阅读说明：本技术 一种滨柃精油的制备方法 (Preparation method of Eurya emarginata essential oil ) 是由 边浩宇 崔大练 陈云飞 于 2021-10-12 设计创作，主要内容包括：本发明提供一种滨柃精油的制备方法,包括以下步骤：S1.将滨柃的枝叶部分置于烘箱中烘22-26小时,取出后转入中药粉碎机中粉碎得到滨柃干粉；S2.将步骤S1得到的滨柃干粉加入无水乙醇中,搅拌均匀后置于超声清洗仪中超声振荡20-40分钟得到提取液,将提取液静置2-4天分层得到上清液一；S3.将步骤S2得到的上清液一加入圆底烧瓶中,将圆底烧瓶置于旋转蒸发仪中,加热后浓缩3-5小时得到浓缩液；S4.将步骤S3得到的浓缩液用离心机离心分离5-15分钟得到上清液二,将上清液二冷冻干燥后得到滨柃精油。本发明稳定可靠,且制得的滨柃精油具有较好的抑菌性能。(The invention provides a preparation method of Eurya emarginata essential oil, which comprises the following steps: s1, placing the branches and leaves of Eurya emarginata into an oven to be dried for 22-26 hours, taking out the Eurya emarginata, and then transferring the Eurya emarginata into a traditional Chinese medicine pulverizer to be pulverized to obtain Eurya emarginata dry powder; s2, adding the Eurya emarginata dry powder obtained in the step S1 into absolute ethyl alcohol, uniformly stirring, placing the Eurya emarginata dry powder into an ultrasonic cleaning instrument, carrying out ultrasonic oscillation for 20-40 minutes to obtain an extracting solution, and standing the extracting solution for 2-4 days for layering to obtain a supernatant I; s3, adding the supernatant I obtained in the step S2 into a round-bottom flask, placing the round-bottom flask into a rotary evaporator, heating, and concentrating for 3-5 hours to obtain a concentrated solution; and S4, centrifuging the concentrated solution obtained in the step S3 by using a centrifugal machine for 5-15 minutes to obtain a supernatant II, and freeze-drying the supernatant II to obtain the Eurya emarginata essential oil. The Eurya emarginata essential oil is stable and reliable, and the prepared Eurya emarginata essential oil has good bacteriostatic performance.)

1. A preparation method of Eurya emarginata essential oil is characterized by comprising the following steps: the method comprises the following steps:

s1, placing the branches and leaves of Eurya emarginata into an oven to be dried for 22-26 hours, taking out the Eurya emarginata, and then transferring the Eurya emarginata into a traditional Chinese medicine pulverizer to be pulverized to obtain Eurya emarginata dry powder;

s2, adding the Eurya emarginata dry powder obtained in the step S1 into absolute ethyl alcohol, uniformly stirring, placing the Eurya emarginata dry powder into an ultrasonic cleaning instrument, carrying out ultrasonic oscillation for 20-40 minutes to obtain an extracting solution, and standing the extracting solution for 2-4 days for layering to obtain a supernatant I;

s3, adding the supernatant I obtained in the step S2 into a round-bottom flask, placing the round-bottom flask into a rotary evaporator, heating, and concentrating for 3-5 hours to obtain a concentrated solution;

and S4, centrifuging the concentrated solution obtained in the step S3 by using a centrifugal machine for 5-15 minutes to obtain a supernatant II, and freeze-drying the supernatant II to obtain the Eurya emarginata essential oil.

2. The method of claim 1, wherein the essential oil of Eurya emarginata comprises: in step S1, the particle size of the Eurya emarginata dry powder is 150 μm.

3. The method of claim 1, wherein the essential oil of Eurya emarginata comprises: in step S2, the ratio of the Eurya emarginata dry powder to the absolute ethyl alcohol is (0.5-1.5) g:2 mL.

4. The method of claim 1, wherein the essential oil of Eurya emarginata comprises: in step S2, the power of the ultrasonic cleaning apparatus is 70%.

5. The method of claim 1, wherein the essential oil of Eurya emarginata comprises: in the step S3, the heating temperature is 70-80 ℃.

6. The method of claim 1, wherein the essential oil of Eurya emarginata comprises: in step S4, the speed of centrifugal separation was 5000 rpm.

