JPH051789A - Buried pipe labelling tape like body - Google Patents

Abstract

PURPOSE:To provide a buried pipe labelling tape like body having a function capable of guiding leaked gas from an underground buried gas pipe to a prescribed place and a function capable of detecting accurately the buried pipe position without being influenced by magnetic line of force generated by induced currents of many other unspecified number of buried pipes in detecting the buried positions of the buried pipes. CONSTITUTION:Labelling indications 5 are applied to one surface 8a of a tape like molding 8 composed mainly of a single layered or plural layered rubber and/or plastic having at least three odd numbered parallel inherent conductors 6A, and groove parts 7 having pressure proof ability bearable to a ground pressure in the ground to the depth of at least 1.5m are also formed continuously on the other surface 8b in the lengthwise direction, and by constituting these groove parts 7 of hollow parts 7A situated between the conductors 6A and grooves 7B to open the respective hollow parts 7A on the other surface 8b, earth and sand or the like can be prevented from entering into these groove parts 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak gas guiding function for guiding leak gas leaked due to corrosion of a gas pipe buried in the ground to a predetermined place, for example, near a used gas meter, and a buried position of the buried pipe. It is related to the embedded tape marker tape body that has a locator function (buried pipe position confirmation function) that can indicate and a buried pipe perforation detection function that can detect the perforated position of the buried pipe if necessary. is there.

[0002]

2. Description of the Related Art Conventionally, as this type of marking tape for a buried pipe, one having only a marking function of simply displaying the date of burial of the buried pipe, for example, Japanese Utility Model Laid-Open No. 62-179478.
There is one having a marker function and a locator function shown in Japanese Patent Laid-Open Publication No. 2-114275, for example, one having a hole detection function in addition to the marker function and the locator function shown in Japanese Utility Model Publication No. 2-114275.

A conventional tape-shaped tape body for buried pipe disclosed in Japanese Utility Model Laid-Open No. 62-179478 will be described with reference to FIG. In the figure, reference numeral 1 denotes a plastic film, which has a printed layer 2 on the surface of which a desired printed display is provided. 3 is an adhesive layer provided on the back surface of the plastic film 1, and 4 is a conductive layer sandwiched between the plastic film 1 and the adhesive layer 3, which is made of a plate-shaped conductor continuous in the longitudinal direction of the plastic film 1. When the composite material composed of the plastic film 1, the printing layer 2, the adhesive layer 3, and the conductive layer 4 is prepared in this manner, the adhesive layer 3 can be applied to the buried pipe,
In the state of being buried in the ground, the plastic film 1 having the printed layer 2 acts as a marker, and the conductive layer 4 retains the function of the locator wire.

A conventional embedding pipe marker tape-shaped body disclosed in Japanese Utility Model Laid-Open No. 2-114275 will be described with reference to FIG. This marker tape-shaped body for a buried pipe is also attached to the buried pipe by the adhesive layer 3 provided on one surface of the plastic film 1 as in the case of FIG. The plastic film 1 printed and printed 2 acts as a marker, the conductors 4a function as locator wires, and since the conductors 4a are used, the tape and the buried pipe are pierced by burying work or other external force. However, if some of the conductors 4a are cut, the pipe perforation can be immediately detected by the disconnection of the conductor 4a, and at the same time, the remaining conductor 4a can retain the function as a locator wire.

[0005]

However, these conventional ones can confirm the position of the buried pipe or the drilling position of the buried pipe by the conductor 4a included in the tape. Regarding the confirmation of gas leakage due to corrosion, etc., there is an inconvenience that a semiconductor gas concentration meter must be installed on the ground at the relevant location for measurement. In addition, with asphalt pavement, there is a major problem that it cannot be detected in an emergency because it cannot be detected unless a measurement is made after making a hole in the pavement surface to expose the ground, and this construction requires labor and time. is doing. Moreover, the gas leak inspection work of the underground pipe must be performed regularly and at intervals of about 5 m, and the work is enormous.

