阅读说明：本技术 一种流体密封的作业舱体及干式舱 (Fluid-tight operation cabin body and dry-type cabin ) 是由 李治淼 任福深 王真力 赵浩贤 刘融 史亮雄 于 2021-08-02 设计创作，主要内容包括：本发明公开了一种流体密封的作业舱体及干式舱,其中的作业舱体包括：舱体及密封结构；所述舱体包括上舱体及下舱体；所述上舱体设置上接口,所述下舱体设置下接口；所述下舱体可以相对于所述上舱体旋转以使所述下接口相对于所述上接口旋转而形成可开合接口,以便管道经由所述接口穿过所述上舱体及所述下舱体形成的作业空间；所述密封结构包括舱体密封机构及接口密封机构；所述舱体密封机构及所述接口密封机构利用充气或充液方式以形成膨出物；所述膨出物,用于完成所述密封；解决现有干式舱的座封设计方案不理想导致座封时间长、座封效果差、不能测量密封压力及密封寿命低的问题。(The invention discloses a fluid-tight operation cabin and a dry cabin, wherein the operation cabin comprises: a cabin body and a sealing structure; the cabin body comprises an upper cabin body and a lower cabin body; the upper cabin body is provided with an upper interface, and the lower cabin body is provided with a lower interface; the lower cabin body can rotate relative to the upper cabin body so that the lower interface rotates relative to the upper interface to form an openable interface, so that a pipeline passes through a working space formed by the upper cabin body and the lower cabin body through the interface; the sealing structure comprises a cabin body sealing mechanism and an interface sealing mechanism; the cabin body sealing mechanism and the interface sealing mechanism form an expansion material by utilizing an inflation or liquid filling mode; said swell for completing said seal; the problems that the existing dry-type cabin seat seal design scheme is not ideal, so that the seat seal time is long, the seat seal effect is poor, the seal pressure cannot be measured, and the seal service life is short are solved.)

1. A fluid-tight working enclosure, comprising:

a cabin body and a sealing structure;

the cabin body comprises an upper cabin body and a lower cabin body;

the upper cabin body is provided with an upper interface, and the lower cabin body is provided with a lower interface;

the lower cabin body can rotate relative to the upper cabin body so that the lower interface rotates relative to the upper interface to form an openable interface, so that a pipeline to be repaired enters a working space formed by the upper cabin body and the lower cabin body through the openable interface;

the sealing structure comprises a cabin body sealing mechanism and an interface sealing mechanism;

the cabin body sealing mechanism is used for sealing a gap between the upper cabin body and the lower cabin body;

the interface sealing mechanism is used for sealing a gap between the pipeline and the interface;

the cabin body sealing mechanism and the interface sealing mechanism form an expansion material by utilizing an inflation or liquid filling mode;

the swelling matter is used for plugging the gap to complete the sealing.

2. The working cabin according to claim 1, wherein:

the cabin body is spherical;

the lower cabin body is connected with the upper cabin body in a mode of overlapping port parts.

3. The working cabin according to claim 2, wherein:

the cabin sealing mechanism comprises a first expansion layer;

the upper cabin body is provided with a first accommodating groove;

the first expansion layer is arranged in the first accommodating groove;

the first expansion layer is connected with a gas or liquid filling device so as to fill gas or liquid into the first expansion layer to enable the first expansion layer to partially expand from the first holding tank to form a first expanded object;

the first bulge for sealing the gap between the upper and lower hull ports.

4. The working cabin according to claim 3, wherein:

the interface sealing mechanism comprises a first sealing system and a second sealing system;

the first sealing system is used for plugging a radial gap between the lower interface and the pipeline;

the second sealing system is used for plugging a residual radial gap between the pipeline and the interface; and

the first sealing system is used for establishing a butt-joint relation with the first sealing system and blocking a gap between butt-joint end faces.

5. The working cabin according to claim 4, wherein:

the first sealing system comprises a second intumescent layer;

a second accommodating groove is formed in the inner side of the lower interface;

the second expansion layer is arranged in the second accommodating groove;

the second expansion layer is connected with a gas or liquid filling device so as to fill gas or liquid into the second expansion layer to expand the second expansion layer from the second holding tank to form a second expanded object;

the second swell is used for plugging the radial gap between the lower interface and the pipeline.

