KR102123857B1 - Concealable solar cell module - Google Patents

Abstract

The concealable solar cell module according to the present invention includes a front glass having a surface modification layer formed on the front surface; A rear substrate facing the rear surface of the windshield and absorbing light incident from the windshield; And a solar cell unit disposed between the front glass and the rear substrate and having unit cells spaced apart from each other.

Description

Concealable solar cell module {CONCEALABLE SOLAR CELL MODULE}

The present invention relates to a concealable solar cell module, and more particularly, to a concealable solar cell module for making an internal solar cell invisible.

Recently, the use of solar power generation facilities capable of producing electric power using solar energy has become common. Solar cells that use this solar energy do not use fossil fuels such as coal or oil, and use solar light, which is pollution-free and infinite energy source, and thus is in the spotlight as a new alternative energy resource in the future. , It is used to obtain power for power generation, such as automobiles.

Although photovoltaic power generation has various application fields, among them, the building integrated photovoltaic (BIPV) technology, which uses solar cells as a covering material for buildings, has recently attracted worldwide attention as a promising new technology in the 21st century.

Building integration technology is an active technology that has evolved from the perspective of the concept of protection against external stimuli as a tool for energy generation, which can take the advantage of supplying and receiving solar cells. The double effect of reducing the required cost can be expected.

One of the solar cells used as exterior materials for buildings is a solar cell window that combines a solar cell with a window.

In this regard, Korean Patent Registration No. 10-1541357 provides a window-type thin film solar cell and a manufacturing method thereof. However, the conventional window-type thin-film solar cell has a black color appearance, and its utilization value as a window-type is low, so it is difficult to commercialize and there is a fatal weakness that it is difficult to show a beautiful appearance while maintaining the efficiency of the solar cell.

Korean Registered Patent No. 10-1541357

The present invention has been made to solve the above problems, and to provide a solar cell module with improved hiding ability.

In addition, the present invention is to provide a solar cell module with improved solar conversion efficiency as well as hiding.

On the other hand, other objects not specified in the present invention will be additionally considered within a range that can be easily inferred from the following detailed description and its effects.

In order to achieve this object, the concealable solar cell module according to an embodiment of the present invention, the front glass is formed with a surface modification layer on the front surface; A rear substrate facing the rear surface of the windshield and absorbing light incident from the windshield; And a solar cell unit disposed between the front glass and the rear substrate and having unit cells spaced apart from each other.

In the concealable solar cell module according to an embodiment of the present invention, the surface modification layer may have a surface roughness Ra of 0.1 to 3 μm.

In the concealable solar cell module according to an embodiment of the present invention, between the front glass and the back substrate, it may further include a color coating layer formed on the back of the windshield.

In the concealable solar cell module according to an embodiment of the present invention, the color coating layer is Al, Zr, Zn, Sn, In, Nb, Cd, Cu, Si, Ti, W, Mo, Co, Au, Ag, Be, Ba, Mg, Sb, Bi, B, Ca, Ce, Pd, Pt, Re, Rh, Ru, Sm and Ta.

In the concealable solar cell module according to an embodiment of the present invention, the color coating layer may have a thickness of 10 nm to 30 μm.

In the concealable solar cell module according to an embodiment of the present invention, between the windshield and the rear substrate, it may further include an anti-reflective coating layer formed on the rear substrate.

In the concealable solar cell module according to an embodiment of the present invention, the rear substrate may be a glass substrate or a black back sheet on which an antireflection coating layer is formed.

In the concealable solar cell module according to an embodiment of the present invention, between the front glass and the back substrate, it may further include first and second bonding films disposed on both sides of the solar cell.

In the concealable solar cell module according to an embodiment of the present invention, the first and second adhesive films are ethylene vinyl acetate, polyvinyl butyral, ethylene vinyl partial oxide, silicon resin, ester resin and olefin resin It may include one or more polymers selected from.

In the concealable solar cell module according to an embodiment of the present invention, the front glass, the rear substrate and a frame for storing the solar cell may be further included.

The concealable solar cell module according to the present invention can implement various colors according to the angle of reflection of sunlight, and can conceal the solar cell configured inside the solar cell module.