Technical Field

The invention relates to a preparation method of Eurya emarginata essential oil.

Background

With the development of society, people are increasingly pursuing quality of life, plant essential oil which is small in harm and environment-friendly and has multiple practical purposes gradually enters the visual field of people, plant essential oil such as rose essential oil is favored by people, and the extraction and research of the plant essential oil are hot topics all the time. Plant essential oil is also called volatile oil, essential oil or aromatic oil, and is a secondary metabolite with volatile aromatic odor generated by plants. The plant essential oil serving as a novel cold sterilization technology has multiple advantages, such as wide antimicrobial spectrum, obvious antibacterial effect and low residual toxicity. As early as four hundred years ago, some plant essential oil extraction and application data are recorded in detail in Bencao gang mu drafted by Li Shizhen. At present, plant essential oil is applied and developed in the aspects of spice industry, medical treatment, agriculture and the like, and has systematic research on the aspects of bacteriostasis, components, physiological action, pharmacological action and the like. The existing plant essential oil has the problems that some plant essential oil extraction cannot be carried out by the most basic steam distillation method in a laboratory, and the bacteriostatic effect of some plant essential oil is not good.

Disclosure of Invention

The invention aims to provide a preparation method of Eurya emarginata essential oil, the preparation method is stable and reliable, and the prepared Eurya emarginata essential oil has good bacteriostatic performance.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a preparation method of Eurya emarginata essential oil comprises the following steps:

s1, placing the branches and leaves of Eurya emarginata into an oven to be dried for 22-26 hours, taking out the Eurya emarginata, and then transferring the Eurya emarginata into a traditional Chinese medicine pulverizer to be pulverized to obtain Eurya emarginata dry powder;

s2, adding the Eurya emarginata dry powder obtained in the step S1 into absolute ethyl alcohol, uniformly stirring, placing the Eurya emarginata dry powder into an ultrasonic cleaning instrument, carrying out ultrasonic oscillation for 20-40 minutes to obtain an extracting solution, and standing the extracting solution for 2-4 days for layering to obtain a supernatant I;

s3, adding the supernatant I obtained in the step S2 into a round-bottom flask, placing the round-bottom flask into a rotary evaporator, heating, and concentrating for 3-5 hours to obtain a concentrated solution;

and S4, centrifuging the concentrated solution obtained in the step S3 by using a centrifugal machine for 5-15 minutes to obtain a supernatant II, and freeze-drying the supernatant II to obtain the Eurya emarginata essential oil.

Further, in step S1 of the present invention, the particle size of the Eurya emarginata dry powder is 150 μm.

Further, in step S2 of the present invention, the ratio of the Eurya emarginata dry powder to the absolute ethanol is (0.5-1.5) g:2 mL.

Further, in step S2 of the present invention, the power of the ultrasonic cleaning apparatus is 70%.

Further, in step S3 of the present invention, the heating temperature is 70-80 ℃.

Further, in step S4 of the present invention, the speed of centrifugation was 5000 rpm.

Compared with the prior art, the invention has the following beneficial effects:

the Eurya emarginata essential oil is prepared by drying and crushing the branches and leaves of Eurya emarginata, mixing the branches and leaves with absolute ethyl alcohol serving as an extractant, carrying out ultrasonic extraction to obtain an extracting solution, standing the extracting solution for layering, carrying out rotary evaporation and concentration, carrying out centrifugal separation, and carrying out freeze drying.

Detailed Description

The present invention will be described in detail with reference to specific embodiments, which are illustrative of the invention and are not to be construed as limiting the invention.

Example 1

The Eurya emarginata essential oil is prepared according to the following steps:

s1, placing the branches and leaves of Eurya emarginata into an oven to be dried for 24 hours, taking out the Eurya emarginata, and transferring the Eurya emarginata into a traditional Chinese medicine pulverizer to be pulverized to obtain Eurya emarginata dry powder with the particle size of 150 mu m;

s2, adding the Eurya emarginata dry powder obtained in the step S1 into absolute ethyl alcohol according to the proportion of 1g to 2mL, uniformly stirring, placing the Eurya emarginata dry powder into an ultrasonic cleaning instrument with the power of 70%, carrying out ultrasonic oscillation for 30 minutes to obtain an extracting solution, and standing the extracting solution for 3 days for layering to obtain a first supernatant;

s3, adding the supernatant I obtained in the step S2 into a round-bottom flask, placing the round-bottom flask into a rotary evaporator, heating to 78 ℃, and concentrating for 4 hours to obtain a concentrated solution;

and S4, centrifuging the concentrated solution obtained in the step S3 for 10 minutes at the speed of 5000rpm of a centrifuge to obtain a supernatant II, and freeze-drying the supernatant II to obtain the Eurya emarginata essential oil.

