KR20130046790A

KR20130046790A - Artificial living structure for the fresh water fishes

Info

Publication number: KR20130046790A
Application number: KR1020110111372A
Authority: KR
Inventors: 최수용
Original assignee: 최수용
Priority date: 2011-10-28
Filing date: 2011-10-28
Publication date: 2013-05-08
Also published as: KR101330164B1

Abstract

The aquatic ecological environment structure of the aquatic organisms for restoration of ecological rivers according to the present invention is a part of the evacuation space for the sudden change of the surrounding environment or the preservation in a crisis situation, and routine swimming (遊泳) living spaces for feeding and feeding activities, spawning spaces for stable growth of spawning, hatching or fry, and resting spaces for relieving instincts and stress. By supplying fresh water from the upstream to the spawning and rest areas, it is possible to provide a natural aquatic environment similar to that for the activation of aquatic life in the ecological rivers and conservation of the aquatic ecosystem. Water and intimate creatures, such as fish and amphibians, are able to multiply, creating a balance between the surrounding waterfront ecosystems and harming human life. The larvae of various insects can also seek to coexist with humans by controlling nature, and play the role of nature-friendly living, eco-friendly emotional cultivation and nature observation, and eco-experience area of neighboring citizens. It will be reborn as a healthy ecological river.

Description

Artificial living structure for the fresh water fishes

The present invention relates to an aquatic ecological environment structure of aquatic organisms for restoration of ecological rivers. More specifically, the present invention relates to an evacuation space for sudden change of surrounding environment or preservation in a crisis situation. A living space for daily swimming and feeding activities is provided, and a spawning space section for stable growth of spawning, hatching or fry, and a resting space section for relieving instinct and stress are provided. This makes it possible for fish that live in the water to live comfortably and provide aquatic environment similar to that of natural state, although not identical to nature for vitalization of aquatic life in the ecological rivers and conservation of the aquatic ecosystem. Concerning the aquatic ecological environment structure of aquatic life for ecological river restoration Will.

In general, a river has a large amount of pollutants deposited on roads, sewers, etc. due to overflowing water, such as rainwater during rainfall, and as a result, the river is discharged by a large amount of water pollutants and pathogenic microorganisms contained in the overflow water. There was a problem of being easily contaminated.

For example, problems such as contamination of water quality by microorganisms, deterioration of aesthetics by contaminants, and closure of rivers occur, resulting in the death of various aquatic organisms in the rivers. In this situation, since there are no measures for the initial stormwater and the overflow, the ecological environment of the river is polluted repeatedly during rainfall, and this problem has a problem that is a major obstacle in restoring the ecological river.

In addition, various artificial structures of natural ecological rivers are provided for the creation of ecological environment for the natural habitat of aquatic organisms, but the composition of these artificial structures provides simple artificial rivers without considering the characteristics of the aquatic organisms or their habitat environment. There was a big problem that it was not helpful to the natural habitat of living things, and wasted only manpower and money to restore ecological rivers.

An object of the present invention is to solve such a conventional problem, evacuation space for the sudden change of the surrounding environment during the life of aquatic life in the water of ecological rivers, and the routine swimming, And a living space for feeding and spawning space for stable growth of spawning, hatching or fry, and a resting space for concealing instincts and stress relief. It is to provide an aquatic environment structure of aquatic organisms for restoration of ecological rivers, which can be generated and live similar to the natural environment.

Another object of the present invention, it is possible to supply fresh living water supplied upstream to the evacuation space, living space, spawning space, or resting space in which these fish live, the habitat activation of aquatic organisms inhabiting ecological rivers and aquatic ecosystem It is to provide an aquatic ecological structure of aquatic organisms for restoration of ecological rivers, which makes it possible to provide a suitable aquatic ecological environment similar to the natural state for the preservation.

