JP3100355B2 - Sea surface sheet type oil fence for heavy oil diffusion prevention - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil fence for preventing the diffusion of heavy oil dropped from the unloading arm or loading arm of a loading or unloading base of a tanker to the sea, and more particularly to an oil fence where oil leaks. With a sheet so as to prevent oil leakage from spreading to the sea surface or into the sea.

[0002]

2. Description of the Related Art As shown in FIGS. 10 and 11, the conventional cargo handling of oil (mainly crude oil) is as follows. The stern portion is moored to the mooring dolphins 2A and 2B, and then the tanker-side freight line 6 and the land-side freight line 7 are connected by a loading arm 5 provided on the cargo handling dolphin. Reference numeral 2 indicates a mooring dolphin.

[0003] In the above-mentioned oil cargo handling operation (oil lifting from the tanker 1 or oil loading on the tanker 1), the highest risk of oil leakage to the sea is the (joining portion of) the loading arm 5. . Oil on the deck of the tanker 1 is drained from the drain tank 8 below the shore manifold.
And the combing 9 around the deck.

As a countermeasure for preventing oil leakage from the joint portion and other portions of the loading arm 5 from spreading to the sea, a short curtain-shaped oil fence 01 is extended around the tanker, and is generally provided. No special oil protection is provided below the loading arm.

A conventional oil fence has a fence depth of about 1 m or less from the sea surface. Reference numeral 40 denotes an underwater strut for supporting the cargo handling dolphin 3, reference numeral 41 denotes a fender, and reference numeral 42 denotes leaked oil.

[0006]

The specific gravity is larger than that of general crude oil, light oil, heavy oil, etc., and it is easy to settle. Also, in order to enable sea transportation by tanker, a surfactant is mixed and the fluidity is increased so that it can be pumped. Given heavy oil (for example, "Orimaru John"), if it leaks on the sea surface, the sedimentation depth into the sea is much deeper than ordinary crude oil, etc., and the leaked oil is due to the contained surfactant It spreads very quickly into the sea.

[0007] For such heavy oil which is easy to settle and spread easily, the conventional oil fences of crude oil and the like have a fence depth from the sea surface of about 1 m or less, so that settling and diffusion are prevented. The impact on the environment of the leaked sea area (for example, death of fish, odor to fish, seawater pollution, seabed / shore pollution, etc.) is extremely large. Another problem is that conventional oil fences do not take measures against heavy rain. The present invention is intended to solve such a problem.

[0008] The above-mentioned "Orimar John" is obtained by mixing about 0.3% of a surfactant in order to enable the transport of tanker of "Orinocotal" produced in the Orinoco River region of Venezuela, and has a specific gravity of Between water and seawater (ρ
{1.008), the particle size is about 15μ, and it is an emulsion.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a method for handling heavy oil which has fallen onto the sea surface from above the sea surface under the loading arm, which is considered to be the highest risk of oil leakage during heavy oil handling. In order to prevent diffusion, in the heavy oil loading dolphin or the oil fence attached to the cargo quay, the oil fence was attached to both sides of the cargo dolphin or to the cargo quay with an interval. A pair of left and right telescopic arm devices, a winding drum rotatably provided between the pair of right and left telescopic arm devices on the dolphin for cargo handling or the quay for cargo handling, and a base end portion on the winding drum. A sea surface sheet that is wound and tied to the front end of the pair of right and left telescopic arm devices and the connecting member between both front ends of the pair of right and left telescopic arm devices. And a means for solving the problems are constituted by a telescopic mechanism of the telescopic arm device.

Further, a touch sensor is provided on the telescopic arm device, and the telescopic arm device is extended and driven until the front end of the telescopic arm device contacts the outer plate of the tanker in response to a detection signal from the touch sensor. A control device capable of transmitting a control signal to the telescopic mechanism is provided as means for solving the problem.

Further, the front end portions of the pair of right and left telescopic arm devices are connected to each other by a connecting member via a connecting member that is bendable and extendable to provide a means for solving the problem.

Further, fence members capable of preventing the heavy oil dropped on the sea surface sheet from flowing out onto the sea surface or into the sea are provided on both sides of the sea surface sheet to solve the problem.