The present invention is intended to solve the above-mentioned problems, in which a fine leak gas in the ground is guided to a predetermined place, for example, the ground near a gas usage meter, and the leak gas is introduced at the guiding point. To obtain a tape-shaped body for a buried pipe that enables the constant measurement of the concentration and can promptly respond to a gas leak in the ground and prevent a major accident caused by leaving the gas leak unnoticed. The purpose is to

[0007]

In order to achieve the above object, a marker tape-shaped body for a buried pipe according to the present invention is a single-layer or multi-layer rubber and / or plastic in which a plurality of conductors are arranged in parallel. A tape-shaped molded product mainly made of a material having a marking on one surface and a groove portion continuous with the other surface in the longitudinal direction and having pressure resistance to endure at least 1.5 m underground pressure. is there. The conductor may be an odd number of at least three, and the groove may be formed of hollow portions located between the conductors and a groove that opens each hollow portion on the other surface.

[0008]

In the present invention, the groove functions as a leakage gas inducing function, the conductor functions as a locator function, and the tape-shaped molded product functions as a marker function. In addition, since the conductor is an odd number of at least three and the groove is composed of the hollow portion and the groove, infiltration of earth and sand or the like into the groove portion can be prevented.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The embodiment shown in FIG. 1 is a marker tape-like body for a buried pipe having a single-layer structure obtained by extrusion molding, press molding, etc., where one surface 8a is marked with a marker 5 and the other surface 8b is a conductor. It is composed of a tape-shaped molding 8 mainly made of rubber and / or plastic in which a plurality of conductors 6 are arranged in parallel so as to form a groove 7 continuous in the longitudinal direction between them.

In the embodiment shown in FIG. 2, a colored and / or plastic film 8A having a marking 5 on one surface 8a is used.
When, and as labeled display surface 5 of the plastic film 8A arranging a plurality of conductors 6 of the cross-sectional area 0.08 mm ² to 3 mm ² in parallel between the other one of the transparent plastic film 8B is an outer surface of plastic The film 8B is a marker tape-shaped body for a buried pipe having a multi-layer structure obtained by sandwiching between the conductors 6 so as to form a groove portion 7 continuous in the longitudinal direction.

Tape-shaped molding 8 used here
Is a polymer that is easy to mold and has high electrical insulation properties. Examples of rubber include EPDM, silicone rubber,
NR, SBR, BR, thermoplastic E as thermoplastic rubber
PR, SBS, SIS, SIBS, thermoplastic urethane rubber, and as the thermoplastic resin PE, PP, PE
Resins such as T and PVC are suitable.

The conductor 6 has a sectional area of 0.08 mm ^{2 to 3} m.
A plurality of single or stranded conductors 6 of m ² , such as copper or nickel, are used. The number of these and the wire diameter (cross-sectional area) depend on the construction conditions such as the size of the buried pipe and the total effective disconnection from the viewpoint of pressure resistance. appropriately selecting the areas to be 0.3 mm ² to 10 mm ^2. The wire diameter (cross-sectional area) of the conductor 6 is 0.08.
was a mm ² to 3 mm ² is difficult to use than strength surface of the conductor to support the ground pressure and thinner than this, the wire diameter (sectional area) is too thick at 3 mm ² or more, the tape-like molded product 8 This is because, in addition to making the thickness unnecessarily thick, the depth of the groove portion 7 is made too deep, which rather results in the entire groove being crushed by the ground pressure.

Furthermore, the groove 7 must be capable of guiding the leaked gas to a predetermined place. That is, it is necessary that the groove portion 7 has a pressure resistance to withstand the weight of earth and sand at least 1.5 m underground and can be completely communicated in the longitudinal direction in that state. For this purpose, the effective cross-sectional area of the groove 7 is good to have an area of 10mm ² ~30mm ^2.
This is because if the cross-sectional area is smaller than this, there is a risk that the leaked gas may not be able to sufficiently pass through due to bending of the tape-shaped molded product 8, and if the cross-sectional area is larger than this, the groove portion 7 is crushed by the ground pressure. This is because there is a risk that it will end up. When forming such a groove portion 7,
It is particularly important to provide the groove portion 7 between the conductors 6 described above,
By reinforcing the pressure resistance by the rigidity of the conductor 6, it is possible to prevent the groove portion 7 from being crushed and blocked due to the ground pressure.

