Development and Evaluation of High Performance Fiber Reinforced Concrete as a Repairing Material

Concrete is the most widely used man-made material in the world and is second only to water in terms of its utilization. Annually, 6 billion tons of concrete is produced in the world and the US consumption of concrete is over 2.5 tons a year per person (SDC Vision 2030 -- US Concrete Industry). It drives a US{dollar}100 billion industry in the United States alone employing over 2 million people. It enjoys huge acceptability over other construction materials across the globe. Though concrete is strong and durable, it does not last forever, especially when exposed to aggressive conditions. Deicing salts, freeze-thaw cycles, high heat, high mechanical loading, seismic events, etc. lead to potential deterioration of the concrete structure. As a consequence, the service life of the structure is reduced. In US, 1 in every 4 bridges is either structurally deficient or functionally obsolete. The nation\u27s crumbling infrastructures and buildings need urgent replacement. The replacement cost of these structures being enormous, there is a pressing need for repairing and rehabilitating these deficient structures.;Keeping the above points in mind, the present study focused on developing a high performance fiber reinforced concrete (HPFRC) material with very high strength and improved ductility, which can rehabilitate the structure by repairing it at a fraction of replacement cost required for new construction.;All the materials used in this study are commercially available in the United States. Initially two HPFRC mixtures were developed using portland cement, two types of fine sand with optimized grading, ultrafine quartz powder, discontinuous steel fibers, and a next generation polycarboxylate-based full range water reducing admixture. The water to cementitious materials ratio and the fiber volume fraction were kept at 0.2 and 2%, respectively. To study the effect of curing temperature on the hardened properties of the mixtures, four different curing conditions were selected. Compressive strength, flexural strength, and flexural toughness were determined for those eight combinations. Compared to high performance fiber reinforced cement composites (HPFRCC) the increase in compressive strength was in the range of 25-105%. Flexural strength was found to be similar to that of HPFRCC. Based on these strength results, the better performing mixture and the two best performing curing conditions were further selected to study the bond behavior of HPFRC to NC.;The bond strength was determined by conducting three tests, such as, direct shear, slant shear, and pull-off. The results showed comparable bond strength in case of direct shear and 20% increase in bond strength by slant shear, when compared with other similar studies. The pull-off strength exceeded the minimum acceptance criterion for bond strength of repairing materials per International Concrete Repair Institute -- Technical Guidelines

Should Sustainability of Fish Stock Be Prioritised Over Catch Efficiency – A Study on Traditional Fishermen in Karimganj District of Assam

Sone Beel, the largest wet land of southern Assam is the home of traditional fishermen who are dependent solely on fishing for their livelihood.  No fishing permits are required in the Sone Beel during the peak fishing season, and as such there is open access to fishing during this period.  This paper estimates technical efficiency of fish catch and its non-input determinants using a stochastic production frontier with inefficiency effects. A sample of 165 fishing teams operating during the monsoon of 2013, were chosen for this purpose.  The study suggests that experience in fishing has a positive influence on technical efficiency while education and income from sources other than fishing have depressing effects on the same.  Uncontrolled fishing in the area during peak fishing seasons is the consequence of overdependence on fishing. There is no institutional mechanism in place to check the rampant use of dense nets that lead to massive loss of non-fish species in the water body.  Thus immediate policy intervention may check loss of fish stock and aquatic species in the region, and can help in restoration of the ecological balance in the Sone Beel. Keywords: Sone Beel, fish catch, technical efficiency, stochastic production frontier, inefficiency effects model, and non-input factors. JEL classification: C 21, Q 22

Elevated temperature erosion of abradable seal coating

Abradable coatings are essentially sealing materials and are deposited by thermal spray techniques. The main function of these coatings is to control the clearance of the gas path of the gas turbine engines. The abradable coating prevents turbine blade damage by abrading itself when there is an offset or vibration during turbine operation. Since the coating is meant to abrade, the preferred coating material is relatively softer than the turbine blade material. As these coatings are prone to solid particle erosion at high temperatures, the erosion response of these coatings at elevated temperatures needs to be investigated. In order to achieve this objective, MCrAlY boron nitride polymer coating was deposited employing an air plasma spraying technique on a Ni-base alloy substrate. The important features of the microstructure and mechanical properties of the coating were examined, and the coating was subjected to erosion at various temperatures under different erosion conditions. The results indicate a ductile erosion behaviour for an abradable top coat. The erosion rate increases with the temperature of the coating. The detailed results of the investigation are presented, and the erosion mechanisms are studied

Technical Efficiency of Fish Catch and Its Socio-Economic Determinants – A Study on Traditional Fishermen of Karimganj District of Assam