6. The working cabin according to claim 5, wherein:

the second sealing system comprises a third intumescent layer;

a third accommodating groove is formed in the upper cabin body;

the third expansion layer is arranged in the third accommodating groove;

a lead connecting groove is arranged between the third accommodating groove and the second accommodating groove;

two ends of the lead groove are butted with two ends of the second accommodating groove, so that two end faces of the third expansion layer are butted with two end faces of the second expansion layer to form a closed structure;

the third expanded layer is communicated with the first expanded layer so that the third expanded layer is expanded from the third holding tank to form the third expanded product when the first expanded layer is subjected to the expansion;

and the third swelling material is used for filling the guiding groove so as to block a residual radial gap between the interface and the pipeline and block a gap between the butt joint end faces of the third expansion layer and the second expansion layer.

7. The working cabin according to claim 6, wherein:

a piston is arranged in the third accommodating groove;

a fourth accommodating groove is formed in the piston;

the third expansion layer is arranged in the fourth accommodating groove;

the third accommodating groove is respectively communicated with the first expansion layer and the third expansion layer;

the gas or liquid filled in the first expansion layer enters the third accommodating groove to drive the piston to approach the guiding groove, so that the third expansion layer expands from the fourth accommodating groove to form the third expanded object.

8. The working pod of any of claims 1-7, wherein:

the lower end of the upper cabin body is connected with a limiting plate;

the limiting plate is used for limiting the lower cabin body to prevent the lower cabin body from falling from the upper cabin body.

9. The working cabin according to claim 8, wherein:

a gear transmission group is arranged in the lower cabin body;

the gear transmission set is used for driving the lower cabin body to rotate so that the lower interface rotates relative to the upper interface to form the openable interface;

and/or the presence of a gas in the interior of the container,

a safety cabin is arranged in the lower cabin body;

escape equipment is arranged in the safety cabin, so that constructors can safely escape from the cabin when the cabin and/or the sealing structure are in failure.

10. A dry tank, comprising:

the working pod of any of claims 1-9.

Technical Field

The present disclosure relates to dry tanks for underwater pipeline construction or repair.

Background

For the dry type cabin for underwater pipeline construction or maintenance, the damaged part of the pipeline to be maintained needs to be positioned inside the operation cabin body so that maintenance personnel can repair the damaged part, and thus the pipeline needs to penetrate through the inside of the operation cabin body; the operation cabin body needs to be seated on the pipeline so as to ensure that the interior of the operation cabin body is in a dry operation environment when repair operation is carried out by maintenance personnel. In the prior art, the seat design scheme of the dry-type cabin is not ideal, and mainly has the advantages of simple seat design scheme, long seat sealing time and poor seat sealing effect.

In addition, the existing dry-type cabin mainly utilizes threads or sealing rings for sealing, so that the size of sealing pressure cannot be accurately measured, and the threads or the sealing rings continuously bear alternating load in the sealing process due to prestress applied to the threads or the sealing rings in the sealing process, so that the sealing service life is shortened.

Disclosure of Invention

In view of this, the present disclosure provides a fluid-tight working chamber and a dry chamber using the same, which solve the problems of long sealing time, poor sealing effect, inconvenient measurement of sealing contact pressure and short sealing life caused by the unsatisfactory sealing design of the conventional dry chamber.

In a first aspect, the fluid-tight working chamber comprises:

a cabin body and a sealing structure;

the cabin body comprises an upper cabin body and a lower cabin body;

the upper cabin body is provided with an upper interface, and the lower cabin body is provided with a lower interface;

the lower cabin body can rotate relative to the upper cabin body so that the lower interface rotates relative to the upper interface to form an openable interface, so that a pipeline to be repaired enters a working space formed by the upper cabin body and the lower cabin body through the openable interface;

the sealing structure comprises a cabin body sealing mechanism and an interface sealing mechanism;

the cabin body sealing mechanism is used for sealing a gap between the upper cabin body and the lower cabin body;

the interface sealing mechanism is used for sealing a gap between the pipeline and the interface;

the cabin body sealing mechanism and the interface sealing mechanism form an expansion material by utilizing an inflation or liquid filling mode;

the swelling matter is used for plugging the gap to complete the sealing.

