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The basic principle involved in the design of S-shaped breakwater is the provision of a wide berm at or around the water level with smaller size armor stones than that used in conventional design, which are allowed to reshape till an equilibrium slope is achieved. An attempt is made to assess the influence of wave height, wave period, and berm width on the stability of S-shaped breakwater with reduced (30% reduction in armor stone weight) armor unit weight. From the investigation, it is found that the berm breakwater with 30% reduced armor weight would be stable for the design wave height if the berm width is 60 cm and wave period 1.2 s. For higher wave periods studied, zero damage wave height reduces by 20-40% of the design wave height. Wave period has large influence on the stability of berm breakwaters. The runup increases with decrease in weight up to Wo/W=0.9. © 2004 Elsevier Ltd. All rights reserved.
(Stability of berm breakwater with reduced armor stone weight) Rao, S.; Pramod, Ch.; Balakrishna Rao, K.B.
2004
Cyclone generated waves play a significant role in the design of coastal and offshore structures. Instead of conventional numerical models, neural network approach is used in the present study to estimate the wave parameters from cyclone generated wind fields. Eleven cyclones, which crossed the southern east coast of India between 1962 and 1979, are considered for analysis in this paper. The parametric hurricane wave prediction model by Young (1988) [Young, I.R., 1988. Parametric hurricane wave prediction model. Journal of Waterways Port Coastal and Ocean Engineering 114(5), 637-652] is used for hindcasting the wave heights and periods. Estimation of wave heights and periods is carried out using back propagation neural network with three updated algorithms, namely Rprop, Quickprop and superSAB. In neural network, the estimation is carried out using (i) difference between central and peripheral pressure, radius of maximum wind and speed of forward motion of cyclone as input nodes and the wave heights and periods as output nodes and (ii) wind speed and fetch as input nodes and wave heights and periods as output nodes. The estimated values using neural networks match well with those estimated using Young's model and a high correlation is obtained namely (0.99). © 2005 Elsevier Ltd. All rights reserved.
(Hindcasting of storm waves using neural networks) Rao, S.; Mandal, S.
2005
[No abstract available]
(Designing lanterns for the efficient lighting of mine roadways - An experimental approach) Mangalpady, M.; Rao, Y.V.; Karmakar, N.C.
2005
Modelling operating speed and speed differential on intermediate lane rural roads
(2012) Sowmya, N.J.; Ravi Shankar, A.U.; Anjaneyulu, M.V.L.R.
Geometric design elements play an important role in defining the operational efficiency of any roadways. Considerable research has been undertaken worldwide to explore the design consistency concept including identifying potential consistency measures and developing models to estimate them. The main objective of this study is to investigate the design consistency of intermediate lane highways existing in Dakshina Kannada district of Karnataka state based on operating speed and speed differential models. The speed measurements are taken at the mid of tangent section and start of the curve during daylight, off-peak periods and under dry weather conditions. The multiple linear regression analysis technique in SPSS (Statistical Package for Social Sciences) software is used for model estimation. Both operating speed (85th percentile speed) and 85th percentile speed differential measures are used with geometric data to identify the design consistency of horizontal curves. A comparative study is performed to identify the variation between these two speed measures. Operating speed and speed differential models for intermediate lane rural roads are presented in this paper. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.
Bond strength behaviour in reinforced concrete members exposed to corrosive environment - An overview
(2013) Shetty, A.; Venkataramana, K.; Babu Narayan, K.S.; Kimura, Y.
Bond resistance of reinforcing bars, embedded in concrete depends primarily on frictional resistance and mechanical interlock. Corrosion of rebars in concrete is one of the major problems in the durability criteria. Local bond stress slip relationship is generally adopted to determine the mechanical properties of the interface between re-bars and concrete. Therefore the attainment of satisfactory performance in bond is an important, aspect of the design and the detailing of reinforcement in structural components. In this paper an overview of factors affecting specimen geometry of bond strength and Types of bond tests were studied. © 2013 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
Portable low cost drill set-up for estimating rock properties
(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2014) Masood; Vardhan, H.; Mangalpady, M.
The mechanical strength of rock is one of the most important factors of concern to engineers involved in mining operations. Information about rock strength is used in rock excavation planning and design operations in civil and mining engineering. Drilling is widely carried out in hard rock’s for blasting the rock mass so that the blasted material can be easily loaded by the excavators. The drillability of rock depends on many factors including rock properties. Whereas properties such as compressive strength, porosity, density etc. are uncontrollable parameters during drilling process. A number of studies have been reported recently on the application of sound level, which have been concentrated on using either CNC or jack hammer machine for drilling purpose. It is worth mentioning that neither CNC machine nor jack hammer drill set-up is the normal way of drilling in rock, nor in mining, civil or any other operations, not even in working with rock in installation of countertops. Therefore, it is difficult to exactly say whether the noise generated during drilling is only from the rock drilling or from the drilling unit itself. In view of the above, it is important to fabricate a new drilling set-up which is a silent unit in itself. Such unit when used for drilling purpose will clearly indicate the change in sound level produced with different rock properties. © 2014 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
Evaluation, ranking, and selection of pretreatment methods for the conversion of biomass to biogas using multi-criteria decision-making approach
(Springer, 2020) Vannarath, A.; Thalla, A.K.
