scholarly journals Analysis of a hybrid composite tank under pressure

Author(s):  
A. Hocine ◽  
D. Chapelle ◽  
A. Benamar ◽  
A. Bezazi
Author(s):  
Rosemere de Araujo Alves Lima ◽  
DANIEL KIOSHI CAVALCANTI ◽  
Hector Costa ◽  
Ricardo Alexandre Amar de Aguiar ◽  
DOINA BANEA ◽  
...  

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 49-56 ◽  
Author(s):  
A. M. Lepikhin ◽  
V. V. Moskvichev ◽  
A. E. Burov ◽  
E. V. Aniskovich ◽  
A. P. Cherniaev ◽  
...  

The results of unique experimental studies of the strength and service life of a metal-composite high-pressure tank are presented. The goal of the study is to analyze the fracture mechanisms and evaluate the strength characteristics of the structure. The methodology included tests of full-scale samples of the tank for durability under short-term static, long-term static and cyclic loading with internal pneumatic pressure. Generalized test results and data of visual measurements, instrumental and acoustic-emission control of deformation processes, accumulation of damages and destruction of full-scale tank samples are presented. Analysis of the strength and stiffness of the structure exposed to internal pneumatic pressure is presented. The types of limiting states of the tanks have been established experimentally. Change in the stress-strain state of the tank under cyclic and prolonged static loading is considered. Specific features of the mechanisms of destruction of a metal-composite tank are determined taking into account the role of strain of the metal liner. The calculated and experimental estimates of the energy potential of destruction and the size of the area affected upon destruction of the tank are presented. Analysis of test results showed that the tank has high strength and resource characteristics that meet the requirements of the design documentation. The results of the experiments are in good agreement with the results of numerical calculations and analysis of the stress-strain state and mechanisms of destruction of the metal-composite tank.


2018 ◽  
Vol 69 (4) ◽  
pp. 921-925
Author(s):  
Cristina Angela Ghiorghe ◽  
Andra Claudia Gamen ◽  
Tiberiu Tirca ◽  
Sorin Andrian ◽  
Anca Melian ◽  
...  

The aim of this study was to evaluate the efficiency of laser therapy in post-operative sensitivity by Visual Analogue Scale (VAS) to the 57 patients after restoration with two different resins composite. In the first group (28 patients, 30 teeth) it was restored the cavity class I Black with micro-hybrid composite Filtek Z250 - Adper Single Bond (3M/ESPE). In the second group (29 patients, 30 teeth) it was restored the cavity class III Black with nano-hybrid composite Ceram X One Sphere Tec-Prime and Bond One (Etch&Rinse) (Dentsply). The restorative treatments were performed by the same practitioner on posterior and anterior teeth diagnosed with mid-sized chronic carious lesions. Total etch (etch and rinse) strategy of adhesion was used for both composite resins. The laser treatment was performed in 2 sessions at 48 hours and after 7 days, for both study groups using laser Whitening Lase II (DMC Dental). Mean scores for VAS indices decreased significantly at 48 hours and 7 days, following laser treatment for all the investigated parameters (materials, sex, age) (p [ 0.05).


Author(s):  
Muhammad Arfat Yameen ◽  
Amir Zeb ◽  
Raza E Mustafa ◽  
Sana Mushtaq ◽  
Nargis Aman ◽  
...  

Background: Incoherent use of antibiotics has led toward resistance in MRSA, which is becoming multidrugresistant with high rate of virulence in the community and hospital settings. Objective: Synergistic anti-MRSA activity was investigated in this study for hybrid material composite spheres of amoxicillin, Ag nanoparticles and chitosan which were prepared by one-step synthesis method and various characterizations were performed. Methods: Antimicrobial-susceptibility assay on MRSA was achieved by disc diffusion and agar dilution techniques while agar well diffusion was used for hybrid composite spheres. The in vitro and cytotoxicity studies was done by skin abrasion mouse model and MTT assay on RD cell respectively. Results: All isolates were resistant with the tested antibiotics except vancomycin. MIC against MRSA showed high resistance with amoxicillin from 4 to 128 mg L-1. The mean diameter of chitosan spheres and Ag nanoparticles was 02 mm and 277 nm respectively. Morphology of spheres was uneven, varied, porous and irregular in SEM and Ag nanoparticles presence and formation was also seen in micrograph. No substantial interface among drug, nanoparticles and polymer was found in XRD and IR showed characteristic peaks of all compound in the formulation. The in vitro assay showed augmented anti-MRSA activity with amoxicillin loaded hybrid composite spheres (22-29 mm). A significant reduction in microbial burden (~6.5 log10 CFU ml-1) was seen in vivo with loaded hybrid composite spheres formulation. The MTT assay indicated no potential cytotoxicity with hybrid composite spheres. Conclusion: Synergistic effect, amoxicillin, new hybrid formulation, anti-MRSA activity, composite spheres. nanoparticles.


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