فهرست مطالب s. patel

The demand for aggregates for civil engineering construction is high in the market. The broad adoption of fly ash for producing fly ash aggregate is the best sustainable solution to fulfill aggregate demand and utilization of unused fly ash. Crushing is an essential step for producing angular-shaped aggregate. In this paper, an experimental study using a laboratory-scaled impact crusher was carried out to investigate the effect of crushing process parameters (feed block size, crusher speed and outlet sieve size) on the quality (particle size distribution, flakiness-elongation index and mechanical properties) of angular-shaped fly ash aggregates produced after crushing high-strength fly ash blocks. Particle size distribution and flakiness-elongation index were found to be changed with crushing parameters. Higher crushing speed resulted in small-size fly ash aggregates. Better particle size distribution of crushed fly ash aggregate was produced using a 60 mm outlet sieve compared to a 30 mm one. Well-graded fly ash aggregates with good particle shape (less flaky and less elongated) for the subbase layer of the road were obtained after crushing fly ash blocks of one-third feed size in a laboratory-scaled impact crusher at a crushing speed of 527 rpm and an outlet sieve of 60 mm. Mechanical properties (impact, crushing and abrasion values) of the fly ash aggregate were not much affected by crushing process parameters. The findings of this study will help in optimizing the crushing operation of the industrial impact crusher to produce high-quality angular-shaped fly ash aggregate on a large scale.

Iron, an essential micronutrient, significantly contributes to growth, immune health, and cognitive development in human health. Inadequate dietary iron intake leads to iron deficiency anemia, affecting nearly 1.6 billion people, especially pregnant women and preschool children. Biofortification and fortification of iron in wheat is an acceptable and cost-effective strategy to alleviate iron deficiencies. This study aims to address iron deficiencies through the strategy of fortification and biofortification of wheat varieties. The study places specific emphasis on the proximate composition and iron/mineral content of different wheat varieties. To achieve these objectives, different spectrometric methods were employed to analyze the wheat samples.

Proximate and mineral quantification were carried out following standard Association of Official Analytical Chemists methods using ultraviolet-visible spectrophotometry, atomic absorption spectrometry, inductive coupled plasma-mass spectroscopy, and prediction was carried out using near-infrared spectra combined with chemometrics.

The samples had moisture content (1.1 - 4.5 percent), protein (18.0 - 22.6 percent), fat (0.3 - 0.6 percent), gluten (6.3 - 10.3 percent), fiber (0.3 - 1.4 percent), alcoholic acidity (0.04 - 0.08 percent), ash (0.9 - 1.7 percent), and carbohydrate (71.1 - 75.2 percent). Iron was determined and compared by spectrophotometric methods. Iron concentration ranged from (0.7 to 6.3 milligrams/100 grams) in ultraviolet-visible analysis, (0.7 to 6.74 milligrams/100 grams) in atomic absorption spectrometry, and (0.81 to 6.8 milligrams/100 grams) in inductive coupled plasma-mass spectroscopy. The obtained results were compared with the standard "Food Composition and Food Safety Standard Authority of India" and predicted using near-infrared spectra combined with chemometrics.

The work aims to investigate the nutritional content of various wheat varieties, particularly focusing on iron content, which could potentially have implications for improving dietary strategies and addressing nutritional deficiencies. The biofortified varieties (HI-8663 and HI-1605) were found to have high iron content when compared to normal wheat. The acquired results bridge the intricate relationship between plant-based diets, micronutrient deficiencies, providing valuable insights into combating iron deficiencies in public health with the potential achievement of improved nutritional understanding, optimized wheat selection, advanced analytical techniques, education, awareness, and iron deficiency mitigation.

Depleting good quality natural aggregates and soils call for the need of use of industrial by-products and waste materials in road construction. Use of wastes and by-products in road construction consume large quantities and resolve issue of their safe disposal. Class C fly ash is the by-product from thermal power plants while quarry dust is waste left behind during quarrying processes. This study investigated the application of class C fly ash and quarry dust mix for utilization in subbase layer of flexible pavement. The class C fly ash and quarry dust mixed were studied with the help of unconfined compressive strength test, repeated load triaxial test, durability test and microstructural analysis. The mixture of 90% fly ash plus 10% quarry dust was found to be suitable with respect to strength and durability criteria to be used as subbase material in flexible pavement. Owing to the formation of cementitious phases during pozzolanic reaction, proposed mix demonstrated significantly higher resilient modulus than conventional granular subbase material. The service life ratio for pavement with proposed mix is 1.2 and 1.26 in fatigue and rutting respectively compared to conventional pavement. The use of quarry dust and fly ash in large quantities in flexible pavement is an economical as well as sustainable solution for road construction.

The prices of aggregate are increasing in India due to the massive demand for natural aggregate for infrastructure development. An attempt has been made to check the feasibility of the past developed technique for developing angular-shaped light-weight fly ash coarse aggregate from three different types of fly ashes. In this study, the effects of binder content, water content and hot water bath curing temperature on the compressive strength of blocks, as well as the impact value of prepared aggregate for fly ash-binder mixes were investigated. A relationship between impact value and compressive strength has also been suggested to predict the impact value of fly ash aggregate based on the compressive strength of block. For making angular-shaped fly ash aggregate, it was found that the fly ash with CaO content of 0.71%-3.85% requires higher binder content and curing temperature than that required for fly ash with CaO content of 10.45%. The resulting lightweight aggregates from three fly ashes have a compacted structure and angular shape for good interlocking. The results of mechanical properties test showed that the aggregate also meets the criteria of Indian code specifications for structural concrete aggregate.

The present study involves a novel approach in manufacturing nano-crystalline dispersions of titanium dioxide, a widely used pigment in the paints and coatings market. These dispersions are developed to provide certain benefits over conventional titanium dioxide powder to improve the coating parameters such as adhesion promotion, hiding, tinting strength, dispersion, and reduced dosage. Dispersions are synthesized using bead mill and high-speed disperser in a unique multi-stage process, thereby developing a scalable technology for industrial synthesis. Characterization of these dispersions, namely XRD, particle size analysis, and FE-SEM, confirmed the presence of nano-crystalline titanium dioxide particles. Moreover, analysis of process variables was also conducted by studying the effect of grinding time on particle-size reduction. Rheological analysis was performed for water and styrene-acrylic copolymer emulsion systems. It was developed a dataset of viscosities. Results of this study can be assessed to create scalable technology for the synthesis of nano-crystalline dispersions, which can be used as a pigment in multipurpose waterborne coating systems.