In addition, since the concealable solar cell module according to the present invention can convert the color of the concealable solar cell module to harmonize with surrounding natural landscapes and buildings, it can be utilized as a window-type solar cell having aesthetics.

In addition, the concealable solar cell module according to the present invention can provide a concealable as well as a solar cell module with improved solar conversion efficiency.

On the other hand, even if the effects are not explicitly mentioned herein, it is noted that the effects described in the following specification expected by the technical features of the present invention and the potential effects thereof are treated as described in the specification of the present invention.

1 is a cross-sectional view showing the configuration of a concealed solar cell module according to an embodiment of the present invention.
2 is a front view schematically showing a concealable solar cell module according to an embodiment of the present invention.
3 is a cross-sectional view showing the configuration of a concealed solar cell according to another embodiment of the present invention.
4 is a photograph showing transparency and color conversion properties for the concealed solar cell modules produced in Examples 1 and 2 and Comparative Examples 1 and 2.
5 is a current-voltage scanning graph for the concealed solar cell modules prepared in Examples 1 and 2 and Comparative Examples 1 and 2.
Figure 6 is a real photo of the concealed solar cell module produced in Example 2.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments allow the disclosure of the present invention to be complete, and the ordinary knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is defined by the scope of the claims. Meanwhile, the terms used in the present specification are for explaining the embodiments and are not intended to limit the present invention. In the present specification, the singular form also includes the plural form unless otherwise specified in the phrase. As used herein, "comprises" and/or "comprising" refers to the components, steps, operations and/or elements mentioned above, the presence of one or more other components, steps, operations and/or elements. Or do not exclude additions. Terms such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are only used to distinguish one component from other components.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The structures of the concealable solar cell modules 1001 and 1002 will be described with reference to FIGS. 1 to 3.

1 is a cross-sectional view showing the configuration of a concealable solar cell module 1001 according to an embodiment of the present invention. Referring to FIG. 1, the concealed solar cell module 1001 basically includes a front glass 100, a solar cell unit 300, and a rear substrate 200.

The front glass 100 may be any glass that has permeability, for example, tempered glass, semi-tempered glass, general plate glass, colored glass, and the like.

The thickness of the front glass 100 may have an appropriate thickness in consideration of strength and permeability. For example, the average thickness of the windshield 100 may be 0.5 mm to 10 mm, but is not limited thereto.

In addition, as shown in FIG. 1, the concealed solar cell module 1001 may further include a surface modification layer 110 formed on the front surface of the windshield 100.

The surface modification layer 110 is formed in a fine concavo-convex shape, so that the sunlight reflected through the windshield 100 and reflected back from the solar cell unit 300 is reflected back in the direction of the solar cell. Can be increased. In the detailed description of the present invention, "fine irregularities" is hemispherical, semi-elliptical, bell-shaped, disc-shaped, cylindrical-shaped, star-shaped, triangular-shaped, square-shaped, hexahedral, tetrahedral, pyramidal, or It may be one or two or more three-dimensional structures selected from these mixed types. The surface modification layer 110 having such a shape has an effect of introducing a nano embossing structure on the front surface of the windshield 100, and accordingly, the concealable solar cell module 1001 according to the present invention. ) To increase the concealability and power generation efficiency.

The method of forming the surface modification layer 110 may use a wet or dry etching method commonly used in this field, and more specifically, performs a silk screen type chemical etching, laser etching, polishing etching, sand blasting, or the like. However, the present invention is not limited to this.

The surface coating layer may have a nano-concave-convex structure by the etching method. For example, the surface roughness Ra of the surface modification layer 110 may be 0.1 to 3 μm. As a preferred example, the average surface roughness Ra of the surface modification layer 110 may be 1 to 3 μm. When the category of the average surface roughness Ra is satisfied, the concealability can be further increased by re-reflecting the sunlight reflected back from the solar cell unit 300 in the direction of the solar cell unit 300, and incident with it It is possible to further improve the power generation efficiency of the solar module by allowing the sunlight to stay inside the concealable solar cell module 1001 as much as possible.