Further, in order to make the sea surface sheet slack, the sea surface sheet is connected to a lower portion of the fence member as a means for solving the problem.

In the sea surface sheet type oil fence for preventing heavy oil diffusion according to the present invention, during the loading and unloading of the tanker, the sea surface sheet is extended on the lower sea surface of the loading arm portion where the danger of oil leakage is most likely to extend. It is possible to receive oil leakage and prevent the diffusion of heavy oil into the sea or the sea surface, even in normal times and abnormal times such as when mooring lines are cut and separated due to gusts and the like. .

[0015] Further, by providing fence members on both sides of the sea surface sheet, oil leaking onto the sea surface sheet can be removed from the sea surface.
It can be prevented from flowing into the sea. This makes it possible to prevent oil leakage and diffusion of heavy oil such as orimulsion, which has a deeper sedimentation depth than general crude oil and diffuses very quickly into the sea.

Further, depending on the state of separation of the tanker, ON / OFF of a touch sensor provided at the front end of the telescopic arm device is performed.
With the OFF signal, the telescopic arm device follows the detachment of the tanker and automatically extends, so that the sea surface sheet is expanded,
It is possible to expand the range of oil leakage.

Still further, by connecting both ends of the connecting member to each other between the front ends of the pair of right and left telescopic arm devices via a bendable and extendable connecting member comprising a hinge and a sleeve, a tanker ship is provided. A pair of right and left telescopic arm devices can follow the needle change.

Also, by providing the sea surface sheet with slack and connecting it to the lower part of the fences at both ends, it is possible to hold rainwater caused by heavy rain during cargo handling of the tanker on the sea surface sheet, so that it can cope with normal rainfall and heavy rain. become.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an entire construction of a sea surface sheet type oil fence for preventing heavy oil diffusion according to an embodiment of the present invention. FIG. 3, FIG. 3 is a plan view thereof, FIG. 4 is a view taken along arrow AA of FIG. 2, FIG. 5 is a view taken along arrow BB of FIG. 3, FIG. FIG. 8 is a side view showing the vicinity of the front end of the telescopic arm device, FIG. 8 is a plan view of the same, and FIG. 9 is a front view showing the vicinity of the side end of the sea surface sheet.
In FIGS. 1 to 7, the same reference numerals as those in FIGS. 10 and 11 indicate substantially the same members.

In this embodiment, the sea surface type oil seal is provided on the dolphin 3 for cargo handling, and the winding drum 13 of the sea surface sheet 10 is rotatable on the dolphin 3 for cargo handling as shown in FIGS. The retractable arm devices 14 are provided on both sides of the winding drum 13. Reference numeral 10a indicates a surface sheet hole of the sea surface sheet 10.

Each telescopic arm device 14 is a first-stage arm 14
A, a second-stage arm 14B and a third-stage arm 14C, and a sea surface sheet is provided at the front end of the foremost third-stage arm 14C.
The 10 tips (the left and right ends) are fastened.

The distance between the tanker 1 and the dolphin 3 for cargo handling in the normal cargo handling state is about several meters (the state indicated by reference symbol A in FIG. 2). When the tanker 1 lands, the telescopic arm device 14 is extended. Then, the sea surface sheet 10 is pulled out.

The extension of the telescopic arm device 14 is continued until the touch sensor 15 (see FIG. 7) attached to the third-stage arm 14C contacts the outer plate 1A of the tanker 1. Therefore, the space between the tanker 1 and the cargo handling dolphin 3 is covered with the sea surface sheet 10 spread on the sea surface.

As a telescopic mechanism of the telescopic arm device 14, a wire winch type, a hydraulic cylinder type or a compressed air cylinder type is suitable, but in this embodiment, the telescopic mechanism shown in FIG. Has adopted.

The telescopic arm device is mounted on the dolphin
Although it can be installed on the side of the cargo handling dolphin, inside the cargo handling dolphin, etc., here, an example in which it is incorporated in the cargo handling dolphin is shown. That is, as shown in FIG. 6, the first-stage arm 14A is provided with an arm recess 25 (see FIG. 2, FIG.
3). A second-stage telescopic cable 16 is attached to the base end of the second-stage arm 14B.
The second-stage arm 14B is wound endlessly around the second-stage telescopic winch 17 via a wire guide roller 19A on the front end of the second-stage arm 14A. Movement and retreat in the direction A, that is, expansion and contraction of the second-stage arm 14B can be performed.