On the other hand, regarding the marker display 5, before or after molding of the tape-shaped molded product 8 or at the same time as molding, a printed display 5a as shown in FIG. 3 is displayed on the surface 8a of the plastic film 8A, or as shown in FIG. The marking display 5b is used as described above, or the printing display 5a is used on the back surface 8b of the plastic film 8A before molding as shown in FIG.

Incidentally, as shown in FIG. 5, in the case where the back surface 8b of the plastic film 8A is printed and displayed 5a, it goes without saying that the resin layer of the plastic film 8A or the entire resin layer 8 must be transparent. Absent. Also, a plastic film 8B in which the conductor 6 is embedded
When the adhesive is provided on the surface, the back surface treatment agent layer 9 is provided on the top of the sign display 5 (the adhesive layer is omitted in FIG. 3).

In the embodiment shown in FIG. 6, a plurality of tape-shaped moldings 8 are provided on one surface, that is, the surface 8a on which the marking 5 is provided, at least near the surface layer portion having a depth of 0.1 mm or less from the surface 8a. A conductor tape 10 composed of a thin wire is a marker tape-shaped body for a buried pipe having a single-layer structure which is continuously buried in the longitudinal direction together with the conductor 6 which is embedded so as to form the groove portion 7 on the other surface. .

In the embodiment shown in FIG. 7, at least when the plastic film 8A and the plastic film 8B are sandwiched between the conductors 6 with the conductors 6 interposed therebetween, as in the case of FIG.
Advance or embedded in parallel in succession conductor 10 composed of a plurality of thin lines of the cross-sectional area 0.01mm ² ~0.08mm ² in the longitudinal direction of the film at the same time is decorated with with the 0.1mm or less from the surface 8a has a depth It is a marker tape-shaped body for a buried pipe obtained in this way.

In the embodiment shown in FIG. 8, the plastic film 8 is used.
A is a multi-layer film, which is a marker tape-shaped body for a buried pipe in which a conductor 10 made of a thin wire is sandwiched.

That is, in FIG. 6 to FIG. 8, the purpose of using the thin wire conductor 10 provided in the vicinity of the surface layer is to pierce the buried pipe with a pickaxe or a claw of a shovel car during excavation work. At this time, the buried tape marker tape-shaped body provided on the peripheral surface of the buried tube is first perforated, the conductor 10 provided in the tape is broken, and the breakage of the conductor 10 is electrically detected on the ground. , It is intended to indirectly detect the perforation of the buried pipe. In the conventional structure shown in FIG. 18, the conductor 4a having a locator function is used.
Although it has a hole detection function in itself, it is not necessary to break the conductor 4a when the locator function is prioritized, so a certain thickness is necessary. Since it is easier to use, it is better to use a thin conductor, and in order to satisfy these two functions at the same time, a wire diameter that meets each purpose must be used, and there is a limit to the selection of the wire diameter. Here, the wire diameter (sectional area) of 0.01mm ² ~0.08mm ² thickness in the cross-sectional area of the fine wire conductors 10 used is suitable. This is because if it is too thick, it cannot have the function of making a broken line along with the drilling of the buried pipe due to an accident during construction, etc.If it is too thin, only the thin wire will break unnecessarily and the buried pipe will be damaged each time. This is because the labor of detecting the presence or absence increases.

Next, FIGS. 9 and 10 show examples of use of the marker tape-shaped body for a buried pipe of the above embodiment. In FIG. 9, the buried pipe 11
10 is an example in which it is mounted over the entire circumference of the tube, and FIG. 10 is an example in which it is mounted only in the necessary part of the tube circumference, and in any case, it can be stopped with a binding tool 12 such as an adhesive tape or a belt at desired intervals. By doing so, even when the buried pipe 11 is pierced due to corrosion or the like, the marking tape-like body for the buried pipe is firmly in contact with the pipe circumferential surface by the underground pressure, so that the minute leaked from the pipe corrosion hole is caused. The gas travels through the groove 7 and is guided to the ground. In addition, the fixing of the marking tape-like body to the rising pipe is performed by taping the entire circumference strictly from the top with vinyl adhesive tape or the like.

