JP2007289880A - Ultrasonic sterilizer and circulation type bath water purification device equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic sterilizer which can efficiently perform the effective sterilization of microorganisms and the prevention of biofilm adhesion at the same time, and a bath water purification device using the ultrasonic sterilizer. <P>SOLUTION: The ultrasonic sterilizer 100 comprises a first oscillator 111 for oscillating ultrasonic waves having a frequency of ≤30 kHz effective for sterilization, and a second oscillator 112 for oscillating ultrasonic waves having a frequency of ≥40 kHz effective for the prevention of biofilm adhesion to the inside of the sterilizer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultrasonic sterilizer that sterilizes microorganisms using a cavitation phenomenon and a circulating bath water purifier using the same.

  Conventionally, sterilizing devices such as bath water purifiers employ ultraviolet sterilization, which mainly irradiates liquids with ultraviolet light, and chlorine sterilization performed by adding chemicals such as chlorine compounds to bath water. ing. However, in these sterilization means, it is necessary to satisfy certain conditions in order to obtain a sufficient sterilization effect. For example, in the case of ultraviolet sterilization, the effect depends on the irradiation amount and irradiation time of ultraviolet rays. The time must be adjusted, and in chlorine sterilization, increasing the amount of added chlorine compound increases the effect, but not only the chlorine smell in the bath water becomes stronger, but also the human body and the environment. There was a problem of causing an adverse effect. In addition, ultraviolet sterilization and chlorine sterilization could not sterilize and kill mold spores and protozoan eggs.

  In recent years, in addition to the above-described ultraviolet sterilization and chlorine sterilization, ultrasonic sterilization using an ultrasonic cavitation phenomenon is used as the sterilization means. Ultrasonic sterilization is a method in which a cavitation phenomenon is generated by irradiating a liquid with ultrasonic waves, thereby sterilizing microorganism cells by mechanical destruction. According to this method, it is not influenced by conditions such as residence time as in the case of ultraviolet sterilization, and since water quality does not change as in the case of chlorine compound sterilization, simple and effective sterilization can be performed. it can. As such a sterilization apparatus using ultrasonic waves, for example, a bath water purification apparatus (see Patent Document 1) in which the ultrasonic frequency is set to 200 to 400 KHz to improve the organic substance decomposition effect, and the efficiency of cavitation generation. For example, there is an ultrasonic device (see Patent Document 2).

However, in the conventional ultrasonic sterilization apparatus, it adheres to the inner wall surface of the piping of the apparatus and becomes a breeding place of bacteria harmful to the human body such as Legionella bacteria, deteriorates the water quality, or corrodes or rusts of the piping. It has not been possible to prevent even the adhesion of a biofilm that causes the occurrence of the biofilm.
JP 2001-327963 A JP-A-11-262762

  Then, this invention makes it a subject to provide the ultrasonic sterilizer which can perform the effective sterilization of microorganisms, and adhesion prevention of a biofilm simultaneously and effectively, and a bathtub water purification apparatus using the same. It is.

  In order to solve the above problem, the means of the invention described in claim 1 is an ultrasonic sterilization apparatus 100 that sterilizes microorganisms by irradiating ultrasonic waves, and oscillates ultrasonic waves having a frequency of 30 KHz or less. An ultrasonic sterilizer 100 including one vibrator 111 and a second vibrator 112 that oscillates an ultrasonic wave having a frequency of 40 KHz or more.

  As a result of intensive studies, the present inventor has found that by simultaneously irradiating ultrasonic waves having a frequency of 30 KHz or lower and ultrasonic waves having a frequency of 40 KHz or higher, an excellent sterilizing effect and biofilm adhesion preventing effect are achieved. The present invention has been conceived. That is, the ultrasonic sterilization apparatus 100 according to claim 1 includes a first vibrator 111 and a second vibrator 112, and simultaneously irradiates ultrasonic waves of the two types of frequency bands, thereby mechanically destroying microorganisms. Sterilization and prevention of biofilm adhesion. By applying this to a water treatment device, etc., it is possible to sterilize microorganisms that live in the water with high efficiency, and maintenance is extremely easy by preventing the biofilm from adhering to the device, and Corrosion of the apparatus is less likely to occur, and the apparatus can have a longer life.