The third stage arm 14C has a second stage arm 14B.
Is transmitted by the connecting cable 18. That is, wire guide rollers 19B and 19C are provided at the front end and the rear end of the second stage arm 14B, respectively.
Further, a connecting cable 18 having one end connected to the front end of the first-stage arm 14A via a tie-down hardware 32A is connected to a wire guide roller.
The other end of the third arm 14C is fixed to the third arm 14C by the securing metal 32B, and the other end is connected to the securing metal 32A through 19B and 19C and is stretched endlessly. An expansion mechanism is configured.

When the second-stage arm 14B moves in the direction of arrow A (forward) due to the forward rotation of the winch 17, the connecting cable 18 also moves, and the connecting cable 18 is fixed (fixed by the securing hardware 32B). The arm 14C is also pushed forward.

In this way, by rotating the winch 17 forward, the second-stage arm 14B and the third-stage arm 14C extend forward, whereby the sea surface sheet 10 is pulled out and extended. The expansion mechanism in FIG. 6 is shown on one side, and it is needless to say that similar ones are disposed on both left and right sides of the dolphin 3 for cargo handling.

Second stage arm 14B and third stage arm 14C
The front ends of the wire stays 20 are connected to the respective tips, and furthermore, arm winches 21 (see FIG. 1) around which the respective wire stays 20 are wound are provided.
The operation of 21 enables the lifting and lowering of the suspension stay 20, and the second-stage arm 14B and the third-stage arm
Each front end of the 14C is supported.

A fence fixing cable 23 is fastened to each front end of each third-stage arm 14C. Each fence fixing cable 23 is extended or retracted by a fence fixing cable winch 24 installed inside or outside the mooring dolphin 2 (or the cargo handling dolphin 3) according to the amount of expansion and contraction of the telescopic arm device 14. This is performed so that the movement of the sea surface sheet 10 due to the swing of the telescopic arm device 14 and the sea surface sheet 10 in the horizontal plane and the tidal current can be prevented.

As shown in FIGS. 2 and 3, the first-stage arm 14A
Is a recess for an arm provided in the dolphin 3 for cargo handling.
Fixed within 25. The width and height of the recess 25 have a space required for maintenance and inspection of the telescopic arm device 14. A second-stage telescopic winch 17 is also provided in the recess 25.

The winding drum 13 can also be provided on the cargo handling dolphin or in the cargo handling dolphin. Here, an example in which the winding drum 13 is incorporated in the cargo handling dolphin is shown. That is, the winding drum 13 is installed in the drum recess 26 in the dolphin 3 for cargo handling. At the bottom of this drum recess 26,
An opening 27 for drawing out the sea surface sheet 10 is formed.

As shown in FIG. 3, the front ends of the third-stage arms 14C on both sides are connected to each other by a connecting member 28 to prevent lateral deflection of the arm tip, and a plurality of floating ropes are connected to the connecting member 28. 29 are linked.

The floating rope 29 assists the extension of the central portion of the sea surface sheet 10 and also serves to reinforce the sea surface sheet 10. Floating ropes 29 are provided with floats 30 in some places to help float the sea surface sheet 10 on the sea surface.

A third-stage arm 14C is connected to both ends of the connecting member 28 via a connecting member consisting of a hinge 31 and a sleeve 32.
Are connected to the front end of the vehicle. Therefore, when the lengths of the extendable arm devices 14 are different from each other (for example, the outer plate 1A of the tanker 1 and the front surface of the dolphin are not always parallel and may be inclined by about 10 to 15 ° depending on the state). When the hinge 31 and the sleeve 32 bend or slightly expand and contract, they can follow.

Further, the winding drum 13 is fed and wound by a winch / drum control device 33 in accordance with the amount of expansion and contraction of the telescopic arm device 14.