This object of the present invention, the first evacuation space portion formed in a box shape is connected to the bottled water supply conduit on the upstream front side, the inlet slit groove and the access hole is formed on the downstream rear side and the evacuation space divided by the partition wall inside And a living space portion in which a living water supply conduit is connected to an upstream front side, a slitting downstream groove is formed on an inclined downstream side, and a living space divided by a partition wall is formed inside, and an upper cover is opened to cover an upper cover. Scattering space portion formed in the shape and connected to the bottled water supply conduit on the front side upstream, the entrance hole is formed on the downstream rear side formed with a triangular pyramid and the rock layer is formed on the inner side, and formed in a box shape and bottled water on the front side upstream Supply space is connected to the supply conduit, the exit hole is formed in the rear and side of the downstream side and the resting space portion formed by the partition partition in the inner side, triangular prism The aquatic organisms for restoring the ecological river according to the present invention includes a second evacuation space formed in an upstream side, wherein a bottled water supply conduit is connected to an upstream front side, an access hole is formed at a downstream rear side, and an evacuation space divided by a partition wall is formed inside. Is achieved by the aquatic ecological structure of the

The aquatic ecological environment structure of aquatic organisms for restoring an ecological river according to an embodiment of the present invention will be clearly understood by the embodiments described in detail below with reference to the accompanying drawings.

The aquatic ecological environment structure of the aquatic organisms for restoration of ecological rivers according to the present invention is a part of the evacuation space for the sudden change of the surrounding environment or the preservation in a crisis situation, and routine swimming (遊泳) living spaces for feeding and feeding activities, spawning spaces for stable growth of spawning, hatching or fry, and resting spaces for relieving instincts and stress. By supplying fresh water from the upstream to the spawning and rest areas, it is possible to provide a natural aquatic environment similar to that for the activation of aquatic life in the ecological rivers and conservation of the aquatic ecosystem. Water and intimate creatures, such as fish and amphibians, are able to multiply, creating a balance between the surrounding waterfront ecosystems and harming human life. The larvae of various insects can also seek to coexist with humans by controlling nature, and play the role of nature-friendly living, eco-friendly emotional cultivation and nature observation, and eco-experience area of neighboring citizens. There is an excellent effect to achieve a rebirth into a healthy ecological river.

1 is a plan view of the underwater ecological environment structure according to an embodiment of the present invention
2A and 2B are longitudinal sectional views showing a perspective view and an installation state of the first evacuation space part;
3A is a perspective view of a living space part
Figure 3b is an enlarged perspective view of the incision slit groove of the living space shown in Figure 3a
Figure 3c is a longitudinal sectional view showing the installation state of the living space shown in Figure 3a
4A and 4B are longitudinal sectional views showing a perspective view and an installation state of a scattering space part;
Figure 5a, 5b is a longitudinal sectional view showing a perspective view and the installation state of the resting space portion
6A and 6B are longitudinal sectional views showing a perspective view and an installation state of the second evacuation space portion;
7A and 7B are schematic plan views showing a state in which infrared cameras are installed in respective spaces of the aquatic ecological environment structure according to the embodiment of the present invention;
8 is a plan view of the underwater ecological environment structure according to another embodiment of the present invention

Hereinafter, with reference to the accompanying drawings will be described in more detail the aquatic eco-environmental structure of aquatic organisms for restoration of ecological rivers of the present invention.

Prior to this, the terms used in the specification and claims should not be construed as limited to ordinary or dictionary meanings, and the inventor must design the concept of the term appropriately in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiment described in the present specification and the constitution shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, at the time of this application, It is to be understood that equivalents and modifications are possible.

The aquatic ecological environment structure (A) of the aquatic organisms for restoring the ecological river according to an embodiment of the present invention, as shown in Figures 1 to 6b, is formed in a box shape is connected to the bottled water supply conduit 6 on the front And a first slit groove (1) and a rear slit groove (11) and an access hole (12) are formed on the downstream side and the rear side and are partitioned by a partition (13) to form an evacuation space (14). The slanted box is formed to have a bottled water supply conduit 6 connected to the front side, and an inclined slit groove 21 is formed on the rear side of the inclined downstream side, and the living space 23 is divided by the partition 22 inside. The formed living space 2 and the upper part are formed in a box shape in which the upper cover 35 is covered, and the bottled water supply conduit 6 is connected to the front, and the entrance hole is formed at the downstream rear side where the triangular pyramid 34 is formed. 31 is formed and the scattering space portion 3 is formed in the scattering space 32, the rock layer 33 is formed inside the box-shaped, The rest space portion 4 is formed with a bottled water supply conduit 6 is connected to the front side and the exit hole 41 is formed on the rear side and the side of the downstream side and the resting space 42 divided by the partition wall 41 is formed on the inner side. ), And formed with a triangular prism shape, the bottled water supply conduit 6 is connected to the front side, and an exit hole 51 is formed at the downstream rear side, and an evacuation space 53 is formed at the inside by the partition wall 52. It includes two evacuation spaces (5).

