Raja Prabu Ramachandran
@vspgitece.gitam.edu
Professor & Director (Accreditation & Ranking) - Department of Electrical Engineering
GITAM : Gandhi Institute of Technology And Management, Visakhapatnam, India
Currently Serving as Director (Accreditation & Ranking) and Director (IQAC) at GITAM : A Category – I Deemed to be University
Published / Presented 100+ Research Articles in Journals / Conferences
Guided 05 Ph.D Scholars, 01 Scholar submitted Thesis & Guiding 03 other Research Scholars
Co Authored 1 Book published by Elsevier & Edited 10+ Conference Proceedings
Successfully Completed 3 Funded Projects
1 Patent got Published
Collaborative Research with Purdue University, USA has resulted in 10+ Joint Publications
Industrial Consultancy to ETA Group, Alstom, Oblum, Apollo Tyres, Garuda VayuSakthi etc.,
Presented Guest Lectures on “Outdoor Polymeric Insulators” at KOBE University, Japan, University of Missouri, USA and at Chongqing University, China on Invitation
Countries visited include USA, UK, Japan, China, UAE, Singapore, Malaysia, Hongkong, Thailand, Srilanka, Muscat, Sarawak etc.,
Member in Professional Societies like IEEE, IE, CIGRE, ISTE, C.Engg.,
EDUCATION
Degree Discipline University Year of Passing
Ph.D. High Voltage Engineering Anna University (CEG) 2006
M.E. Power System Engineering Annamalai University 1990
B.E. Electrical & Electronics Engineering Annamalai University 1988
Training "Electroporation for Effective Cancer
(Post Doctorate) Treatment (Bio Electrics)" Purdue University, USA 2008
P.G.D.B.A. Business Administration Annamalai University 1989
RESEARCH INTERESTS
Bio Electrics
Outdoor Polymeric Insulators
Micro Grid Protection
Pulsed Electric Field
FUTURE PROJECTS
Electro Chemo Therapy for Effective Cancer Treatment
Electrochemotherapy (ECT) is an evolving technique to treat various types of skin, chest wall breast cancer and basal cell carcinoma with minimal side effects. Electrochemotherapy was the only available alternative treatment for patients suffering from lung cancer who are unfit to undergo surgery. This procedure utilizes hydrophilic chemo drugs such as bleomycin and cisplatin which are aided by electroporation to create apoptosis. ECT has an overall response of 80-90% for un-respectable recurrent disease. Typically eight 1200V/cm, 100μs pulses are applied in the clinics.
Applications Invited
Collaborators & Students
Newer Materials for Outdoor Polymeric Insulators
POLYMERIC insulators are being accepted increasingly for use in outdoor applications. The tremendous growth is due to their advantages over the traditional ceramic and glass insulators. It includes lightweight, higher mechanical strength to weight ratio, resistance to vandalism, better performance in the presence of heavy pollution in wet condition, and better withstand voltage than porcelain insulators. However, because polymeric insulators are relatively new, the expected lifetime and their long-term reliability are not known, and therefore are of concern to users.
Applications Invited
Collaborators & Students
Liquid Food Preservation Using Pulsed Electric Field
Pulsed electric field (PEF) treatment has been prevailing for the past two decades as the successful nonthermal food preservation technique due to it’s low energy consumption, retaining of food’s quality attributes such as taste, color, freshness, texture and especially the nutritional qualities when compared with heat treatment methods. The high voltage pulses can be delivered to liquid foods through electrodes where the cell inactivation takes place by means of electroporation phenomenon. The configuration of electrodes and the electric field distribution inside the PEF treatment chamber is supposed to have a greater impact on bacterial inactivation. There are many electrode configurations available where parallel plate electrodes were used in initial studies, and stainless steel was used as the electrode material for most of the PEF applications.