Lignocellulosic biomass resources include agri-waste and agri-biomass which are utilized as a suitable feedstock for bioenergy production. The recalcitrant nature of these biomass can be reduced by the application of various pretreatment methods to access the cellulosic content. This study depicts the evaluation and ranking of different pretreatment methods, and selecting the rank 1 as the best pretreatment method using multiple attribute decision-making approach to facilitate the increased biogas yield. The evaluation was done using technique for order preference by similarity to ideal solution (TOPSIS) and integrated design of experiments (DoE)–TOPSIS. Seven alternatives with five relevant attributes were adopted for this study. Based on the above decision-making framework, alkaline pretreatment (Ca(OH)2 (8%)) option was ranked first for both the techniques. The second and third options were NaOH and NH3.H2O (10%) pretreatment, respectively. The integrated DoE–TOPSIS method has reduced the uncertainty in results by considering different weight sets and replications. The model results and experimental results were in good agreement and portray the best pretreatment method to be employed in the anaerobic digestion, thus, minimizing the series of digestion test during the downstream process of pretreatment aided anaerobic digestion. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
Dynamic performance evaluation of automated QFT robust controller for grid-tied fuel cell under uncertainty conditions
(Elsevier Ltd, 2020) Gudimindla, H.; K, M.S.
Power flow control and peak point tracking are significant in grid-tied renewable energy systems to improve power factor and efficient energy extraction. In this paper, the design of robust controllers for the power electronic converters of the grid-connected PEM fuel cell with thermal modeling is deliberated. Further, the transfer function model of the power electronic converters is derived by considering uncertainty in system parameters. A low complexity algorithm is used to design the converter parameters from the uncertainty range. The proposed robust automated power flow controller is designed to minimize the objective function using a genetic algorithm in the quantitative feedback theory framework. The robustness and disturbance rejection with enhanced transient response of the proposed controller is evaluated under heavy and light loading conditions, DC-link voltage and grid voltage distortion uncertainty conditions are investigated. Finally, comprehensive simulations are performed to validate the proposed controller performance with the existing controller under the above-mentioned uncertainty conditions. © 2020 Elsevier Ltd
Physical model studies on damage and stability analysis of breakwaters armoured with geotextile sand containers
(Elsevier Ltd, 2021) Elias, T.; Shirlal, K.G.; E.v, K.
Harnessing the advantages of geotextile sand containers (GSCs), numerous submerged breakwaters and shoreline protection structures have been constructed worldwide. But an emerged breakwater structure with geotextile armour units, capable of replacing the conventional structures, is rarely discussed. A 1:30 scaled physical experimentation is chosen as a preliminary investigation to test the feasibility of using GSCs as breakwater armour units. Structural design is evolved based on a comprehensive literature survey. The paper focuses on the stability parameters and damage characteristics of the proposed structure. Four different configurations are subjected to waves, confining to Mangaluru's wave parameters. Effect of armour unit size and sand fill ratio on the stability of the structure is analysed and it is concluded that changing sand fill ratio from 80% to 100% shot up the structural stability to a maximum of 14%. Increasing bag size also resulted in the increased stability up to 8%. Experiments revealed that the best performing configuration could withstand wave heights up to 2.7 m. Stability curves for all tested configurations are discussed and can serve as an effective guideline for designing GSC breakwaters. © 2020 Elsevier Ltd
Experimental Investigation of the Hydraulic Performance of Breakwater Structures with Geotextile Armor Units
(American Society of Civil Engineers (ASCE), 2022) Elias, T.; Shirlal, K.G.
Geotextile sand containers (GSCs) gained popularity recently as a modern age coastal protection measure. Its usability as an ecofriendly alternative for traditional breakwaters overcomes issues such as scarcity and quarrying prohibition of natural rocks. The current work involves a 1:30 scaled physical experimentation on the hydraulic performance of an emerged, nonovertopping breakwater model with GSCs. Four configurations of GSC structures are analyzed for their runup, rundown, and reflection characteristics confining to wave parameters of Mangaluru. The study revealed that the reflection coefficient (Kr) for GSC structures could range from 0.26 to 0.69. In addition, reducing GSC fill percentage from 100 to 80 is found to be more effective (up to 64%) in reducing reflection, runup, and rundown rates, than altering GSC size. These results can serve as a practical guideline for designing GSC breakwaters. © 2022 American Society of Civil Engineers.

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