Journal Articles

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A coordinated control strategy for a diesel-electric tugboat system for improved fuel economy /
(IEEE, 2020-07-21) Upadhyayula, Ramesh Srinivas
Recent growth in seaborne trade has increased the tugboat operation cycle to maneuver incoming marine vessels at port. To meet the tugboat load demand for maneuvering, multiple power sources are being employed on-board. This necessitates a coordinated control strategy for the effective operation of these multiple power sources. To design an effective coordinated control strategy, this article initially estimates multiple power sources capacities (doubly fed induction machine (DFIM) and battery storage system) for a diesel-electric tugboat system based on a real-time tugboat operation cycle obtained from Visakhapatnam port, India. With respect to these multiple power sources, a coordinated control strategy for a better fuel efficiency is proposed based on a state machine control algorithm. The proposed control strategy operates a variable speed diesel-electric generator (diesel engine coupled DFIM) at a minimum specific fuel consumption value and battery based on its state of charge. To show the efficacy of the proposed variable speed diesel-electric system, fuel consumption is computed, which resulted in 26.42% of saving in comparison with a traditionally used diesel-mechanical tugboat. To evaluate the real-time system (2 MW DFIM + 150 kWh battery), MATLAB/Simulink tool is used and an experimental demonstration is performed on a laboratory prototype.
A description of tidal propagation in Hooghly estuary using numerical and analytical solutions
(Ocean Engineering, 2018) Jena, B. K.; Sivakholundu, K. M.; Rajkumar, J.
A tidal propagation characteristic of Hooghly estuary is presented using numerical (ADCIRC) and analytical models (Friedrichs and Aubrey, 1994) along with observations. The analytical model is based on Friedrichs and Aubrey (1994) that simplifies the governing hydrodynamic equations greatly by retaining only those terms that are significant without losing the overall understanding of the propagation process. The analytical model is compared with corresponding 2-D depth averaged numerical (ADCIRC) model that retains all non-linear terms. The assumptions for simplification are found to be reasonable in the light of close agreement among analytical, numerical models and observations. A plan-form geometrical characteristic as well as hydrodynamic variable of the Hooghly has been compared with that of Delaware estuary for corroborating similar tidal propagation process. The Hooghly estuary has flood dominant asymmetric tidal propagation and a positive amplitude growth factor (μ). The observed tidal celerity (phase speed) on an average is slightly more than frictionless celerity. Using the conventions of Toffolon et al. (2006), Hooghly can be classified into ‘strongly convergent – strongly dissipative’ estuary. From the results it can be construed that the estuary is yet to stabilise and reach its equilibrium morphology. It can be close to its equilibrium as very little amplification (0.1 m) is noticed in the predominant semi-diurnal constituent M2 over 78 km (barely 7%) in the estuary. The parameters of width variation (γ) and the ratio between friction and inertia (χ) have been used to define the marginal condition for amplification. The relative position of Hooghly in terms of marginal condition is consistent with similar set of estuaries elsewhere that have been grouped using the above parameters.
A new archaeological find in the Gulf of Cambay, Gujarat
(Journal of the Geological Society of India, 2002) Kathiroli, S.; Badrinarayanan, S.; Venkata Rao, D.; Rajaguru, S.; Sivakholundu, K. M.; Sasisekaran, B.
Detailed underwater surveys carried out in the Gulf of Cambay, about 20 km west of Hazira, deploying side scan sonar and sub bottom profiler brought to light, the presence of a submerged palaeochannel traceable to a length of 9 km. Associated with this on either side are basement like features found in a grid pattern at water depths of 20-40 m. Sub-surface sampling carried out with dredge and grab sampler revealed stone artefacts, potsherds, hearth pieces, animal bones and human teeth embedded in fluvial sands and silts. In the upper part of the deposit, a carbonised wooden log was found and dated to around 9500 years BP by 14C method. Marine magnetic survey carried-out does not indicate the presence of any major metallic debrislobjects. This appears to be one of the early records of prehistoric human activity of early Holocene age in the marine environment of India.
