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									 INTERNATIONAL JOURNAL OF MECHANICAL ISSN 0976 – 6340(Print),
 International Journal of Mechanical Engineering and Technology (IJMET), ENGINEERING
 ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME
                              AND TECHNOLOGY (IJMET)

ISSN 0976 – 6340 (Print)
ISSN 0976 – 6359 (Online)                                                         IJMET
Volume 5, Issue 5, May (2014), pp. 123-132
© IAEME: www.iaeme.com/ijmet.asp
Journal Impact Factor (2014): 7.5377 (Calculated by GISI)                    ©IAEME
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        EXPERIMENTAL AND ANALYSIS OF FRICTION DRILLING ON
                     ALUMINIUM AND COPPER

                                T.PRABHU1, Mr. A. ARULMURUGU2
                          1
                         PG Student Department of Mechanical Engineering,
                     Regional centre Anna University of Technology, Coimbatore.
                           2
                             Assistant Professor Department of Mechanical,
                     Regional centre Anna University of Technology, Coimbatore.




 ABSTRACT

         Friction drilling is a non-traditional hole making method that uses the heat generated from
 friction between a rotating conical tool and work piece to soften and penetrate the work material and
 generated a hole. Friction drilling is also called as thermal drilling, flow drilling, form drilling or
 friction stir drilling. High temperature and strain in friction drilling material properties and
 microstructure. The work piece enable softening, deformation and displacement of work material and
 creates a bushing surrounding the hole without generating chip or waste material. The research
 characterizes the experimental and analysis of friction drilling on the aluminium and copper alloy by
 HSS and Tungsten carbide tool. It is show that materials with different compositions and thermal
 properties affect the selection of friction drilling process parameters. So this research is to
 experimental and analysis the friction drilling process on the two material and study the behaviours
 of it.

 Keywords: Friction Drilling, Aluminium & Copper

 1. INTRODUCTION

          Drilling is a process of producing round holes in a solid material or enlarging existing holes
 with the use of multi-tooth cutting tools called drills or drill bits Various cutting tools are available
 for drilling, but the most common is the twist drill. But here friction drilling is going to experiment in
 aluminum alloy and copper alloy by HSS and tungsten carbide tool. Friction drilling, also known as
 thermal drilling, flow drilling, form drilling, or friction stir drilling, is a nontraditional hole-making
 method. The heat generated from friction between a rotating conical tool and the work-piece is used
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ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME

to soften the work-material and penetrate a hole. Figure.1 shows a schematic illustration of the five
steps in friction drilling. The tip of the conical tool approaches and contacts the work-piece, as
shown in Fig.1.1 (a). The tool tip, like the web center in twist drill, indents into the work-piece and
supports the drill in both the radial and axial directions. Friction on the contact surface, created from
axial force and relative angular velocity between tool and Work-piece, produces heat and softens the
work-piece material.
        As the tool is extruded into the work-piece, as shown in Fig.1.1 (b), it initially pushes the
softened work-material sideward and upward. With the work-piece material heated and softened the
tool is able to pierce through the work-piece, as shown in Fig.1.1 (c). Once the tool penetrates the
work-piece, as shown in Fig.1.1 (d), the tool moves further forward to push aside more work-piece
material and form the bushing using the cylindrical part of the tool. As the process is completed, the
shoulder of the tool may contact the work-piece to collar the back extruded burr on the bushing.
Finally, the tool retracts and leaves a hole with a bushing on the work-piece as shown in the Fig.1.1
(e). Friction drilling is a technique to create a bushing on sheet metal, tubing, or thin walled profiles
for joining devices in a simple, efficient way. The bushing created in the process is usually two to
three times as thick as the original work-piece. This added thickness can be threaded, providing a
more solid connection for attachment than attempting to thread the original sheet. Figure 1.2 shows a
cross section of the bushing produced for a tapped and untapped hole. All work-material from the
hole contributes to form the bushing. In addition, no cutting fluid or lubricant is necessary, which
makes friction drilling a totally clean, environmentally friendly process.