On the other hand, the solar cell unit 300 is disposed between the front glass 100 and the rear substrate 200, may be provided with a unit cell 301 spaced apart from each other. As a specific and non-limiting example, the solar cells used in the solar cell unit 300 include crystalline solar cells, amorphous solar cells, thin film solar cells, dye-sensitized solar cells, organic solar cells, and the like. May be

The solar cell unit 300 serves to convert sunlight into electrical energy by absorbing incident sunlight. However, the unit cell 301 provided in the solar cell unit 300 reflects the incident sunlight to the outside, so that the solar cell unit 300 has a unique color when viewed from the outside. There is a problem that the color of the module is limited.

In detail, the existing solar cell module may exhibit colors such as black, blue, and brown depending on the type of solar cell located therein. If these colors are not properly matched with the background of the surrounding environment, they can not only cause discomfort, but also damage the aesthetics of nature or buildings. CIGS-based solar cells do not harmonize with the natural landscape because they display a dark brown or black color, and silicon-based solar cells exhibit a blue color, so there is a problem that the exterior of the building becomes monotonous when installed in buildings.

As an example for solving this problem, the concealed solar cell module 1001 according to the present invention is disposed facing the rear surface of the windshield 100 and absorbs light incident from the windshield 100. It may include a rear substrate 200. For example, the rear substrate 200 may have an absorbance of 70% or more with respect to the standard light source D65. The absorbance may be defined as {(incident light intensity-(reflected light intensity + transmitted light intensity))/(incident light intensity)}*100).

The rear substrate 200 may be used in a thin film solar cell commonly used in this field, but preferably a glass substrate, ceramic substrate, stainless steel including soda-lime glass (SLG). A metal substrate, a polymer substrate, or the like may be used, and more preferably, a glass substrate or black back sheet on which the antireflective coating layer 210 is formed may be used.

2, the role of the rear substrate 200 will be described in more detail. 2 is a front view schematically showing a concealable solar cell module 1001 according to an embodiment of the present invention. 2, the unit cell 301 of the solar cell unit 300 may be arranged in a plurality of rows and columns. The incident sunlight passes between the unit cells 301 to reach the rear substrate 200. If, when the rear substrate 200 reflects the sunlight incident from the windshield 100, the unit cell 301 is exposed to the outside, the color of the solar cell module becomes monotonous and cloudy. .

In order to solve the above problems, the rear substrate 200 according to the present invention is between the front glass and the rear substrate so as to absorb sunlight incident from the front glass 100, and is disposed on the rear substrate. It may include an anti-reflective coating layer 210. The anti-reflection coating layer 210 not only absorbs incident sunlight, but also has no diffuse reflection, thereby making the color of the concealed solar cell module 1001 more vivid, thereby improving the aesthetics of the solar cell module 1001.

As the material used for the anti-reflection coating layer 210, inorganic particles, organic particles and/or organic/inorganic hybrid particles may be used. For example, carbon nanotubes, graphene, carbon black, vine black, lamp black, ivory black, titanium black, etc. may be used, but are not limited thereto. .

3 is a cross-sectional view showing the configuration of a concealable solar cell module 1002 according to another embodiment of the present invention. As shown in Figure 3, the concealed solar cell module 1002 is between the front glass 100 and the rear substrate 200, the color coating layer 120 formed on the rear surface of the front glass 100 It may further include.

The color coating layer 120 reflects a part of the sunlight incident from the outside and transmits the other part to serve to convert the color of the concealed solar cell module 1002. In detail, the color coating layer 120 reflects a part of sunlight incident from the outside to convert the color of the concealed solar cell module 1002 to impart aesthetics, and also transmits the other part to transmit the solar warfare. Light energy may be supplied to the branch 300.

The color coating layer 120 may be formed of a single film or a composite film.

When the color coating layer 120 is a single film, Al, Zr, Zn, Sn, In, Nb, Cd, Cu, Si, Ti, W, Mo, Co, Au, Ag, Be, Ba, Mg, Sb, Bi , B, Ca, Ce, Pd, Pt, Re, Rh, Ru, Sm, and Ta.

As a specific and non-limiting example, the color coating layer 120 is BN, SiN _X (0.2 ≤ x ≤ 1.3), a metal nitride film including TiN, TaN _x (0.5 ≤ x ≤ 1.5), and the like; TiO ₂ , Cr ₂ O ₃ , Al ₂ O ₃ Nb ₂ O ₄ A metal oxide film including, etc.; Or a metal film including Ag, Ni, Cr, Ge, Ga, Si, or the like.