(Experimental Example 1) For a buried pipe shown in FIG. 1, on the outer surface of a 25 A lamp outer tube in which a pinhole is artificially formed on the tube surface to cause gas leakage and a rising tube is provided at the end. Fix the marking tape-shaped body and set it to a depth of 0.5 m.
It was buried in the ground with a length of 20 m. At the end of this rising tube, a semiconductor gas leak tester (maximum sensitivity of 10
(ppm) was used to detect leakage gas, and the results shown in Table 1 were obtained.

(Experimental Example 2) In the same test as in Experimental Example 1 described above, a labeled tape-shaped body for a buried pipe shown in FIG. 7 was used, and a thin wire conductor 10 was intentionally broken. When subjected to the experiment, the results shown in Table 2 were obtained.

By the above two experimental examples 1 and 2, FIG.
It can be seen that the marker tape-shaped body for a buried pipe shown in FIG. 8 has an excellent gas guiding function and pipe perforation detection function in addition to the locator function.

Next, still another embodiment of the present invention will be described with reference to the drawings. The same or corresponding parts as those of the embodiment shown in FIGS. 1 to 10 are designated by the same reference numerals and the description thereof will be omitted. In each of the embodiments of FIGS. 11 to 14, a groove portion 7 including an odd number of conductors 6A, hollow portions 7A located between the conductors 6A, and a groove 7B for opening each hollow portion 7A on the other surface 8b. And are embedded in parallel.

The conductor 6A here has a cross-sectional area of 0.2.
An odd number of single or stranded wires such as copper and nickel having a size of mm ^{2 to 2} mm ² are used. The odd number of conductors 6A is used here in the case where a plurality of buried pipes are buried in parallel to confirm the position of the buried pipe. It was often difficult to accurately detect the intended buried pipe due to the generation of magnetic lines of force due to the secondary induced current. Therefore, if the odd-numbered conductors 6A are included in the tape-shaped molded product 8 and a plurality of the left and right n-numbers of the odd-numbered conductors 6A that are connected in parallel and one in the center are connected in series and a measurement current is applied. Since n times as much current flows in the left and right conductors in the center line, a strong line of magnetic force appears in the center line for the measurement of lines of magnetic force, and moreover, in the left and right conductors 6A, proportional to the respective current values. The generated magnetic field lines appear symmetrically at equal intervals depending on the position of the central magnetic field line, so that it is possible to facilitate accurate detection of the target buried pipe position without being confused with the placement positions of other underground pipes. Because. Further, the wire diameter (cross-sectional area) of the conductor 6A is 0.2 mm ² ~
To a 2 mm ² is because it is difficult to use than strength surface for supporting the ground pressure and thinner than this, 2 mm diameter (sectional area) is too thick is ² or more, the thickness of the tape-like molded product 8 This is because in addition to making the thickness unnecessarily large, the area of the hollow portion 7A of the conductor 6A is limited, resulting in incomplete induction of leakage gas. The number of the odd-numbered conductors 6A and the pitch between the conductors are determined depending on the pressure resistance strength depending on the construction conditions such as the size of the buried pipe. However, in the case of a lamp outer tube, the pitch between the conductors 6A should be about 10 mm. It is preferable that three or five odd-numbered conductors 6A are internally provided.

Further, the hollow portion 7A must have a leak gas guiding function capable of guiding the leak gas to a predetermined place. That is, it is necessary that the hollow portion 7A has a pressure resistance to withstand the weight of earth and sand at least 1.5 m underground, and in that state, it can be completely communicated in the longitudinal direction of the tape. For this purpose, the effective area of the hollow portion 7A is 10 mm ^{2 to} 30 m.
Those having an area of m ² are preferable. This is because if the cross-sectional area is smaller than this, there is a risk that the leaked gas may not be able to sufficiently pass through due to the bending of the tape-shaped molded product 8 or the like, and if the cross-sectional area is larger than this, the hollow portion 7 is caused by the ground pressure.
This is because A may be crushed. In forming such a hollow portion 7A, the hollow portion 7A
It is particularly important to provide A between the above-mentioned conductors 6A, and the reinforcement of pressure resistance due to the rigidity of the conductor 6A can prevent the groove portion 7 from being crushed or blocked due to the ground pressure. The hollow portion 7A needs to be provided on the inner surface 8b of the tape-shaped molded product 8. This is the hollow part 7 due to the ground pressure and the flow of underground mud and sand.
This is because it is necessary to prevent the inflow of sediment into A. on the other hand,
Groove 7B communicating from hollow portion 7A to inner surface 8b (unlabeled surface)
The shape and size of the shape may be as narrow as possible, for example, in the shape of a slit in order to prevent the entry of earth and sand into the hollow portion 7A and to facilitate the attachment of the tape-shaped molded product 8 to the embedded pipe. Moreover, the leakage gas can be captured sufficiently even in the slit-shaped groove 7B due to the leakage (penetration) phenomenon of the leakage gas due to the ground pressure.