The bottled water supply conduit 6 consists of a separate independent conduit to supply clean water at a place where clean water, such as first-class water or second-class water, is located upstream.

As shown in FIGS. 2A and 2B, the first evacuation space portion 1 is formed in a box shape in which all sides are blocked, and an incision slit groove 11 is formed to allow the aquatic life to enter and exit the downstream side. A plurality of access holes 12 are formed at the rear side, and inside the partition slit groove 11 and the access hole 12 are partitioned into partitions 13 so that aquatic organisms can enter safely and the sand and gravel are bottomed. An evacuation space 14 is formed.

On the partition 13, a through hole 131 is formed to facilitate movement to another evacuation space 14 in which aquatic organisms are divided.

The front of the first evacuation space (1) is a clean, such as first or second water to block the inflow of contaminated water or inflow of pollutants in accordance with the change of the surrounding environment and to keep the interior of the evacuation space (14) always clean A bottled water supply conduit 6 through which water is supplied is provided.

The bottled water introduced through the bottled water supply conduit 6 is discharged to the outside through the inlet slit groove 11 and the entrance hole 12 of the side and rear in the state filled in the evacuation space 14, the inflow and outflow continue It is made so that the contaminated water does not flow into the evacuation space (14). Since the evacuation space 14 is always filled with uncontaminated bottled water, it is possible to maintain a clean state, thereby preventing the aquatic organisms in the evacuation space 14 from being killed by contaminated water or contaminants.

The first evacuation space (1) is installed to be always submerged under the water surface (W) of the river is embedded in the stepped beam (7) of the river with a lot of underwater life, the interior of the evacuation space 14 is not contaminated Since the living water is always filled, it acts like a spring rising under a large stone, so that there is water at all four seasons in spring, summer, autumn, and winter, and the evacuation of living things is possible.

The living space portion 2, as shown in Figures 3a to 3b, the four sides are formed to be blocked in the downstream side is formed in the inclined box shape inclined slit groove for access of the aquatic organisms on the inclined rear surface ( 21 is formed, the living space 23 is divided by the partition wall 22 to form a sand and gravel on the bottom, the other living space 23 is divided into aquatic life on the partition 22 Through hole 221 is formed to facilitate movement to.

The downstream rear side of the living space part 2 is formed to be inclined at an angle to be inclined by extending from the riverside to the center of the river so that sand can be easily swept away by the running water to prevent the sand from being accumulated by the running water.

The upstream side of the living space 2 has a clean surface such as primary or secondary water to keep the interior of the living space 23 clean at all times in order to prevent the inflow of polluted water or contaminants caused by changes in the surrounding environment. Bottled water supply conduits 6 through which water is supplied are connected.

The living water flowing through the bottled water supply conduit 6 is discharged to the outside through the incision slit groove 21 in the rear in the state filled in the living space 23, so that the inflow and outflow is continuously made and the living space 23 ), No contaminated water flows in. Since the living space 23 is always filled with uncontaminated bottled water, it is possible to maintain a clean state to prevent the aquatic organisms in the living space 23 from being killed by contaminated water or pollutants. The cutting slit groove 21 is a wooden board 21a is supported by the guide rail 21b on the top, so that the wooden board 21a rises, so that the height of the cutting slit groove 21 is set to the height of the wooden board 21a. It can be adjusted by adjusting.

The living space 2 can be installed anywhere regardless of the place, and since 2/3 is installed in the bottom surface G of the river in the waterside part, clean water is provided in the living space 23. In the filled state, it acts as a pool of natural rivers, acting like a spring rising under a large stone, and thus there will be water at all seasons, so that living things such as fish and amphibians are possible.

As shown in FIGS. 4A and 4B, the scattering space part 3 is formed in a box shape in which an upper part is opened to cover an upper cover 35, and a bottled water supply conduit 6 is connected to an upstream side and a triangular pyramid. Scattering space 32 is formed with a hole 31 for the entrance and exit of aquatic organisms on the downstream rear side formed with the 34 and a rock layer 33 for scattering and hatching of the aquatic organisms or growth of fry Is formed.