This paper has measured the technical efficiency of fish catch and its socio-economic determinants among traditional fishermen dwelling in the neighbourhood of the Shon Beel in Karimganj district of Assam, India. Empirical estimations are on the basis of primary data collected from a sample of fishermen during the peak fishing season of 2014. The study uses a log-linear stochastic production frontier with inefficiency effects where selected non-input socioeconomic variables are hypothized to explain variations in catch efficiency across fishing teams.  The study finds that technical efficiency of fish catch at the fishing team level is influenced positively by experience and per –capita household expenditure.  Non-fishing income, dependency ratio, and education are found to have a dampening effect on catch efficiency.  The study opines that excessive fishing in the Sone Beel in recent years has necessitated greater catch effort to get the same quantity of catch.  This is indicative of falling fish stock, premature catch, and consequently falling average size of catch irrespective of species. Keywords: Fish catch, Technical Efficiency, Inefficiency Effects Model, Stochastic Production Frontier, Non-input Factors. JEL classification: Q 22, C 21

Attention at SemEval-2023 Task 10: Explainable Detection of Online Sexism (EDOS)

In this paper, we have worked on interpretability, trust, and understanding of the decisions made by models in the form of classification tasks. The task is divided into 3 subtasks. The first task consists of determining Binary Sexism Detection. The second task describes the Category of Sexism. The third task describes a more Fine-grained Category of Sexism. Our work explores solving these tasks as a classification problem by fine-tuning transformer-based architecture. We have performed several experiments with our architecture, including combining multiple transformers, using domain adaptive pretraining on the unlabelled dataset provided by Reddit and Gab, Joint learning, and taking different layers of transformers as input to a classification head. Our system (with team name Attention) was able to achieve a macro F1 score of 0.839 for task A, 0.5835 macro F1 score for task B and 0.3356 macro F1 score for task C at the Codalab SemEval Competition. Later we improved the accuracy of Task B to 0.6228 and Task C to 0.3693 in the test set

Motivation Level of Employee’s in Small Scale Industries in Aligarh District of Uttar Pradesh (India)

One of the most important concerns of a management or manager is to motivate people to make their optimum contribution to the achievement of organizational goals. Therefore, it becomes important for him to understand what motivates people to behave as they do. Some human behaviour is random and consist of emotions and reflexes, most of it is goal directed in the sense that it is aimed at the satisfaction of some need. Since the needs of the employees and the organisation are not always the same, the manager can better integrate these two sets of needs by gaining an insight into the needs of his employees and then channelise them in the direction of organizational needs. The present paper is an attempt in this direction intended to examine the “Motivation level of employees in small scale industries”. Keywords: Employees, Motivation, Organization, Small Scale Industries

Microstructure and Wear of Cathodic Arc Physical Vapour Deposited on TiAlN, TiCrN and n TiAlN Alpha Si3N4 Films

Present study examined the microstructural features, hardness and wear performance of TiAlN, TiCrN and            n-TiAlN/α-Si3N4 coatings deposited by cathodic arc physical vapour deposition (CA-PVD) technique on M-50 steel keeping in mind a possible application of hybrid bearings in next generation aero-engine. Microstructural features of the coatings were evaluated using scanning electron microscopy (SEM) and transmission electron microscopy. Hardness was measured using microhardness tester. Wear test was carried out with the help of ‘Bruker’ tribometer. Worn surfaces were characterised employing SEM. Results show that TiCrN coating has crystalline columnar structure and other coatings have nano-crystalline structures. Besides improved hardness, TiAlN has best wear resistance and TiCrN coating exhibits least friction coefficient

DOTIE - Detecting Objects through Temporal Isolation of Events using a Spiking Architecture

Vision-based autonomous navigation systems rely on fast and accurate object detection algorithms to avoid obstacles. Algorithms and sensors designed for such systems need to be computationally efficient, due to the limited energy of the hardware used for deployment. Biologically inspired event cameras are a good candidate as a vision sensor for such systems due to their speed, energy efficiency, and robustness to varying lighting conditions. However, traditional computer vision algorithms fail to work on event-based outputs, as they lack photometric features such as light intensity and texture. In this work, we propose a novel technique that utilizes the temporal information inherently present in the events to efficiently detect moving objects. Our technique consists of a lightweight spiking neural architecture that is able to separate events based on the speed of the corresponding objects. These separated events are then further grouped spatially to determine object boundaries. This method of object detection is both asynchronous and robust to camera noise. In addition, it shows good performance in scenarios with events generated by static objects in the background, where existing event-based algorithms fail. We show that by utilizing our architecture, autonomous navigation systems can have minimal latency and energy overheads for performing object detection