Study of Mechanical Properties of Jute-Banana-Glass Fiber Reinforced Epoxy Composites under Various Post Curing Temperature

2015 ◽  
Vol 766-767 ◽  
pp. 211-215 ◽  
Author(s):  
M. Ramesh ◽  
R. Vimal ◽  
K. Hari Hara Subramaniyan ◽  
C. Aswin ◽  
B. Ganesh ◽  
...  

With recent developments in technology and science, we have been depending heavily on synthetic materials for various applications. In the present work, jute, banana and glass fibers are reinforced with epoxy resin in alternative positioning and various probabilities at different post curing temperature to form sandwich type composites. The composite block was cured at room temperature for 24hrs. The cold cured composite block was then post cured at various post curing temperature of 30°C, 60°C, 90°C, 120°C, 150°C and 180°C and 3KPa pressure in the hot press for 10minutes. The tensile and flexural properties of the composites obtained at different post curing temperature were studied. The morphology of the tensile fracture was studied using scanning electron microscopy analysis.

2021 ◽  
Vol 871 ◽  
pp. 87-91
Author(s):  
Cai Tang ◽  
Jun Wen ◽  
Hui Ji Fan

The annealing process of an improved Q420 cold drawn tube was studied by using different annealing temperatures (430°C, 450°C, 470°C, 490°C and 510°C) with a same annealing holding time (3h). The effect of different annealing temperatures on the mechanical properties, microstructure and fracture features of the cold drawn tube was studied by means of tensile test, microstructure observation and scanning electron microscopy analysis. The results show that, annealing temperature has great influence on the strength and plasticity of the cold drawn tube. When the annealing temperature increased to 450°C, banded microstructure was mitigated and the pearlite is relatively dispersed. The tensile fracture morphology under the annealing temperature of 450°C has more dimples and deeper bremsstrahlung than other annealing temperatures. The best annealing process of the cold drawn tube was 450°C×3h. Under this annealing process, the cold drawn tube with good strength and toughness can be obtained.


Author(s):  
J. P. Benedict ◽  
R. M. Anderson ◽  
S. J. Klepeis

Ion mills equipped with flood guns can perform two important functions in material analysis; they can either remove material or deposit material. The ion mill holder shown in Fig. 1 is used to remove material from the polished surface of a sample for further optical inspection or SEM ( Scanning Electron Microscopy ) analysis. The sample is attached to a pohshing stud type SEM mount and placed in the ion mill holder with the polished surface of the sample pointing straight up, as shown in Fig 2. As the holder is rotating in the ion mill, Argon ions from the flood gun are directed down at the top of the sample. The impact of Argon ions against the surface of the sample causes some of the surface material to leave the sample at a material dependent, nonuniform rate. As a result, the polished surface will begin to develop topography during milling as fast sputtering materials leave behind depressions in the polished surface.


2021 ◽  
pp. 232020682199798
Author(s):  
Beyza Unalan Degirmenci ◽  
Alperen Degirmenci ◽  
Emine Kara

Aim: Natural antioxidants were offered as the answer of dentin adhesion issue. The aim of this study is to investigate the effects of proanthocyanidin and lycopene as pretreatment agents on the sound and caries-affected dentin surface on microtensile bond strength and microleakage. Materials and Methods: This study was designed as in vitro because of that 84 mandibular molar teeth were collected. Forty-two of the included teeth were carious teeth, while the other 42 were without caries. Sixty of them were used for microleakage and 24 for microtensile bond strength testing and scanning electron microscopy analysis. The samples were divided into six subgroups randomly according to dentin pretreatments: 5% proanthocyanidin, 5% lycopene, and no antioxidant application. After the restorative procedures, samples were attached to the microtensile tester. Samples were subjected to tensile stress in the load cell until they broke at a speed of 0.5 mm per min. Microtensile bond strength (µTBS) and microleakage test data were analyzed with two-way analysis of variance, Bonferroni correction, and Tamhane’s T2 tests. Results: Two-way variance analysis showed that dentin pretreatment applications, dentin substrate, and the interaction between these two parameters had statistically significant effects on µTBS values ( P < .001). There was no difference between dentin pretreatment applications in terms of microleakage scores ( P > .05). Conclusion: The application of dentin pretreatment with proanthocyanidin is a successful procedure that increases the bond strength in both dentin substrate, while pretreatment with lycopene in caries-affected dentin reduces it.


