Experimental Shear Study on Reinforced High Strength Concrete Beams Made Using Blended Cement

With the increased application of High Strength Concrete (HSC) inconstruction and lack of proper guidelines for structural design in India,behavioral study of high strength concrete is an important aspect ofresearch. Research on the behavior of HSC reinforced beams with concretestrength more than 60 MPa has been carried out in the past and is stillcontinuing to understand the structural behavior of HSC beams. Along withthe many benefits of the high strength concrete, the more brittle behavior isof concern which leads to sudden failure. This paper presents the behaviorof reinforced HSC beams in shear with considering the effects of variousfactors like shear reinforcement ratio, longitudinal reinforcement ratio, l/dratio (length to depth ratio), etc. Ten numbers Reinforced Concrete Beamsof various sizes using concrete mix with three different w/c ratios (0.46, 0.26and 0.21) were cast for shear strength assessment. The beams were tested insimply supported condition over two fixed steel pedestals with load rate of0.2 mm/minute in displacement control. Mid-point deflection was measuredusing LVDT. A comparative analysis of theoretical approaches of Eurocode, extension of current IS code up to M90 and the experimental datawas done to understand the behavior of beams. Shear capacities of beamswithout any factors of safety were used to assess the actual capacities andthen was compared with the experimental capacity obtained. Results ofthis study can be used in the design of high strength concrete and will bemore reliable in Indian continent as the regional materials and exposureconditions were considered

Microstructural Characteristics of Accumulative Roll Bonded Ni-Al Based Metal Intermetallic Laminate Composite

The present investigation is an attempt to develop metal-intermetallic laminate composites based on Ni-Al system. In this study, Ni and Al foils (460 and 90 μm respectively) have been used for the development of Ni-Al laminate using accumulative roll bonding technique at 773 K. The laminate composites were then subjected to controlled annealing at 773 K, 823 K and 873 K for 1, 2 and 4 h to affect reaction at the Ni/Al interface leading to intermetallic compound formation. The accumulative roll bonded laminates showed good bonding of layers. Annealing treatment at 773 K led to slow formation of reaction product but maintained the interface integrity. Annealing at 873 K led to de-lamination of individual layers prior to the completion of reaction. A qualitative compositional analysis at the interfaces reflected the formation of Al-Ni copmpounds, and also a gradual compositional gradient across the interface. This process seems to be of promise so far as the continuous production of large scale metal-intermetallic laminate composites are concerned. A further study is underway to circumvent the delamination problems and property evaluation

Use of bottom ash as part replacement of sand for making concrete blocks

Coal-based thermal power plants all over the world facing serious problems of handling and disposal of the ash produced. The productive use of coal Bottom Ash (BA) is the best way to alleviate the problems associated with its disposal. This paper covers the studies on laboratory scale evaluation of vibro compaction concrete blocks using BA I, BA II & BA III collected from three different location of Coal Fed Thermal Power Station. In the present investigation laboratory investigation have been carried to utilize BA as part replacement of sand in concrete. This study cover manufacture of concrete blocks without flyash & with BA using for making solid block as per specification laid down in IS:2185 using vibro compaction machine. Three different sources of BA were used in concrete mix each @ 30%, 40% & 50% replacement by weight of sand were adopted in making concrete blocks. Comparative study of compressive strength of concrete at different age of curing, wet density, drying shrinkage is reported in this study. Wet density is found to be lower in blocks containing BA & dry shrinkage values are found well within the limits of specifications. Concrete Blocks having BA @ 30% by weight of sand are found suitable for use in the manufacture of concrete blocks

Analysis of genetic diversity among tropical and subtropical maize inbred lines using SSR markers

Genetic diversity of 24 tropical and subtropical elite maize lines was assessed at molecular level employ-ing 42 Simple Sequence Repeats. A total of 107 alleles with an average of 2.55 alleles per locus were detected. The Polymorphism Information Content (PIC) values of 42 SSR loci ranged from 0.08 (UMC1428) to 0.68 (UMC2189 and UMC2332) with the overall calculated PIC mean value of 0.44, whereas the Discrimination Rate (DR) value for SSR markers ranged from 0.09 (UMC2089) to 0.42 (UMC1311) with the average DR value of 0.26. Pair-wise genet-ic similarity (GS) values, calculated by Jaccard’s coefficients, ranged between 0.25 and 0.78 with a mean genetic similarity of 0.63, indicating the existence of adequate amount of genetic divergence among the genotypes selected for the study. The cluster dendrogram separated all the inbred lines into six main clusters with sub clusters based on genetic similarity. Factorial analysis also confirmed a nearly similar pattern for grouping these inbred lines as pre-sented by cluster dendrogram. In this study, SSR markers were found to be powerful tool for detection of genetic diversity in maize inbred lines. These findings could provide information for effective utilization of these materials for development of maize hybrids as well as for genetic improvement of inbred lines