The first test example: test for Candida albicans inhibition zone

Test equipment: a culture dish; a conical flask; an ultra-clean bench; 1000mL porcelain cup; an induction cooker; an electric heating constant temperature incubator; a constant temperature shaking table; a one-ten-thousandth balance; inoculating a loop; a fine lamp; coating rods; a filter paper sheet; a glass rod; an autoclave; and (4) a liquid transferring gun.

Test reagents: candida albicans strain; eurya emarginata essential oil prepared in example 1; LB broth; agar powder; and (3) water.

The test method comprises the following steps:

(1) taking a sterilized sterile plate, pouring the LB culture medium which is dissolved and cooled to about 50 ℃ into the plate according to a sterile operation method, and cooling the plate to prepare a flat plate.

(2) Preparing bacterial suspension, taking a sterile test tube, inoculating 1-2 rings of Candida albicans into sterile water by using an inoculating ring, and fully and uniformly preparing the bacterial suspension.

(3) Inoculating, sucking 0.1mL of the prepared bacterial suspension by using a sterile pipette, inoculating on a flat plate, and uniformly spreading by using a sterile glass shovel.

(4) And (3) dipping, namely dipping the sterile filter paper sheet into the supply agent (the Eurya emarginata essential oil prepared in example 1).

(5) Adding the medicinal preparation, clamping the medicinal filter paper with sterile forceps (taking care to drain the medicinal liquid), spreading on the same bacteria-containing plate, respectively, taking care that the medicinal preparation is not contaminated, performing mark culture on the back of the plate, culturing the plate at 37 deg.C for 48-72 hr, and observing the result.

The test results are shown in table 1:

TABLE 1

Test example two: test for inhibition zone of Escherichia coli

Test equipment: a culture dish; a conical flask; an ultra-clean bench; 1000mL porcelain cup; an induction cooker; an electric heating constant temperature incubator; a constant temperature shaking table; a one-ten-thousandth balance; inoculating a loop; a fine lamp; coating rods; a filter paper sheet; a glass rod; an autoclave; and (4) a liquid transferring gun.

Test reagents: e, Escherichia coli strains; eurya emarginata essential oil prepared in example 1; LB broth; agar powder; and (3) water.

The test method comprises the following steps:

(1) taking a sterilized sterile plate, pouring the LB culture medium which is dissolved and cooled to about 50 ℃ into the plate according to a sterile operation method, and cooling the plate to prepare a flat plate.

(2) Preparing bacterial suspension, taking a sterile test tube, inoculating 1-2 rings of Escherichia coli into sterile water by using an inoculating ring, and fully and uniformly preparing the bacterial suspension.

(3) Inoculating, sucking 0.1mL of the prepared bacterial suspension by using a sterile pipette, inoculating on a flat plate, and uniformly spreading by using a sterile glass shovel.

(4) And (3) dipping, namely dipping the sterile filter paper sheet into the supply agent (the Eurya emarginata essential oil prepared in example 1).

(5) Adding the medicinal preparation, clamping the medicinal filter paper with sterile forceps (taking care to drain the medicinal liquid), spreading on the same bacteria-containing plate, respectively, taking care that the medicinal preparation is not contaminated, performing mark culture on the back of the plate, culturing the plate at 37 deg.C for 48-72 hr, and observing the result.

The test results are shown in table 2:

	blank group	1	2	3	4	5	6	Mean value
									Diameter of bacteriostatic circle (mm)	0	1.8	2.2	2.0	1.8	2.6	2.2	2.1

TABLE 2

Test example three: test for inhibition zone of Staphylococcus aureus

Test equipment: a culture dish; a conical flask; an ultra-clean bench; 1000mL porcelain cup; an induction cooker; an electric heating constant temperature incubator; a constant temperature shaking table; a one-ten-thousandth balance; inoculating a loop; a fine lamp; coating rods; a filter paper sheet; a glass rod; an autoclave; and (4) a liquid transferring gun.