2021 ◽  
Vol 14 (7) ◽  
pp. 686
Author(s):  
Raquel Porto ◽  
Ana C. Mengarda ◽  
Rayssa A. Cajas ◽  
Maria C. Salvadori ◽  
Fernanda S. Teixeira ◽  
...  

The intravascular parasitic worm Schistosoma mansoni is a causative agent of schistosomiasis, a disease of great global public health significance. Praziquantel is the only drug available to treat schistosomiasis and there is an urgent demand for new anthelmintic agents. Adopting a phenotypic drug screening strategy, here, we evaluated the antiparasitic properties of 46 commercially available cardiovascular drugs against S. mansoni. From these screenings, we found that amiodarone, telmisartan, propafenone, methyldopa, and doxazosin affected the viability of schistosomes in vitro, with effective concentrations of 50% (EC50) and 90% (EC90) values ranging from 8 to 50 µM. These results were further supported by scanning electron microscopy analysis. Subsequently, the most effective drug (amiodarone) was further tested in a murine model of schistosomiasis for both early and chronic S. mansoni infections using a single oral dose of 400 mg/kg or 100 mg/kg daily for five consecutive days. Amiodarone had a low efficacy in chronic infection, with the worm and egg burden reduction ranging from 10 to 30%. In contrast, amiodarone caused a significant reduction in worm and egg burden in early infection (>50%). Comparatively, treatment with amiodarone is more effective in early infection than praziquantel, demonstrating the potential role of this cardiovascular drug as an antischistosomal agent.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2264
Author(s):  
Raphael H. M. Reis ◽  
Fabio C. Garcia Filho ◽  
Larissa F. Nunes ◽  
Veronica S. Candido ◽  
Alisson C. R. Silva ◽  
...  

Fibers extracted from Amazonian plants that have traditionally been used by local communities to produce simple items such as ropes, nets, and rugs, are now recognized as promising composite reinforcements. This is the case for guaruman (Ischinosiphon körn) fiber, which was recently found to present potential mechanical and ballistic properties as 30 vol% reinforcement of epoxy composites. To complement these properties, Izod impact tests are now communicated in this brief report for similar composites with up to 30 vol% of guaruman fibers. A substantial increase in impact resistance, with over than 20 times the absorbed energy for the 30 vol% guaruman fiber composite, was obtained in comparison to neat epoxy. These results were statistically validated by Weibull analysis, ANOVA, and Tukey’s test. Scanning electron microscopy analysis disclosed the mechanisms responsible for the impact performance of the guaruman fiber composites.


2021 ◽  
Vol 27 (S1) ◽  
pp. 3168-3170
Author(s):  
Hazel Jaynelle Morales-Rodriguez ◽  
Javier Camarillo-Cisneros ◽  
María Alejandra Favila-Pérez ◽  
Alva Rocío Castillo-González ◽  
Celia María Quiñonez-Flores ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2250
Author(s):  
Mohammad Amjadi ◽  
Ali Fatemi

Short glass fiber-reinforced (SGFR) thermoplastics are used in many industries manufactured by injection molding which is the most common technique for polymeric parts production. Glass fibers are commonly used as the reinforced material with thermoplastics and injection molding. In this paper, a critical plane-based fatigue damage model is proposed for tension–tension or tension–compression fatigue life prediction of SGFR thermoplastics considering fiber orientation and mean stress effects. Temperature and frequency effects were also included by applying the proposed damage model into a general fatigue model. Model predictions are presented and discussed by comparing with the experimental data from the literature.


2006 ◽  
Vol 12 (S02) ◽  
pp. 1270-1271
Author(s):  
M Olszta ◽  
J Dougherty ◽  
M Horn ◽  
EC Dickey

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005


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