Applications Invited
Collaborators & Students
Scopus Publications
Scopus Publications
Regin Bose Kannaian, Belwin Brearley Joseph, and Raja Prabu Ramachandran
MDPI AG
To meet the increased customer demands, microgrid evolved. The structure of microgrid changes dynamically due to the intermittent nature of renewable-based generation, status of the distributed generator and opening of breakers for fault/maintenance. Hence, the magnitude of fault current is dynamic in nature. In order to deal with these dynamic changes, this paper addresses an adaptive central microgrid controller-based protection and relay coordination scheme, which revises the relay settings dynamically (both radial and looped configuration) for every change in topology. In the proposed algorithm, the primary relay responds to a fault immediately since the individual relays are given with fault level setting. For any abnormality in the network, the fault location is determined both via local relay and microgrid central controller (MCC). Hence, even though the local relay fails to identify the fault due to high fault impedance, the MCC locates the fault accurately and isolates the minimum faulty part. The coordination between relays is carried out by MCC in a time-graded manner based on microgrid central protection and relay coordination algorithm. The proposed algorithm is tested using Matlab in a microgrid built based on the IEEE 33 bus distribution network.
Namburi Nireekshana, R. Ramachandran, and G. V. Narayana
FOREX Publication
One of the most important strategies for running and controlling an electric power system is the load frequency controller. LFC can be used to solve a variety of issues, such as when a generating unit is rapidly turned off by protection equipment or when a heavy load is quickly connected or disconnected. When disturbances disrupt the natural power balance, the frequency deviates from what it should be. LFC is in charge of balancing the load and restoring the natural frequency to its proper level. In this case, load frequency control optimization techniques are used in the Multiple Connect Area System to provide reliable and quality operation on frequency and tie line power flow. The purpose of this paper is to demonstrate how optimising LFC in a two-area interconnected energy system with hydro, thermal plants, and a particle swarm optimization (PSO) method may improve power system stability and save revenue on power generation. A standard (PID) controller is used to control the system. The PSO optimization approach is utilised to determine the optimal gain values of the controllers kp, ki, and kd.
Belwin J. Brearley, R. Raja Prabu, K. Regin Bose, and V. Sankaranarayanan
Informa UK Limited
The relay co-ordination is the nerve centre of the microgrid system, as the same is responsible for the reliability of operation and enhanced efficacy. This research work focuses on an ‘adaptive ce...
S. Pachamuthu, D. Najumnissa, K. Sankaranarayanan, and R. P. Ramachandran
Engineering, Technology & Applied Science Research
An electroporator is an instrument used for delivering electrical pulses to a tumor. In this work, an electroporator consisting of three main system blocks, namely High Voltage (HV) source, nanosecond (ns) switching, and pulse generation, was designed, developed, and evaluated to generate high voltage ns pulses to treat tumors. The high-voltage source block was used to convert the 9.6V DC from the battery to a variable HV output and store this charge for later use. The ns switching block contained a MOSFET-based low-side switch which applies short ns pulses to the load. The pulse generation block generates short ns pulses and supplies the adequate current to turn on the MOSFET at a quicker rate aiding the application of these pulses to the load. This process was simulated using PSpice software and the results are presented.
Ramya Ramaswamy, , Dr. R. Raja Prabu, Dr. V. Gowrisree, , and
Blue Eyes Intelligence Engineering and Sciences Engineering and Sciences Publication - BEIESP
Electroporation is an effective phenomenon of inactivating viable pathogens present in the liquid food for pulsed electric field (PEF) applications. It is a technique which depends on applied electric field strength for causing pores on cell plasma membrane. The various parameters which affect the electroporation efficacy are, the electric field intensity, pulse width, number of pulses, pulse interval and the electrode. The electrode provides a contact between the high voltage pulse generator and the liquid food, and it plays an important role in getting the required inactivation outcome. The electric field distribution varies based on electrode designs. Parallel plate electrodes are generally used due to the uniform electric field it delivers in the inactivation area, where high possibility of microbial inactivation will occur. This paper analyses the effectiveness of round edged parallel plate electrodes immersed in water which provides uniform electric field distribution in the inactivation area. Analyses have been performed on electric field distribution through four kinds of materials such as glass, alumina, quartz and plexiglass, which contains these electrodes in the center filled with sterile water. The electrodes are circular, and edge smoothened and hence the field distribution is also analyzed on electrode edges. The distance between the electrodes including the surface material is kept at 5 mm. The diameter of the electrodes are 40 mm and the electric field simulations are implemented in ANSYS MAXWELL v 15.0. Based on results it is reported that alumina required less peak voltage for generating 20 kV/cm field strength (nominal field required for bacterial inactivation) when compared with other materials. Also alumina exhibited less reduction of field travelling through it, and resulted in 82% of field application in the inactivation area which is comparatively higher than other materials. The results indicate that alumina is highly recommended for future noninvasive pulsed electric field applications.