2. WORKING PRINCIPLE

         Friction drilling is a process that uses friction to produce bushings in metal tubing and flat
stock. The combined rotational and downward force of our special friction Drilling tool bit creates
frictional heat. Temperatures can reach 900ºC for the tool, and 700ºC for the work piece. The
material is transformed into a "super-plastic" state, allowing the tool to displace material and form a
bushing. The height of the bushing is roughly 3 to 4 times the original metal thickness. These
bushings are ideal for threaded applications, as the number and strength of threads is significantly
increased. It is an excellent alternative to weld nuts or threaded inserts. The bushing can also be used
as a support hole for welded, soldered or brazed connections as well as for a load-bearing surface.
The Thermal Drilling System can be used in most ferrous and non-ferrous metals including mild
steel, stainless steel, copper, brass and aluminum, with material thickness up to 12 mm. In general,
all malleable materials can be thermal drilled. Standard drills are available in any size up to 25.4 mm.
diameter. Larger drill sizes are available on request.
         No special equipment is required. A standard drill press, milling machine or CNC machining
center is suitable. Thermal Drilling is also ideal for automation because it is a chip less process,
produces accurate holes, and has a long tool life. Thermal Drilling is also well suited for short run or
prototype work because of its ease of use. There is absolutely no cutting involved during the creation
of the hole.
         Friction drilling is a non-traditional hole making method that uses the heat generated due to
the friction between a rotating conical tool and the work piece to soften and penetrate the work-
material and generate a hole in a sheet material and at the result a bushing forms. In friction drilling
forms bushings from the sheet metal material, it is clean and chip less drilling method. The material
Properties and microstructures are changed in friction drilling because of high temperature and
strain. In machining and production methods these result soften unwanted but they are unavoidable
and important to affect the quality of friction drilled holes. Contrary to the traditional drilling there is
no chip and waste material, all extruded material contributes to form the bushing and it eliminates
chip generation in friction drilling, therefore it can be called clean and chip less hole making process.

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ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME

Tool life is increased, time of processing and cost of drilling is reduced, and bushing form is thicker
than the work piece about three times, which provides longer contact area that fitted a shaft firmly.

According to the tool geometry there are four steps in friction drilling.
 (i) First, the tip of the tool Approaches and penetrates the work piece.
 (ii) Second, the generated heat that softens the work material due to the friction on the
       contact surface which is between tool and work piece.
 (iii) Third, he softened Material is pushed sideward and tool moves forward to form the
       bushing using the cylindrical section of the tool.
 (iv) Fourth, the extruded burr on the boss pressed to the work piece surface by the shoulder of
       the tool and finally the tool retract and leave a hole with a bushing.