The rock layer 33 arranges four basic rocks 331 at regular intervals on sand and gravel laid on the bottom surface of the scattering space 32 in order to provide an optimal spawning space for aquatic organisms entering the spawning space. One roof rock 332 having a large diameter is disposed on the four foundation rocks 331 to provide scattering and hatching places.

The rock layer 33 may further include a base rock 331 and a roof rock 332 formed thereon to form a rock layer 33 having a multilayer structure.

A bottled water supply conduit on the upstream side of the scattering space part 3 is supplied with fresh bottled water to keep the inside of the scattering space 32 clean at all times in order to prevent the inflow of polluted water or contaminants due to changes in the surrounding environment. (6) is connected.

The bottled water introduced through the bottled water supply conduit 6 is discharged to the outside through the entrance hole 31 on the downstream rear side in the state of being filled in the scattering space 32 so that the inflow and outflow is continuously made. 32) no contaminated water flows in. Since the scattering space 32 is always filled with uncontaminated bottled water, it is possible to maintain a clean state to prevent the aquatic organisms in the scattering space 32 from being killed by contaminated water or pollutants.

In addition, both ends are formed in a horn shape on the downstream rear side of the scattering space part 3 so that sand can be easily swept away from the flowing water to prevent the sand from being accumulated by the flowing water. Since 3 is inserted and installed so as to always be submerged in the water surface (W), the aquatic organisms in the spawning space portion 3 are scattered and hatched, and the growth of the fry is possible stably.

As shown in FIGS. 5A and 5B, the resting space part 4 is formed in a box shape in which all sides are blocked so that the bottled water supply conduit 6 is connected to the upstream front side, and the aquatic organisms enter and exit the downstream rear side and the side surface. An access hole 41 is formed therein and is divided by a partition wall 43 in which a through hole 431 is formed, thereby forming a resting space 42 in which sand and gravel are laid on the bottom.

The bottled water supply conduit in which fresh bottled water is supplied on the upstream side of the rest space part 4 so as to keep the inside of the rest space 42 clean at all times in order to prevent the inflow of polluted water or the inflow of pollutants due to changes in the surrounding environment. (6) is connected, the bottled water flowing through the bottled water supply conduit (6) is discharged to the outside through the entrance hole 41 formed in the downstream rear and side in the state filled in the rest space 42 inflow and outflow Since the contaminated water is not introduced into the resting space 42, the resting space 42 is always filled with uncontaminated bottled water so that it can be kept clean. In addition, since two-thirds of the bottom surface (G) of the river is installed, since the fountain is buried under a large stone while living water is filled in the resting space 42, water is always present in four seasons. It will be possible to rest, even in the dry season will be able to rest.

The second evacuation space portion 5, as shown in Figure 6a, 6b, is formed in the shape of a triangular prism to reduce the resistance due to running water is installed in the center of the river for the entry of underwater life on the downstream rear An access hole 51 is formed, and the inside is divided by a partition wall 52 in which a through hole 521 is formed to facilitate the movement of aquatic life, and an evacuation space 53 formed with sand and gravel is formed at the bottom thereof. In addition, the bottled water supply conduit in which fresh bottled water is supplied to keep the interior of the evacuation space 53 clean at all times in order to prevent inflow of contaminated water or contaminants due to changes in the surrounding environment in the evacuation space 53 on the upstream side. (6) is connected, the bottled water flowing through the bottled water supply conduit (6) is discharged to the outside through the entrance hole 51 formed in the rear rear in the state filled in the evacuation space 53, the inflow and outflow continue Since the contaminated water does not flow into the evacuation space 53, the evacuation space 53 is always filled with uncontaminated bottled water to maintain a clean state. In addition, since 2/3 is installed in the bottom surface G of the river, the living water is kept in the evacuation space 53 so that it can be safely evacuated to the poisons introduced into the river, thereby ensuring a safe habitat environment. will be.

According to an embodiment of the present invention, the first evacuation space part 1, the living space part 2, the scattering space part 3, the resting space part 4, and the second evacuation space part 5 are the flow direction of the stream. It is possible to freely change the location according to the environment of the river or to install.

