CN110594678A - Municipal street lamp based on solar energy - Google Patents

Municipal street lamp based on solar energy Download PDF

Info

Publication number
CN110594678A
CN110594678A CN201910878195.2A CN201910878195A CN110594678A CN 110594678 A CN110594678 A CN 110594678A CN 201910878195 A CN201910878195 A CN 201910878195A CN 110594678 A CN110594678 A CN 110594678A
Authority
CN
China
Prior art keywords
solar
street lamp
municipal street
universal joint
driving motor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
CN201910878195.2A
Other languages
Chinese (zh)
Inventor
黄喜杰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CN201910878195.2A priority Critical patent/CN110594678A/en
Publication of CN110594678A publication Critical patent/CN110594678A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S9/00—Lighting devices with a built-in power supply; Systems employing lighting devices with a built-in power supply
    • F21S9/02—Lighting devices with a built-in power supply; Systems employing lighting devices with a built-in power supply the power supply being a battery or accumulator
    • F21S9/03—Lighting devices with a built-in power supply; Systems employing lighting devices with a built-in power supply the power supply being a battery or accumulator rechargeable by exposure to light
    • F21S9/035—Lighting devices with a built-in power supply; Systems employing lighting devices with a built-in power supply the power supply being a battery or accumulator rechargeable by exposure to light the solar unit being integrated within the support for the lighting unit, e.g. within or on a pole
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V21/00—Supporting, suspending, or attaching arrangements for lighting devices; Hand grips
    • F21V21/10—Pendants, arms, or standards; Fixing lighting devices to pendants, arms, or standards
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S30/00—Structural details of PV modules other than those related to light conversion
    • H02S30/10—Frame structures
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S30/00—Structural details of PV modules other than those related to light conversion
    • H02S30/20—Collapsible or foldable PV modules
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21W—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO USES OR APPLICATIONS OF LIGHTING DEVICES OR SYSTEMS
    • F21W2131/00—Use or application of lighting devices or systems not provided for in codes F21W2102/00-F21W2121/00
    • F21W2131/10—Outdoor lighting
    • F21W2131/103—Outdoor lighting of streets or roads
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/72—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps in street lighting
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Non-Portable Lighting Devices Or Systems Thereof (AREA)

Abstract

The invention relates to the technical field of street lamp lighting, and discloses a solar-energy-based municipal street lamp which comprises a bottom plate, wherein an upright post is arranged on the upper surface of the bottom plate, a lamp holder is arranged on the right side of the upright post, a lamp holder is arranged at the end part of the lamp holder, a support column is arranged at the top end of the upright post, a rotating seat is arranged at the upper end of the support column and is rotatably connected with the upper part of a fixed plate, rotating shafts are arranged on the front side and the rear side of the fixed plate and are rotatably connected with a solar panel, a driving motor is arranged at the bottom of the upright post, an output shaft of the driving motor is connected with a lead screw, the middle part. The solar street lamp is suitable for a solar-based municipal street lamp, the slide block is driven by the driving motor to move up and down, so that the fixing plate rotates, and in the rotating process of the fixing plate, the two solar panels are opened or closed under the action of the first supporting rod, so that the wind resistance of the whole device is improved.