Further, for the purpose of facilitating attachment to the buried pipe, a surface layer 8 having a groove 7B as shown in FIG.
The pressure-sensitive adhesive layer 13 can be provided at a desired position of b. In construction, the release paper 14 on the adhesive layer 13
By temporarily fixing it to the buried pipe while removing it, it can be easily attached to the circular buried pipe.

Next, FIGS. 15 and 16 show examples of use of the marker tape-shaped body for a buried pipe of the above embodiment. FIG. 15 shows an example in which the embedded pipe 11 is mounted over the entire circumference of the pipe, and FIG. 16 shows an example in which it is mounted only in a necessary portion of the pipe circumference. In any case, a binder such as an adhesive tape or a belt is arranged at a desired interval. 1
You can stop at 2. When the embedded pipe 11 is attached to the peripheral surface in this manner, when the embedded pipe 11 is pierced due to corrosion or the like, fine gas leaking from the corrosion hole is formed in the leaked gas capturing groove portion 7 that is in close contact with the embedded pipe 11. The gas is captured and guided to the ground through the hollow portion 7A which is a leakage gas guide hole. In this case, FIG.
If a part of the buried pipe 11 is covered as shown in FIG. 5, the above-mentioned function can be sufficiently fulfilled. This is because the gas under the ground has a property of infiltrating into the void portion where the ground pressure is not applied. In addition, since the hollow portion 7A, which is a guide hole, is provided in the inner layer 8b, the labeling tape-shaped body is fixed to the rising pipe, so that a vinyl adhesive tape or the like can be used from the top without paying attention to gas leakage to the outside air. Simply tap around the entire circumference or apply a rubber or plastic tube.

(Experimental Example 3) A conductor 6A is provided on the peripheral surface of a 25A lamp outer tube in which a pinhole is artificially formed on the tube surface so that gas leakage occurs and a rising tube is provided at the terminal. Fixing the marker tape-shaped body for buried pipe shown in FIG. 11 using three conductors of 0.7 sq as shown in FIG.
When a leak gas was detected by using a semiconductor type gas leak tester (maximum sensitivity: 10 ppm) with a length of 20 m in the ground at a depth of 0.5 m, the results shown in Table 3 were obtained.

(Experimental Example 4) Under the same test conditions as in Experimental Example 3 above, in order to investigate the locator function, two conductors left and right out of the three conductors contained in the marking tape-like body were connected in parallel, and this 2 While the current is flowing by connecting the book and the central line in series, the position of the buried pipe is detected from the ground by the buried pipe detector (magnetic field line measuring device) using the marker tape-shaped body shown in FIG. 4 results were obtained. NOTES 1 and 2 were measured at 3 points at intervals of 5 m in the length direction.

By the above two experimental examples 3 and 4, FIG.
It can be seen that the buried pipe marker tape-shaped body shown in FIG. 14 has an excellent gas guiding function and a buried pipe position detecting function. That is, the detection sensitivity of the leaked gas was extremely excellent, and good gas leak detection was performed, thereby demonstrating the excellent leaked gas guiding function of the marker tape-shaped body shown in FIGS. 11 to 14. Further, when the position of the buried pipe equipped with the marker tape-shaped body shown in FIGS. 11 to 14 was detected from the ground, Table 4
It is possible to detect magnetic lines of force at three points at equal intervals as shown in Fig. 11 and to easily distinguish it from other embedded pipes (non-energized embedded pipes) shown in Figs. Was recognized.