  Moreover, the means which invention of Claim 2 took is the circulation type bathtub water purification apparatus 200 which purifies bathtub water, Comprising: The ultrasonic sterilizer 100 of Claim 1 is provided in the flow path through which bathtub water passes. Is a circulating bath water purification device 200, characterized in that

  That is, this circulating bathtub water purification apparatus 200 includes a first vibrator 111 that oscillates an ultrasonic wave having a frequency of 30 KHz or less and a first ultrasonic wave that oscillates an ultrasonic wave having a frequency of 40 KHz or more in a flow path such as a pipe through which bath water passes. By disposing the ultrasonic sterilization apparatus 100 including the two vibrators 112, sterilization of the bath water passing through the flow path and adhesion of the biofilm to the inside of the apparatus are prevented. By disposing such an ultrasonic sterilizer 100, microorganisms that cause diseases such as Legionella in the bath water, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, compared to conventional ultraviolet sterilization and chlorine sterilization. Can be safely and reliably sterilized, and can prevent corrosion and deterioration inside the apparatus due to biofilm adhesion, so that the maintenance of the circulating bath water purification apparatus 200 is extremely easy and has a long life. can do.

  According to the ultrasonic sterilization apparatus described in claim 1, the ultrasonic sterilizer includes a first vibrator that oscillates an ultrasonic wave with a frequency of 30 KHz or less and a second vibrator that oscillates an ultrasonic wave with a frequency of 40 KHz or more. Microorganisms present in the liquid irradiated with sound waves can be sterilized safely and reliably, and when applied to a water treatment device or the like, it prevents the biofilm from adhering to the inside of the water treatment device. Therefore, the maintenance of the apparatus can be facilitated and the life can be extended.

  According to the circulation type bathtub water purification apparatus described in claim 2, the ultrasonic water sterilizer according to claim 1 is disposed in the flow path through which the bathtub water passes, whereby the bathtub water is sterilized safely and reliably. In addition, since it is possible to prevent the biofilm that causes corrosion and rust inside the apparatus from adhering, it is possible to provide a circulating bath water purification apparatus that is easy to maintain and has a long life.

The present invention is an ultrasonic sterilizer and a circulating bath water purifier equipped with the same.
The ultrasonic sterilizer includes a first vibrator and a second vibrator. These vibrators convert electrical signals output from an ultrasonic oscillator into mechanical vibrations and output them as ultrasonic waves. The first vibrator oscillates an ultrasonic wave having a frequency of 30 KHz or less that is effective for sterilization. Among these frequency bands, an element that emits an ultrasonic wave having a frequency of 15 to 20 KHz is particularly effective. On the other hand, the second vibrator oscillates an ultrasonic wave having a frequency of 40 KHz or more, which is effective for preventing biofilm adhesion. Among these frequency bands, particularly, an ultrasonic wave having a frequency of 40 to 100 KHz is irradiated. It is valid. The type and shape of the first vibrator and the second vibrator are not particularly limited as long as they can oscillate ultrasonic waves in the above specific frequency range. For example, piezoelectric ceramics, piezoelectric polymer films, A vibrator such as a piezoelectric ZnO thin film can be used, and a vibrator having a bar shape or a plate shape can be used. Further, a unit in which the first vibrator and the second vibrator are integrated may be used, or separate members may be used in combination. Further, regarding its form, for example, it can be a so-called throwing type, a flange type, a bottoming type, etc., which are put into a processing tank and disposed.

  The circulating bathtub water purification apparatus is characterized in that the above-described ultrasonic sterilizer is provided in a flow path such as a pipe through which bathtub water circulates. For configurations other than the ultrasonic sterilizer, the same configuration as the conventional circulating bath water purification device can be adopted, for example, a hair collector for removing solids such as hair floating in the bath water, In addition to the filter, a heating device for heating the circulated bathtub water can be provided. A plurality of ultrasonic sterilizers may be provided, or the first vibrator and the second vibrator may be separately provided at different locations. Other sterilization means such as an ultraviolet sterilizer or a chemical agent such as a chlorine compound may be provided. Moreover, since an ultrasonic sterilizer is provided in flow paths, such as piping, it can also be retrofitted to the existing circulation bathtub purification apparatus.

