JP6815003B2 - disinfectant - Google Patents

Description

The present invention relates to a disinfectant for spraying, a method for producing the same, and a method for detecting the same.

At present, the great damage to livestock caused by foot-and-mouth disease virus, bird flu, etc. has become a social problem in livestock farmers nationwide. Conventionally, in livestock farmers and the like, in order to prevent the introduction of pathogens into the vicinity of the barn and the like, as described in paragraphs 0002 to 0003 of Non-Patent Document 1 and Patent Document 1, slaked lime (calcium hydroxide (Ca (Ca (Ca)) OH) The method of sprinkling the powder of ₂ ) on the ground is widely used.

"Feeding Hygiene Management Standards (Cow, Buffalo, Deer, Sheep, Goat)", Ministry of Agriculture, Forestry and Fisheries, October 2011, p. 6-8

Japanese Unexamined Patent Publication No. 2012-217453

The disinfecting effect of slaked lime is due to the sterilization of pathogens and the inactivation of viruses due to its alkalinity. However, slaked lime reacts with rainwater in which carbon dioxide in the atmosphere is dissolved and changes to calcium carbonate, which lowers the pH. Therefore, the disinfecting effect cannot be maintained for a very long period of time.

Therefore, an object of the present invention is to provide a disinfectant for spraying which has a relatively long disinfecting effect and is sustainable, a method for producing the same, and a method for detecting the disinfectant.

The present invention is a disinfectant for spraying and contains a granulated product composed of slaked lime and zeolite, and the ratio of the mass of slaked lime to the total mass of slaked lime and zeolite is 0.4 or more . Further, it is preferable that the granulated product is imparted with a slow-release effect in terms of pH retention effect as compared with the granulated product containing slaked lime and not containing zeolite. Further, according to the method for increasing the duration of the disinfecting effect by slaked lime according to another aspect of the present invention, the ratio of the mass of slaked lime to the total mass of slaked lime and zeolite in the granulated product composed of slaked lime and zeolite is 0. Zeolite is mixed with slaked lime to granulate so that it becomes 4 or more. By using slaked lime as a granule, the pH can be less likely to decrease. Therefore, the disinfecting effect is relatively long-lasting (slow-release).

Further, in the present invention, it is preferable to contain the granulated product having a particle size of 1.0 mm or more. According to this, the disinfecting effect can be surely slowed down by including the granulated product having a particle size of 1.0 mm or more.

Further, in the present invention, the particle size is preferably 10.0 mm or less. When the particle size is 10 mm or less, it can be sprayed with a general commercially available granule sprayer.

Further, in the present invention, it is preferable to contain the granulated product having a particle size of 1.0 to 2.0 mm. According to this, uniform and even spraying is possible.

Further, in the present invention, the average number of long and short lengths of the granulated product is preferably 1.40 or less. According to this, the surface area per unit mass of the granulated product is reduced to some extent, so that the disinfecting effect tends to last for a long time.

Further, in the present invention, it is preferable that the granulated product contains a porous substance. According to this, the disinfecting effect can be sustained longer due to the adsorption effect of the porous substance.

Further, in the present invention, it is preferable that the porous substance is zeolite. When zeolite is used, the slow-release of the disinfecting effect is likely to be ensured.

Further, in the present invention, it is preferable to contain a dye that can detect a decrease in disinfecting effect by changing the color according to pH. According to this, the decrease in the disinfecting effect can be grasped by the change in color. Therefore, it is easy to know when the disinfectant must be re-sprayed.

In the method for producing a disinfectant containing a granulated product composed of slaked lime and zeolite according to another aspect of the present invention, the ratio of the mass of slaked lime to the total mass of slaked lime and zeolite after granulation is 0.4 or more. The granulated product is produced by granulating slaked lime and zeolite so as to be. According to this, the size of slaked lime can be adjusted by granulation, and the scattering and outflow of the disinfectant can be suppressed .

In the method for detecting a disinfectant according to another aspect of the present invention, a disinfectant containing a granulated product consisting of slaked lime and zeolite and having a ratio of the mass of slaked lime to the total mass of slaked lime and zeolite being 0.4 or more. And a dye that can detect a decrease in the disinfecting effect by changing the color according to the pH are sprayed simultaneously or individually. According to this, the decrease in the disinfecting effect can be grasped by the change in color. Therefore, it is easy to know when the disinfectant must be re-sprayed. In the present invention, "simultaneously spraying" means "simultaneously spraying" even when the dye is contained in the disinfectant.