More specifically, the color coating layer 120 may have a thickness of 10 nm to 30 μm, and preferably 10 nm to 1 μm. When the thickness is satisfied, various colors such as purple, blue, yellow, orange, and red may be implemented according to the angle of incident sunlight. More preferably, the color coating layer 120 may have an average thickness of 40 nm to 200 nm. When the category of the average thickness is satisfied, the concealability and conversion efficiency aimed at in the present invention can be further improved.

According to an embodiment of the present invention, when the front glass 100 is provided with the surface modification layer 110 and the color coating layer 120, the reflectance for the standard light source D65 is 20 to 40%, and the transmittance is 80 To 60%. If the reflectance is less than 20%, there is a problem that the internal solar cell is exposed due to low concealability, and if the reflectance is more than 40%, there is a problem that the conversion efficiency of the solar cell is reduced, so the reflectance is preferably 20 to 40%. Do.

Meanwhile, the concealable solar cell modules 1001 and 1002 according to an embodiment of the present invention are between the front glass 100 and the rear substrate 200, and are disposed on both sides of the solar cell unit 300. , The second adhesive film (10, 11) may further include.

The first and second adhesive films 10 and 11 are for the purpose of bonding and filling for placing and sealing the solar cell unit 300 between the windshield 100 and the rear substrate 200. In detail, the first and second adhesive films 10 and 11 may block moisture or oxygen that adversely affects the solar cell unit 300. It is preferable that the first and second adhesive films 10 and 11 are excellent in preventing hydrolysis or deterioration due to infrared rays and have high transmittance to sunlight.

The first and second adhesive films 10 and 11 are integrated with the solar cell unit 300 by a lamination process while being disposed on both sides of the solar cell unit 300, and are corroded by moisture penetration. And protect the solar cell unit 300 from impact. For example, the first and second adhesive films 10 and 11 are ethylene vinyl acetate (EVA, ethylene vinylacetate), polyvinyl butyral (PVB), ethylene vinyl acetate partial oxide, silicon resin, and ester resin And one or more polymers selected from olefinic resins, but is not limited thereto.

In addition, the concealable solar cell modules 1001 and 1002 according to an embodiment of the present invention may further include a frame (not shown) for accommodating the windshield, the rear substrate and the solar cell along its circumference. As described above, the concealed solar cell modules 1001 and 1002 in which various components are integrated into one by a lamination process are housed in a frame and protected from an external environment or impact. The frame may be made of a material that does not cause corrosion and deformation due to an external environment, such as aluminum coated with an insulating material.

The concealed solar cell modules 1001 and 1002 described above may include a junction box (not shown) for finally collecting the current and voltage produced by the solar cell unit 300, but are not limited thereto.

Hereinafter, the present invention will be described in detail by examples. The examples described below are only for making the present invention easily understood by those skilled in the art, and the present invention is not limited by the following examples.

[Example 1]

Consists of a surface modification layer 110, a front glass 100, a first adhesive film 10, a solar cell part 300, a second adhesive film 11, an anti-reflective coating layer 210 and a rear substrate 200 A concealable solar cell module 1001 was produced.

Tempered glass was used as the front glass 100.

The surface of the tempered glass was corroded using a screen printing method to form a surface modification layer 100. The main component of the etching paste used in the screen printing method was ammonium bifluoride (NH ₄ FHF). At this time, the average surface roughness Ra of the surface modification layer 110 was 1.77 μm.

The solar cell unit 300 is composed of a unit cell 301, and a conventional silicon semiconductor cell is used.

The back substrate 200 used a back sheet made of a composite film of a fluorine film and a PET film, and the anti-reflection coating layer 210 was formed by coating a carbon black dispersion on the back substrate 200. .

As the first adhesive film 10, an ethylene vinyl acetate (EVA) sheet was used. For the second adhesive film 11, a polyvinyl butyral (PVB) sheet was used.

