Detonation mechanism in explosive mixtures containing polystyrene foam

1992 ◽  
Vol 28 (6) ◽  
pp. 650-654 ◽  
Author(s):  
V. I. Nifad'ev ◽  
N. M. Kalinina
Author(s):  
C. W. Price ◽  
E. F. Lindsey ◽  
R. M. Franks ◽  
M. A. Lane

Diamond-point turning is an efficient technique for machining low-density polystyrene foam, and the surface finish can be substantially improved by grinding. However, both diamond-point turning and grinding tend to tear and fracture cell walls and leave asperities formed by agglomerations of fragmented cell walls. Vibratoming is proving to be an excellent technique to form planar surfaces in polystyrene, and the machining characteristics of vibratoming and diamond-point turning are compared.Our work has demonstrated that proper evaluation of surface structures in low density polystyrene foam requires stereoscopic examinations; tilts of + and − 3 1/2 degrees were used for the stereo pairs. Coating does not seriously distort low-density polystyrene foam. Therefore, the specimens were gold-palladium coated and examined in a Hitachi S-800 FESEM at 5 kV.


2019 ◽  
Vol 1 (1) ◽  
pp. 28
Author(s):  
Norsyamira Shahrin ◽  
Rabiatul Adawiyah Abd Rahman ◽  
Noorliza Zainol ◽  
Noor Saliza Salmi ◽  
Mohd Faisal Abdul Wahab

Food handler still fails to play their part even when the government imposes “No Plastic Bag” campaign and a ban on polystyrene foam to pack foods. This research focuses on eco-friendly food packaging based on the perception and practice of young consumers, especially the undergraduates of Mara University of Technology Penang Campus (UiTMPP). Questionnaire was constructed and distributed to 315 respondents.  The collected data were analyzed with simple descriptive statistic of frequency, mean and standard deviation. Most of the respondents are aware on eco-friendlyfood packaging. They agreed that the university should propose some alternative to control and reduce non-biodegradable foods packaging. 


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Rubén Lopez Benítez ◽  
Tomás Reyes del Castillo ◽  
David Benz ◽  
Carsten Fechner ◽  
Lorant Szabo ◽  
...  

Abstract Background The aim of this study was to present a percutaneous transhepatic biliary puncture simulator that can be used without radiation exposure and that reflects the conventional anatomy of the biliary ducts and its vicinity structures. Methods An anatomically based model of the biliary tree was developed using a cord network fixed to a wooden frame. The skin, ribs, intercostal muscles, and right lower lobe pleura were simulated using foam sponge, plastic tubes, a polystyrene foam panel, and an air pad, respectively. For the puncture, we used a 20-G Chiba needle and a wire with distal double arches; these were used to troll a cord, simulating the successful puncture of a bile duct. A camera was also placed above the model to allow the trainees to train eye-hand coordination while viewing the image on a monitor in real time. The simulator was tested with 60 radiology residents to evaluate the confidence and skills transferability of the training model. Results After receiving an introduction of the system and 5 min of training under tutor surveillance, all participants were able to troll a cord of the biliary simulator by themselves in less than 4 min. Only one participant punctured the simulated pleura. The participants’ evaluations showed positive results, with increased user confidence and skills transferability after the training session. Conclusions This proposed simulator can be an effective tool to improve a trainee’s confidence and competence while achieving procedural and non-procedural interventional radiology skills related to the liver. Trial registration Retrospectively registered


2021 ◽  
pp. 0021955X2110210
Author(s):  
Alejandro E Rodríguez-Sánchez ◽  
Héctor Plascencia-Mora

Traditional modeling of mechanical energy absorption due to compressive loadings in expanded polystyrene foams involves mathematical descriptions that are derived from stress/strain continuum mechanics models. Nevertheless, most of those models are either constrained using the strain as the only variable to work at large deformation regimes and usually neglect important parameters for energy absorption properties such as the material density or the rate of the applying load. This work presents a neural-network-based approach that produces models that are capable to map the compressive stress response and energy absorption parameters of an expanded polystyrene foam by considering its deformation, compressive loading rates, and different densities. The models are trained with ground-truth data obtained in compressive tests. Two methods to select neural network architectures are also presented, one of which is based on a Design of Experiments strategy. The results show that it is possible to obtain a single artificial neural networks model that can abstract stress and energy absorption solution spaces for the conditions studied in the material. Additionally, such a model is compared with a phenomenological model, and the results show than the neural network model outperforms it in terms of prediction capabilities, since errors around 2% of experimental data were obtained. In this sense, it is demonstrated that by following the presented approach is possible to obtain a model capable to reproduce compressive polystyrene foam stress/strain data, and consequently, to simulate its energy absorption parameters.


Author(s):  
Ning Zhang ◽  
Yunfei Qi ◽  
Suhuan Tian ◽  
Yue Wang ◽  
Ping Cui ◽  
...  

2020 ◽  
Vol 17 ◽  
pp. 100577 ◽  
Author(s):  
Zhe Wang ◽  
Weimin Liang ◽  
Minglun Cai ◽  
Yanhua Tang ◽  
Song Li ◽  
...  

2013 ◽  
Vol 32 (3) ◽  
pp. 193-209 ◽  
Author(s):  
Lin Jiang ◽  
Huahua Xiao ◽  
Yang Zhou ◽  
Weiguang An ◽  
Weigang Yan ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document