[0032]

As described above, according to the present invention, by providing the groove portion, in addition to the locator function (buried pipe position confirmation function) and the pipe perforation portion detection function, a great effect that leak gas can be detected can be obtained. To be That is, the gas leak in the buried pipe can be easily detected at any time in the vicinity of the used gas amount detection meter, so that the gas leak in the underground pipe can be quickly caught. As a result, it is possible to prevent an explosion accident caused by a gas accumulation in the ground.
Further, it has an extremely great effect that the burden of the gas leak inspection work can be greatly reduced. On the other hand, since it has a buried pipe position detection function, the buried position of the buried pipe can be immediately detected, and the presence or absence of pipe perforation due to an industrial accident, etc. can also be immediately detected, so there will be no accident of backfilling as a work error. It has a great effect that quick accident handling and highly safe work can be performed.

Further, according to the present invention, since the gas guide hole, that is, the groove is not clogged by the earth and sand by forming the groove with the hollow portion and the groove, there is an effect that the gas leak detection of the buried pipe is reliable. is there. Further, according to the present invention, since the buried pipe position detection function is provided by detecting magnetic field lines at equal intervals at n locations by using odd-numbered conductors, the buried position of the buried pipe can be immediately detected and can be distinguished from other buried pipes. Therefore, it has a great effect that quick accident handling and highly safe work can be performed. Furthermore, the method of attaching to the buried pipe is also extremely simple, such as temporary fixing, and the effect that the conventional construction time for attaching the locator wire to the buried pipe can be greatly reduced can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a sectional view showing another embodiment of the present invention.

FIG. 6 is a sectional view showing another embodiment of the present invention.

FIG. 7 is a sectional view showing another embodiment of the present invention.

FIG. 8 is a sectional view showing another embodiment of the present invention.

9 is a perspective view showing an example of use of FIG. 1. FIG.

FIG. 10 is a perspective view showing an example of use of FIG.

FIG. 11 is a sectional view showing another embodiment of the present invention.

FIG. 12 is a sectional view showing another embodiment of the present invention.

FIG. 13 is a sectional view showing another embodiment of the present invention.

FIG. 14 is a sectional view showing another embodiment of the present invention.

FIG. 15 is a perspective view showing an example of use of FIG.

16 is a perspective view showing a usage example of FIG. 11. FIG.

FIG. 17 is a sectional view showing a conventional one.

FIG. 18 is a cross-sectional view showing another conventional device.

[Explanation of symbols]

5,5a, 5b Marking display 6 conductors 7 groove 7A hollow part 7B groove 8 Tape-shaped moldings 8a One side 8b the other side Conductor consisting of 10 thin wires 11 buried pipe

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akio Fujii             3-2028 Tachibana, Nishinari-ku, Osaka-shi, Osaka             Inside the company Kyowa (72) Inventor Yoshihiro Okamoto             1823-7 Osa, Ichihara-shi, Chiba (72) Inventor Wataru Takahashi             7-5-16-1101 Machiya, Arakawa-ku, Tokyo

Claims (6)

[Claims] 1. A tape-shaped molded article containing, as a main material, a single-layer or multi-layer rubber and / or plastic in which a plurality of conductors are arranged in parallel, one side of which is marked and the other side of which is marked. At least 1.5m underground in the longitudinal direction
A marking tape-like body for a buried pipe, characterized in that a groove having a pressure resistance to withstand the ground pressure is formed. 2. The marker tape-shaped body for a buried pipe according to claim 1, wherein the groove is formed by the inside of the conductor. 3. The conductor is composed of at least three odd-numbered conductors, and the groove portion is composed of a hollow portion located between the conductors and a groove for opening each hollow portion on the other surface. 1. Marking tape for buried pipe. 4. The cross-sectional area of the hollow portion is 10 mm ^{2 to} 30 mm.
^{2. The} marker tape-shaped body for a buried pipe according to claim 3, wherein 5. The marker tape-shaped body for a buried pipe according to claim 1, wherein an adhesive layer for temporary fixing is provided on the other surface. 6. A tape-shaped molded article, wherein conductors composed of a plurality of thin wires are embedded in parallel in the longitudinal direction in a surface layer portion having a depth of at least 0.1 mm or less from a sign display surface. The marker tape-shaped body for a buried pipe according to claim 1 or 3.