scholarly journals In-situ checking various mechanical parameters of original nail connections between crossbeams and wooden support, in the framework of an innovative method for rationally dimensioning the crossbeams of panel paintings, applied on an original artwork

Author(s):  
MAZZANTI Paola ◽  
RIPARBELLI Lorenzo ◽  
GUALDANI Giovanni ◽  
CASTELLI Ciro ◽  
RICCIARDI Luciano ◽  
...  
Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2313
Author(s):  
Maria Luisa Beconcini ◽  
Pietro Croce ◽  
Paolo Formichi ◽  
Filippo Landi ◽  
Benedetta Puccini

The evaluation of the shear behavior of masonry walls is a first fundamental step for the assessment of existing masonry structures in seismic zones. However, due to the complexity of modelling experimental behavior and the wide variety of masonry types characterizing historical structures, the definition of masonry’s mechanical behavior is still a critical issue. Since the possibility to perform in situ tests is very limited and often conflicting with the needs of preservation, the characterization of shear masonry behavior is generally based on reference values of mechanical properties provided in modern structural codes for recurrent masonry categories. In the paper, a combined test procedure for the experimental characterization of masonry mechanical parameters and the assessment of the shear behavior of masonry walls is presented together with the experimental results obtained on three stone masonry walls. The procedure consists of a combination of three different in situ tests to be performed on the investigated wall. First, a single flat jack test is executed to derive the normal compressive stress acting on the wall. Then a double flat jack test is carried out to estimate the elastic modulus. Finally, the proposed shear test is performed to derive the capacity curve and to estimate the shear modulus and the shear strength. The first results obtained in the experimental campaign carried out by the authors confirm the capability of the proposed methodology to assess the masonry mechanical parameters, reducing the uncertainty affecting the definition of capacity curves of walls and consequently the evaluation of seismic vulnerability of the investigated buildings.


2006 ◽  
Vol 519-521 ◽  
pp. 1341-1348 ◽  
Author(s):  
Sybrand van der Zwaag ◽  
E. Anselmino ◽  
A. Miroux ◽  
David J. Prior

To obtain further progress and a more detailed understanding of the mechanisms involved in recrystallisation, new and more accurate techniques such as in-situ observations are necessary. This innovative method has been used to monitor the recrystallisation process in a FEGSEM equipped with hot stage. Observations are done in backscatter mode with particular attention to orientation contrast. EBSD maps of the observed areas can be acquired before and after recrystallisation. Details of the movement of the interfaces between the recrystallised region and the parent structure are recorded and analysed. The results show that the grain boundaries observed do not move smoothly but with a jerky motion. The recrystallising front sweeps through small areas, corresponding to single sub-grains or small groups of them, very rapidly and then stops at other sub-grain boundaries for varying time before progressing to the following area.


2019 ◽  
Vol 35 (5) ◽  
pp. 709-712 ◽  
Author(s):  
M. Sütel ◽  
A. Schwitalla ◽  
T. Zimmermann ◽  
W.D. Müller

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 664 ◽  
Author(s):  
Iwona Karbownik ◽  
Olga Rac-Rumijowska ◽  
Marta Fiedot-Toboła ◽  
Tomasz Rybicki ◽  
Helena Teterycz

The paper presents a method of modifying polyacrylonitrile (PAN) fibers using polyaniline (PANI). The PAN fibers were doped with polyaniline that was obtained in two different ways. The first consisted of doping a spinning solution with polyaniline that was synthesized in an aqueous solution (PAN/PANI blended), and the second involved the synthesis of polyaniline directly in the spinning solution (PAN/PANI in situ). The obtained fibers were characterized by the methods: X-ray powder diffraction (XRD), scanning electron microscope (SEM), fourier-transform infrared spectroscopy (FTIR), thermogravimetry (TG) and differential scanning calorimetry (DSC). Analysis of the results showed strong interactions between the nitrile groups of polyacrylonitrile and polyaniline in the PAN/PANI in situ fibers. The results of mechanical strength tests indicated that the performance of the PAN/PANI mixture significantly improved the mechanical parameters of polyaniline, although these fibers had a weaker strength than the unmodified PAN fibers. The fibers obtained as a result of the addition of PANI to PAN were dielectric, whereas the PANI-synthesized in situ were characterized by a mass-specific resistance of 5.47 kΩg/cm2.


2020 ◽  
Vol 51 (10) ◽  
pp. 2016-2021
Author(s):  
Alessandra Botteon ◽  
Chiara Colombo ◽  
Marco Realini ◽  
Chiara Castiglioni ◽  
Anna Piccirillo ◽  
...  

2020 ◽  
Vol 10 (2) ◽  
pp. 468 ◽  
Author(s):  
Zhifeng Qi ◽  
Zhongqiang Shan ◽  
Weihao Ma ◽  
Linan Li ◽  
Shibin Wang ◽  
...  

Nanoscale silicon film electrodes in Li-ion battery undergo great deformations leading to electrochemical and mechanical failures during repeated charging-discharging cycles. In-situ experimental characterization of the stress/strain in those electrodes still faces big challenges due to remarkable complexity of stress/strain evolution while it is still hard to predict the association between the electrode cycle life and the measurable mechanical parameters. To quantificationally investigate the evolution of the mechanical parameters, we develop a new full field 3D measurement method combining digital image correlation with laser confocal profilometry and propose a strain criterion of the failure based on semi-quantitative analysis via mean strain gradient (MSG). The experimental protocol and results illustrate that the revolution of MSG correlates positively with battery capacity decay, which may inspire future studies in the field of film electrodes.


2020 ◽  
Vol 42 ◽  
pp. 139-146 ◽  
Author(s):  
Francesca Mariani ◽  
Alessandro S. Savoia ◽  
Giosuè Caliano

2009 ◽  
Vol 15 (5) ◽  
pp. 403-414 ◽  
Author(s):  
Sarah L. Ellis ◽  
Brenda Williams ◽  
Stephen Asquith ◽  
Ivan Bertoncello ◽  
Susan K. Nilsson

AbstractThe ultrastructural study of rare cells within their nichein situis very difficult. We have developed a method for locating individual transplanted cells and simultaneously identifying and analyzing the molecules and cellular phenotypes surrounding themin situusing transmission electron microscopy. This innovative method involves triple immunogold labeling combined with serial ultrathin sectioning. We demonstrate the validity of this approach by examining the niche of individual transplanted cells from a population highly enriched for hemopoietic stem cells and the ultrastructural expression of two key stem cell regulatory molecules, hyaluronic acid and osteopontin. In addition, we describe the phenotypes of the surrounding cells.


2020 ◽  
Vol 8 (20) ◽  
pp. 6900-6905 ◽  
Author(s):  
Yishuo Hu ◽  
Xiangbin Zeng ◽  
Tingting Ren ◽  
Yonghong Xiao ◽  
Yang Zeng ◽  
...  

This paper describes an innovative method known as pulsed laser induced synthesis to quickly and efficiently produce MoS2 films. Additionally, in situ doping of various elements can be realized via a similar process. This indicates that the proposed method will be a key technology contributing to the industrialization of MoS2 films and other TMDCs.


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