Durability properties of fly ash and silica fume blended concrete for marine environment

1803-1812The improvement in durability and strength by replacing the conventional components with supplementary materials in concrete is one of the recently focused areas in concrete technology. From the previous till the recent times serious efforts have been taken to improve the structural adequacy and durability characteristics of concrete so as to efficiently replace the usual conventional concrete. In this present research work, the mechanical and durability properties of the concrete blended with fly ash (FC) and silica fume (SC) are studied in detail. The partial replacement of cement with silica fume and fly ash in the concrete improves the overall property of the concrete, gives a way for the reuse of the supplementary material to be efficiently brought back giving a cleaner environment. The fly ash is used with the replacement percentages of 10, 15 and 20 of the cement whereas for silica fume the replacement percentages are 8, 10 and 12, respectively. Also the study is extended to combination mixes to test the strength and durability and it has been found that the increase in the percentage of the silica fume increases the strength reduces the workability and permeability to a high extent and the inclusion of the fly ash paves a way for the increase in the durability property. The effect of the cementitious material with FC and SC on the concrete is compared with the nominal concrete and also the suitability in the usage of marine environment is validated in accordance with the International codes

A prospective study on clinical outcome of humerus shaft fracture and nonunion treated with antero medial plating

Background: Humeral shaft fractures have an incidence of 13 per 100000 per year and account for 3% of total fractures. The following study is carried out with intention for determining and verifying facts around plate osteosynthesis on anteromedial surface of humerus through anterior approach.Methods: This is a prospective study of 38 patients presenting with humerus shaft fracture and non-union to the Balaji Institute of Surgery Research and Rehabilitation for the Disabled (BIRRD) from April 2015 to March 2016. Inclusion criteria were age>18 years, acute humerus shaft fractures and nonunion of humerus shaft. Exclusion criteria were undisplaced fractures, fractures associated with neurovascular injury, compound and pathological fractures, infected non unions. The functional outcome was graded based on the QuickDASH score. Fisher’s exact test was used to find the association between categorical data.Results: Clinical union was noted in 87% of the patients and radiological union in 74% at the end of three months. The average time period required to achieve union was 13.57 weeks. Based on Quick DASH score, 66% of them had excellent outcome, 24% had good outcome, 10% had fair outcome, and none had poor outcome.Conclusions: It may be concluded that, anteromedial plating through anterior approach for the treatment of humerus shaft fractures and non union leads to a satisfactory functional outcome in most of the patients. Most of the fractures were united by 3 months with good range of motion of shoulder and elbow

Utilization of steel slag in development of sustainable and durable concrete.

This paper reflects the results of an experimental investigation of the strength, permeability, abrasion, carbonation, and shrinkage characteristics of concrete containing various percentages of steel slag as partial replacement of natural fine aggregates. M 30 Grade concrete was designed as per specific national specifications. Steel slag was used to replace natural sand in the range of 0– 50%. It was observed that the steel slag blended concrete with up to 50% substitution exhibited a comparable compressive and flexural strength when compared to the control specimens. From the Dorry’s abrasion test, it was noted that the specimens could be implemented in heavy-duty floor tiles and even extended to pavement construction. The shrinkage strains, water permeability, and carbonation of steel slag blended concrete were observed to be increasing with increasing replacement amounts of steel slag in the place of natural fine aggregates. The concrete containing steel slag replacing up to 40% of natural fine aggregates can be recommended for all heavy load involving structural applications, and substitution levels beyond 40% could be recommended for non-structural applications, pavements, etc

Outcome of delayed versus immediate casting on spasticity of lower limb muscles in cerebral palsy post-botulinum toxin injection

Background: Botulinum toxin type A (BTX-A) is widely used to treat spasticity in children. The optimal strategy for the combined treatment of casting and BTX-A injections is not known. This prospective study is conducted to know the functional outcome of immediate versus delayed casting post-BTX-A injection in children with cerebral palsy (CP). Aims and Objectives: The aim of this study is to compare delayed versus immediate casting as an adjunct to botulinum toxin therapy for spasticity of lower limb muscles in CP. The objectives of the study are to test the hypothesis that delayed casting is superior to immediate casting post-botulinum toxin injection and to know the feasibility of using the Edinburgh visual gait score (EVGS) as a single qualitative and quantitative outcome measure. Materials and Methods: A prospective study is conducted to compare immediate casting with delayed casting post-botulinum toxin injection to spastic lower limb muscles in patients with CP from July 2018 to February 2019. Inclusion criteria: A diagnosis of CP with associated spastic monoplegia, diplegia, or hemiplegia with aided or unaided ambulation. Exclusion criteria: History of orthopedic surgery in the preceding 12 months; selective dorsal rhizotomy; mixed CP; ataxia; athetosis; non-ambulatory subjects. Results: The botulinum toxin injection + delayed POP casting group fared better in terms of clinical and functional outcome (as shown by improved EVGS scores) in our study. Conclusion: There is a clear benefit in delaying casting after the injection of Botulinum toxin in the recurrence of spasticity

Behaviour of a biocompatible titanium alloy during orthogonal micro-cutting employing green machining techniques

The sustainability of a process is the objective of modern industries aiming to reduce waste in production, since consumers require high quality and efficiency with fair price. Thus, a good understanding of the process should be its starting point. The manufacture of dental implants is an example in which waste reduction is important for the reduction of prices due to the demand for great quality and accuracy. This study observed the behaviour of sustainable micro-cutting applied to the Ti-6Al-7Nb titanium alloy, considering the ploughing effect on minimum quantity lubrication (MQL) and high-speed machining (HSM) conditions. When compared with dry condition and low-speed cutting in orthogonal micro-cutting, the use of HSM in dry cutting was more efficient than using MQL. The dry condition presented lower surface roughness, whilst the cooled/lubricated condition presented lower burr formation.publishe

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