A program to compute the area of an irregular polygon on a spheroidal surface
(Computers and Geosciences, 1998) Sivakholundu, K. M.; Prabaharan, N.
A secure way to message based on internet protocol on RSA algorithm using DNA encoding with laplace transform computing /
(Springer Nature, 2024-01-01) Sirisha, P.
Security plays a vital role in transmitting confidential information. Cryptographic algorithms are essential in providing data security against malicious attacks. The DNA- based cryptographic algorithm is one of the valuable methods for protection. RSA algorithm is widely used in the popular implementations of Public Key Infrastructures. This model presents a new approach to show how cryptography works in DNA computing. It could also transmit messages securely and effectively using the RSA algorithm with Laplace Transform belonging to public key cryptography. DNA computing technique and Laplace Transform with RSA algorithm to encrypt the message are used in this model. The proposed model shows the frequency, time, and statistical analysis to get good results.
A study for validating, rectifying and optimizing the flow in the test section of a circulating water channel /
(Journal of Naval Architecture and Marine Engineering, 2021-12-31) Godey, Avinash
The Circulation Water Channel (CWC) is an experimental facility available at Indian Maritime University, Visakhapatnam Campus. A study for comparing the flow pattern and velocity in the test section, for different configurations of the CWC, is complex. To study the flow, a physical model of the CWC, with different configurations, should be made, which in overall is a complicated and time-consuming exercise. But this difficulty can be overcome through using Computational Fluid Dynamics (CFD) analysis, as in this study, where a CFD analysis is done using ‘STAR-CCM+’ software. A CFD model of the existing CWC [corresponding to the 1:4 scale setup at IMUV], is first made, and its validity is checked, by comparing the results of the CFD analysis, against those results obtained from the experimental analysis. On successfully validating the results, modifications are suggested for rectifying the disturbance which is present in the test section. The test section is the area in the CWC where experimental activities are carried out. In order to carry out the experiments with a certain degree of accuracy, it is important to have a smooth streamlined flow in the test section. To ensure this, a honeycomb structure is positioned such that the flow enters the test section through the honeycomb, which streamlines the flow. On successfully rectifying the disturbance, studies are carried out to improve the streamlined flow in the test section, for which, different configurations of honeycomb structure are studied. The optimum honeycomb structure, which produces a smooth flow in the test section of a CWC is found out, by conducting analyses for different shapes - i.e. for shapes ranging from rectangular to hexagonal and circular, against different inlet velocities.
A study on the seasonal variability of nearshore waves off Visakhapatnam, east coast of India
(International Journal of Innovative Research and Development, 2012)
Wave rider buoy data during the period June 2009 to May 2010 was analyzed to examine the seasonal trends in the nearshore waves off Visakhapatnam, east coast of India. During fair weather conditions, wave heights were observed to be higher in the southwest monsoon season with maximum significant wave height (Hs) of about 2.76 m in the month of July and average Hs of about 1.6 m. The higher values of spectral band width emphasize that the wave heights covered a wide range for major period of the year. A large standard deviation of swell period represents the occurrence of distant swell in a wide range to the study region. The seasonal cycle of wave heights off Visakhapatnam, East Coast of India is dominated by SW monsoon winds. The waves at study area are resultant of sea and large swells from south of Bay of Bengal
Accident analysis of river boats capsize in inland waters and safety aspects related to passenger transporation
(International Journal of Innovation Research & Development, 2015-07) Kalyani, T.; Vidyasagar, D. S. P.; Srinival, V. S. J.