FIG. 1 is a graph showing the particle size distribution of slaked lime and zeolite granules produced while changing the mixing ratio of slaked lime and zeolite for each mixing ratio. FIG. 2 is a graph showing the particle size distribution of the slaked lime granules produced while changing the rotation time of the granulator for each rotation time. FIG. 3 is a graph showing the particle size distribution of slaked lime and zeolite granules produced while changing the rotation time of the granulator for each rotation time. FIG. 4 is a graph showing the pH change of the slaked lime powder. FIG. 5 is a graph showing the pH change of slaked lime granules having different particle sizes for each particle size. FIG. 6 is a graph showing the pH changes of slaked lime and zeolite granules having different mixing ratios for each mixing ratio. FIG. 7 is a graph showing pH changes of slaked lime, blast furnace slag, and zeolite granules having different mixing ratios for each mixing ratio. FIG. 8 is a graph showing pH changes of slaked lime and zeolite powders and granules thereof.

Hereinafter, a disinfectant for spraying, a method for producing the same, and a method for detecting the disinfectant according to the embodiment of the present invention will be described. This disinfectant is used to prevent pathogens from invading the barn, farm, etc. by spraying it around the barn, inside the barn, on the outer edge of the farm, etc. This disinfectant contains granules containing slaked lime, zeolite and pigment (for example, thymol blue) (hereinafter, simply referred to as granules). The pH of slaked lime is around 12 to 13.

In general, it is said that a pH of 9 or higher has antiseptic activity against pathogens (“Guidelines for the Prevention of Specific Livestock Infectious Diseases Regarding Foot-and-Mouth Disease”, published by the Minister of Agriculture, Forestry and Fisheries, October 1, 2011, p.27). It is even better that the pH is 10 or higher. On the other hand, slaked lime reacts with carbon dioxide in the atmosphere and changes to calcium carbonate. Therefore, when the pH of the slaked lime contained in the disinfectant is changed to calcium carbonate and the pH becomes close to neutral, it becomes difficult to obtain the disinfecting effect. In this regard, slaked lime is used as a granule in the disinfectant of the present embodiment. The granulated product has a smaller surface area per unit mass than the powder. Therefore, the contact area with carbon dioxide in water or the atmosphere becomes small, and the reaction between calcium hydroxide and carbon dioxide is suppressed. This makes it difficult for the pH of the disinfectant to drop. Therefore, the disinfecting effect is relatively long and sustainable.

Zeolites are porous substances and can adsorb granules or their components. Due to this adsorption effect, the disinfecting effect of the disinfectant can be sustained for a long time. That is, the slow-release of the disinfecting effect is likely to be ensured. Further, as the porous substance, any one or more of silica gel, mesoporous silica, activated alumina, activated carbon, carbon molecular sieve and the like can be used instead of or in addition to zeolite.

Thymol blue is a pigment that exhibits blue in an aqueous solution having a pH of 10 or higher, green at pH 9, yellow at pH 3 to 8, orange at pH 2, and red at pH 1. Therefore, when the pH of the disinfectant decreases, the color of thymol blue changes, so that it can be visually indicated that the alkalinity of the disinfectant has weakened. Therefore, it is easy to grasp the timing when the disinfectant becomes less effective and the disinfectant must be re-sprayed. Further, as described above, the pH of 9 or more is considered to have antiseptic activity against pathogens. From this, thymol blue, whose color changes at pH 9, is particularly effective in detecting the disinfecting effect. In addition, thymol blue is vivid in color, making it easy to identify color changes.

A dye other than thymol blue may be used. In this case, any dye may be used as long as a decrease in disinfecting effect can be detected by a change in color. The amount of dye may be increased or decreased depending on the degree of coloration of the disinfectant. Further, since the disinfectant is sprayed around the barn, inside the barn, on the outer edge of the farm, etc., the pigment used for the disinfectant is preferably one that does not easily affect the environment. For example, in addition to thymol blue, litmus, red diso pigment, high red G150 (grape peel pigment), high red RA200 (red radish pigment), curcumin (turmeric pigment) and the like can be mentioned. The dye may be a natural material or a chemically synthesized product as long as it does not easily affect the environment. As described above, in the method for detecting a disinfectant of the present embodiment, a decrease in the disinfecting effect of the disinfectant is detected by using thymol blue or another pigment whose color changes based on a change in pH.