Further, the cabin body is spherical;

the lower cabin body is connected with the upper cabin body in a mode of overlapping port parts.

Further, the cabin sealing mechanism comprises a first expansion layer;

the upper cabin body is provided with a first accommodating groove;

the first expansion layer is arranged in the first accommodating groove;

the first expansion layer is connected with a gas or liquid filling device so as to fill gas or liquid into the first expansion layer to enable the first expansion layer to partially expand from the first holding tank to form a first expanded object;

the first bulge for sealing the gap between the upper and lower hull ports.

Further, the interface sealing mechanism comprises a first sealing system and a second sealing system;

the first sealing system is used for plugging a radial gap between the lower interface and the pipeline;

the second sealing system is used for plugging a residual radial gap between the pipeline and the interface; and

the first sealing system is used for establishing a butt-joint relation with the first sealing system and blocking a gap between butt-joint end faces.

Further, the first sealing system comprises a second intumescent layer;

a second accommodating groove is formed in the inner side of the lower interface;

the second expansion layer is arranged in the second accommodating groove;

the second expansion layer is connected with a gas or liquid filling device so as to fill gas or liquid into the second expansion layer to expand the second expansion layer from the second holding tank to form a second expanded object;

the second swelling substance is used for blocking the radial gap between the lower interface and the pipeline.

Further, the second sealing system comprises a third intumescent layer;

a third accommodating groove is formed in the upper cabin body;

the third expansion layer is arranged in the third accommodating groove;

a lead connecting groove is arranged between the third accommodating groove and the second accommodating groove;

two ends of the lead groove are butted with two ends of the second accommodating groove, so that two end faces of the third expansion layer are butted with two end faces of the second expansion layer to form a closed structure;

the third expanded layer is communicated with the first expanded layer so that the third expanded layer is expanded from the third holding tank to form the third expanded product when the first expanded layer is subjected to the expansion;

and the third swelling material is used for filling the guiding groove so as to block a residual radial gap between the pipeline and the interface and block a gap between the butt joint end faces of the third expansion layer and the second expansion layer.

Further, a piston is arranged in the third accommodating groove;

a fourth accommodating groove is formed in the piston;

the third expansion layer is arranged in the fourth accommodating groove;

the third accommodating groove is respectively communicated with the first expansion layer and the third expansion layer;

the gas or liquid filled in the first expansion layer enters the third accommodating groove to drive the piston to approach the guiding groove, so that the third expansion layer expands from the fourth accommodating groove to form the third expanded object.

Further, the lower end of the upper cabin body is connected with a limiting plate;

the limiting plate is used for limiting the lower cabin body to prevent the lower cabin body from falling from the upper cabin body.

Further, a gear transmission group is arranged in the lower cabin body;

the gear transmission set is used for driving the lower cabin body to rotate so that the lower interface rotates relative to the upper interface to form the openable interface;

and/or the presence of a gas in the interior of the container,

a safety cabin is arranged in the lower cabin body;

escape equipment is arranged in the safety cabin, so that constructors can safely escape from the cabin when the cabin and/or the sealing structure are in failure.

In a second aspect, a dry tank, comprises:

the working nacelle according to any of the first aspect.

The present disclosure has the following beneficial effects:

the operation cabin disclosed by the invention comprises the following steps that firstly, the structural design of the cabin body that the upper cabin body and the lower cabin body can rotate relative to each other is adopted, the sealing between the upper cabin body and the lower cabin body and the sealing between the pipeline and the cabin body interface are required to be carried out to ensure that the operation cabin body provides a dry-type operation environment, then, the gap between the upper cabin body and the lower cabin body is sealed by utilizing the cabin body sealing mechanism, the gap between the pipeline and the interface is sealed by utilizing the interface sealing mechanism, the cabin body sealing mechanism and the interface sealing mechanism adopt an inflation or liquid-filling expansion system to promote the expansion system to generate an expansion object, finally, each gap is sealed by utilizing the expansion object to seal, the sealing between the upper cabin body and the lower cabin body and the sealing between the pipeline and the cabin body interface are finally finished, the expansion object is formed by the expansion system being expanded and deformed by inflation or the liquid-filling, the sealing effect is good in a mode of sealing each gap, and the problems that the seating time is long and the seating time is caused by the non-ideal design scheme of the existing dry-type cabin can be effectively solved, Poor seating effect. In addition, the expansion layer is in a zero-stress state in the sealing process, so that the problem that the sealing element bears prestress can be effectively solved; meanwhile, the pressure of the gas or liquid filled in the expansion layer is known, so that the problem that the sealing contact pressure is not measurable can be effectively solved.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural view of a fluid-tight working enclosure according to an embodiment of the present disclosure;