The planer shape of the sea surface sheet 10 is formed in a wide trapezoidal shape before the leading end portion (on the side of the dolphin 3 for cargo handling), so that the winding onto the winding drum 13 can be performed more easily. Therefore, the width of the winding drum 13 is set to be longer than the interval between the left and right telescopic arm devices 14.

As shown in FIG. 9, both end fence members 11 with floats 34 are provided at both ends of the sea surface sheet 10 so as to prevent the leaked oil from flowing out of the sea surface sheet 10. I have. In addition, both ends are connected by a lower portion 11a of the fence member 11 so that the sea surface sheet 10 has slack. As a result, rainwater during loading on the sea surface sheet 10 can be retained on the sea surface sheet 10. The dotted line in FIG. 9 indicates a state in which rainwater has accumulated on the sea surface sheet.

When the sea surface sheet 10 is wound, the fence members 11 on both ends are also wound. From this viewpoint, a trapezoidal sea surface sheet that becomes narrower toward the front end can prevent bulkiness when the sea surface sheet is wound. Can be said to be a desirable shape. Reference numeral 34a indicates a weight attached below the float 34, and has a function of erecting the fences on both ends in the sea.

At the time of extension, the front end of the sea surface sheet 10 is fastened to the front end of the third-stage arm 14C and the connecting member 28, and is supported at a position higher than the sea surface as shown in FIG. And the dolphin side of the sea surface sheet 10 is also wound around the winding drum 13, so there is no risk of oil leakage from this side.

The sea surface sheet 10 is extended even when the tanker is abnormally detached due to breakage of mooring lines due to gusts or the like (indicated by reference numeral B in FIG. 2) with respect to the normal tanker position indicated by reference numeral A in FIG. Oil leakage from the loading arm 5 occurring during this time can be received, and the tanker 1
Even in a state in which the oil is separated far away, the oil leakage is retained on the sea surface sheet 10 and the diffusion to the sea surface and offshore can be prevented until a separate recovery operation is performed.

At the time of the above-mentioned abnormal separation of the tanker, the ON / OFF signal of the touch sensor 15 provided at the front end of the third-stage arm 14C is received according to the separation state of the tanker 1, and the front end of the telescopic arm device 14 is received. A control device (not shown) capable of transmitting a control signal for extending and retracting the telescopic arm device 14 to the telescopic mechanism until the portion comes into contact with the outer plate 1A of the tanker 1 is provided. Telescopic arm device
The sea surface sheet 10 is stretched by extending 14. On the other hand, when the sea surface sheet 10 is stored, the sea surface sheet 10 is slowly wound under the monitoring and assistance of the worker on the winding state on the winding drum 13.

7 and 8, reference numeral 35 denotes a roller fender. The roller fender 35 functions as a fender capable of coping with a large draft change of the tanker 1. Further, a spring 36 for constantly protruding the roller fender 35 is provided at a mounting portion of the roller fender 35, so that the roller fender 35 can follow a lateral run-out due to the rocking of the tanker 1. Reference symbol S indicates a shrinkage allowance of the roller fender 35.

Reference numeral 37 denotes a flap-shaped oil receiver. The oil receiver 37 is divided into a required number over the entire length of the connecting member 28, and each divided portion is connected by a garment-like sheet so as to be bendable.
The oil leakage between the first and the second is guided onto the sea surface sheet 10. The stopper 38 is for suppressing the oil receiver 37 from falling below a predetermined angle.

As a material of the sea surface sheet 10, a vinyl sheet, a rubber sheet, a silt fence, a silt fence + rubber coating, or the like is suitable, and a material obtained by combining these with an oil adsorption mat is also a preferable material.