Test reagents: a staphylococcus aureus species; eurya emarginata essential oil prepared in example 1; LB broth; agar powder; and (3) water.

The test method comprises the following steps:

(1) taking a sterilized sterile plate, pouring the LB culture medium which is dissolved and cooled to about 50 ℃ into the plate according to a sterile operation method, and cooling the plate to prepare a flat plate.

(2) Preparing bacterial suspension, taking a sterile test tube, inoculating 1-2 rings of staphylococcus aureus to sterile water by using an inoculating ring, and fully and uniformly preparing the bacterial suspension.

(3) Inoculating, sucking 0.1mL of the prepared bacterial suspension by using a sterile pipette, inoculating on a flat plate, and uniformly spreading by using a sterile glass shovel.

(4) And (3) dipping, namely dipping the sterile filter paper sheet into the supply agent (the Eurya emarginata essential oil prepared in example 1).

(5) Adding the medicinal preparation, clamping the medicinal filter paper with sterile forceps (taking care to drain the medicinal liquid), spreading on the same bacteria-containing plate, respectively, taking care that the medicinal preparation is not contaminated, performing mark culture on the back of the plate, culturing the plate at 37 deg.C for 48-72 hr, and observing the result.

The test results are shown in table 3:

TABLE 3

As can be seen from tables 1 to 3, the Eurya emarginata essential oil prepared in the example 1 of the invention has good bacteriostatic effect on Candida albicans, Escherichia coli and Staphylococcus aureus.

Test example four: turbidimetry for testing bacteriostatic effect of Eurya emarginata essential oil on Candida albicans

Test equipment: superclean bench, alcohol burner, spectrophotometer, cell, constant temperature shaking table, pipette, erlenmeyer flask, aseptic PC pipe.

Test reagents: beef extract peptone medium, candida albicans strain; the Eurya emarginata essential oil prepared in example 1.

The test method comprises the following steps:

the Eurya emarginata essential oil, 0.5mL and 1mL, was removed with a pipette and transferred to a 250mL Erlenmeyer flask containing 94mL and 95mL of LB liquid, and labeled 1 and 2, respectively. Transferring 5mL of candida albicans overnight culture solution (cultured for 10-12h) into a triangular flask containing 95mL of LB solution, uniformly mixing the culture solution and the triangular flasks with a blank label and labels 1 and 2, placing the mixture into a shaking table for shaking culture at 37 ℃ (shaking frequency is 250r/min), respectively culturing 0, 1.5, 3, 4, 6, 8, 10, 12, 14, 16, 18 and 20h, strictly sampling 3mL according to aseptic operation, placing the sample into a sterile PC tube, sealing the tube by using a sealing film, immediately placing the sample into a refrigerator for storage, and finally determining the absorbance at the same time. And (4) immediately putting the triangular flask back to the shaking table after sampling, and continuing shaking culture for subsequent sampling.

And (3) turbidimetry determination: the measurement was carried out by photoelectric turbidimetry using an uninoculated LB medium as a control at a wavelength of 600nm, and the measurement was carried out sequentially from the earliest initial culture broth.

The test results are shown in table 4:

Time	0	1.5	3	4	6	8	10	12	14	16	18	20
													blank group OD	0.087	0.109	0.382	0.432	0.731	1.109	0.898	1.392	1.581	1.645	1.622	1.903
No. 1 bottle OD	0.539	0.604	0.739	0.87	0.98	1.105	1.029	1.339	1.453	1.674	1.675	0.821
													No. 2 bottle OD	0.985	1.049	2.12	1.242	1.586	1.632	1.457	1.727	1.628	1.807	1.799	1.782

TABLE 4

As can be seen from table 4:

1. under normal culture conditions, the culture medium becomes more turbid with time, the concentration of the candida albicans is increased continuously, and the concentration of the candida albicans tends to be stable after about 12 hours.

2. In the culture medium containing 0.5mL of Eurya emarginata essential oil (bottle No. 1), the concentration of Candida albicans tended to increase gradually, but at 18h the bacterial liquid concentration dropped abruptly due to the consumption of nutrients and the inhibition of Eurya emarginata essential oil.