Microbiological Indices for Diagnosis of Heavy Metal Contaminated Soils

Heavy metal contamination has gained popularity worldwide due to their persistent nature in the environment, on the top of that non-biodegradable nature makes its accumulation easy to toxic levels. Understanding the nature of contamination has become a major concern before heavy metals deteriorate the quality of soil; to diagnose heavy metal pollution suitable indices are required. Microbial indices gaining importance because of their sensitive nature towards change in surrounding, which is the imperative quality required to select microbes as environmental indicators. Albeit enough literature is present related to this topic but the information is scattered so role of this chapter is imperative. The chapter will be helpful for the reader to provide a thorough understanding of merits and demerits of microbiological indices for heavy metal contaminated and restituted soils. The changes in microbiological indices and their mechanism of response towards heavy metal stress are effectively summarized. Research gap and future needs of microbial diagnosis of heavy metal contaminated soils are discussed

The role and significance of Magnesium in modern day research-A review

Magnesium is one of the largely available elements in the earth's crust. It has a low structural density with high specific strength. This unique material property has forced an increase in the use of magnesium and its alloys in various applications pertaining to industrial sector, automobiles, aerospace and biomedical. Since magnesium is a highly reactive metal, it is prone to higher rate of corrosion as compared to its counterparts. Thus, it is essential to analyze the corrosion behavior of magnesium and its alloys in its applications. An appropriate process is to be followed in the design and development of magnesium alloys which overcome the limitations of magnesium and enhance the desired material properties in accordance to their applications. This review paper summarizes the importance of magnesium and its material properties. The influence of various alloying elements on the mechanical properties of magnesium is reviewed. The broad classification of Mg alloys and their behavioral trends are detailed. The corrosion behavior of magnesium and the influence of corrosion products on the material characteristics of magnesium, in aqueous medium, are discussed. The manufacturing techniques of magnesium alloys along with the secondary techniques are also covered. The various applications and the limitations of magnesium in these applications are covered. A complete section is dedicated towards detailing the recent trends of magnesium (Mg) alloys, i.e., the biodegradable nature and applications of Mg alloys. The influence of biocorrosion on Mg alloys and techniques to overcome it have been deliberated. This paper provides a thorough review on recent developments of magnesium with respect to engineering applications

Leptin gene polymorphism in association with lactation milk yield in Murrah buffaloes

PCR amplification of exon-2 of leptin gene yielded an amplified product of 210 bp in Murrah buffaloes. RFLP of leptin gene done with Aci1 restriction enzyme revealed 3 types of genotypes CC, TC and TT in Murrah buffaloes of NDRI herd with a frequency of 0.26 , 0.73 and 0.013% respectively. Results suggested that CC genotype of leptin gene in Murrah buffaloes is significantly associated with 305 days milk yield. Overall study suggested the scope of considering genetic information of leptin gene in breeding and management strategies for the improvement of Murrah buffaloes of NDRI herd

Mast cell-mediated immune regulation in health and disease

Mast cells are important components of the immune system, and they perform pro-inflammatory as well as anti-inflammatory roles in the complex process of immune regulation in health and disease. Because of their strategic perivascular localization, sensitivity and adaptability to the microenvironment, and ability to release a variety of preformed and newly synthesized effector molecules, mast cells perform unique functions in almost all organs. Additionally, Mast cells express a wide range of surface and cytoplasmic receptors which enable them to respond to a variety of cytokines, chemicals, and pathogens. The mast cell’s role as a cellular interface between external and internal environments as well as between vasculature and tissues is critical for protection and repair. Mast cell interactions with different immune and nonimmune cells through secreted inflammatory mediators may also turn in favor of disease promoting agents. First and forefront, mast cells are well recognized for their multifaceted functions in allergic diseases. Reciprocal communication between mast cells and endothelial cells in the presence of bacterial toxins in chronic/sub-clinical infections induce persistent vascular inflammation. We have shown that mast cell proteases and histamine induce endothelial inflammatory responses that are synergistically amplified by bacterial toxins. Mast cells have been shown to exacerbate vascular changes in normal states as well as in chronic or subclinical infections, particularly among cigarette smokers. Furthermore, a potential role of mast cells in SARS-CoV-2-induced dysfunction of the capillary-alveolar interface adds to the growing understanding of mast cells in viral infections. The interaction between mast cells and microglial cells in the brain further highlights their significance in neuroinflammation. This review highlights the significant role of mast cells as the interface that acts as sensor and early responder through interactions with cells in systemic organs and the nervous system