Influence of Geopolymerization Factors on Sustainable Production of Pelletized Fly Ash–Based Aggregates Admixed with Bentonite, Lime, and GGBS

This experimental research investigates the influence of geopolymerization factors such as Na₂O dosages, water and mineral admixture [bentonite (BT), burnt lime (BL), and ground granulated blast furnace slag (GGBS)] on physiomechanical properties of the pelletized fly ash (FA)–based aggregates. Taguchi’s L₉ orthogonal array was adopted to design the mixing ratios for three kinds of fly ash–based aggregates (in the combinations of FA-BT, FA-BL, and FA-GGBS). The degree of geopolymerization of the produced aggregates was characterized using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and a scanning electron microscope (SEM). Most influential response indices in the production of pelletized aggregates were identified using gray relational analysis. The physiomechanical characteristics of the fly-ash aggregates were significantly improved by admixing BL than that of GGBS and BT. However, pelletization efficiency was seen to be superior for GGBS-substituted fly-ash aggregates. The quantified amount of hydration products, i.e., sodium alumino-silicate hydrate (N-A-S-H)/calcium alumino-silicate hydrate (C-A-S-H) for fly ash–based aggregates intensified on increasing Na₂O and mineral admixture dosages. The results strongly suggest the existence of a linear relationship between the quantified amount of N-A-S-H/C-A-S-H and individual pellet strength of produced aggregate. The FTIR spectrum showed strong and broadened bands of Si-O terminal for all types of aggregates, representing the conversion of unreacted minerals to chains of aluminosilicate gel (geopolymerized hydration product). Further, it can also be inferred from gray relational analysis that among all other factors, Na₂O content significantly impacted the engineering properties of produced fly ash–based aggregates

Effect of Boron Carbide on wear resistance of graphite containing Al7029 Based Hybrid Composites and its Dry Sliding Wear Characterization Through Experimental, Response Surface Method and ANOVA

Composites are often chosen for tribological applications due to its tailored material properties. The development of hybrid metal matrix composites and the study of their wear behavior has been a prominent focus of materials science research. Present paper deals with fabrication of Al-7029/B4C/Gr hybrid composite using stir casting. Particle distribution and material phase are identified by SEM and XRD. Hardness of the composite increased to 101 BHN while base alloy with 63 BHN. Pin-on-disc Tribometer used to carry wear test and the experimentation conducted by considering three input wear control parameters: 15–35 N (load), 1.5–3.5 m/s (speed) and 200–600 m (distance). Addition of 6%B4C/3%Gr, wear rate of hybrid composites reduced. ANOVA confirmed that load as the most influencing parameter on wear rate. RSM results correlates with mean effect plots of ANOVA and experiments and found that the results are in good compliance. SEM graphs of worn surface confirms that more wear occurred with increased load

Clinicopathological, radiological and bronchoscopic evaluation of suspected lung malignancy

Background: This study was conducted to evaluate the clinical, pathological and radiological profile of suspected lung malignancy and its correlation with bronchoscopic findings.Methods: A hospital based prospective study was conducted in the department of pulmonary medicine on 74 patients who were suspected with lung malignancy, clinically or radiologically. Following a detailed clinical examination, chest x-ray and CECT thorax, patients were included in the study and were subjected to bronchoscopy. Based on the bronchoscopic findings BAL, TBNA, forceps biopsy and TBLB were performed.Results: Out of 74 patients, most of them belonged to the age group of 51-65 years. Majority were males. Cough was the most common symptom. 51 patients had weight loss and 48 had associated reduced appetite. 50 (67.6%) were smokers. Out of them 43 (86%) were beedi smokers. In CT thorax, most common presentation was mass lesion followed by consolidation, nodules and interstial thickening. Right side was the most common side involved. Bronchoscopy revealed intraluminal growth as the most common finding and the most common pattern noted was fungating growth. Squamous cell carcinoma was the most common cell type noted in 9 (27.03%) followed by adenocarcinoma and small cell carcinoma. Squamous cell carcinoma presented more commonly as central mass with intraluminal growth and adenocarcinoma presented more commonly as peripheral lesions with extraluminal compression in bronchoscopy.Conclusions: Elderly smokers with cough and loss of appetite with weight loss can be suspicious of lung malignancy. CT and bronchoscopy are essential for the diagnosis of lung malignancy