Further, in order to enhance the disinfecting effect, a disinfecting component other than slaked lime may be contained in the granulated product. For example, even if one or more of organic antibacterial agents such as quaternary ammonium salts, alcohols / aldehydes, carboxylic acids, esters, phenols, chlorine compounds, and peroxides are contained in the granules. Good. Alternatively, the granulated product may contain any one or more of inorganic antibacterial agents such as silver ions, copper ions, titanium oxide, and nanoparticles. In addition, any one or more of hypochlorite, hydrogen peroxide, acidic electrolyzed water, antibacterial agents such as ozone, and antibiotics may be contained in the granules.

The granulated product of the present embodiment is produced by granulating slaked lime, zeolite, and dye (thymol blue, for example) powder using a wet granulation method. In addition, a binder may be used. As the granulator, a conventionally known granulator such as a pan-type granulator or a mixed granulator is used. In granulation, the hardness, particle size, and length of the granulated product are adjusted as follows.

The hardness of the granulated product can be freely adjusted from 0.5 N / mm, which can be easily crushed, to about 100 N / mm or more, which is not easily crushed, depending on the mixing ratio of the raw materials and the like. The hardness of the granulated product is appropriately adjusted within the range of being crushed by the load of a person, a vehicle, or the like. As an example, the hardness of the granules is adjusted according to the use of the disinfectant, such as making the hardness so that it is not crushed by the load of a person but is crushed by the load of the vehicle. Further, by adjusting the amount of the binder added, it is possible to adjust the granulated product to a desired hardness. For example, depending on the usage environment of this disinfectant, such as when spraying on muddy ground, the granules may easily collapse unless a binder is added. In that case, the hardness of the granulated product can be adjusted by adding a binder. As the binder, any one or more of polyvinyl alcohol, polyvinylpyrrolidone, carboxylmethyl cellulose, polyacrylic acid, starch, sucrose, lignin, lignin sulfonate, cellulose, wax and the like are used.

The particle size of the granulated product can be controlled by the type and mixing ratio of the powder used as the raw material, the amount of water added during granulation, the type of granulator and the granulation conditions (granulation time and blade rotation speed). is there. For example, in the process of coagulation granulation, powders as raw materials are aggregated to form an agglomerate. The agglomerates further collect powder and grow, or the small agglomerates collide with each other to grow further. Therefore, for example, it is possible to control the particle size distribution of the granulated product by changing the granulation time or the rotation speed of the bread of the pan-type granulator. In addition, the mixing type granulator is equipped with chopper blades that crush large aggregates. Therefore, it is possible to control the particle size distribution by changing the size of the chopper blade and its rotation speed. When granulating the granulated product, the particle size distribution is controlled and the yield is increased by changing the above-mentioned various conditions so that the granulated product having the particle size suitable for the intended use is contained in the largest amount. In addition, if necessary, those having the desired particle size are sorted by sieving or the like.

For example, when the particle size of the granulated product is 1.0 mm or more, the disinfecting effect can be surely slowed down. Further, for example, since vehicles frequently pass through the entrance of a facility or the like, slaked lime powder has been thickly sprayed in the past. As the granulated product in the disinfectant used in such a place, it is preferable to use one having a relatively large particle size of about 2.0 mm to 5.0 mm. For disinfection of puddles and ponds that have already been contaminated with pathogens, it is advisable to use granules with a large particle size of 5.0 mm or more. Further, by setting the particle size of the granulated product to 10.0 mm or less, it is possible to spray it with a general commercially available granule sprayer such as a fertilizer spreader, a seed spreader, and a snow melting agent sprayer. Further, when a granulated product having a particle size of 1.0 mm to 2.0 mm is used, uniform spraying with little unevenness is possible.

The length of the granulated product is preferably 1.40 or less. The length of the granulated product is the ratio of the major axis to the minor axis of the particles constituting the granulated product. The closer the length is closer to 1, the closer it is to a sphere / cube. The closer it is to a sphere or cube, the smaller the area per unit mass. Therefore, the contact area with air and rain is reduced, and the disinfecting effect of the disinfectant is maintained for a long time.