        The tool tip and the friction force On the contact area which is between the tool work piece
interfaces, like the web centre of the twist drill deals into the work piece and support the drilling both
radial and axial directions. The softened material pushed sideward by the tool which extruded and
pierces through the work piece. The tool tip penetrates the work piece and tool waves further forward
to push the softened material and form the bushing with using the cylindrical part of the tool.
        The purpose of the bushing is increased the thickness for threading and available clamp load.
Friction drilling is suitable apply to ductile materials. The petals and cracks formations are generated
at the bushing which obtained at the end of friction drilling of brittle cast metals. Petal formation
generates a Bushing with limited load capability for thread fastening. The difference in brittle and
ductile work pieces can be seen as the brittle work-material does not form a bushing with desired
shape and ductile work-material has a smooth, cylindrical bushing with sufficient length. The ratio of
work piece thickness (t), to tool diameter, (d), is an important parameter in friction drilling. The high
of bushing contributed at high t/d represents that a relatively longer portion of material is displaced
materials with higher strength requires more thrust force to be penetrated. The bushing shape, the
cylindricality, petal formation, bushing wall thickness, and surface roughness are made to judge the
friction drilled hole quality. The bushing shape, which becomes cylindrical, has less fracture as work
piece temperature increases. At high spindle speed and pre-heating, the thrust force, torque, energy
and power reduce for friction drilling of brittle cast metals. The thrust force and torque are reduced at
higher feed rates and shorter cycle time for hole drilling. The bushing height is usually two to three
times as thick as the original workpiece.The ductility of work piece material, which is extruded onto
both the front and back sides of the material drilled, increases due to the frictional heat. The length
the threaded section of the hole can increases about three to four times because of the added height of
the bushing shape. The bushing shape is to increase thickness to threading and available clamp load
the friction drilling tools geometry is important. The tool geometry becomes from five regions,
which are called centre, conical, cylindrical, shoulder, and shank regions. The centre region, like the
web of twist drill provides the support in the both radial and axial directions. Conical region has
sharper angle than the centre region. This region rubs against workpiece in the contact area which is
between and Pushes the material sideward to shape the bushing. Shoulder region touch to the work
piece to round the entry edge of the hole. Shank region grippes the tool to holder of the machine.
        The temperature in the work piece cause to undesired material damage and improper bushing
Formation. In friction drilling of materials which thermal conductivities are high, a large portion of
the heat is transferred into the work piece. Low Temperature causes insufficient ductility and
softening resulting in high thrust force and improper Bushing formation. These effects removed with
selection of low spindle speeds for materials which have low thermal conductivity coefficient and
high spindle speeds for material which have high heat Conductivity coefficient. The low elongation
of materials suggests the high fracture and petal Formation. The frictional heat which generated at
the tool-work piece interface provides information about thermal properties. The high thermal

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ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME

conductivity of the material cause to more heat transfer away from the tool-work piece interface
quickly, which reduces the work piece temperature and ductility for bushing Formations. In friction
drilling the work piece material melting temperature is important. The maximum temperature which
is generated is about 1/2-2/3 of the work piece melting temperature. The material Plasticity is
increased at elevated temperature which occurred at high rotational speed and pre-heating conditions.
Most of the energy converts into heat and transfers to the work piece and tool. The tool surface
temperature increases with increasing spindle speed and the more friction heat is generated. The
friction coefficient, which is between the tool and work piece contact area, increases with increasing
the number of holes drilled, thus raising the surface temperature. Lower thermal conductivity of the
tool and work piece material causes to increase both tool surface temperature and the temperature,
which is in Contact area between tool-work piece interfaces. The lower tool thermal conductivity
resulted in less significant variation in axial thrust force produced and tool surface temperature.
        With increasing spindle speed the metal crystallization energy is increased and generated
Uneven melting temperature, thus the surface roughness value is smaller. Large feed rates are caused
to insignificant melting temperature and incomplete melting of the material. The material, which is
incomplete melting, adhering on drill and therefore the surface roughness of the hole is Increased.
Slow feed rates are caused to material melting temperature, which have different cooling Speeds.
The upper material layer is cool down faster than the lower material layer. Thus the drill tool adhere
the metal chip, and obtain a bad hole surface quality. The greater the number of hole drilled the
Higher the tool surface temperature. This can be attributed to the greater surface roughness, as a
result of adhesion tool to work piece. The purpose of this experimental study is investigated the
friction drilling of aluminum alloys and copper alloy which have different thermal conductivity
coefficient. It was analyzed the effect of the thermal conductivity on the surface roughness, bushing
height and bushing wall thickness, depended on the spindle speeds and feed rates.




                (a)            (b)             (c)                (d)                (e)

               Figure 1. A schematic illustration of the five steps in friction drilling.




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                                       Figure 2. Resulting hole and bushing.