"Inland waterway transportation (IWT) is one of the oldest economically and environmentally sustainable modes of transportation for passengers and cargo. India has an estimated navigable length of 14,500 km of inland waterways, including river systems, canals, backwaters, creeks and tidal inlets, that can effectively support mechanized crafts. Besides this, country boats of various capacities also operate in various rivers and canals. In IWT sector, the environmental conditions, nature of operations, human error (crew and passengers) and lack of safety standards, etc., pose a number of risks to safety of passengers and vessels. Though this sector is economically viable, the rate of accidents are high and need to be focused to minimize the accidents. Formal Safety Assessment (FSA) is the scientific method that is being currently used for the analysis of maritime safety and for the formulation of related regulatory policies. This paper discusses the methodologies involved in FSA, highlights the qualitative analysis in hazard identification and risk analysis process i.e., hazards that are identified during various operations in IWT sector and by using the expert judgment, these hazards are prioritized by the risk ranking matrix. Accident analysis of recent boat accidents that occurred at various locations of inland waters is presented by means of fault tree diagrams focusing the faults of the top event (capsize) as part of qualitative risk analysis. Further, it discusses the safety aspects related to the passenger transportation, highlighting the human errors and perational risks in IWT sector of India. This paper concludes by suggesting the measures to reduce the risk to the passengers and vessels related to various operational and environmental conditions"
Advanced in autonomous underwater vehicles : design and performance perspective /
(OnePetro, 2014-01-01) Raj, Saurabh; Chandra, Saurav
An Autonomous Underwater Vehicle (AUV) is a self-powered underwater information gathering system controlled by on board computer. An AUV has been designed basically to complete three tasks namely oceanographic sampling, exploration, and observation. Oceanographic instrumentation can be used for sampling and data collection in particular location under a specified depth. In current scenario when global warming has become a challenging task for our environment which will result in rising water level also, we can utilize autonomous underwater vehicle as most suitable tool for conduction of surveys concerning these global environmental problems. Future ocean sampling and surveillance systems should be capable of global deployment, sustained presence, three dimensional adaptive aperture, real time control and robust performance. These requirements can be met affordably by a network of Autonomous Underwater Vehicles (AUVs).Thus for the precision exploration we need more advanced and affordable vehicle. One of the most important components of an AUV is a sensor used for measuring different parameters in air and marine environment. Currently researchers need small, cheaper, efficient underwater sensors which can perform also in rough sea condition. Priced appropriately, and readily available with defined physical and software interfaces, these components open the door to the development of a low-R&D, simplified vehicle. Hydrodynamic properties and propulsion efficiency should be enhanced in order to improve the performance of the vehicle. Application of solar energy and variable buoyancy concept is to be utilized to improve the endurance of the vehicle. The autonomy of an AUV is to be modified in order to optimize efficiency. Biomimetics (bio inspired AUVs) are better performing, more efficient and have large potential scope of developing more advance AUVs.
Aerodynamic analysis of deployable wing arrangement for space shuttle /
(Springer Nature, 2022-11-28) Janardhanan, Sheeja
The study space for morphing wings is astonishingly wide and provides ample scope for enhancements up against fixed wings. Morphing-wing research has accumulated considerable recognition in the aerospace community over the last decade, and a folding wing is a promising approach that can improve aircraft proficiency over multiple varieties of missions which conclusively enhance the capability of the space shuttle. In this paper, the conventional shape of the wings is being refashioned to serve the requirements for maintaining the flight and also for navigation. The idea was sparked by the traditional Japanese fan and has a hinged mechanism similar to that of the fan. This work introduces a novel concept for retractable dynamic wings on a space shuttle. Modeling of the spacecraft with modified wings is done in SOLIDWORKS. The aerodynamic analysis is performed using the computational fluid dynamics (CFD) method with ANSYS FLUENT® (2020 R1) as the solver. The aerodynamic force coefficients are estimated for five different specific deployment phases, viz., zeroth (0°), one quarter (7.5°), half (15°), three-quarter (22.5°), and full (30°) phases. The result reveals that the coefficient of drag drops and the coefficient of lift rises from the primary phase to the final phase providing promising inputs into the idea of retractable wings.
An Improved cipher based automatic theorem proving technique for encryption and decryption
(Advances in Mathematics: Scientific Journal, 2020) Talari, Surendra.; Amiripalli, S. S.; Sirisha, P.; Sateesh kumar, D; Krishna Deepika, V.