As described above, in the method for producing a disinfectant according to the present embodiment, a granulated product is produced by granulating a raw material containing slaked lime. According to this, it becomes possible to adjust the size and the like of the granulated product by granulation. Therefore, it is possible to suppress the scattering and outflow of the disinfectant. Further, by granulating, in addition to the above-mentioned zeolite and pigment, an antibacterial agent different from slaked lime can be easily contained in the disinfectant.

[Example]
Examples of the present invention will be described in detail below.

<Difference in particle size of granules due to different mixing ratios of slaked lime and zeolite>
Powder of slaked lime (manufactured by Hokkaido Calming Co., Ltd.) and zeolite (manufactured by Hokkaido Zeolite) at a mass ratio of slaked lime: zeolite 20: 0, 18: 2, 16: 4, 14: 6, 12: 8, 10:10 , 8:12, and 4:16, and a mixing type granulator (manufactured by Pacific Kiko Co., Ltd., WB-75) while adding water so that the mass ratio of this mixed powder: water is 2: 1. Using a mold), granulation was performed with a rotation time of about 300 seconds. Then, after drying the granulated product at 60 ° C. for 12 hours, the particle size is in the range of less than 1 mm, in the range of 1 to 2 mm, in the range of 2 to 3.35 mm, in the range of 3.35 to 5.6 mm, and 5. The granules were sifted into each range exceeding 6 mm. Then, the mass of the granulated product was measured for each of the above particle size ranges to determine the content rate. The results are shown in FIG. According to this, the particle size tends to increase as the amount of zeolite added increases.

<Difference in particle size of granulated product due to different granulation time>
Using a mixing granulator (manufactured by Pacific Kiko Co., Ltd., WB-5 type), slaked lime powder was added for 30 seconds and 60 seconds while adding water so that the mass ratio of slaked lime: water was 2: 1. Granulation was performed with a rotation time of 120 seconds, 300 seconds, or 600 seconds. After the granules are dried at 60 ° C. for 12 hours, the particle size is in the range of less than 0.09 mm, 0.09 to 0.25 mm, 0.25 to 0.5 mm, 0.25 to 0.5 mm. Range, 0.5 to 1.0 mm range, 1.0 to 2.0 mm range, 2.0 to 3.35 mm range, 3.5 to 5.6 mm range, and more than 5.6 mm. Sifted into each range of ranges. Then, the mass was measured for each of the above particle size ranges. The results are shown in FIG. Similarly, slaked lime and zeolite were granulated at a mass ratio of slaked lime: zeolite at a ratio of 1: 1 and sieved within the above particle size range, and the mass in each particle size range was measured. The results are shown in FIG. According to this, it was found that the particle size tends to increase as the granulation time increases.

<pH change of slaked lime powder>
Indoors, an artificial turf was placed on a tray, a box made of drawing paper was placed on it, and slaked lime powder was sprayed therein. On top of the slaked lime powder, the average daily rainfall of Hokkaido was sprayed once a day. Then, the change in pH of slaked lime was measured. The pH was measured based on the general chemical pH measurement method of soil described in "Analytical Method for Soil / Crop Nutrition Diagnosis 2012, Agricultural Research Headquarters, Hokkaido Research Organization". The result is shown in FIG. In the following experiment for measuring the change in pH of the granulated product, the pH was measured by the same method as above while replacing the powder with the granulated product.

<Difference in pH change between granulated products with different particle sizes>
Using a mixing granulator (manufactured by Pacific Kiko Co., Ltd., WB-75 type), slaked lime powder is sprinkled in a rotation time of about 300 seconds while adding water so that the mass ratio of slaked lime: water is 2: 1. Granulated. Then, the granules are dried at 60 ° C. for 12 hours and then sieved, and the particle size exceeds 1 to 2 mm, 2 to 3.35 mm, 3.5 to 5.6 mm, and 5.6 mm. Sorted into ranges. Then, the change in pH of the granulated product with respect to the range of these particle sizes was measured. The result is shown in FIG.