In the first evacuation space part 1, the living space part 2, the scattering space part 3, the resting space part 4, or the second evacuation space part 5 according to the embodiment of the present invention, FIG. As illustrated in FIG. 7B, the monitor or TV 8 is connected to the monitor or TV 8 separately or in combination so that the ecological situation of the aquatic organisms living in each space part can be confirmed near the stream. Infrared camera 9 is installed so that it is possible to see in real time the activity of aquatic organisms inhabiting and acting in each space part.

Bottled water supplied through the bottled water supply pipe 6 to the first evacuation space (1), living space (2), spawning space (3), rest space (4), second evacuation space (5) The principle is to collect the raw water of the first-class or second-class water that flows uncontaminated and always near the main stream, and communicate with the bottled water supply conduit (6) to supply the bottled water, but if this method is not easy, By digging the bottom surface of the fresh water generated in the bottom of the tank (not shown) is collected and supplied to each space through the bottled water supply conduit (6), so each space is always uncontaminated by fresh bottled water Maintain state.

In the embodiment of the present invention, the bottled water supply conduit 6 is illustrated as being branched to each space portion in the bottled water supply conduit 6 connected to the water tank, but is not limited thereto, and one bottled water supply conduit is connected through each space portion. It will also be said to belong to the scope of the invention.

In the embodiment of the present invention, the first evacuation space part (1), living space part (2), spawning space part (3), resting space part (4), Underwater ecological environment structure (A) including two evacuation space portion (5) is installed to provide a natural habitat environment of aquatic organisms, as shown in Figure 8, while providing a natural habitat environment of aquatic organisms An ecological river in which the transport passage 100 is installed so that all animals such as amphibians or reptiles and mammals can move along the ecological river in the waterside part of the ecological river where the aquatic ecological environment structure A is installed, and the transport passage 100 is installed. Blocking noise and light on the bridge to enable animals such as amphibians or reptiles and mammals, which are sensitive to noise and light generated on the bridge, to easily move the transport passage 100 under the bridge. One barrier wall 110 is installed, and the wire mesh 120 is installed on the left and right roads (R) side of the barrier wall installed on the bridge, so that the ferns grow on the wire mesh, so that the barrier wall is created in an eco-friendly way. By creating an ecological environment necessary for the natural habitat of amphibians or reptiles and mammals, not only for natural ecology, it is possible to reinvigorate the diversity of rivers, rivers and wetland organisms, revitalize natural habitats, protect ecosystems and preserve them. Ecological destruction can be prevented beforehand.

The aquatic ecological environment structure (A) of the aquatic river restoration aquatic organisms according to an embodiment of the present invention having such a configuration is a preservation in a sudden change of the surrounding environment or a crisis in the life of aquatic organisms in the water of the ecological river The first evacuation space (1) for living, the living space (2) for daily swimming and feeding activities, the spawning space (3) for stable growth of spawning, hatching or fry, It is composed of a rest space part (4) and a second evacuation space part (5) for instinct and stress relief, thus inducing the natural formatting of aquatic organisms because it is a structure and form that reproduces the natural ecological environment in nature. By providing a strengthening ecological environment system, aquatic organisms secure natural habitats, such as the natural aquatic environment, which must be created so that aquatic organisms, amphibians, and aquatic insects can reproduce and inhabit. It is possible to provide a natural aquatic environment for the activation of aquatic organisms in the ecological rivers and preservation of aquatic ecosystems by creating an optimal environment in which ecological rivers are located. Larvae can also seek to coexist with human beings by controlling nature, and play a role of nature-friendly living, eco-friendly emotional cultivation and nature observation, eco-experience field of neighboring citizens, It can be reborn as a healthy ecological river.