FIG. 2 is a diagram illustrating a relative rotation of the upper and lower cabins according to the embodiment of the disclosure;

fig. 3 is a schematic longitudinal cutting structure of the working cabin according to the embodiment of the disclosure;

FIG. 4 is an enlarged partial view of section I of FIG. 3 of an embodiment of the present disclosure;

FIG. 5 is a schematic view of an interface sealing mechanism with a piston structure according to an embodiment of the disclosure;

FIG. 6 is a schematic view of a gas or liquid filled passage of a first intumescent layer in accordance with embodiments of the disclosure;

figure 7 is a schematic view of the inflation or liquid-filling channel location of the second intumescent layer of an embodiment of the disclosure.

Detailed Description

The present disclosure is described below based on examples, but it is worth explaining that the present disclosure is not limited to these examples. In the following detailed description of the present disclosure, some specific details are set forth in detail. However, the present disclosure may be fully understood by those skilled in the art for those parts not described in detail.

Furthermore, those of ordinary skill in the art will appreciate that the drawings are provided solely for the purposes, features, and advantages of the present disclosure, and are not necessarily drawn to scale.

Also, unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, the meaning of "includes but is not limited to".

FIG. 1 is a schematic structural view of a working nacelle according to an embodiment of the disclosure; FIG. 2 is a diagram illustrating a relative rotation of the upper and lower cabins according to the embodiment of the disclosure; as shown in fig. 1 and 2: the operation cabin body comprises a cabin body and a sealing structure; the cabin body comprises an upper cabin body 1 and a lower cabin body 2; the upper cabin body 1 is provided with an upper interface 11, and the lower cabin body 2 is provided with a lower interface 21; the lower chamber 2 can rotate relative to the upper chamber 1 to rotate the lower interface 21 relative to the upper interface 11 to form an openable interface, so that the pipeline 3 passes through the working space 100 formed by the upper chamber 1 and the lower chamber 2 through the openable interface; the sealing structure comprises a cabin sealing mechanism and an interface sealing mechanism, wherein the cabin sealing mechanism is used for sealing a contact gap between the upper cabin body 1 and the lower cabin body 2, and the interface sealing mechanism is used for sealing a radial gap between the pipeline 3 and the openable interface (the upper interface 11 and the lower interface 21). The cabin body sealing mechanism and the interface sealing mechanism disclosed by the invention generate the bulges in an inflation or liquid filling mode, and the contact gap and the radial gap are sealed by the bulges to complete the sealing between the upper cabin body and the lower cabin body and the sealing between the pipeline and the openable and closable interface.

And moreover, the gas filling or liquid filling mode provides a sealing mode, so that on one hand, the sealing pressure of the sealing structure can be accurately measured, and on the other hand, the sealing structure does not bear prestress, so that the sealing pressure can be effectively controlled, and the service life of the sealing structure is prolonged.

In fig. 1 and 2, the capsule body be spherical, lower capsule body 2 is connected through the mode that the port part overlaps with last capsule body 1, it is specific after inserting the lower port of last capsule body 1 with the upper port of lower capsule body 2, weld limiting plate 5 at the lower port of last capsule body 1, through this limiting plate 5 restriction lower capsule body 2 in order to avoid it to drop from last capsule body 1, can also take place relative rotation between lower capsule body 2 and the last capsule body 1 simultaneously, when lower capsule body 2 rotates to all to enter into in the last capsule body 1, the joint that can open and shut is whole to be opened makes the capsule body can ride and sit on waiting to maintain pipeline 3, then drive lower capsule body 2 rotatory, the joint that can open and shut is closed, wait to maintain pipeline 3 and enter into the operation space 100 that upper capsule body and lower capsule body formed.