According to this, the smaller the particle size of the granulated product, the faster the pH decreased. It is considered that this is because the surface area per unit mass was reduced by performing granulation, so that the contact area with carbon dioxide in water or the atmosphere was reduced, and the reaction between calcium hydroxide and carbon dioxide was suppressed. Further, according to FIG. 4, in the case of powder, the pH is around 9 in 40 days, but when granulated, it can be seen that the pH is maintained at around 11 even after 40 days. Therefore, it was found that by incorporating a slaked lime granule having a particle size of 1.0 mm or more into the disinfectant, the disinfecting effect of the disinfectant can be imparted to a slow effect.

<Difference in pH change due to different mixing ratios of slaked lime and zeolite>
Similar to the above, slaked lime and zeolite powder are mixed with slaked lime: zeolite mass ratio at 20: 0, 18: 2, 16: 4, 14: 6, 12: 8, 10:10, 8:12, 4:16, and The mixture was mixed at a ratio of 0:20, and the mixture was granulated with a rotation time of about 300 seconds while adding water so that the mass ratio of the mixed powder: water was 2: 1. Then, the granules dried at 60 ° C. for 12 hours were screened, and the change in pH of the granules was measured for each mass ratio using the granules having a particle size of 1 mm to 2 mm. The results are shown in FIG. According to this, the pH of the granulated product consisting only of slaked lime began to decrease after 30 days, and after 70 days, it fell below pH 10, which is a guideline for the decrease in disinfection efficacy. For granules containing 20% slaked lime and 80% zeolite, the pH began to gradually decrease and fell below pH 10 after 50 days. On the other hand, the granulated product containing 40% or more of slaked lime and zeolite maintained a higher pH for a long period of time than the granulated product containing 100% slaked lime. It is considered that this is because granulating slaked lime together with zeolite imparted a slow-release effect to the disinfectant with respect to the pH retention effect.

<Differences in pH change due to different mixing ratios of slaked lime, blast furnace slag, and zeolite>
Similar to the above, slaked lime, blast furnace slag (manufactured by Nippon Steel Cement Co., Ltd.), and three-component powder of zeolite are mixed with slaked lime: blast furnace slag: zeolite mass ratio of 81: 9:10, 72:18:10, 63:27: 10, 54:36:10, 45:45:10, 72: 8:20, 64:16:20, 56:24:20, 48:32:20, 40:40:20, 63: 7:30, Mix at a ratio of 56:14:30, 49:21:30, 42:28:30, and 35:35:30, and add water so that the mass ratio of this mixed powder: water is 2: 1. Granulation was performed with a rotation time of about 300 seconds. Then, the granules dried at 60 ° C. for 12 hours were screened, and the change in pH of the granules was measured for each mass ratio using the granules having a particle size of 1 mm to 2 mm. The results are shown in FIG. It is considered that the slaked lime, blast furnace slag, and zeolite granules are also given slower effect than the results for the slaked lime-only granules (Fig. 6). This result is considered to be due to the adsorption of slaked lime and blast furnace slag on the porous material zeolite. The blast furnace slag is a material generated in the pig iron manufacturing process, the steel manufacturing process, and the like. Blast furnace slag contains calcium oxide as one of the main components. Calcium oxide reacts with water to produce slaked lime.

<Change in pH persistence with or without granulation>
Regarding (a) a mixture of slaked lime and zeolite powder at a mass ratio of 1: 1 and (b) a granulated product obtained by mixing slaked lime and zeolite at a mass ratio of 1: 1 to change the pH. It was measured. Regarding (b), the granulated product obtained as follows was used. First, a mixed powder of slaked lime and zeolite is mixed with water so that the mass ratio of powder: water is 2: 1 using a mixed granulator (manufactured by Pacific Kiko Co., Ltd., WB-5 type) for 60 seconds. Granulated in the rotation time of. Then, the granules dried at 60 ° C. for 12 hours were sifted, and those having a particle size of 1 mm to 2 mm were used. The results are shown in FIG. It was clarified that the granulated product maintained the alkalinity for a longer period of time than the powder of slaked lime and zeolite. This means that simply mixing slaked lime and zeolite has little effect, and granulation tends to show slow-release.