Globalization has positively influenced almost every sector in India. In the present digital world, security and management of information in the cyber space is quite crucial. The multifarious dimension of cryptography plays an important role in exchange of information securely. In this paper we propose one new crypto system technique using Automatic Theorem Proving concept by assigning various ciphers to the antecedent and consequent rules. Here we form the sequent using plaint text, connective symbols then encrypt this plain text into various levels using antecedent rules and consequent rules and the corresponding assigned ciphers. Since it involves various levels of encryptions and decryptions, it is difficult to the attacker to decrypt the plain text, so that security is more. Though the encryption and decryption run time of the proposed technique is feasible, the security levels are infeasible.
An overview of the opportunities and challenges in entrepreneurship /
(IJOMSR, 2024-04-24) Verma, Sonali; Shukla, Vikesh Kumar; Sharma, Navneet
Firstly, it is important to mention the classification of a generation before understanding what a millennium is? There are five generations divided, namely (a) Baby Boomers, (b) Gen X, (c) Millennials, (d) Gen, and (e) Alpha. In the past few decades, millennials have received a lot of attention due to their transformation into adults. As the largest generation currently active in the workforce, they have sufficient numbers and power to stand up for what they deserve, and employers who hope to attract and retain millennial talent should pay attention. Millennials are often told to focus on effort rather than achievement, and often receive rewards for participation rather than performance. Millennials face certain challenges in the job market, such as technology (artificial intelligence) for job screening, higher entry qualifications, lack of experience, dishonest recruitment, safety, climate change, economy, etc. The "millennials" are the first generation of "digital indigenous people", who have never known a world without digital technology. Their use of smartphones and applications supports them in completing tasks
Analysing volatility spillovers between grain and freight markets /
(Portal hrvatskih znanstvenih i stručnih časopisa, 2020-12-21) Rao, Bhavana Venkata Ramalingeswar
The International Grain Council (IGC) circulates two price indices which are the Grain and Oilseeds Index (GOI) and the Grain and Oilseeds Freight Market Index (GOFI). These two indices indicate the respective market prices. The GOI markets are affected by various factors like supply and demand, weather, freight markets, etc. This research article attempts to explore and analyse volatility in GOI and GOFI markets using various GARCH family models, that is Exponential Generalized Autoregressive Conditional Heteroskedasticity (EGARCH) analysis. The multivariate Dynamic Conditional Correlation Generalized Autoregressive Conditional Heteroskedasticity model (DCC GARCH) is used to find the spillovers between the two markets and thereby explore the effect of GOFI on GOI markets from the year 2013. The research article consists of four sections after introducing the subject namely a literature review, research methodology and models, analysis and conclusions of the study.
Antifouling paint schemes for green ships
(Ocean Engineering, 2019) Mukherjee, A.; Madhu, Joshi; Misra, S. C.; Ramesh, U. S.
Recent advances in antifouling (AF) paints in general prevent fouling in about 95% of the vessel's immersed surface. However the remaining area which amounts to 5% or less of the total area does get fouled. Although this level of fouling has marginal impact on the routine performance of the vessel it is a predominant vector for the transmigration of invasive species which is now a serious environmental concern. Virtually all ocean going vessels are coated with antifouling paints predominant among them are “Self polishing coatings”. CFD analysis conducted on various types of vessels have indicated that there are certain “hotspots” where the polishing rates are exceedingly high and would polish the AF paints at a much faster rate and ultimately result in the failure of the AF coating. A possible solution to this issue is to first identify these hotspots and suitable paint schemes/formulations are to be applied in such areas. An experimental procedure utilizing a “drum-test” apparatus can be used to compute the coating thicknesses based on wall shear stresses. Such painting schemes would prevent the premature failure of the AF coating in general and significantly reduce the risk of transmigration of invasive species in particular.
