Faculty Publications
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Publications by NITK Faculty
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Item Performance of QPSK modulation for FSO geo-synchronous satellite communication link under atmospheric turbulence(2013) Jokhakar Jignesh, D.; Sripati, U.; Kulkarni, M.In recent years, free space optical (FSO) communication has gained a considerable interest amongst the researchers due to certain benefits it has to offer over RF links such as availability of large unlicensed bandwidth, high data rates, negligible electromagnetic interference, ease of installation etc. However the conventionally used FSO systems use On-Off Keying (OOK) as the modulation technique. Such a link requires high levels of transmit power. In this paper, we have suggested the use of QPSK modulation technique which allows us to reap the benefits of coherent detection. Our calculations show that QPSK is more inert to the changes in atmospheric conditions like temperature, air pressure, humidity, aerosol concentration etc. © 2013 IEEE.Item Growth and temperature dependent electrical properties of ZnO nanostructures(2013) Santhosh Kumar, A.; Nagaraja, K.K.; Nagaraja, H.S.Zinc oxide (ZnO) nanostructured films are grown using Polyvinyal alcohol (PVA)-citric acid modified sol gel process and the effect of (0, 1, and 2Wt%) PVA content on growth, crystallanity, microstructure and electrical properties are investigated. The XRD patterns confirm that the films are polycrystalline nature. 1 Wt% assisted grown samples are found to be good crystallanity with (002) preferred orientation. The SEM micrographs confirm that the 1 Wt% PVA assisted grown films are composed of vertically oriented ∼1.2 μm length nanorods. The temperature dependent electrical resistivity of the films has been measured using the four-probe method. The electrical resistivity found to be 7.08 ω-cm at room temperature for vertically oriented nanorods composed films, which are grown using 1Wt% PVA. © 2013 AIP Publishing LLC.Item EIS study and role of chloride ions concentration and temperature on passivity of AZ91D Mg alloy(Trans Tech Publications Ltd ttp@transtec.ch, 2015) Arya, S.B.; Kanaujia, A.Mg alloy shows higher specific strength and ductility relative to aluminum and also lower machining and casting costs over to steels. However, it also shows limitation to use in many industrial applications due to the relatively poor corrosion resistance in many aqueous solutions. Corrosion and passivation study of magnesium alloy (AZ91D) in various Cl¯ ions concentrations and temperatures were carried out using electrochemical impedance spectroscopy (EIS) in NaCl solutions of 0.4, 0.6, 0.8 & 1.0 molar (M) concentrations. The passivation behavior was also observed at temperature of 45°C, 55°C and 65 °C in 3.5 wt% NaCl solutions. The total polarization resistance was observed about 5530, 4030, 2465 and 2000 Ohms.cm2 in solutions of 0.4, 0.6, 0.8 & 1.0 M NaCl respectively indicate reduction of film stability at higher chlorides concentration. A similar trend was found on increasing temperatures of 3.5 wt% NaCl solutions at 45°C, 55°C and 65 °C and noticed about 970, 600 and 300 Ohms.cm2 respectively showed significant decline of passivity and more pitting tendency. © (2015) Trans Tech Publications, Switzerland.Item Effect of thermal response on physical properties during drilling operations-A case study(Elsevier Ltd, 2018) Vijay Kumar, S.; Murthy, Ch.S.N.; Kunar, B.M.The temperature induced or generated during deep hole drilling operations is due to the heat generated between the interface of work piece surface and the tool surface. Several research study have been conducted to predict the temperature involved while drilling process as a predominant functions of many parameters like feed rate, torque, depth of cut etc. Similarly many experimental procedures have been conducted by several researchers to measure temperature directly by using thermocouples, infrared measurement, pyrometer, and thermisters etc. There is no precise experimental method is available to measure analytical value of energy, power, heat flux etc, while drilling process. The temperature rigma depends on material compositions and physical properties. This paper presents the influence of temperature on physical properties of some study samples during drilling operations. © 2017 Elsevier Ltd.Item Identification of effective location of thermocouples from the contact interface(Elsevier Ltd, 2019) Palanikumar, P.; Gnanasekaran, N.; Subrahmanya, K.; Kaliveeran, V.This paper describes an experimental and analytical investigation of the temperature rise at the contact interface which occurs during dry sliding of SS304 alloy. Experiments were conducted on rotatory type pin on disk tribometer. Cylindrical pin of 3 mm radius of contact and 165 mm diameter circular disk having flat surface were utilized to simulate Hertzian contact configuration. Rise in contact interface temperature due to sliding was measured using K-type thermocouples which are attached to the pin at 4 mm and 7 mm distance from the contact surface. The temperature at the contact surface during dry sliding experiment was calculated from the measured temperature data obtained from thermocouple pasted at 4 mm and 7 mm locations using inverse heat transfer method. Heat measured at different locations along the longitudinal axis of the pin increased with sliding distance. The temperature data obtained from finite element analysis is verified by comparing it with experimental results to identify effective location of thermocouples to measure the contact interface temperature. © 2019 Elsevier Ltd.Item Temperature Measurement During Rotary Drilling of Rocks - A Statistical Approach(Springer Nature, 2020) Vijay Kumar, S.; Kunar, B.M.; Murthy, C.S.N.This paper discusses a statistical analysis to measure the temperature during rotary drilling of fine-grained sandstone (pink) using embedded thermocouple method. The regression models consist of three input variables such as diameter of the bit, rpm and rate of penetration for different depth of thermocouples. Experimental test were conducted in computer numerical control (CNC) vertical machining centre. The measured temperature has been applied to study the influencing parameter using statistical technique. Analysis of variance (ANOVA) shows that the percentage contribution ratio of each operational parameters on temperature (output response). The most influencing parameter for temperature is rate of penetration with a percentage contribution of 71.32%, followed by drill bit diameter and spindle speed which contribute 19.27% and 2.99% respectively. The ANOVA and regression models for temperature give p-values of less than 0.05. Hence the predicted regression models are statistically significant and good predictive capabilities with acceptable accuracy. © 2020, Springer Nature Switzerland AG.Item Evaluation of solar PV panel performance under humid atmosphere(Elsevier Ltd, 2020) Tripathi, A.K.; Ray, S.; Mangalpady, A.; Prasad, S.The main aim of this paper is to study the effects of humidity on the PV panel. In this paper, the panel performance was studied in the laboratory under varied humid atmosphere. The PV performance parameters were computed by measuring its output voltage and current, amount of solar radiation incident on the panel's surface and its surface temperature by varying humidity levels artificially in the laboratory. From the studies it was observed that with rising humidity levels, solar insolation and panel power output decrease. With an increment of 50.15% in the humidity level, the panel power output reduces by 34.22%. Moreover, it was found that due to the increase in humidity from 65.40% to 98.20% the panel temperature got lowered by 11.40%. © 2020 Elsevier Ltd. All rights reserved.Item Temperature- and SNR-based On Demand Routing Protocol for Underwater Communication(Institute of Electrical and Electronics Engineers Inc., 2021) Nair, A.; Chandavarkar, B.R.Underwater Communication comes with various obstacles which involves the interaction between acoustic signals and the physical features of the medium which include pH value, salinity and temperature. This paper focuses on surveying and proposing routing algorithms which takes into consideration of the temperature and well as the various factors that affect it within the medium. The paper proposes a new routing algorithm which will decide the next hop to be chosen based on the best Signal to Noise Ratio (SNR) value of its neighbours and it's study based on the effect temperature has on it. A model to calculate temperature has been developed. The SNR value being calculated considers physical parameters of the medium including pH, salinity and temperature. The routing algorithm is mathematically modelled and then simulated in UnetStack 3 for proof of correctness. © 2021 IEEE.Item A Detailed Case Study Report on a Section of Four-Lane National Highway Project of Bengaluru-Mangaluru(Springer Science and Business Media Deutschland GmbH, 2024) Srinivas, M.; Sinha, C.; Akshay, K.; Marella, D.A comprehensive study of the project titled “Four-laning of Bengaluru-Mangaluru from km 270 + 270 (Periya Shanthi) to km 318 + 755 (Bantwal)†was conducted to assess the project’s potential, necessities, and requirements. The evaluation also addressed the challenges encountered due to the project’s location in a mountainous terrain region. The major issue encountered and understood through this study was that the project is delayed more than usual due to many difficulties and challenges encountered by them under various circumstances. Based on the survey and research work done, it was understood that the region of Dakshina Kannada where the project is being done has high temperature during summers due to which ice cubes were used to maintain temperature for concrete batching. The objective of the project is to eliminate the hairpin bends which slowed down the traffic movement by straightening them to reduce congestion as there are many pilgrimage places, business hubs, and tourist places in the project vicinity. Some of the main reasons for the delay of the project was unseasonal rainfall, felling of trees, obstructing the Right of Way (ROW), the inability to move the utility units to the project site due to insufficient ROW, landslides, and many more reasons. Currently, the Extension of time (EOT) has been requested by the Contractor to NHAI, as the project has been delayed. This research paper further explores the detailed causes and gives a complete insight into the project. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Predictive Intelligent System Development for Disease Classification in Diagnostic Applications(Springer Science and Business Media Deutschland GmbH, 2024) Shrivathsa, T.V.; Rao, S.S.; Karanth, P.N.; Adiga, K.; Mahabala, M.; Dakappa, P.H.; Prasad, K.With ever increasing explosion in information domain and demand for highest accuracy in medical diagnosis, the existence of a reliable, accurate prediction system is the need of the hour. In this work, an effective prediction system has been developed for accurate classification of undifferentiated ailments using a unique approach. Prediction of undifferentiated diseases at an early stage always helps in better diagnosis. Illnesses like tuberculosis, non-tubercular bacterial infection, dengue fever, non-infectious diseases have regular manifestation of fever. In present work, the uniqueness lies in the use of only temperature data of the patient being referred in predicting the nature of fever, with highest degree of accuracy, instead of several self-defined parameters over limited interval of time. The system has been developed based on artificial intelligent technique, and optimization has been achieved by assessing the performance of different classifiers available. Using prediction model with classifiers, decision can take over comparative results between different classifier algorithms. A result of predictive system defines the combination of good classifier and system developed. Accuracy score and other salient parameters describe the complete picture of the system. Predictive model development in this work proved to be one of the best assistant tools to a doctor to take call over the disease crucial period. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.