Dry sliding friction and wear behavior of hybrid glass - carbon fiber reinforced PA66/PTFE composites

The tribological response and the frictional effects in dry sliding wear behaviour of hybrid Glass –Carbon composites under the action of sliding load and sliding velocity was studied. The material systems considered for the investigation were PA66/PTFE blend (80/20 wt. %), Blend(PA66/PTFE)/10 wt.% short glass fiber (SGF), Blend (PA66/PTFE)/10 wt.% short carbon fiber (SCF) and Blend (PA66/PTFE)/10 wt.% SGF/10 wt.% SCF (GC).These composites were produced using melt mixing method through extrusion and followed by injection molding. The experimentation was conducted as per ASTM G99 method. The experimentation data revealed that the significant wear resistance was exhibited by Glass-Carbon hybrid composites under the action of all the test parameters. This is attributed to the hybrid effect of fibres which may restrict the early reaching of softening point of polymers thereby preventing melting wear. Further, the formation of uniform and defined transfer polymer substrate on the steel disc surface reduced the frictional effects. Further, Blend/SCF composites were better than Blend/SGF composites. The composites studied were sensitive to applied normal load compared to velocity. The combined matrix and fiber wear were credited to the critical wear volume loss. Fiber misalignment, matrix deformation, melting wear and fiber peeling were some of the failure mechanisms observed in the morphological study of hybrid composites through SEM images

Anodic Polarization of Copper Single Crystal Planes in Sulphuric Acid

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Spatio-temporal dynamics of total suspended sediments in the Belize Coastal Lagoon

Increased tourism in Belize over the last decade and the growth of the local population have led to coastal development and infrastructure expansion. Land use alteration and anthropogenic activity may change the sediment and nutrient loads in coastal systems, which can negatively affect ecosystems via mechanisms such as reducing photosynthetically active radiation fields, smothering sessile habitats, and stimulating eutrophication events. Accurate monitoring and prediction of water quality parameters such as Total Suspended Sediments (TSS), are essential in order to understand the influence of land-based changes, climate, and human activities on the coastal systems and devise strategies to mitigate negative impacts. This study implements machine learning algorithms such as Random Forests (RF), Extreme Gradient Boosting (XGB), and Deep Neural Networks (DNN) to estimate TSS using Sentinel-2 reflectance data in the Belize Coastal Lagoon (BCL) and validates the results using TSS data collected in situ. DNN performed the best and estimated TSS with a testing R2 of 0.89. Time-series analysis was also performed on the BCL’s TSS trends using Bayesian Changepoint Detection (BCD) methods to flag anomalously high TSS spatio-temporally, which may be caused by dredging events. Having such a framework can ease the near-real-time monitoring of water quality in Belize, help track the TSS dynamics for anomalies, and aid in meeting and maintaining the sustainable goals for Belize

Plant growth-promoting actinobacteria: a new strategy for enhancing sustainable production and protection of grain legumes

Grain legumes are a cost-effective alternative for the animal protein in improving the diets of the poor in South-East Asia and Africa. Legumes, through symbiotic nitrogen fixation, meet a major part of their own N demand and partially benefit the following crops of the system by enriching soil. In realization of this sustainability advantage and to promote pulse production, United Nations had declared 2016 as the “International Year of pulses”. Grain legumes are frequently subjected to both abiotic and biotic stresses resulting in severe yield losses. Global yields of legumes have been stagnant for the past five decades in spite of adopting various conventional and molecular breeding approaches. Furthermore, the increasing costs and negative effects of pesticides and fertilizers for crop production necessitate the use of biological options of crop production and protection. The use of plant growth-promoting (PGP) bacteria for improving soil and plant health has become one of the attractive strategies for developing sustainable agricultural systems due to their eco-friendliness, low production cost and minimizing consumption of non-renewable resources. This review emphasizes on how the PGP actinobacteria and their metabolites can be used effectively in enhancing the yield and controlling the pests and pathogens of grain legumes

Mechanical assisted modification of halloysite nano clay: expoxy composites

Modification of Halloysite nano clay has been done using 3-aminopropy ltriethoxysilane in the presence of distilled water as solvent media. Untreated and modified nano clay was characterized by Powder X-ray diffractometer (PXRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR). Functionalization of Halloysite nano clay is also strongly affected the morphological parameters and enabling the application in epoxy nano composite. However, the influence of modified clay concentration on the mechanical properties of epoxy/nanoclay composites, with different concentrations (2%, 3%, 4% and 5%) of nano clay in the epoxy resin was investigated. Experimental results showed that the mechanical properties of epoxy were improved upto 4 wt% of HNP's, evidently because of the loading of modified clay. The tensile strength, tensile Modulus, flexural strength, flexural modulus and fracture toughness of the nanocomposites increased by 13%, 17%, 9%, 14%and 27% respectively this demonstrated that the composites were strengthened

Thermal Response of Long Jute and Banana Hybrid Epoxy Fibrous Natural Composites

<p>The thermal response of long Jute and Banana reinforced epoxy natural composites has been investigated. The materials systems used for the investigation are : Epoxy (EP), Epoxy/4 wt.% Banana fiber (BF)/4 wt.% Jute fiber (JF) (EP8), Epoxy/8 wt.% BF/8 wt.% JF (EP16), Epoxy/12 wt.% BF/12 wt.% JF (EP24), and Epoxy/16 wt.% BF/16 wt.% JF (EP32). These composites were processed and fabricated using hand – lay-up technique. The thermal response of the aforesaid material systems were studied using thermogravimetric analysis (TGA). The % weight loss of these composites at defined temperature has been recorded from the thermograms. The hybridization effect of long jute and banana fibers on the thermal stability of epoxy fibrous composites were investigated. It is revealed from the experimentation that higher loading of natural fibers has enhanced the thermal stability of composites. The percentage weight loss of these composites has been controlled at higher thermal load using the combined effect of natural fibers.</p><p>Keywords:- Thermal; Jute Fiber; Banana Fiber; Epoxy; Natural Composites.</p&gt