Application of flux cored arc welding (fcaw) without pre-heating for heavy structures in ship building fabrication & construction of heavy offshore structural steels /
(Journal of Construction Engineering, Technology & Management, 2020-06-04) Rao, K.S. Jagan; Nagesh, Bh.; Kumar, I.N. Niranjan
In fusion welding processes, the reason often given to explain the need for preheating, controlling the inter pass temperature (in multi-pass welds), and post-weld heat treatment (PWHT) is to reduce the risk of residual stresses and it can be removed by heating weldment in the heat affected zone (HAZ). Cold cracking is a hydrogen embrittlement phenomenon, often referred to as hydrogen induced cracking or HAZ cracking. During the construction and fabrication of heavy offshore structures, several failures have been noticed during the welding of structures with higher plate thicknesses where preheating is not properly done. However, many welding engineers cannot readily arrange the preheating in offshore structures, oil and gas installations and in other locations where heavy ship building activities are being done. In this context, experimental studies have been performed on transient heat transfer in welding distortion control by using flux-cored arc welding process (Dual Shielded-DS) without application of pre-heating as specified by the various welding international codes. The authors have studied various samples and tested them in which the FCAW welding has been done with and without preheat. The eight-step welding method enunciated by welding standards with preheating has been slightly modified into again eight step method without preheating and still obtained the same strength, toughness, hardness and stiffness. The use of tubular electrodes with very small diameters has extended the use of this process to work pieces of smaller section size. A main advantage of using flux-cored arc welding (DS) is the ease with which specific weld-metal things can be developed. By adding alloying elements to the flux core, resulting in increased tensile strength and hardness. The process is easy to automate and is readily adaptable to flexible manufacturing systems and robotics.
Assessment of coringa mangrove shoreline migration using geospatial techniques
(Journal of Operational Oceanography, 2020-11-06) Sharma, Garima.; Patnaik, K. V. K. R. K.
Coringa Mangroves in the Kakinada Bay have evolved as the second-largest mangroves in the East Coast of India over the last century. The Coringa Mangrove shoreline has accreted considerably in the past decades as observed from the satellite imageries, adding value to the natural biodiversity of flora and fauna. This study is focused on quantifying the long term changes of Coringa mangrove shoreline using the Landsat imageries for years 1977, 1988, 2000, and 2013 using the Digital Shoreline Analysis System. For a mangrove shoreline length of 20.5 km, 41 transects were cast at an interval of 500 m for calculating the change and their migration distance using three statistical methods, namely End Point Rate (EPR), Net Shoreline Movement (NSM) and Linear Regression Rate (LRR). Results showed that there was considerable growth of mangroves in the bay leading to the seaward migration of the mangrove shoreline from the year 1977– 2013. The study observed the difference in the mangrove shoreline migration dynamics in the South-eastern (near the bottom of the spit) and the western part of the Kakinada Bay. The calculated average degradation rate due to erosion is −5.19 m.yr−1 and the average accretion rate leading to their growth is 14.83 m.yr−1 for all transects of the 20.5 km mangrove shoreline stretch during this period. The results hold importance as they help in identifying the regions prone to mangrove degradation and enable management planning for the protection of the eroding stretch of the mangrove shoreline.
Assessment of Coringa Mangrove shoreline migration using geospatial techniques
(Taylor and Francis, 2022-05-04) Sharma, G.; Patnaik, K. V. K. R. K.
Coringa Mangroves in the Kakinada Bay have evolved as the second-largest mangroves in the East Coast of India over the last century. The Coringa Mangrove shoreline has accreted considerably in the past decades as observed from the satellite imageries, adding value to the natural biodiversity of flora and fauna. This study is focused on quantifying the long term changes of Coringa mangrove shoreline using the Landsat imageries for years 1977, 1988, 2000, and 2013 using the Digital Shoreline Analysis System. For a mangrove shoreline length of 20.5 km, 41 transects were cast at an interval of 500 m for calculating the change and their migration distance using three statistical methods, namely End Point Rate (EPR), Net Shoreline Movement (NSM) and Linear Regression Rate (LRR). Results showed that there was considerable growth of mangroves in the bay leading to the seaward migration of the mangrove shoreline from the year 1977–2013. The study observed the difference in the mangrove shoreline migration dynamics in the South-eastern (near the bottom of the spit) and the western part of the Kakinada Bay. The calculated average degradation rate due to erosion is −5.19 m.yr−1 and the average accretion rate leading to their growth is 14.83 m.yr−1 for all transects of the 20.5 km mangrove shoreline stretch during this period. The results hold importance as they help in identifying the regions prone to mangrove degradation and enable management planning for the protection of the eroding stretch of the mangrove shoreline.