<Shape of particles of granules>
The slaked lime powder and the three samples of granulated product A and granulated product B granulated from the slaked lime powder are observed under a microscope, and the major axis of 100 particles contained in each sample is orthogonal to the major axis. The minor axis was measured. Then, the major / minority calculated by the major axis / minor axis was derived for each particle. The granulated product A uses a mixing type granulator (manufactured by Pacific Kiko Co., Ltd., WB-5 type) while adding water to the slaked lime powder so that the mass ratio of powder: water is 2: 1. Then, the granules were granulated with a rotation time of 60 seconds and dried at 60 ° C. for 12 hours. Then, the granulated product was sieved to separate those having a particle size of 1 to 2 mm. For the granulated product B, a mixed type granulator (manufactured by Pacific Kiko Co., Ltd., WB-5 type) is used while adding water so that the mass ratio of powder: water is 2: 1 with slaked lime powder as a raw material. The granules were granulated at a rotation time of 600 seconds and dried at 60 ° C. for 12 hours. Then, the granulated product was sieved to separate those having a particle size of 1 to 2 mm. As a result of deriving the long and short degrees as described above, the average number of long and short particles contained in the granulated product A is 1.37 ± 0.22, and the average number of long and short particles contained in the granulated product B is 1. It was 25 ± 0.20, and the average number of particles contained in the slaked lime powder was 1.45 ± 0.35. From this, it was found that the particles of the slaked lime granules produced by the standard granulation time of 60 seconds or more had an average number of 1.40 or less in terms of long and short. In addition, as a result of measuring the bulk density of the granulated product granulated while changing the rotation time in various ways, the bulk density increased as the rotation time increased. One of the reasons for the change in bulk density is that the more complex the shape, the lower the bulk density. From the results of deriving the longness and shortness and the bulk density as described above, it was found that the particles of the granulated product have a more regular shape (a shape closer to a sphere or a cube) due to the granulation than the powder of the raw material.

<Modification example>
The above is a description of a preferred embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and various changes can be made as long as it is described in the means for solving the problem. It is possible.

In the above-described embodiment, a granulated product obtained by granulating both slaked lime and a pigment is used as a disinfectant. However, the disinfectant containing the slaked lime granules containing no pigment and the pigment may be individually sprayed. For example, after spraying a disinfectant consisting of granules containing only slaked lime, a pigment may be further sprayed on the sprayed disinfectant.

Further, in the above-described embodiment, the disinfectant may contain both a granule containing slaked lime and a powder of slaked lime as a raw material. By containing even a small amount of granulated product, it is possible to impart slower effect to the disinfecting effect of the disinfectant as compared with a disinfectant consisting only of slaked lime powder as a raw material that does not contain granulated product.

Claims (10)

A disinfectant for spraying, which comprises a granulated product comprising slaked lime and zeolite and having a mass ratio of slaked lime to 0.4 or more of the total mass of slaked lime and zeolite . The disinfectant for spraying according to claim 1, wherein the granulated product is imparted with a slow-release effect in terms of pH retention effect as compared with a granulated product containing slaked lime and not containing zeolite. .. The disinfectant for spraying according to claim 2 , wherein the granulated product having a particle size of 1.0 mm or more is contained. The disinfectant for spraying according to any one of claims 1 to 3, wherein the particle size is 10.0 mm or less. The disinfectant for spraying according to claim 3 or 4 , wherein the granulated product having a particle size of 1.0 to 2.0 mm is contained. The disinfectant for spraying according to any one of claims 1 to 5 , wherein the average number of long and short granules is 1.40 or less. The disinfectant for spraying according to any one of claims 1 to 6 , which contains a pigment capable of detecting a decrease in disinfecting effect by changing the color according to pH. A method for producing a disinfectant containing granules composed of slaked lime and zeolite. After granulation, slaked lime and zeolite are prepared so that the ratio of the mass of slaked lime to the total mass of slaked lime and zeolite is 0.4 or more. A method for producing a disinfectant, which comprises producing the granulated product by granulating. A disinfectant containing granules consisting of slaked lime and zeolite and the ratio of the mass of slaked lime to the total mass of slaked lime and zeolite is 0.4 or more, and the disinfecting effect is reduced by changing the color according to pH. A method for detecting a disinfectant, which comprises spraying a dye capable of detecting the above-mentioned substances simultaneously or individually. In a granulated product composed of slaked lime and zeolite, the zeolite is mixed with slaked lime and granulated so that the ratio of the mass of slaked lime to the total mass of slaked lime and zeolite is 0.4 or more. A method of increasing the duration of the disinfectant effect.