3. In the culture medium containing 1mL of Eurya emarginata essential oil (bottle No. 2), the bacterial liquid showed a large increase at 3 hours and then tended to a gradual increase at 4 hours, probably due to the sustained inhibition of Eurya emarginata essential oil.

Test example five: turbidimetry for testing bacteriostatic effect of Eurya emarginata essential oil on escherichia coli

Test equipment: superclean bench, alcohol burner, spectrophotometer, cell, constant temperature shaking table, pipette, erlenmeyer flask, aseptic PC pipe.

Test reagents: beef extract peptone culture medium, Escherichia coli strain; the Eurya emarginata essential oil prepared in example 1.

The test method comprises the following steps:

the Eurya emarginata essential oil, 0.5mL and 1mL, was removed with a pipette and transferred to a 250mL Erlenmeyer flask containing 94mL and 95mL of LB liquid, and labeled 1 and 2, respectively. Transferring 5mL of Escherichia coli overnight culture solution (cultured for 10-12h) into a triangular flask containing 95mL of LB solution, uniformly mixing the culture solution and the triangular flasks with a blank label and labels 1 and 2, placing the mixture in a shaking table for shaking culture at 37 ℃ (shaking frequency is 250r/min), respectively culturing 0, 1.5, 3, 4, 6, 8, 10, 12, 14, 16, 18 and 20h, strictly sampling 3mL of the culture solution according to aseptic operation, placing the sample into a sterile PC tube, sealing the tube by using a sealing film, immediately placing the sample into a refrigerator for storage, and finally determining the absorbance at the same time. And (4) immediately putting the triangular flask back to the shaking table after sampling, and continuing shaking culture for subsequent sampling.

And (3) turbidimetry determination: the measurement was carried out by photoelectric turbidimetry using an uninoculated LB medium as a control at a wavelength of 600nm, and the measurement was carried out sequentially from the earliest initial culture broth.

The test results are shown in table 5:

Time	0	1.5	3	4	6	8	10	12	14	16	18	20
													blank group OD	0.173	0.232	0.411	0.409	0.297	0.494	0.598	0.619	0.789	0.893	0.946	0.795
No. 1 bottle OD	0.639	0.938	0.931	0.569	0.968	0.666	1.141	1.236	1.322	1.495	1.08	0.453
													No. 2 bottle OD	0.469	0.597	0.531	0.737	0.658	0.664	0.744	0.747	0.847	0.857	1.074	0.944

TABLE 5

As can be seen from table 5:

bottle No. 2 is more stable than bottle No. 1 and bottle No. 2.

The overall trend of vial No. 2 was similar to that of the blank group, probably due to the lack of significant bacteriostasis in vial No. 2.

3. The occurrence of a precipitate in vial No. 1 was found during the test, and it was presumed that the sudden rise followed by the cliff-like drop in vial No. 1 was due to the precipitate, resulting in a large change in the concentration of the absorbance test sample taken.

Test example six: turbidimetry for testing bacteriostatic effect of Eurya emarginata essential oil on staphylococcus aureus

Test equipment: superclean bench, alcohol burner, spectrophotometer, cell, constant temperature shaking table, pipette, erlenmeyer flask, aseptic PC pipe.

Test reagents: beef extract peptone medium, staphylococcus aureus strain; the Eurya emarginata essential oil prepared in example 1.

The test method comprises the following steps:

the Eurya emarginata essential oil, 0.5mL and 1mL, was removed with a pipette and transferred to a 250mL Erlenmeyer flask containing 94mL and 95mL of LB liquid, and labeled 1 and 2, respectively. Transferring 5mL of staphylococcus aureus overnight culture solution (cultured for 10-12h) into a triangular flask containing 95mL of LB solution, uniformly mixing the culture solution and the triangular flask with a blank label and labels 1 and 2, placing the mixture into a shaking table for shaking culture at 37 ℃ (shaking frequency is 250r/min), respectively culturing 0, 1.5, 3, 4, 6, 8, 10, 12, 14, 16, 18 and 20h, strictly sampling 3mL according to aseptic operation, placing the sample into a sterile PC tube, sealing the tube by using a sealing film, immediately placing the sample into a refrigerator for storage, and finally determining the absorbance at the same time. And (4) immediately putting the triangular flask back to the shaking table after sampling, and continuing shaking culture for subsequent sampling.