  The ultrasonic sterilization apparatus according to the present invention is not limited to the application to the circulating bath water purification apparatus, but for example, to a batch type sterilization apparatus used for sterilization processing such as food and medical instruments. Of course, application is also possible.

  Embodiments of the present invention will be described below with reference to the drawings. Of course, the following examples only show preferred examples of the present invention, and the technical scope of the present invention is not limited to the following examples.

  FIG. 1 shows the basic structure of the ultrasonic sterilizer 100. The ultrasonic sterilizer 100 includes a first oscillator 120A, a second oscillator 120B, a first vibrator 111, a second vibrator 112, and a diaphragm 113 (in FIG. 1, the first oscillator 120A and the second oscillator 120B). Are shown in an overlapping manner, and the first vibrator 111 and the second vibrator 112 are also shown in an overlapping manner). The ultrasonic sterilizer 100 and the processing tank 500 constitute a food sterilizer 600.

  The first oscillator 120A and the second oscillator 120B are connected to a power source, and generate ultrasonic waves having a frequency of 30 KHz or less effective for sterilization and ultrasonic waves having a frequency of 40 KHz or more effective for preventing biofilm adhesion. The electrical signal is output to a first vibrator 111 and a second vibrator 112 described later. The first vibrator 111 and the second vibrator 112 are connected to the oscillator 120 and disposed below the processing tank 500 via the diaphragm 113. The first vibrator 111 and the second vibrator 112 are integrally arranged, and convert electrical signals output from the oscillator 120 into ultrasonic waves having frequencies of 30 KHz or less and 40 KHz or more, respectively, and via the diaphragm 113. Irradiate the treatment tank 500. The ultrasonic waves in the two frequency bands oscillated from the first vibrator 111 and the second vibrator 112 are irradiated to the liquid in the processing tank 500, thereby causing a cavitation phenomenon in the liquid. Microorganism cells and the like are destroyed by the shock wave generated by the above, and sterilization and biofilm removal are performed.

  Tables 1 to 6 show the results of the sterilization effect test in the case where the ultrasonic sterilizer is irradiated with ultrasonic waves using vibrators having frequencies of 15 KHz, 20 KHz, 28 KHz, 40 KHz, 50 KHz, and 100 KHz, respectively. The test method is as follows.

  In view of the presence of general bacteria and low-concentration fungi of about 1000 CFU / ml in normal bath water, Legionella pneumophila subsp. Pneumophilila ATCC 33152, Escherichia coli ATCC 8739, Staphylococcus aureus (Staphylococcus aureus subsp.aureus ATCC 12600), Pseudomonas aeruginosa ATCC10145, and mold spores (Aspergillus niger IFO 6341) as test strains, Legionella, Staphylococcus aureus, E. coli and Pseudomonas Bacterial fluid was prepared so as to be on the order of 1000 CFU / ml and mold spores on the order of 100 CFU. The bacterial solution was prepared by suspending in Sterile deionized water for S. aureus, and Legionella, Escherichia coli, Pseudomonas aeruginosa and mold spores were prepared by suspending in sterile physiological saline or sterile phosphate buffer.

Cavitation with ultrasonic waves of 15 KHz, 20 KHz, 28 KHz, 40 KHz, 50 KHz, and 100 KHz was applied to each bacterial solution for 2 minutes, and sampling was performed at intervals of 15 seconds. As for Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, 1 ml was sampled and applied to the medium, followed by culturing for 48 hours. For mold spores, 1 ml was sampled and applied to the medium and cultured for 72 hours. For Legionella, 100 ml was sampled and subjected to filter concentration and alkali treatment, and then applied to BCYEα agar medium for 5 days. Culture was performed.

  From Tables 1-6, when the ultrasonic wave of frequency 15KHz, 20KHz, and 28KHz was irradiated, the effective bactericidal effect was seen with respect to each microbe. Among them, when ultrasonic waves with a frequency of 15 KHz and 20 KHz were irradiated, since all the bacteria were completely killed when the reaction time passed 30 seconds, irradiation with ultrasonic waves with a frequency of 15 to 20 KHz was performed. It was found to be particularly effective for sterilization.