                                                         Table No: 1

  Tool style             Short                       Short/Flat                     Long                      Long/Flat

Description    Short parallel sides         Short parallel sides behind   Longer parallel-sided       Longer parallel-sided
               behind the leading taper.    the leading taper. Milling    body that extends           body that extends behind
               This produces a short        cutters are incorporated      behind the leading taper.   the leading taper. Milling
               conical (tapered) bush       into the collar. This         This produces a long        cutters are incorporated
               and a rolled collar on top   produces a short conical      cylindrical bush and a      into the collar. This
               of the working surface.      (tapered) bush and a flat     rolled collar on top of     produces a long
                                            surface on top of the         the working surface         cylindrical bush and a
                                            working surface.                                          flat surface on top of the
                                                                                                      working surface



 Hole Form




   Picture




        Today, the availability of this old technology is reliable and the process is fast, Friction
Drilling is a process for generating bushings or holes in thin-walled sheet metal, metal tubes, or pipes
without metal removal. A rotating, center punch type tool Center drill is forced into the material. The
heat generated by the friction, heats the surrounding area and plasticizes the material. Without
removing material, a hole is then formed by the entering tool, similar to a forging process. The
excess material increases the wall thickness of the metal and provides an area of increased support.

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International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME

This eliminates additional welded bracing or the insertion of plugs. Friction drilling is an excellent
process to create reliable, stronger connections or bushings.




                          Fig 3 Key dimensions of the friction drilling tool


h: The length of the tool cylindrical region (mm)
hl: The length of the tool conical region (mm)
hn : The length of the tool tip region (mm)
ß: Tool conical angle
a: Tool tip angle
d: Hole diameter (mm)
ØD1: Tool shoulder diameter (mm)
ØD: Tool shank diameter (mm)
T: Material thickness (mm)
ha: Bushing height (mm)
L: Tool handle region (mm)
T: Tool shoulder region (mm)

3. APPLICATIONS

        Potential automotive applications for friction drilling are shown in Fig. 1.2. These include
seat frame, exhaust system parts, fuel rail, seat handle, foot pedal, oxygen sensor, and castings. It is
believed that the friction drilling technique can be applied on a broader scale in automotive industry.
Potential for substitution of a friction drilling fastening process will need to be evaluated on a case-
by-case basis. Aluminum and magnesium castings require bolt bosses and thick flanges to
accommodate fastening. In hydro formed components, punching holes and attaching weld nuts and
clinch nuts are very difficult and/or expensive to accomplish. In certain cases, it appears that sheet
metal components are made thicker than necessary for the sole purpose of providing more thread
engagement for fasteners. In other cases a threaded hole is needed for attachment of an electrical
ground, which requires little load carrying capability.




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Figure 4. Automotive applications of friction drilling including (a) seat frame, (b) exhaust O2 sensor
            boss, (c) exhaust part, (d) seat handle, (e) foot pedal, and (f)oxygen sensor

4. ADVANTAGES

   Advantages of the friction drilling System are:
   1. Very fast process
   2. Stronger joints
   3. Cost-effective
   4. No special machines needed
   5. Small investment
   6. High quality
   7. No additional components
   8. Less production steps
   9. Clean workspace
   10. Chip less process
   11. The process reshapes all material so that no material is lost. The sleeve that is about 3 times
       longer than the original diameter of the target material makes it possible to make very strong
       bolt joints in thin material.
   12. Moreover, it is a clean process, because no litter (particles) is produced




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5. OBJECTIVE

 1. To Experiment the friction drilling on the material and identify the different parameters like
    temperature, stress, strain
 2. To design the friction drill tool
 3. To study about the material properties of and tool properties
 4. To identify the stress and strain in the tool by analysising
 5. To identify the mach inability of the material(Aluminum and copper )
 6. To analysis the microstructure of the material before and after drilling
 7. To analysis stress /strain of work piece and tool by ansys software