Fig. 3 is a schematic longitudinal cutting structure of the working cabin according to the embodiment of the disclosure; FIG. 4 is an enlarged partial view of section I of FIG. 3 of an embodiment of the present disclosure; as shown in fig. 3 and 4: the cabin body sealing mechanism comprises a first expansion layer 13, a first accommodating groove 12 is arranged on the upper cabin body 1, the first accommodating groove 12 is formed at the position where the port parts of the lower cabin body 2 and the upper cabin body 1 are overlapped, and the first expansion layer 13 is arranged in the first accommodating groove 12; the first expansion layer 13 is connected with an inflation or liquid filling device so as to inflate or fill liquid into the first expansion layer 13, so that the first expansion layer 13 partially expands out of the first holding tank 12 to form a first expanded object, a contact gap between the port of the upper cabin body and the port of the lower cabin body is sealed by the first expanded object, water outside the cabin body enters the working environment 100 of the cabin body from the contact gap between the upper cabin body and the lower cabin body, and the dry-type operation environment is damaged.

The first expansion layer 13 may be an elastic pipe, and the initial state of the first expansion layer 13 in the first accommodation groove 12 is not inflated or filled with liquid and is not expanded and deformed, so that the relative rotation between the upper and lower cabins is not hindered; when the cabin body is mounted on the pipeline 3 to be maintained, the first expansion layer 13 with elasticity is inflated or filled with liquid, and when the first expansion layer 13 is inflated or filled with liquid to a certain amount, the first accommodating groove 12 is filled with the first expansion layer 13, and the first accommodating groove 12 is expanded continuously and is expanded out of the first accommodating groove 12, because the first accommodating groove 12 is opened at the position where the ports of the upper cabin body 1 and the lower cabin body 2 are partially overlapped, the expanded object of the first expansion layer 13 further seals the contact gap between the port of the upper cabin body and the port of the lower cabin body, and the sealing between the lower cabin body 2 and the upper cabin body 1 is completed.

In fig. 3 and 4, the interface sealing mechanism is used to seal the gap at the interface between the pipeline and the cabin, because the structure at the interface is complex, the interface sealing mechanism of the present disclosure is subdivided into a first sealing system and a second sealing system, where the first sealing system is used to seal the radial gap between the lower interface 21 and the pipeline 3, and the radial gap between the pipeline and the rest of the interface is completed by the second sealing system, so as to finally complete the end face sealing between the pipeline and the openable and closable interface.

The first sealing system comprises a second expansion layer 23, because the interface between the pipeline 3 and the cabin body is an openable and closable interface formed by an upper interface 11 and a lower interface 21, the port of the upper cabin body is partially overlapped with the port of the lower cabin body, and the port of the lower cabin body is positioned at the inner side of the port of the upper cabin body, the second accommodating groove 22 is arranged at the inner side of the lower interface 21, the second expansion layer 23 is arranged in the second accommodating groove 22, and the second expansion layer 23 is connected with an inflation or liquid filling device so as to inflate or fill the second expansion layer 23 from the second accommodating groove 22 to form a second bulge, and the radial gap between the lower interface 21 and the pipeline 3 is sealed by the second bulge.

The second expansion layer 23 can also be a pipe with elasticity, and the same expansion sealing principle as the first expansion layer 13 is adopted, namely when the pipeline 3 does not ride at the joint, the second expansion layer 23 is in an initial state, cannot expand out of the second accommodating groove 22, and cannot influence the pipeline 3 to enter the joint; when the pipe 3 rides on the joint, the second expansion layer 23 is inflated or filled with liquid, the second expansion layer 23 gradually expands and finally expands from the second accommodating groove 22, and the expanded matter further seals the radial gap between the lower joint 21 and the pipe 3, so that the radial gap sealing between the lower joint 21 and the pipe 3 is completed.