[Example 2]

A concealable solar cell module 1002 was manufactured in the same manner as in Example 1, except that a color coating layer 120 was formed on the rear surface of the front glass 100. The color coating layer 120 was formed of a TiO ₂ film by sputtering a Ti target. At this time, the color coating layer 120 has an average thickness of 80 nm and includes rutile TiO ₂ .

The windshield manufactured in Example 2 is shown in Table 1 below. The windshield 100 according to Example 2 has a surface modification layer 110 formed on the front surface, and a rear surface. The color coating layer 120 was formed in. The instrument used for the measurement of the transmission reflection was MINOLTA CM-5, the light source was D65, and the measurement area was 30 mm.

Group Traits L*(D65) a*(D65) b*(D65) 550nm Y (D65) Reflection measurement SCI 64.19 -2.7 -7.14 33.11% 33.03% Transmission measurement - 85.53 1.09 4.52 67.13% 67.05%

6 is a real photo of the concealed solar cell module 1002 produced by the method of Example 2. As shown in FIG. 6, the concealable solar cell module 1002 according to the present invention is capable of large-sized 980 mm × 1940 mm in width and length, and the unit shell inside the solar cell is not visible at all, and the luxurious light blue color is used. Since it shows, it can be seen that the aesthetic properties are excellent.

[Comparative Example 1]

It was carried out in the same manner as in Example 1, except that a concealed solar cell module without the surface modification layer 110 was manufactured. In detail, the concealable solar cell module according to Comparative Example 1 is a windshield 100 from the left, a first adhesive film 10, a solar cell unit 300, a second adhesive film 11, an anti-reflective coating layer 210 ) And the back substrate 200 were produced.

[Comparative Example 2]

A concealable solar cell module was manufactured in the same manner as in Comparative Example 1, except that a color coating layer 120 was formed on the rear surface of the front glass 100.

FIG. 4 is a photograph showing transparency and color conversion properties for the concealed solar cell modules prepared in Examples 1 to 2 and Comparative Examples 1 to 2. In detail, FIG. 4 is a photograph taken under visible light by placing a component comprising the windshield 100 prepared in Examples 1 and 2 and Comparative Examples 1 and 2 on a black backsheet.

The Clear Glass shown in FIG. 4 shows Comparative Example 1 using the above-described front glass 100, and Coating Glass shows Comparative Example 2 in which the color coating layer 120 is formed on the rear surface of the above-mentioned front glass 100, Etching Glass shows Example 1 in which the surface modification layer 110 is formed on the front surface of the front glass 100, and Etching-Coating Glass is the front surface modification layer 110 on the front surface of the front glass 100 and the rear surface. The second embodiment in which the color coating layers 12 are formed is shown.

As shown in FIG. 4, when the surface modification layer 110 is formed on the front surface of the front glass 100, it can be seen that the black back sheet, which is the rear substrate 300, is not visible. In addition, when the surface modification layer 110 and the color coating layer 120 are formed on the front surface of the front glass 100, the black back sheet is not visible, and the color of the coating is changed to give an aesthetic sense. .

5 is a current-voltage scanning graph for the concealed solar cell modules prepared in Examples 1 and 2 and Comparative Examples 1 and 2. The inset shown in each graph represents the measurement conditions and experimental results.

Table 2 below shows the conversion efficiency (Eff.), the maximum power point (MPP), and the concealment results, which are the experimental results shown in FIG. 5. The concealment result was expressed as X when the silicon semiconductor cell was visually confirmed under fluorescent light emitting a visible light (380-700 nm) wavelength, △ when partially confirmed, and ○ when not confirmed at all.

Conversion efficiency
(%) Maximum power point
(W) Concealment result Comparative Example 1 16.33 10.205 X Comparative Example 2 12.63 7.894 X Example 1 17.02 10.639 △ Example 2 15.23 9.521 ○

[Examples 3 to 9 and Comparative Examples 3 to 6]

Surface modification layer 110, front glass 100, color coating layer 120, first adhesive film 10, solar cell unit 300, second adhesive film 11, anti-reflective coating layer 210 and back A concealable solar cell module 1002 made of a substrate 200 was manufactured.

The average surface roughness Ra of the surface modification layer 110 and the thickness of the color coating layer 120 are listed in Table 3 below. Each average surface roughness Ra was formed by changing the etching time, and the thickness of the color coating layer 120 was formed by changing the sputtering time.

