the driver or passenger. To address this issue, introducing some shape patterns, e.g., origami folding pattern, to the column may become a solution. The present work investigates the compressive properties and behavior of a square box column structure which adopts the Miura origami folding pattern. Several test pieces of single-cell Miura origami column with varying folding angle and layer height are fabricated by a 3D printer. The filament is made of Polylactic Acid (PLA), which is a brittle material. Then, compression tests are carried out to understand its compressive mechanical properties and behavior. The results show that introducing a Miura origami pattern to form a thin-walled square column can dramatically lower down the initial peak stress by 96.82% and, at the same time, increase its ductility, which eventually improves the energy absorption capacity by 61.68% despite the brittle fracture behavior.


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