The operation and effect of the sea surface sheet type oil fence for preventing heavy oil diffusion according to this embodiment are summarized as follows. 1) During the cargo handling of the tanker, the sea surface sheet 10 can be extended by extending the telescopic arm device 14 on the lower sea surface of the loading arm portion at the highest risk of oil leakage,
As a result, even during normal times and abnormal times such as when mooring lines are cut and separated due to gusts etc., oil leakage is received,
It can prevent the diffusion of heavy oil into the sea and the sea surface. 2) By providing the fence members 11 on both sides of the sea surface sheet 10, oil leaking onto the sea surface sheet 10 can be prevented from flowing out to the sea or into the sea. This makes it possible to prevent the diffusion of heavy oil such as orimulsion, which has a much deeper sedimentation depth than general crude oil and very quickly diffuses into the sea, to prevent oil leakage and diffusion. 3) By connecting both ends of the sea surface sheet 10 to the lower part of the fence member 11 with a slack, the sea surface sheet 10 can be slack and can cope with heavy rain during cargo handling. 4) Telescopic arm device 14 according to the state of separation of tanker
The telescopic arm device 14 follows the detachment of the tanker according to the ON / OFF signal of the touch sensor 15 provided at the front end of the tanker, and the sea surface sheet is expanded by automatically extending the tanker 1.
And the dolphin 3 for cargo handling can be covered with the sea surface sheet.

5) By connecting both ends of the connecting member to each other between the front ends of the pair of right and left telescopic arm devices via a bendable and extendable connecting member consisting of a hinge and a sleeve, the ship needle of the tanker is connected. The pair of right and left telescopic arm devices can follow the change. 6) The edge is cut off from the tanker side, so no equipment on the tanker side is required and oil protection can be supported independently from the quay side. 7) Maintenance and inspection are easy because the mechanical part is in the air and is installed in the recess in the dolphin. 8) Since the sea surface sheet is stored in the air, there is no marine organisms attached and maintenance is easy. 9) Since the arm and the take-up drum enter the dolphin side from the front of the dolphin when the arm is stored, maintenance and inspection of the telescopic arm and the take-up drum are easy. If necessary, it is possible to protect from waves, splashes, etc. by using GATE that moves up and down. 10) At the front end of the telescoping arm device, a fender with a spring mechanism that is normally extended can be absorbed by the spring when the tanker sways. 11) The fence fixing cable 23 can prevent the lateral deflection of the arm tip, and can prevent the flow of the sea surface sheet due to the tide.

In the above example, the oil fence is attached to a dolphin for cargo handling using reinforced concrete. The same applies to a dolphin for cargo handling using a steel pipe or the like.
It is needless to say that the same operation and effect can be obtained even when the oil fence having the above configuration is attached to (the front surface of) the quay for cargo handling. In this case, the pair of right and left telescopic arm devices are mounted on (the front surface of) the cargo handling quay at a predetermined interval, and when not in use, the telescopic arm device and the sea surface sheet are stored. The front can be effectively used.

When the tanker is unloaded on land, the loading arm 5 connecting the tanker 1 and the oil pipe 7 on land is most likely to be damaged, as shown in FIG. The risk of oil leakage is very high. Therefore, it is very effective to provide an oil fence of the above-described mechanism for receiving leaked oil at the lower part of the loading arm on the sea surface.

The extension range of the sea-surface sheet-type oil fence is determined in the longitudinal direction of the quay in consideration of the amount of movement of the tanker in the front-rear direction and the scattering range of oil leakage in the installation range of the loading arm on the quay. Usually it is about 20 m.

Further, in the direction perpendicular to the quay, the mooring line of the tanker is cut due to the range of the quay and the outer plate 1A of the tanker during normal mooring of the tanker and gusts, etc., so that the tanker detaches from the quay, and The coupling at the tip of the connected loading arm is disengaged and the oil inside the arm falls and scatters on the sea surface. Usually, it is about 25 m.

[0052]

As described above in detail, the following effects and advantages can be obtained by the sea surface sheet type oil fence for preventing heavy oil diffusion according to the present invention. (1) During loading and unloading of a tanker, the sea surface sheet can be extended by extending the telescopic arm device on the lower sea surface of the loading arm where the danger of oil leakage is the highest, so that it can be used during normal times and gusts Accordingly, even in an abnormal situation such as when the mooring line breaks and separates, oil leakage can be received and heavy oil can be prevented from diffusing into the sea or the sea surface. (2) By providing fence members on both sides of the sea surface sheet, it is possible to prevent oil leaking onto the sea surface sheet from flowing out into the sea or into the sea. This makes it possible to prevent oil leakage and diffusion of heavy oil such as orimulsion, which has a deeper sedimentation depth than general crude oil and diffuses very quickly into the sea. Also,
Can handle heavy rainfall during cargo handling. (3) In accordance with the detachment state of the tanker, the extendable arm device follows the detachment of the tanker by the ON / OFF signal of the touch sensor provided at the front end of the extendable arm device and automatically extends. The sea surface sheet is expanded, and the range of receiving oil leakage can be expanded. (4) A change in the needle of the tanker by connecting both ends of the connecting material to each other between the front ends of the pair of right and left telescopic arm devices via a bendable and extendable connecting member comprising a hinge and a sleeve. Also, a pair of right and left telescopic arm devices can follow.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the entire configuration of a heavy oil diffusion preventing sea surface sheet type oil fence as one embodiment of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a plan view showing the extension mechanism.