Ramya Ramaswamy, Raja Prabu Ramachandran, and V. Gowrisree
Praise Worthy Prize
Pulsed electric field treatment has been successfully applied in various liquid foods in order to inactivate microorganisms through the process of electroporation. The shelf life of liquid foods can be extended using pulsed electric field treatment thereby maintaining the quality attributes of foods with less energy consumption when compared with other heat treatment methods. However, few efforts have been made by using Pulsed electric field technology on electric field application through specific electrode materials focusing on specific type of microorganisms. In this research, Pulsed Electric Field treatment chamber has been modelled using electromagnetic simulation software and has been implemented practically for experimental testing. Titanium electrodes have been used for successful pulsed power applications on culture medium, where Staphylococcus aureus ATCC 25923 was inoculated at 107 colony forming units per ml in sterile water. The impact of Pulsed Electric Field application on microbial colonies has been observed for treatment time variation from one to six minutes. The pulse width has been set to 1 microsecond at a pulse repetition rate of 50 pulses per second. The results have demonstrated that: (i) up to 85% of field reduction could be observed on simulated electrode edges; (ii) under experimentation, the best inactivation efficiency has been obtained at one minute (Continuous) and six minutes (Discrete), with field requirements of 35 kV/cm and 39 kV/cm, resulting in 1.89 and 1.82 of bacterial log reduction respectively.
Ramya RAMASWAMY, Raja PRABU RAMACHANDRAN, and V. GOWRISREE
Japan Society for Food Engineering
Research Scholar, Department of Electrical and Electronics Engineering, BS Abdur Rahman Crescent Institute of Science and Technology, Seethakathi Estate, Vandalur, Chennai 600048, India. Professor, Department of Electrical and Electronics Engineering, BS Abdur Rahman Crescent Institute of Science and Technology, Seethakathi Estate, Vandalur, Chennai 600048, India. Professor, Department of Electrical and Electronics Engineering, College of Engineering, Anna University, Guindy, Chennai 600025, India.
Ramya Ramaswamy and Raja Prabu Ramachandran
IEEE
Electromagnetic simulation is performed on two compact electrode designs to obtain higher electric field distribution between high voltage and ground electrode, which ensures high bacterial inactivation in liquid food. Electric field simulations are performed initially for test voltages of 1kV to 5kV to understand the nature of electric field distribution in the inactivation area. Then the applied voltage is gradually increased to induce transmembrane potential on the cell membrane. The microorganism modeled for field analysis is Staphylococcus aureus. For both the round edged and torus tube designs, the transmembrane potential of 0.5V to 1V is achieved with the spherical cell, modeled between the high voltage and the ground electrode, which shows pore formation possibility. Dimensions of the electrodes are maintained in mm and cm suitable for laboratory scale, continuous pulsed electric field treatments. In both the designs, emphasis is on the simulation to achieve higher electric field application in the inactivation area, which can be realized through satisfying electroporation phenomenon. From the observed results, it is understood that greater electric field application is achievable even using small efficient electrode designs, which in turn assures i) A greater bacterial inactivation in the liquid food and ii) A compact pulsed electric field experimental prototype.
T. D. Sudhakar, K. N. Srinivas, M. Mohana Krishnan, and R. Raja Prabu
Springer Singapore
Belwin J. Brearley and R. Raja Prabu
Elsevier BV
T. D. Sudhakar, M. Mohana Krishnan, K. N. Srinivas, and R. Raja Prabu
IEEE
Nowadays the usage of renewable energy source is being encouraged in developing countries to meet the power shortages. The produced supply must follow the precised guidelines, so that the supply can be connected to the grid system. In this work, a grid connected module is developed using a DC - DC converter and conventional H - bridge inverter. The aim of the proposed methodology is to reduce the size of the filter used across the inverter and it is achieved. This is done by applying SPWM wave to the DC - DC SEPIC converter and the H - bridge inverter is operated at normal power frequency.