And (3) turbidimetry determination: the measurement was carried out by photoelectric turbidimetry using an uninoculated LB medium as a control at a wavelength of 600nm, and the measurement was carried out sequentially from the earliest initial culture broth.

The test results are shown in table 6:

TABLE 6

As can be seen from table 6:

the data fluctuation is large, especially the trough value of the bottle No. 2 is even negative, while the bottle No. 1 with 0.5mL difference of the concentration of the essential oil from the bottle No. 2 is in an ascending trend and has a large number of wave peaks, and the occurrence of the situation can be caused by the generation of precipitates.

Example 2

The Eurya emarginata essential oil is prepared according to the following steps:

s1, placing the branches and leaves of Eurya emarginata into an oven to be dried for 22 hours, taking out the Eurya emarginata, and transferring the Eurya emarginata into a traditional Chinese medicine pulverizer to be pulverized to obtain Eurya emarginata dry powder with the particle size of 150 mu m;

s2, adding the Eurya emarginata dry powder obtained in the step S1 into absolute ethyl alcohol according to the proportion of 1.5g to 2mL, uniformly stirring, placing the Eurya emarginata dry powder into an ultrasonic cleaning instrument with the power of 70 percent, carrying out ultrasonic oscillation for 40 minutes to obtain an extracting solution, and standing the extracting solution for 2 days for layering to obtain a first supernatant;

s3, adding the supernatant I obtained in the step S2 into a round-bottom flask, placing the round-bottom flask into a rotary evaporator, heating to 80 ℃, and concentrating for 3 hours to obtain a concentrated solution;

and S4, centrifuging the concentrated solution obtained in the step S3 for 15 minutes at the speed of 5000rpm of a centrifuge to obtain a supernatant II, and freeze-drying the supernatant II to obtain the Eurya emarginata essential oil.

Example 3

The Eurya emarginata essential oil is prepared according to the following steps:

s1, placing the branches and leaves of Eurya emarginata into an oven to be dried for 26 hours, taking out the Eurya emarginata, and transferring the Eurya emarginata into a traditional Chinese medicine pulverizer to be pulverized to obtain Eurya emarginata dry powder with the particle size of 150 mu m;

s2, adding the Eurya emarginata dry powder obtained in the step S1 into absolute ethyl alcohol according to the proportion of 0.5g to 2mL, uniformly stirring, placing the Eurya emarginata dry powder into an ultrasonic cleaning instrument with the power of 70 percent, carrying out ultrasonic oscillation for 20 minutes to obtain an extracting solution, and standing the extracting solution for 4 days for layering to obtain a first supernatant;

s3, adding the supernatant I obtained in the step S2 into a round-bottom flask, placing the round-bottom flask into a rotary evaporator, heating to 70 ℃, and concentrating for 5 hours to obtain a concentrated solution;

and S4, centrifuging the concentrated solution obtained in the step S3 for 5 minutes at the speed of 5000rpm of a centrifuge to obtain a supernatant II, and freeze-drying the supernatant II to obtain the Eurya emarginata essential oil.

Example 4

The Eurya emarginata essential oil is prepared according to the following steps:

s1, placing the branches and leaves of Eurya emarginata into an oven to be dried for 25 hours, taking out the Eurya emarginata, and transferring the Eurya emarginata into a traditional Chinese medicine pulverizer to be pulverized to obtain Eurya emarginata dry powder with the particle size of 150 mu m;

s2, adding the Eurya emarginata dry powder obtained in the step S1 into absolute ethyl alcohol according to the proportion of 1.2g to 2mL, uniformly stirring, placing the Eurya emarginata dry powder into an ultrasonic cleaning instrument with the power of 70 percent, carrying out ultrasonic oscillation for 35 minutes to obtain an extracting solution, and standing the extracting solution for 3 days for layering to obtain a first supernatant;

s3, adding the supernatant I obtained in the step S2 into a round-bottom flask, placing the round-bottom flask into a rotary evaporator, heating to 75 ℃, and concentrating for 3.5 hours to obtain a concentrated solution;

and S4, centrifuging the concentrated solution obtained in the step S3 for 8 minutes at the speed of 5000rpm of a centrifuge to obtain a supernatant II, and freeze-drying the supernatant II to obtain the Eurya emarginata essential oil.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.