The front glass 100, the solar cell unit 300, the rear substrate 200, the first adhesive film 10, and the second adhesive film 11 were performed in the same manner as in Example 2.

Table 3 below lists the visible light hiding results for the hiding solar cell module of the present invention. The visible light concealability was calculated by measuring the spectral reflectance in the visible light region (380-700 nm) by a Macbeth light densitometer, and evaluating according to the following evaluation criteria. Although A, B, C, and D are practically acceptable standards, A has a small concealment effect and is difficult to achieve the effect desired in the present invention.

A: Optical density exceeding 0.7

B: The optical density is more than 0.6 and less than 0.7

C: Optical density is more than 0.5 and less than 0.6

D: Optical density is more than 0.4 and less than 0.5

E: Optical density is less than 0.4

Average surface roughness Ra of the surface modification layer 110
(㎛) Color coating layer 120 average thickness
(nm) Visible light hiding Example 2 1.77 80 C Example 3 1.05 80 B Example 4 2.33 80 D Example 5 2.85 80 B Comparative Example 3 3.31 80 E Comparative Example 4 0.85 80 A Example 6 1.77 63 B Example 7 1.77 40 B Example 8 1.77 150 C Example 9 1.77 200 D Comparative Example 5 1.77 30 A Comparative Example 6 1.77 220 E

As shown in Table 3, in the concealed solar cell module 1002 according to the present invention, the average surface roughness Ra of the surface modification layer 110 is included in the range of 1 μm to 3 μm, and the average of the color coating layer 120 It can be seen that when the thickness is at least 40 nm or more, the visible light hiding property is improved. On the other hand, although not listed in Table 2, when the average thickness of the color coating layer 120 is 40 nm to 200 nm (Examples 6 to 9), the solar conversion efficiency is maintained at about 14% or more, but the color When the average thickness of the coating layer 120 exceeds 200 nm, a problem that the photovoltaic conversion efficiency rapidly decreases to about 12% or less occurs, so the average thickness of the color coating layer 120 is preferably 40 nm to 200 nm.

As described above, in the present invention, it has been described by specific matters and limited embodiments and drawings, which are provided to help the overall understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention Various modifications and variations can be made by those skilled in the art.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and should not be determined, and all claims that are equivalent or equivalent to the scope of the claims as well as the claims to be described later belong to the scope of the spirit of the invention. .

10: first adhesive film 20: second adhesive film
100: windshield 110: surface modification layer
120: color coating layer 200: rear substrate
210: anti-reflection coating layer 300: solar cell
301: unit cell 1001, 1002: concealed solar cell module

Claims (10)

A front glass having a surface modification layer having a surface roughness Ra of 1 to 3 μm on the front surface;
A rear substrate facing the rear surface of the windshield and absorbing light incident from the windshield; And
A solar cell unit disposed between the front glass and the rear substrate and having unit cells spaced apart from each other;
An anti-reflective coating layer between the front glass and the rear substrate and formed on the rear substrate;
A concealable solar cell module further includes a color coating layer having a thickness of 40 nm to 200 nm on the rear surface of the windshield.
delete delete According to claim 1,
The color coating layer,
Al, Zr, Zn, Sn, In, Nb, Cd, Cu, Si, Ti, W, Mo, Co, Au, Ag, Be, Ba, Mg, Sb, Bi, B, Ca, Ce, Pd, Pt, A concealable solar cell module comprising at least one element selected from Re, Rh, Ru, Sm and Ta.
delete delete According to claim 1,
The rear substrate,
A concealable solar cell module, which is a glass substrate or black back sheet on which an antireflection coating layer is formed.
According to claim 1,
A concealable solar cell module further comprising first and second bonding films disposed on both sides of the solar cell, between the front glass and the rear substrate.
The method of claim 8,
The first and second adhesive films,
A concealable solar cell module comprising at least one polymer selected from ethylene vinyl acetate, polyvinyl butyral, ethylene vinyl acetate partial oxide, silicon resin, ester resin and olefin resin.
According to claim 1,
A concealable solar cell module further comprising a frame for storing the windshield, the rear substrate and the solar cell.

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