T. D. Sudhakar, M. Raja Rajan, K. N. Srinivasan, R. Raja Prabu, T.V. Narmadha, and M. Mohana Krishnan
Indian Society for Education and Environment
Background: Due to increasing power demand across the country, the usage of renewable systems is being increased. One such efficient and compactly available renewable energy is solar power. In this paper, a clear view of harnessing maximum DC solar power output and converting it to AC is discussed. Methods: A method of grid interconnection of solar powered inverter is presented with IEEE-15 bus system as an example model using Matlab simulation. Findings: A detailed analysis of bus voltage, load current and line current is made with the simulated model. Applications/Improvements: The data obtained could be used for fine optimization of the position in which the distribution generator interconnection is to be made.
Raja Prabu Ramachandran, S. Madhivanan, Raji Sundararajan, Cindy Wan-Ying Lin, and Kavitha Sankaranarayanan
Elsevier
Cancer therapies mainly target the uncontrolled proliferation of the cancerous cells. A translational therapy for inoperable, chemo– and radio-resistant tumors is electroporation-based chemotherapy, known as electrochemotherapy, a physical means of using electrical pulses in conjunction with minimal doses of the chemo drug to achieve proliferation control. It is applicable to all histologies of tumors and its efficacy depends on a variety of factors, including the electric field intensity, the pulse duration and the number of pulses. In this chapter, we describe the optimization of pulse parameters for effective electroporation of leukemic and cervical cancer cell lines. Human promyelocytic leukemia (HL60), human acute myeloid leukemia (KG1) and human cervical (ME180) cancer cell lines were subjected to electroporation in the presence of various doses of FDA approved chemo drug, Bleomycin. The effect of curcumin and electroporation is also tested for HL60 cells. The results indicate that by using electroporation, chemo drug molecules could be uploaded into these cells to control proliferation. This promises to be a very useful tool for treating patients suffering from chemo-refractive tumors.
Kavitha Sankaranarayanan, Raja Prabhu Ramachandran, and Raji Sundararajan
Elsevier
Cancer stem cells (CSCs) have the potential to be chemo-resistant and recurrent and/or to become metastatic tumors. It is highly critical to control the proliferation of CSCs using alternative therapies. Towards this end, we studied the proliferation control of cancer-stem-cell like mesenchymal cells using electrical pulses and Bleomycin, a FDA approved (in the US, and the respective medical agencies in the other countries) chemotherapeutic drug. For this purpose, adult human mesenchymal stem cells (hMSCs), derived from bone marrow, were used. Both low intensity, long duration (200 V/cm, 10 ms) and high intensity, short duration (1200 V/cm, 100 μs) pulses were applied and their efficacies studied. The results indicate that electrical pulses-based therapy could be utilized economically and efficiently to control the proliferation of hMSCs and shows promise of an easy transition to use in the clinic.
Raji Sundararajan, Therese Salameh, Ignacio G. Camarillo, R. Raja Prabu, Arutselvan Natarajan, and Kavitha Sankaranarayanan
Elsevier
K. G. Shanmuga Priya, R. Raja Prabu, C. L. G. Pavan Kumar, and R. Sarathi
IEEE
Electrical trees were experimentally generated in XLPE cable insulation under AC and composite voltage formed with AC and DC voltages. Bush type and tree like tree structures were generated. Analysis of time to failure due to electrical trees was made by adopting Weibull distribution studies. The life of cable insulation due to electrical tree failure is enhanced in presence of offset voltage. The rate of tree propagation is high under AC voltage with positive offset. Applied voltage and failure time of insulation shows inverse relationship. It is realized that, the frequency content of the UHF signal generated during tree propagation lies in the range 1-3 GHz. The Phase resolved partial discharge (PRPD) analysis indicates that discharges occur in the rising portion of the applied AC voltage. With composite voltages, the discharges occurs near the zero crossing and is predominant with positive DC voltage superposed with AC voltage.
Anila Thyagarajan, R. Raja Prabu, and G. Uma
IEEE
This paper will focus on the Power Management solution of vehicles via Modeling, analysis and simulation of a 42V/14V dc/dc converter based architecture. This architecture is considered to be technically a viable solution for automotive dual-voltage power system for passenger car in the near future. An interleaved dc/dc converter system is chosen for the automotive converter topology due to its advantages regarding filter reduction, dynamic response, reduced ripples and power management. Presented herein, is a model based on one kilowatt interleaved sixphase buck converter designed to operate in a Discontinuous Conduction Mode (DCM). The control strategy of the converter is based on a voltagemode-controlled Pulse Width Modulation (PWM) with a Proportional-Integral-Derivative (PID). The effectiveness of the interleaved step-down converter is verified through simulation results using Matlab/Simulink.