  Table 7 shows the results of the biofilm removal effect test when ultrasonic waves having a frequency of 15 KHz, 20 KHz, 28 KHz, 40 KHz, 50 KHz, and 100 KHz are irradiated. The test method is as follows.

  Biofilms are formed by the propagation of microorganisms using water stains as nutrient sources. In view of the fact that the microbial membrane is formed of lipids and proteins, and that the dirt in the bath water contains sebum, dirt, etc., a pseudo biofilm was prepared and used as a test sample. The pseudo biofilm was prepared by adding yeast extract so as to be 0.1% after heating and dissolving animal fats and oils.

1 ml of the simulated biofilm prepared as described above was spread thinly on the bottom of a 100 ml beaker, dried and solidified, weighed, and 20 ml of sterile physiological saline was added. Cavitation by ultrasonic waves generated from vibrators with frequencies of 15 KHz, 20 KHz, 28 KHz, 40 KHz, 50 KHz, and 100 KHz was applied to each of these for 15 seconds, and after removing the biofilm that floated, the beaker was dried and the weight was measured. The removal rate of the pseudo biofilm was calculated from the measured value and the weight of the beaker before ultrasonic irradiation.

  From Table 7, the removal rate was as high as 98% or higher at frequencies of 40 KHz, 50 KHz, and 100 KHz, and the pulverized biofilm was observed at frequencies of 28 KHz or lower, but the removal rate remained at around 75%. From this, it was found that ultrasonic wave irradiation with a frequency of 40 to 100 KHz is particularly effective for removing the biofilm.

In Tables 8 to 16, sterilization in the case of combining ultrasonic waves with frequencies of 15 KHz, 20 KHz and 28 KHz showing high sterilization effect and ultrasonic waves with frequencies of 40 KHz, 50 KHz and 100 KHz showing high biofilm removal effect, respectively. And the result of the biofilm removal effect test is shown. In the test, 1 ml of a pseudo biofilm prepared by adding yeast extract so as to be 0.1% after heat-dissolving animal oil was spread on the bottom of a 100 ml beaker and dried and solidified, and then the weight was measured. Thereafter, each bacterial solution prepared by the same method as the above bactericidal effect test was added. Cavitation due to ultrasonic waves generated from a vibrator having a frequency of 40 KHz or 50 KHz is applied to this for 15 seconds, and then cavitation due to ultrasonic waves generated from vibrators having a frequency of 15 KHz, 20 KHz, and 28 KHz is applied for 15 seconds to obtain 0.1 ml of a bacterial solution. Were collected and cultured. Further, the bacterial solution was removed together with the floated quality, dried and weighed, and the removal rate of the pseudo biofilm was calculated from the measured value and the weight of the beaker before cavitation.

  From the test results shown in Tables 8 to 16, it is possible to obtain an excellent sterilization effect and biofilm removal effect simultaneously and effectively by combining an ultrasonic wave with a frequency of 20 KHz or less and an ultrasonic wave with a frequency of 40 to 100 KHz. all right. In particular, it was confirmed that both the bactericidal effect and the biofilm removal effect were the best when the ultrasonic wave having a frequency of 20 KHz and the ultrasonic wave having a frequency of 40 KHz were irradiated in combination.

  By the way, in the food sterilization apparatus of the prior art, chlorine sterilization and alcohol sterilization are performed, but in order to avoid the odor remaining, a complicated process of washing with water again after sterilization has been performed. However, in the above-described food sterilization apparatus 600, by using the ultrasonic sterilization apparatus 100 of the present invention, it is possible to simultaneously remove and sterilize mud dirt and the like without adding odor, and the efficiency is greatly improved. improves.