1. First evacuation space 2. Living space 3. Scattering space
4. Rest space 5. Second evacuation space 6. Bottled water supply conduit

Claims

In the aquatic ecological environment structure (A) of aquatic life for ecological river restoration,
The aquatic ecological environment (A) is formed in a box shape, the bottled water supply conduit (6) is connected to the front side and the inlet slit grooves (11) and access holes (12) are formed on the inner side and the rear side, respectively, A first evacuation space portion 1 in which an evacuation space 14 divided by the partition 13 is formed,
The living space part 2 having the living water supply conduit 6 connected to the front side and the inclined slit groove 21 formed on the inclined downstream rear side and the living space 23 divided by the partition 22 therein; ,
The upper opening is formed in a box shape in which the upper cover 35 is covered, and the bottled water supply conduit 6 is connected to the front side, and the access hole 31 is formed at the downstream rear side where the triangular pyramid 34 is formed. A scattering space portion 3 in which a scattering space 32 in which 33 is formed is formed;
The resting space portion is formed in a box shape, the bottled water supply conduit 6 is connected to the front side, and the entrance hole 41 is formed at the rear side and the side of the downstream side, and the resting space 42 formed by the partition wall 41 is formed inside. (4) and,
The second evacuation space is formed in the shape of a triangular prism, the bottled water supply conduit 6 is connected to the front surface, the entrance hole 51 is formed on the downstream rear side, and the evacuation space 53 divided by the partition wall 52 is formed inside. Underwater ecological environment structure of aquatic organisms for restoration of ecological river, characterized in that it comprises a portion (5).

The method of claim 1,
The first evacuation space (1) is formed in a box shape closed on all sides, the incision slit groove (11) is formed on the side, a plurality of access holes (12) are formed on the rear side and the through hole (131) is formed inside The evacuation space 14 divided into the partitions 13 is formed, and the lower part is embedded in the stepped beams 7 and is installed so as to be always locked under the water surface W of the river. Ecological Environment Structure.

The method of claim 1,
The living space portion 2 is formed in the shape of a box obliquely inclined to the four sides of the downstream rear side, the inclined slit groove 21 for the entry and exit of aquatic life is formed on the inclined rear side, the inside of the through hole Ecological river, characterized in that the living space 23 is divided by the partition wall 22 formed with the sand (221) formed on the floor and sand and gravel is formed, and 2/3 is embedded in the bottom surface (G) of the river Underwater ecological structure of aquatic life for restoration.

The method of claim 1,
The scattering space portion 3 is formed in a box shape in which an upper portion is opened to cover an upper cover 35, and a bottled water supply conduit 6 is connected to an upstream front side, and a triangular pyramid 34 enters and exits on a downstream rear side. A hole 31 is formed and a scattering space 32 is formed in which a rock layer 33 is formed for scattering and hatching of aquatic organisms or growth of fry, and 2/3 of the hole 31 is formed in the bottom surface G of the stream. Underwater ecological environment structure of aquatic organisms for restoration of ecological river, characterized in that the installation.

The method of claim 1,
The resting space portion 4 is formed in a box shape clogged in all directions, the bottled water supply conduit 6 is connected to the front side of the upstream side, and the access hole 41 is formed on the rear side and the side of the downstream side and the through hole 431 inside. The partition 43 is divided by the partition 43 is formed with a rest space 42 is sand and gravel is laid on the bottom, ecological river restoration, characterized in that installed in the bottom 2/3 of the river bottom surface (G) Underwater ecological structure of aquatic organisms.

The method of claim 1,
The second evacuation space portion 5 is formed in a triangular prism shape and a plurality of entrance holes 51 for entrance and exit of aquatic organisms are formed on the rear surface, and through holes 521 are formed to facilitate movement of the aquatic organisms inside. It is divided by the partition 52 and forms a evacuation space 53 in which sand and gravel are laid on the bottom, and the bottled water supply conduit 6 is connected to the front to install 2/3 in the bottom surface G of the river. Underwater ecological environment structure of aquatic organisms for restoration of ecological river, characterized in that it becomes.

The method of claim 1,
The first evacuation space part 1, the living space part 2, the spawning space part 3, the resting space part 4, or the second evacuation space part 5 are aquatic organisms living in the space part. Underwater ecological environment of the ecological river restoration, characterized in that the infrared camera (9) connected to the monitor or TV (8) is installed to observe the ecological situation of the river near the monitor or TV (8) Structure

The transport passage 100 is installed to move the amphibians or reptiles to the waterfront of the ecological river where the aquatic ecological environment A is installed, and the noise and light on the bridge formed across the river where the transport passage 100 is installed. Underwater ecology of the ecological river restoration underwater life, characterized in that the wire barrier 120 is installed so that the barrier wall 110 and the fern plants grow on the left and right of the barrier wall to form a natural friendly barrier wall to block Environmental structure.