At this time, the remaining radial gap at the interface between the pipe 3 and the pipe 3 is not sealed, except after the radial gap between the lower interface 21 and the pipe 3 is sealed by the first sealing system. The second sealing system comprises a third expansion layer 15, a third accommodating groove 14 is arranged in the upper cabin body 1, the third expansion layer 15 is arranged in the third accommodating groove 14, a lead connecting groove 24 is arranged between the third accommodating groove 14 and the second accommodating groove 22, and two ends of the lead connecting groove 24 are butted with two ends of the second accommodating groove 22, so that the third expansion layer 15 can be butted with the second expansion layer 23 in an end face mode to form a closed structure; the third expansion layer 15 is communicated with the first expansion layer 13, when the first expansion layer 13 expands, the third expansion layer 15 expands from the third accommodating groove 14 to form a third expanded object, and the connecting groove 24 is filled with the third expanded object to seal the residual radial gap at the interface of the pipeline and the joint and seal the gap between the butt joint end face 25 of the third expansion layer 15 and the second expansion layer 23. Similarly, the third expansion layer 15 may also be an elastic pipe, and the same expansion sealing principle as the first expansion layer 13 is adopted, that is, when the pipe 3 does not ride on the interface, the third expansion layer 15 is in an initial state, and will not expand from the third accommodating groove 14, and will not affect the pipe 3 entering the interface; when the pipe 3 is mounted at the joint, the third expansion layer 15 is inflated or filled with liquid along with the first expansion layer 13, and the third expansion layer 15 gradually expands and finally expands from the third accommodation groove 14.

Under the combined action of the second expansion layer 23 and the third expansion layer 15, a completely closed sealing structure can be formed between the pipeline 3 and the radial gap at the interface, so that the end face sealing between the pipeline and the interface is ensured.

Because the third accommodating groove 14 is formed in the side wall of the upper cabin 1, and the difficulty in controlling the expansion and expansion of the third expansion layer 15 is high, the piston 17 is arranged in the third accommodating groove 14, as shown in fig. 5, the fourth accommodating groove 16 is arranged in the piston 17, the third expansion layer 15 is arranged in the fourth accommodating groove 16, the third accommodating groove 14 is respectively communicated with the first expansion layer 13 and the third expansion layer 15, and the gas or liquid filled in the first expansion layer 13 enters the third accommodating groove 14 to drive the piston 17 to approach the guide groove 24, so that the third expansion layer 15 can be expanded from the fourth accommodating groove 16 and directly enter the guide groove 24, and the expansion is not facilitated due to the too deep depth of the third accommodating groove 14.

FIG. 6 is a schematic view of a gas or liquid filled passage of a first intumescent layer in accordance with embodiments of the disclosure; in fig. 6, in order to inflate or inflate the first expandable layer, it is clear that a communication channel needs to be established between the first expandable layer 13 and the inflation or inflation device. The upper cabin body 1 is provided with a straight pipe section structure 10, the straight pipe section structure 10 is connected with a transportation channel of the cabin body, specifically, a communication channel 18 is arranged in the pipe wall of the straight pipe section structure 10, and the communication channel 18 is communicated with the first expansion layer 13 and the third expansion layer 15 and used for the gas or liquid in the first expansion layer 13 and the third expansion layer 15 to enter and discharge.

FIG. 7 is a schematic view of the inflation or liquid-filling channel location of the second intumescent layer of an embodiment of the disclosure; in fig. 7, since the second receiving groove is disposed inside the lower interface 21, the present disclosure provides an inflation or filling channel 26 at a suitable position of the lower tank sidewall, the inflation or filling channel 26 communicating with the second expandable layer 23 disposed inside the second receiving groove 22.

Of course, the disclosed working pod is intended for subsea pipeline maintenance, so it may be preferable to use liquid-filled equipment.

In fig. 7, a gear transmission set 6 is arranged in the lower cabin, and the present disclosure drives the lower cabin 2 to rotate through the gear transmission set 6 so that the lower interface 21 rotates relative to the upper interface 11 to form an openable and closable interface.

In fig. 1 and 2, a safety cabin 4 is arranged in the lower cabin body of the present disclosure, and necessary escape equipment is placed in the safety cabin 4, so that when the cabin body and/or the sealing structure fails, maintenance constructors can use the escape equipment to ensure safe escape from the cabin body.

The above-mentioned embodiments are merely embodiments for expressing the disclosure, and the description is more specific and detailed, but not construed as limiting the scope of the disclosure. It should be noted that, for those skilled in the art, various changes, substitutions of equivalents, improvements and the like can be made without departing from the spirit of the disclosure, and these are all within the scope of the disclosure. Therefore, the protection scope of the present disclosure should be subject to the appended claims.