  FIG. 2 is a block diagram of the circulating bathtub water purification device 200. The circulating bath water treatment apparatus 200 includes a first ultrasonic sterilization apparatus 101, a second ultrasonic sterilization apparatus 102, a hair collector 220, a pump 230, a filter 250, and a heater 260. These members are attached to the pipe 270. The hair collector 220 is a filter that removes solids such as hair floating in the bath water, and is arranged between the pump 230 and the bath 210. The pump 230 circulates the bathtub water in the bathtub 210 inside the apparatus. The heater 260 is disposed at the end of the pipe 270, and heats the bathtub water whose water temperature has decreased while passing through the pipe 270 before discharging it to the bathtub 210. The chemical injection device 240 automatically applies an appropriate amount of chlorine compound according to the circulation speed of the bath water (including not only the water in the bathtub 210 but also the water flowing in the pipe 270 constituting the circulating flow path). And is disposed between the pump 230 and the filter 250. Here, the reason why the medicine injection device 240 is provided in FIG. 2 is illustrated assuming that it is retrofitted to an existing device, and is not an essential component in the present invention, but the first ultrasonic sterilization device. You may remove after attaching 101 and the 2nd ultrasonic sterilizer 102. FIG. That is, from the viewpoint of retrofitting an existing apparatus, it is obvious that the essential constituent requirements of the circulating bath water purification apparatus 200 are the first ultrasonic sterilization apparatus 101 and the second ultrasonic sterilization apparatus 102. In addition, it does not matter whether the bathtub water is hot spring water.

  FIG. 3 shows a state in which the first ultrasonic sterilizer 101 and the second ultrasonic sterilizer 102 are disposed in the pipe 270. The first ultrasonic sterilization apparatus 101 is for sterilizing bacteria and harmful microorganisms (pathogenic protozoa, etc.) by oscillating ultrasonic waves having a frequency of 20 KHz. The first vibrator 111 and the first oscillator 120A And the first diaphragm 113A. The second ultrasonic sterilizer 102 is for removing biofilm, scale and other deposits by oscillating an ultrasonic wave having a frequency of 40 KHz. The second vibrator 112, the second oscillator 120B, The second diaphragm 113B.

  As described above, according to the bathtub water treatment apparatus 200 of the present invention, since the first ultrasonic sterilization apparatus 101 and the second ultrasonic sterilization apparatus 102 are provided, two different wavelength bands are used. It is possible to sterilize bacteria and harmful microorganisms at one wavelength while removing the impact pressure at the time of shrinkage destruction of the material, and to remove deposits such as biofilm that becomes a hotbed for microbial contamination in the pipe 270 at the other wavelength. It becomes possible. Of course, the efficacy (characteristics) of the first ultrasonic sterilization apparatus 101 and the second ultrasonic sterilization apparatus 102 is as shown in each table as in the above-described ultrasonic sterilization apparatus 100.

  By the way, in the conventional bath water treatment apparatus, the alkaline fountain has a significant sterilizing effect, and the acidic fountain causes a neutralization reaction. On the other hand, in the sterilization apparatus using ozone, ultraviolet rays, or photocatalyst, the entire system needs to be replaced, so that the introduction cost increases, and the effect is difficult to obtain unless it is circulated several times. In addition, chemical sterilization may cause harmful substances to humans, and photocatalysis may not be effective when the concentration of bacteria and microorganisms is low. It was. However, according to the circulation bathtub water treatment apparatus 200 of the present invention, since it has the above-described configuration, it can be used regardless of water quality such as pH, and can be retrofitted to an existing system. The entire system does not need to be replaced significantly, and the introduction cost can be kept low. Moreover, it is possible to prevent the generation of harmful substances due to chemical reaction and to obtain a high bactericidal effect of bath water regardless of the concentration of bacteria and microorganisms.

  Moreover, since the 1st ultrasonic sterilizer 101 and the 2nd ultrasonic sterilizer 102 are comprised separately (separate body), it becomes possible to select the arrangement | positioning location. In the embodiment shown in FIG. 2, the first ultrasonic sterilizer 101 is disposed between the filter 250 and the heater 260, and the second ultrasonic sterilizer 102 is disposed between the pump 230 and the filter 250. Has been. The second ultrasonic sterilizer 102 is preferably provided at the corner of the pump 230 or the pipe 270 in order to remove deposits such as biofilms. It is preferable to provide in the part where a flow becomes slow. In this way, by making it possible to select the location of the ultrasonic sterilizer, it can be installed at the most efficient position when retrofitting to existing equipment or when designing and constructing new equipment. is there.

  In addition, as shown in FIG. 2, the first ultrasonic sterilizer 101 is disposed downstream (downstream) of the filter 250, so that deposits such as biofilm removed by the second ultrasonic sterilizer 102 are used. It is possible to sterilize the bath water after the water is removed, and it seems that the effect is improved. The test results shown in the above-mentioned tables are test results in a state where bacteria / microorganisms are contained in deposits such as biofilms. From this test result, the first stage of the filter 250 (upstream side) It is confirmed that there is no problem even if one ultrasonic sterilizer 101 is provided.