Description

Municipal street lamp based on solar energy
Technical Field
The invention relates to the technical field of street lamp lighting, in particular to a municipal street lamp based on solar energy.
Background
The solar street lamp uses sunlight as an energy source, the solar panel charges the storage battery in the daytime, the storage battery supplies power to the lamp source at night, complex and expensive pipelines are not needed for laying, the layout of the lamp can be adjusted randomly, the solar street lamp is safe, energy-saving and pollution-free, does not need manual operation, is stable and reliable in working, and saves electricity and is free of maintenance. The solar street lamp is powered by a crystalline silicon solar cell, a maintenance-free valve-controlled sealed storage battery (a colloid battery) stores electric energy, and the ultra-high-brightness LED lamp is used as a light source and is controlled by an intelligent charging and discharging controller and used for replacing the traditional public power lighting street lamp. However, the solar panel with a large area is arranged on the upper portion of the solar street lamp, and when the typhoon comes, the solar panel is blown by the typhoon, and the solar panel is likely to be damaged.
Chinese patent (publication number: CN 208349175U) discloses a municipal street lamp based on solar power generation, which comprises a supporting rod, wherein a solar panel is fixedly arranged on the outer surface of the upper end of the supporting rod, the lower end of the solar panel is provided with an insect killing lamp, the outer surface of the lower end of the solar panel is fixedly provided with a jack, the outer surface in front of the jack is provided with a first fixing hole and a second fixing hole, the first fixing hole is positioned at the upper end of the second fixing hole, one side of the insecticidal lamp is provided with a fixing block, a first fixing button and a second fixing button are interactively arranged on the outer surface of one side of the fixing block, the first fixing button is positioned at the upper end of the second fixing button, the device can realize that solar energy converts the electric energy into and supplies power to whole device, but the device's solar panel still can not receive, and when leading to the typhoon, whole device still has the danger of damaging.
Disclosure of Invention
The invention provides a municipal street lamp based on solar energy, which solves the problems in the background art.
In order to achieve the purpose, the invention provides the following technical scheme:
a municipal street lamp based on solar energy comprises a bottom plate, wherein an upright post is arranged on the upper surface of the bottom plate, a lamp holder is arranged on the right side of the upright post, a lamp cap is arranged at the end part of the lamp holder, a support column is arranged at the top end of the upright post, a rotating seat is arranged at the upper end of the support column and is rotatably connected with the upper part of a fixed plate, rotating shafts are arranged on the front side and the rear side of the fixed plate and are rotatably connected with a solar panel, a driving motor is arranged at the bottom of the upright post, an output shaft of the driving motor is connected with a lead screw, a sliding block is in threaded connection with the middle part of the lead screw, a second universal joint is arranged on the left side of the sliding block and is hinged with the lower end of a second support rod, a fourth universal joint is connected with the upper end of the second support rod, the upper part of the fourth universal joint is connected with the, the third universal joint is connected with the lower part of the solar panel.
As a preferable technical scheme of the invention, a sliding groove is arranged on the left side of the upright post and is connected with a sliding block in a sliding manner.
As a preferred technical scheme of the invention, the upper part of the chute is provided with a bearing seat, and the bearing seat is rotationally connected with the upper end of the screw rod.
As a preferable technical scheme of the invention, a storage battery is arranged inside the upright post.
As a preferred technical scheme of the invention, the periphery of the solar panel is provided with a fixing frame, and the middle part of the fixing frame is provided with a battery piece.
As a preferable technical scheme of the invention, a diversion trench is arranged between the two battery pieces.
In a preferred embodiment of the present invention, the fixing frame has a drain opening at a lower portion thereof.
The invention has the following advantages:
the solar street lamp is suitable for a solar-based municipal street lamp, the slide block is driven by the driving motor to move up and down, so that the fixed plate rotates, and in the rotating process of the fixed plate, the two solar panels are opened or closed under the action of the first supporting rod, so that the two solar panels are closed in typhoon, the device is prevented from being blown out in strong wind, the wind resistance of the whole device is improved, and the service life of the device is prolonged.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a municipal street lamp based on solar energy.
Fig. 2 is a left side view of a solar-based municipal street light.
Fig. 3 is a schematic perspective view of a solar panel in a solar-based municipal street lamp when folded.
FIG. 4 is a schematic structural diagram of a solar panel in a solar-based municipal street lamp.
In the figure: 1. a base plate; 2. a column; 3. a drive motor; 4. a screw rod; 5. a first universal joint; 6. a first support bar; 7. a slider; 8. a bearing seat; 9. a second universal joint; 10. a second support bar; 11. a solar panel; 12. a third universal joint; 13. a fourth universal joint; 14. a fixing plate; 15. a rotating shaft; 16. a support pillar; 17. a rotating seat; 18. a lamp holder; 19. a lamp cap; 20. a chute; 21. a fixing frame; 22. a battery piece; 23. a diversion trench; 24. and a water outlet.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
Referring to fig. 1-3, a municipal street lamp based on solar energy comprises a bottom plate 1, wherein a stand column 2 is arranged on the upper surface of the bottom plate 1, a lamp holder 18 is arranged on the right side of the stand column 2, a lamp holder 19 is arranged at the end of the lamp holder 18, a support column 16 is arranged at the top end of the stand column 2, a rotating seat 17 is arranged at the upper end of the support column 16, the rotating seat 17 is rotatably connected with the upper portion of a fixing plate 14, rotating shafts 15 are arranged on the front side and the rear side of the fixing plate 14, the rotating shafts 15 are rotatably connected with a solar panel 11, a fixing frame 21 is arranged around the solar panel 11, a battery piece 22 is arranged in the middle of the fixing frame 21, the battery piece 22 can convert light energy into electric energy.
The solar photovoltaic power generation system is characterized in that a driving motor 3 is arranged at the bottom of the stand column 2, an output shaft of the driving motor 3 is connected with a lead screw 4, a sliding block 7 is in threaded connection with the middle of the lead screw 4, a bearing seat 8 is arranged on the upper portion of the sliding groove 20, the bearing seat 8 is rotatably connected with the upper end of the lead screw 4, the sliding groove 20 is arranged on the left side of the stand column 2, the sliding block 7 is in sliding connection with the sliding groove 20, a second universal joint 9 is arranged on the left side of the sliding block 7, the second universal joint 9 is hinged with the lower end of a second supporting rod 10, the upper end of the second supporting rod 10 is connected with a fourth universal joint 13, the upper portion of the fourth universal joint 13 is connected with the lower portion of a fixing plate 14, first universal joints 5 are arranged on the front side and the rear side of the middle of the stand column.
Example two
Referring to fig. 4, the other contents of the present embodiment are the same as those of the first embodiment, except that: a diversion trench 23 is arranged between the two battery pieces 22, and a drainage port 24 is arranged at the lower part of the fixing frame 21. Because this device is installed in the open air, consequently the rainwater can fall on solar panel 11 during rainy day, in order to discharge the rainwater as fast as possible, prevent that the device from soaking in the aquatic for a long time and influencing the normal operating of device, set up guiding gutter 23 between battery piece 22, the rainwater falls on solar panel 11, can collect guiding gutter 23 in, under the effect of gravity, the rainwater moves the lower part of fixed frame 21 along guiding gutter 23, and discharge through outlet 24, solar panel 11's normal operating has been guaranteed.
In the implementation process of the invention, when the weather is low, the driving motor 3 is started, the output shaft of the driving motor 3 drives the screw rod 4 to rotate, so that the screw rod 4 drives the slide block 7 to move upwards, the slide block 7 pushes the fixing plate 14 to rotate clockwise through the second support rod 10, at the moment, the fixing plate 14 drives the solar panels 11 to rotate clockwise, in the process of rotating the solar panels 11, under the action of the first support rod 6, the two solar panels 11 rotate towards two sides around the fixing plate 14, at the moment, the two solar panels 11 are opened and rotate clockwise, the solar panels 11 face the sun, at the moment, the whole device starts the solar energy conversion work, when typhoon occurs, the driving motor 3 is started in a reverse direction, the driving motor 3 controls the screw rod 4 to rotate, so that the slide block 7 moves downwards, at the moment, the slide block 7 pulls the fixing plate 14 to, therefore, the fixing plate 14 rotates towards the direction of the upright post 2, and meanwhile, in the rotating process of the fixing plate 14, the first supporting rod 6 pushes the two solar panels 11 to rotate close to each other, so that the two solar panels 11 are folded together, at the moment, the solar panels 11 are folded and arranged on one side of the upright post 2, the contact area with typhoon is greatly reduced, the connection with the upright post 2 is tighter, and the solar panels 11 are prevented from being blown out by strong wind; the solar-energy-based municipal street lamp is suitable for a solar-energy-based municipal street lamp, the driving motor 3 drives the sliding block 7 to move up and down, so that the fixed plate 14 rotates, and in the rotating process of the fixed plate 14, the two solar panels 11 are opened or closed under the action of the first supporting rod 6, so that the two solar panels 11 are closed in typhoon weather, the device is prevented from being blown out in strong wind, the wind resistance of the whole device is improved, and the service life of the device is prolonged.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims (7)