Amirthalingam
Science Publications
The aim of this study is to use a solid state circuit breaker for the improvement of transient stability margin. Long distance AC transmission is often subject to stability problems, which limits the transmission capability. Interconnected power systems suffer from weakly damped swings between synchronous generator and sub systems. The development of modern power system has lead to an increasing complexity in the study of power system and also presents new challenges to power system stability and in particular to the aspects of transient stability and small signal stability. Transient stability control plays a significant role in ensuring the stable operation of power systems in the event of large disturbances and faults and is thus a significant area of research. This study investigates the improvement of transient stability of a two area system, using Solid State Circuit Breaker which is capable of fast switching in case of faults and thus controlling the real and reactive power flows in a faulted transmission line. Simulations are carried out in Matlab/Simulink environment for two area system model with Solid State Circuit Breaker to analyze the effects of SSCB on transient stability performance of the system. From the simulation results, swing curves of the three phase faulted power system without SSCB gets increases monotonically and thus the system can be considered as unstable whereas the swing curves of the system with an SSCB reaches to a steady state.
A. Kalai Murugan and R. Raja Prabu
IEEE
This work deals with protection of thirty bus system using Solid State Circuit Breaker. The Solid State Circuit Breakers (SSCBs) based on high power semiconductors, offer considerable advantages when compared to mechanical circuit breakers with respect to speed and life. The distortions caused by the three phase short circuit can be reduced to 100 μs, in contrast to 100 ms achieved by the present technology. The Solid State Circuit Breaker uses high power anti parallel switches to carry bidirectional current. During normal operation the solid state circuit breaker is "on". During faults, the gate of the SSCB is pulse modulated to prevent the circuit current from exceeding a predetermined limit. The load voltage is sensed and it is used to turn on and turn off the SSCB. The thirty bus system with SSCB is modeled and simulated using Matlab/Simulink. The circuit model and results of simulation for thirty bus system employing SSCB are presented in this paper. Simulations demonstrate that the protection circuit provides a fast and maintenance free protection solution for multi bus system.
Sadasivam Pachamuthu, Vishveswaran Jothi, Mohamed I Neamathulla, P. S. S. Samu Safwan, Arun Kuppan, Rajaprabu Ramachandran, Raji Sundararajan, and Kavitha Sankaranarayanan
IEEE
Electrochemotherapy is an effective palliative way of treating inoperable chemo-resistant cancers. It is a therapeutic technique for treating tumors with nonpermeant drugs using electroporation of cells. The cells are electroporated to form temporary hydrophilic pores. The various parameters which affect the electroporation efficacy are, the voltage (electric field intensity), pulse length, number of pulses, pulse interval and the electrode. The electrode provides a contact between the high voltage pulse generator and the patient, and as such it plays a vital role in the treatment outcome. In general, needle array electrodes are used in many cases, including treating of deep seated tumors. The electric field distribution varies according to the electrode design. This paper explores the effectiveness of a pentagonal array electrode with a centre electrode for obtaining uniform electric field distribution in the treated area. This model is symmetrical in which surrounding electrodes are displaced by 4 mm from the centre electrode. The diameter of the needle is 1 mm. The electric field simulations were implemented in 2D in ANSYS 13.0. The electric field considered for the analysis is 1200 V/cm, same as what is currently used in the clinics. The results indicate that the electric field distribution is uniform at a value of 1200 V/cm.