  The first ultrasonic sterilization apparatus 101 and the second ultrasonic sterilization apparatus 102 described above are arranged in two places. That is, a first vibrator that oscillates an ultrasonic wave having a frequency of 20 KHz that is effective for sterilization is disposed between the filter 250 and the heater 260, and is effective for removing the biofilm between the pump 230 and the filter 250. A second vibrator that oscillates an ultrasonic wave having a frequency of 40 KHz is disposed. In this way, by arranging the first vibrator and the second vibrator that oscillate in different frequency bands separately, while removing the biofilm, scale and other deposits, the cause of the deposit such as biofilm Bacteria and microorganisms living in the bath water can be sterilized reliably.

  More specifically, since the first vibrator 111 is disposed on the downstream side (rear stage) of the second vibrator 112, the biofilm is first generated by ultrasonic waves with a frequency of 40 KHz irradiated from the second vibrator. The attached matter such as the flakes is peeled off, and then the microorganisms living in the water and the causative germs such as the peeled biofilm are sterilized by the ultrasonic wave with a frequency of 20 KHz irradiated from the first vibrator. . In addition, since the configuration is simple, maintenance of the apparatus becomes extremely easy and a long life can be realized.

  Moreover, as shown in FIG. 3, in any of the first ultrasonic sterilization apparatus 101 and the second ultrasonic sterilization apparatus 102, the ultrasonic wave is uniformly applied to the bath water passing through the pipe 270 in any of the apparatuses. The diaphragms 113 </ b> A and 113 </ b> B are formed to have a substantially semicircular cross section according to the shape of the pipe 270, and are attached to the outer periphery of the pipe 270 so as to be able to do so. Thus, since it is set as the structure which irradiates an ultrasonic wave radially with respect to the bathtub water which passes the piping 270, it becomes possible to improve sterilization efficiency. In addition, since the sterilizing effect is high in this way, it can be provided outside the pipe 270 and can be easily retrofitted to existing equipment. Furthermore, since it is configured to be attached to the outside of the pipe 270, the vibrators 111 and 112 and the diaphragms 113A and 113B do not directly touch the bathtub water passing through the pipe 270. Can be further improved.

  Although the present invention has been described based on the above embodiments, the above embodiments can be variously improved and modified without departing from the spirit of the present invention. The technical scope of the present invention includes these improvements. Variations are included.

  For example, in the circulating bath water purification apparatus 200 of the above embodiment, one each of the first vibrator 111 and the second vibrator 112 are provided. However, when the pipe 270 is long, a plurality of the first vibrator 111 and the second vibrator 112 may be provided. Thereby, while being able to remove effectively the biofilm adhering over the full length of the piping 270, the biofilm accumulate | stored in a curved part etc. can also be removed effectively.

  Further, in the circulating bath water purification apparatus 200 of the above embodiment, the first vibrator 111 and the second vibrator are separately provided, but of course they may be integrally provided. . However, it is preferable to arrange them separately as in the above embodiment.

It is a figure showing an example applied to a food sterilizer while showing a schematic diagram of an ultrasonic sterilizer concerning an example. It is a block diagram of the circulation type bathtub water purification apparatus which concerns on an Example. It is the schematic which shows the arrangement | positioning state of the ultrasonic sterilizer arrange | positioned at the circulation type bathtub water purification apparatus which concerns on an Example.

Explanation of symbols

100, 101, 102 Ultrasonic sterilizer 111 First vibrator 112 Second vibrator 200 Circulating bath water purifier

Claims (2)

An ultrasonic sterilization apparatus that sterilizes microorganisms by irradiating ultrasonic waves,
An ultrasonic sterilization apparatus comprising: a first vibrator that oscillates an ultrasonic wave having a frequency of 30 KHz or less; and a second vibrator that oscillates an ultrasonic wave having a frequency of 40 KHz or more. A circulating bathtub water purification device for purifying bathtub water,
A circulating bath water purifier, wherein the ultrasonic sterilizer according to claim 1 is disposed in a flow path through which bath water passes.

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