1. A municipal street lamp based on solar energy comprises a bottom plate (1), wherein the upper surface of the bottom plate (1) is provided with a stand column (2), the right side of the stand column (2) is provided with a lamp holder (18), the end part of the lamp holder (18) is provided with a lamp holder (19), the municipal street lamp is characterized in that the top end of the stand column (2) is provided with a support column (16), the upper end of the support column (16) is provided with a rotating seat (17), the rotating seat (17) is rotatably connected with the upper part of a fixed plate (14), the front side and the rear side of the fixed plate (14) are provided with rotating shafts (15), the rotating shafts (15) are rotatably connected with a solar panel (11), the bottom of the stand column (2) is provided with a driving motor (3), an output shaft of the driving motor (3) is connected with a screw rod (4), the middle part of the screw rod (4) is connected with a sliding block, fourth universal joint (13) is connected to the upper end of second bracing piece (10), and the lower part of fixed plate (14) is connected on the upper portion of fourth universal joint (13), both sides are equipped with first universal joint (5) around the middle part of stand (2), and the lower extreme of first bracing piece (6) is articulated in first universal joint (5), and third universal joint (12) are connected to the upper end of first bracing piece (6), and solar panel (11)'s lower part is connected in third universal joint (12).
2. The solar-based municipal street lamp according to claim 1, wherein the upright (2) is provided with a chute (20) on the left, and the chute (20) is slidably connected with the slide block (7).
3. The solar-based municipal street lamp according to claim 2, wherein the chute (20) is provided with a bearing seat (8) at the upper part, and the bearing seat (8) is rotatably connected with the upper end of the screw rod (4).
4. A municipal street light based on solar energy according to claim 1 or 2, characterized in that the post (2) is internally provided with a battery.
5. The solar-based municipal street lamp according to claim 1, wherein a fixing frame (21) is provided around the solar panel (11), and a battery plate (22) is provided in the middle of the fixing frame (21).
6. The municipal street light based on solar energy according to claim 5, wherein a flow guide groove (23) is provided between the two battery pieces (22).
7. The solar-based municipal street lamp according to claim 6, wherein the lower part of the fixed frame (21) is provided with a drain opening (24).
CN201910878195.2A 2019-09-17 2019-09-17 Municipal street lamp based on solar energy Withdrawn CN110594678A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910878195.2A CN110594678A (en) 2019-09-17 2019-09-17 Municipal street lamp based on solar energy