FIG. 4 is a view taken in the direction of arrows AA in FIG. 2;

FIG. 5 is a view taken in the direction of arrows BB in FIG. 3;

FIG. 6 is a schematic plan view showing the extension mechanism.

FIG. 7 is a side view showing the vicinity of the front end of the telescopic arm device.

FIG. 8 is a plan view of the same.

FIG. 9 is a front view showing the vicinity of a side end of the sea level sheet.

FIG. 10 is a plan view showing a cargo handling situation of a conventional tanker.

FIG. 11 is a side view of the same.

[Explanation of symbols]

 01 Conventional oil fence 1 Tanker 2 Dolphin for mooring 3 Dolphin for cargo handling 4 Mooring line 5 Loading arm 6 Fuel oil pipe (tanker side) 7 Fuel oil pipe (land side) 8 Drain tank 9 Combing 10 Sea surface sheet 11 Fence member 13 Winding drum 14 Telescopic arm device 14A First-stage arm 14B Second-stage arm 14C Third-stage arm 15 Touch sensor 16 Second-stage telescopic cable 17 Second-stage telescopic winch 18 Connecting cable 19A, 19B, 19C Wire guide roller 20 Wire Stay 21 Winch (for arm suspension) 22 Distance meter 23 Fence fixing cable 24 Winch (for fence fixing cable) 25 Arm recess 26 Drum recess 27 Opening 28 Connecting material 29 Floating rope 30 Float 31 Hinge 32 Sleeve 32A, 32B Wire Securing hardware

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tsutomu Matsumoto 1-1, Akunouramachi, Nagasaki City Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (56) References JP-A-8-209668 (JP, A) JP-A-8 −3974 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02B 15/06

Claims (5)

(57) [Claims] An oil fence attached to a dolphin for handling heavy oil or a quay for cargo handling to prevent the diffusion of the heavy oil dropped onto the sea surface from above the sea surface during heavy oil handling. A pair of left and right telescopic arm devices in which the oil fence is mounted on both sides of the cargo dolphin or on the cargo quay at an interval; and a pair of right and left telescopic arms of the cargo dolphin or the cargo quay. A winding drum rotatably provided between the arm devices; a base end portion wound around the winding drum; and a distal end portion having a front end portion and a pair of left and right telescopic arm devices. Heavy oil diffusion, characterized by comprising a sea surface sheet tied to a connecting member at the tip of the arm device, and a telescopic mechanism of the telescopic arm device. Sea-sheet type oil fence for stop. 2. A touch sensor is provided on the telescopic arm device, and the telescopic arm device receives the detection signal from the touch sensor, and operates until the front end of the telescopic arm device contacts the outer plate of the tanker. The sea surface sheet type oil fence for preventing heavy oil diffusion according to claim 1, further comprising a control device capable of transmitting a control signal for extending and driving to the expansion and contraction mechanism. 3. The pair of right and left telescopic arm devices, wherein front end portions of the telescopic arm devices are connected to each other by a connecting member via a connecting member that is bendable and extendable. Sea surface sheet type oil fence for preventing heavy oil diffusion. 4. A fence member capable of preventing the heavy oil dropped on the sea surface sheet from flowing out onto the sea surface or into the sea is provided on both sides of the sea surface sheet. Sea surface sheet type oil fence for heavy oil diffusion prevention according to any one of 1 to 3. 5. The sea surface sheet for preventing heavy oil diffusion according to claim 4, wherein both sides of the sea surface sheet are connected to a lower portion of the fence member so that the sea surface sheet has slack. Type oil fence.