6. FRICTION DRILLING TOOL

        The Thermal Drilling System can be used in most ferrous and non-ferrous metals including
mild steel, stainless steel, copper, brass and aluminum, with material thickness Thermal drilling is a
process that uses friction to produce bushings in metal tubing and flat stock. The combined rotational
and downward force of our special Thermal Drilling tool bit creates frictional heat. Temperatures can
reach      900      C      for    the     tool,    and      700     C      for    the     work      piece.
The material is transformed into a "super-plastic" state, allowing the tool to displace material and
form a bushing.
        The height of the bushing is roughly 3 to 4 times the original metal thickness.
These bushings are ideal for threaded applications, as the number and strength of threads is
significantly increased. It is an excellent alternative to weld nuts or threaded inserts. The bushing can
also be used as a support hole for welded, soldered or brazed connections as well as for a load-
bearingsurface.Up to 12 mm. In general, all malleable materials can be thermal drilled. Standard
drills are available in any size up to 25.4 mm. diameter. Larger drill sizes are available on request.
        No special equipment is required. A standard drill press, milling machine or CNC machining
center is suitable. Thermal Drilling is also ideal for automation because it is a chip less process,
produces accurate holes, and has a long tool life. Thermal Drilling is also well suited for short run or
prototype work because of its ease of use.
Temperature distribution
        The temperatures involved in the friction drilling process are measured using an infrared
thermometer. Fig 4 depicts the temperature involved in the friction drilling process for various
speeds. Friction drilling of aluminum, brass and stainless steel attained a maximum temperature of
164, 252 and 468oC respectively. Higher can increase the frictional heat transfer between the tool
and the work piece. Heat flux involved in the Process of friction drilling is dependent on the speed of
the friction drill tool. Since the speed is increased, frictional heat flux and heat transfer is increased
which in turn increases the temperature of the work piece. At the final stages of the tool penetration,
higher temperature is involved and the temperatures gradually reduce at of the tool from the work
Process parameters
        Frictional heat and feed pressure produce the material deformation and displacement. The
frictional heat is generated through the rotational speed, the corresponding axial force (contact
pressure) and feed rate. This means that, independently of the core hole size, the drill unit to be used
must be capable of a speed of up to 500 rpm, a machine output of up to 5 KW, and a feed rate of up
to 1000 mm/min. The right combination of feed rate and speed depends on the type (stainless steels,
steel, or non-ferrous metals) and thickness of the material. For optimized results, the material must
retain the correct temperature during forming and must not cool down too rapidly. Data listed later in
this document are intended as reference values only and can vary significantly for different material
grades and thicknesses.

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7. AXIAL FORCE

       The required axial force at the start of the flow punch forming process is very high and
decreases towards the end of the process when the core hole is fully formed. When processing thin
materials, relining may be necessary to prevent deflection.

8. ROTATIONAL SPEED RPM

       The normal speed for small core hole diameters is relatively high, at approx. 3000 rpm, and
can be as high as 4500 rpm for non-ferrous metals. For larger core hole diameters such as M20, the
necessary speed is only approx. 1000 rpm. Stainless steel, with a lower thermal conductivity, can be
processed at speeds up to 20% lower.
For working with center drill and centertap the following safety rules should be obeyed:
   • Always wear safety goggles.
   • When working with the flat flow punch formers that are used to remove the collar, proper
       protective clothing and safety goggles should be worn if no safety guard is installed on the
       machine to protect against flying chips.
   • The flow punch former is glowing hot initially after use and should not be touched without
       proper safety gloves or before it has cooled down.
   • The work part gets very hot and should not be touched without proper safety gloves or before
       it has cooled down.
   • The safety instructions for the recommended parting medium should be obeyed. The safety
       data sheets will be supplied if needed.
   • At the start of the flow punch forming process, the collet chuck should be tightened after 5 to
       10 forming operations to prevent the part from slipping or falling out.

9. CONCLUSION

Comparison with Conventional Drilling Process
        In friction drilling tool wear is very minimal in comparison with twist drill. Also the
unwanted chips are not produced and the walls of the hole drilled are stronger in grain orientation in
comparison with twist drill where holes are made by cutting the grains abruptly. Only concern of
friction drilling is the higher thrust force, clamping force and elevated temperature which were
within tolerable level in this experimentation. It can be observed from Table 4 that the roundness
errors are higher in comparison with twist drill but it is of non significant order when comparing the
severity of the friction drilling process.