Assessment of coringa mangrove shoreline migration using geospatial techniques /
(Taylor & Francis, 2020-11-06) Sharma, Garima; Patnaik, K.V.K.R.K.
Coringa Mangroves in the Kakinada Bay have evolved as the second-largest mangroves in the East Coast of India over the last century. The Coringa Mangrove shoreline has accreted considerably in the past decades as observed from the satellite imageries, adding value to the natural biodiversity of flora and fauna. This study is focused on quantifying the long term changes of Coringa mangrove shoreline using the Landsat imageries for years 1977, 1988, 2000, and 2013 using the Digital Shoreline Analysis System. For a mangrove shoreline length of 20.5 km, 41 transects were cast at an interval of 500 m for calculating the change and their migration distance using three statistical methods, namely End Point Rate (EPR), Net Shoreline Movement (NSM) and Linear Regression Rate (LRR). Results showed that there was considerable growth of mangroves in the bay leading to the seaward migration of the mangrove shoreline from the year 1977–2013. The study observed the difference in the mangrove shoreline migration dynamics in the South-eastern (near the bottom of the spit) and the western part of the Kakinada Bay. The calculated average degradation rate due to erosion is −5.19 m.yr−1 and the average accretion rate leading to their growth is 14.83 m.yr−1 for all transects of the 20.5 km mangrove shoreline stretch during this period. The results hold importance as they help in identifying the regions prone to mangrove degradation and enable management planning for the protection of the eroding stretch of the mangrove shoreline.
Biophysical responses to tropical cyclone Hudhud over the Bay of Bengal
(Taylor & Francis, 2021-07-03) Maneesha, K.; Prasad, D. H.; Patnaik, K. V. K. R. K.
Cyclone Hudhud originated in the Andaman Sea on 6 October 2014. Later, it intensified into a cyclonic storm on 8 October and eventually made landfall at Visakhapatnam on 12 October as a very severe cyclonic storm. It was intensified off of Visakhapatnam by high stratified waters with a thick barrier layer that held significant heat content. In this study, we analysed the data along the cyclone track using a combination of satellite, in-situ Argo and Bio-Argo data to assess the upper oceanic changes along the Hudhud track. Notable changes were detected in the upper ocean due to its extreme intensification and prior passage through cold-core eddies. A high translation speed and persistent stratification dominated the effects caused by the cold-core eddies on the intensification of the cyclone and the same was attributed to the upwelled subsurface chlorophyll maxima. The biophysical changes in the top 150 m layer derived from Argo floats were in good agreement with the satellite and model data. Further, it was observed that the increase in lightning flash rates also influenced surface productivity during the cyclone. Subsequent to the passage of the cyclone, the ocean took two weeks to achieve its original state.
Carbon emissions for Indian Railways
(IRFCA, 2013) Arun Kishore, Eswara
Indian railways is a critical infrastructure in the transportation of goods across India. It plays a vital role in the geographically balanced economic growth. By transporting a large volume of goods in comparison to air or road modality, it offers a better solution in cutting emissions. In this present paper a study is conducted based on data published by various governmental bodies; to quantify emissions from the transportation of goods by Indian railways. A comparison is attempted between the electric and diesel electric options for railways at the end, which will set out recomendations for a national policy for a healthier environment. The market share of Indian Railways is consistently falling over the years, it is losing to road transport. In the context it is worth mentioning that from the various studies published internationally, there is a close competition between railways and water transport in respect of environmental performance. Road transport is third choice in relation to Water transport & Railways wrt environmental performance. Major part of Railways goods is based on six major industries viz Electricity, Coal, Steel, Crude Petroleum, Petroleum Refinery products & Cement. A study by KPMG 1 found that the market share of transportation in India is 62% by Road, 29% by Railways,5% by Coastal, 4% by pipelines & < 1% by Airways. These statistics show that emissions from transportation can be reduced drastically by transportation modal shift to coastal waterways and railways combination.