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910878195.2A CN110594678A (en) 2019-09-17 2019-09-17 Municipal street lamp based on solar energy

Publications (1)

Publication Number Publication Date
CN110594678A true CN110594678A (en) 2019-12-20

Family

ID=68860373

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910878195.2A Withdrawn CN110594678A (en) 2019-09-17 2019-09-17 Municipal street lamp based on solar energy

Country Status (1)

Country Link
CN (1) CN110594678A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111795345A (en) * 2020-07-23 2020-10-20 漳州市灿华电子科技有限公司 Intelligent durable street lamp
CN113375116A (en) * 2021-06-28 2021-09-10 南京光唯智能科技有限公司 Photovoltaic LED street lamp based on thing networking
WO2021218051A1 (en) * 2020-04-29 2021-11-04 深圳市洲明科技股份有限公司 Solar power generation assembly, automatic solar tracking system and smart street lamp

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021218051A1 (en) * 2020-04-29 2021-11-04 深圳市洲明科技股份有限公司 Solar power generation assembly, automatic solar tracking system and smart street lamp
CN111795345A (en) * 2020-07-23 2020-10-20 漳州市灿华电子科技有限公司 Intelligent durable street lamp
CN113375116A (en) * 2021-06-28 2021-09-10 南京光唯智能科技有限公司 Photovoltaic LED street lamp based on thing networking

Similar Documents

Publication Publication Date Title
CN105674197B (en) A kind of intelligent folding type LED street lamp using photovoltaic rain water electricity generating
CN106641997A (en) Clean type solar street lamp used for aided maintenance
CN110594678A (en) Municipal street lamp based on solar energy
CN206572421U (en) A kind of cleaning type auxiliary maintaining solar street light
CN210345281U (en) Angle adjustable device of solar street lamp
CN217235454U (en) Solar street lamp capable of automatically adjusting light according to weather
CN109099374B (en) Energy-saving environment-friendly street lamp
CN212081084U (en) Solar street lamp with automatic cleaning function
CN210424826U (en) Solar LED street lamp with good wind resistance
CN112128693A (en) High-performance solar street lamp
CN2896653Y (en) Horizontal rotary conic-face reflection type vane gentle-breeze, solar wind-light intercompensating generating system
CN218348545U (en) Community intelligent street lamp with insect repelling structure
CN218895318U (en) Solar street lamp
CN113983409B (en) Intelligent solar LED street lamp of way pole integral type
CN216203181U (en) Intelligent street lamp pole with solar cell panel capable of automatically turning
CN105719574A (en) Energy-saving and environment-friendly LED intelligent traffic flow guide display screen
CN212984398U (en) Self-generating intelligent canopy
CN212961338U (en) Solar energy and wind energy street lamp
CN212226921U (en) Solar street lamp convenient to adjust light-emitting panel angle of meeting
CN212584845U (en) Rain-shielding multifunctional solar street lamp
CN212408483U (en) Wind-solar hybrid street lamp
CN110645521A (en) Energy-saving power supply device for new energy street lamp
CN212618024U (en) Foldable solar LED street lamp cap
CN114484358A (en) Wind-solar complementary street lamp utilizing natural resources
CN218671809U (en) Self-powered street lamp convenient to solar panel adjusts

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WW01 Invention patent application withdrawn after publication

Application publication date: 20191220

WW01 Invention patent application withdrawn after publication