10. ACKNOWLEDGEMENT

 •   Behind every achievement lies an unfathomable sea of gratitude to those who actuated it,
     without them it would never have into existence. To them we lay the word of gratitude
     imprinted within us.
 •   First and foremost, I am grateful to God for giving me good health throughout the period I was
     working on my project.
 •   I owe my thanks to the Dean Dr.M.SARAVANA KUMAR., M.B.A., Ph.D. for providing with
     all facilities to work on my project successfully.
 •   Also, I take this opportunity to convey my sincere thanks to the Head of the Department Dr. M.
     SAKTHIVEL M.E., Ph.D., without whom this project would have been a distant reality.


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 •     I would like to express my warm acknowledgement and my sincere thanks to my Guide Mr. A.
       ARULMURUGU M.E., Regional Centre of Anna University, Coimbatore for his
       encouragement, support and time for guiding me throughout this project. I am very much
       grateful to him for his constructive criticism and suggestions throughout the duration of my
       project.
 •     Also I would like to thank all the staffs who either have directly or indirectly given his or her
       suggestions and supports throughout this project and my respects and love to my parents and all
       other family members and friends for their love and encouragement.

11. REFERENCES

 1.     Scott F.Miller, Peter J Blau, Albert J Shih,Microstructural Alterations Associated With
        friction drilling of steel,Aluminium and Titanium(2005)
 2.     Scott F.Miller, Peter J Blau, Albert J Shih, Tool wear in friction drilling (2006)
 3.     Cebeliozek, ZulkufDemir, Investigate the effect of tool conical angle on the bushing height,
        wall thickness and forming in friction drilling of A7075-T651 aluminum alloy(2013)
 4.     P.V.Gopal Krishna, K.Kishore and V.V.Sathyanarayana some investigations in friction
        drilling AA6351 using high speed steel (2010)
 5.     Pantawane.P.D, AhujaB.B Experimental investigation and multi-objective optimization of
        friction drilling process on AISI 1015(2011) Volume 2 ISSN 0976-59
 6.     S.Indumathi, V.Diwakar Reddy, G.Krishnaiah Grey relational analysis to determine optimum
        process parameters for thermo mechanical form drilling-riveting (2013) Volume 1 Issue 3
        July
 7.     B.PadmaRaju, M.KumaraSwamy Effect of tool material in friction drilling a case study
        (2012) volume 2
 8.     B.PadmaRaju, M.KumaraSwamy, Finite element simulation of a friction drilling process
        using Deform-3D (2012)
 9.     Cebeliozek, ZulkufDemir Investigate the surface roughness and bushing shape in friction
        drilling of A7075-T651 and St37 Steel (2013
 10.    Wei-Liangku, Ching-lien hung, Shin-min lee, Optimization in thermal friction drilling for
        SUS 304 Stainless steel (2010)
 11.    G.Somasundaram,S.RajendraBoopathy and K.Palanikumar Modeling and analysis of
        roundness error in friction drilling of aluminum silicon carbide metal matrix composite(2011)
 12.    L.Francis Xavier D.Elangovan, Effective parameters for improving deep hole drilling process
        by conventional method (2013) volume 2
 13.    S.Madhavan, S.Balasivanadha prabu Experimental investigation and analysis of thrust force
        in drilling of carbon fiber reinforced plastic composites using response surface
        methodology(2012) vol 2 Issue 4 july
 14.    Somasundaam G, Rajendra Boopathy S, Fabrication and friction drilling of aluminum silicon
        carbide metal matrix composite (2010) volume 1
 15.    J.Pradeep Kumar, P.Packiaraj, Effect of drilling parameters on surface roughness, tool wear,
        material removal rate and hole diameter error in drilling of ohns (2012)
 16.    P. Govinda Rao, Dr. C L V R S V Prasad, Dr.D.Sreeramulu, Dr.V. Chitti Babu and
        M.Vykunta Rao, “Determination of Residual Stresses of Welded Joints Prepared Under The
        Influence of Mechanical Vibrations By Hole Drilling Method and Compared By Finite
        Element Analysis” International Journal of Mechanical Engineering & Technology (IJMET),
        Volume 4, Issue 2, 2013, pp. 542 - 553, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359.



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