Raji Sundararajan, Ramya Rajendran, Sajan S. Shahid, D. K. Santosh, Snehalatha Radhakrishnan, K. Priyadarshan, S. Varsha, U. Vimal Kumar, Rajaprabu Ramachandran, and Kavitha Sankaranarayanan
IEEE
Cancer remains responsible for several million deaths each year, occurring worldwide. The conventional treatment strategies for cancer cause a plethora of side effects along with an exorbitant treatment cost per sitting. The focus now is on the development of new modalities of treatments which could minimize the side effects and prove to be an affordable treatment option to the patients. Usage of electrical pulses along with drugs - Electrochemotherapy (ECT) is a fast rising option for the treatment of chemo-refractive cancers. This has proven to be more efficient and effective than other existing methods of treatment and there is a growing evidence of research and clinical trials on the same. The major advantage that this mode of treatment offers is the massive reduction in the dosage of drug that is administered, thus significantly reducing the intensity of undesired side effects. The applied electrical pulses can be of two types - that for reversible and irreversible electroporation of cells. While reversible electroporation is primarily used as a means for delivery of molecules into the cell, irreversible electroporation is a mode which could be applied as such in the absence of a chemodrug to kill the cancerous cells. This would be of immense significance in the clinical scenario since it could be targeted treatment while totally eliminating the necessity of any chemodrug. In this paper we give a detailed report on the effect of such high voltage pulses on cancer cells. The variables tested out in the pulse parameters used include intensity of electric field applied, pulse duration, number of pulses and time interval between each train. The electric field applied is varied between 500V/cm to 2500V/cm with a pulse duration ranging from microseconds to milliseconds to keep the energy delivery constant. The effect of the parameters individually and effect of combination of all these parameters on the cells is studied and discussed in this paper. This study could be of clinical relevance in the translation of these findings to application at the patient-level.
R. Sundararajan, R. P. Ramachandran, and K. Sankaranarayanan
IEEE
Our study indicates that indeed it is possible to control the proliferation of adult hMScs. These results could be used to arrest cancer stem cells from proliferation and thus pave the way for a physical cancer therapy that can be out-patient-based using reduced doses of highly toxic chemo drugs, thus enhancing quality of life by reducing cost and side effects.
RECENT SCHOLAR PUBLICATIONS
Publications
International / National Journals : 34
International / National Conferences : 70
Total Publications : 104
GRANT DETAILS
Principal Investigator
AICTE, GOI, under R&D scheme
Project worth of Rs. 6 Lakhs
Duration – 3 years (2001 – 04)
Performance Study of Outdoor Polymeric Insulators.
Project completed successfully and completion report is submitted.
Developed high voltage test facilities with the help of AICTE grant at Crescent Campus.
Test facilities are as per IEC / ASTM standards
Principal Investigator
AICTE, GOI, under MODROB scheme
“Modernization of Power Electronics Lab”
Project worth of Rs. 8 Lakhs
Duration – 2 years (2006 – 08)
Project completed successfully and completion report is submitted.
Developed Power Electronics Lab facilities with the help of AICTE grant.
Co-Investigator
Project from DRDO, GOI
“Low Magnetic Field Sensors”
Project worth of Rs. 8.9 Lakhs
Duration – 3 years (2010 – 13)
Project completed successfully and completion report is submitted.
RESEARCH OUTPUTS (PATENTS, SOFTWARE, PUBLICATIONS, PRODUCTS)
Title : Silicone / EPDM Polymeric blend compound with ATH & Silica fillers for High Voltage Outdoor Insulators
Application No. : 201641026589
Publication Date : 19.08.2016
Journal No. : 34.2016
Patent Office : IPR, Chennai
CONSULTANCY
Consultancy to M/s. Oblum Industries, Hyderabad in the “Outdoor Polymeric Insulators”
Consultancy to M/s. Alstom Unit, Pondy, in the “Outdoor Polymeric Insulators”
Industrial Training Programme to ETA-STAR-ASCON Group Industries
Industrial Training Programme to Apollo Tyres
Regular Consultancy to University Estate Office (Campus Electrical Maintenance & HT Sub Station)
Industrial Consultancy to M/s. Garuda Vayu Sakthi Ltd.,
Consultancy to several academic institutions on NAAC Accreditation & NBA Accreditation
Consultancy to several academic institutions on implementation of Outcome Based Education
Industry, Institute, or Organisation Collaboration
Purdue University, USA
University of Missouri, Columbia, USA
PPKS, Sarawak, Malaysia
UNIMAS, Sarawak, Malaysia
UITM, Sarawak, Malaysia
ETA-ASCON-STAR, Dubai
AU-KBC, Chennai, India
Apollo Tyres, Chennai, India
Frontier Lifeline Research Institute, Chennai, India
Chennai Power Desalination Training (CPDT), Chennai, India
Mando Automotives India Pvt. Limited
STARTUP
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SOCIAL, ECONOMIC, or ACADEMIC BENEFITS
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