阅读说明：本技术 一种基于植物除臭剂雾化技术的废气除臭方法 (Exhaust gas deodorization method based on plant deodorant atomization technology ) 是由 邹阳 邹军 刘梅森 陈慧 唐忠月 于 2021-10-20 设计创作，主要内容包括：本发明提供了一种基于植物除臭剂雾化技术的废气除臭方法,先以泡桐叶、芳樟叶、冬青叶、松针、柏树皮、槐角、木槿皮、柚子皮、水葫芦根、麻欠树皮、芥菜籽等为原料,经两步提取分别得到水溶性成分和油溶性成分,混合乳化,制成除臭剂,然后将该除臭剂利用高压雾化设备雾化喷洒,即可实现废气除臭。本发明方法简单方便,成本低,除臭效果好,具有极好的应用推广前景。(The invention provides a waste gas deodorization method based on a plant deodorant atomization technology, which comprises the steps of taking paulownia leaves, cinnamomum camphora leaves, Chinese ilex leaves, pine needles, cypress bark, sophora fruit, shrubalthea bark, shaddock peel, hyacinth reed root, yamaowen bark, mustard seeds and the like as raw materials, respectively obtaining water-soluble components and oil-soluble components through two-step extraction, mixing and emulsifying to prepare a deodorant, and then atomizing and spraying the deodorant by using high-pressure atomization equipment to realize waste gas deodorization. The method is simple and convenient, has low cost and good deodorization effect, and has excellent application and popularization prospects.)

1. A waste gas deodorization method based on a plant deodorant atomization technology is characterized by comprising the following specific steps in parts by weight:

(1) firstly, crushing and mixing 20-30 parts of paulownia leaves, 18-22 parts of cinnamomum camphora leaves, 15-18 parts of Chinese ilex leaves, 15-17 parts of pine needles, 12-15 parts of cypress barks, 12-15 parts of sophora fruits, 10-12 parts of shrubalthea barks, 10-12 parts of shaddock peels, 8-10 parts of hyacinth reed roots, 5-7 parts of yaqiancha barks and 5-7 parts of mustard seeds to obtain mixed powder, adding the mixed powder into 350-450 parts of water after steam explosion treatment, performing microwave extraction, and centrifuging to obtain an extracting solution I and residues;

(2) adding the residue into 120-150 parts of tert-butyl alcohol and ethyl ether mixed solution, performing ultrasonic extraction under the condition of a pulsed electric field, centrifuging to obtain a supernatant, and performing rotary evaporation to remove tert-butyl alcohol and ethyl ether to obtain an extracting solution II;

(3) then adding 6-8 parts of polyglycerol-10 myristate into the extracting solution I, slowly adding the extracting solution II at a constant speed while stirring, and homogenizing and emulsifying to obtain the deodorant;

(4) and finally, adding the deodorant into high-pressure atomization equipment, atomizing into 20-30 mu m atomized particles through an atomization nozzle, and directly spraying the atomized particles into the waste gas to realize waste gas deodorization.

2. The method according to claim 1, wherein in the step (1), the specific method of the steam explosion treatment is as follows: and (3) loading the mixed powder into a blasting cavity of steam blasting equipment, keeping the mixed powder for 1-2 minutes under the condition of 2-3 MPa, and then quickly releasing the pressure.

3. The method according to claim 1, wherein in the step (1), the microwave extraction process conditions are as follows: and (3) irradiating for 5-7 minutes by using 300-500W microwave.

4. The method according to claim 1, wherein in the step (2), the volume ratio of the tert-butyl alcohol to the diethyl ether in the tert-butyl alcohol diethyl ether mixed solution is 1: 2 to 3.

5. The method of claim 1, wherein in step (2), the pulsed electric field conditions are as follows: the electric field intensity is 30-40 kV/cm, the pulse time is 400-500 mu s, and the pulse frequency is 300-400 Hz.

6. The method according to claim 1, wherein in the step (2), the process conditions of the ultrasonic extraction are as follows: extracting with 400-500W ultrasonic wave for 40-50 min.

7. The method according to claim 1, wherein in the step (3), the addition time of the extract II is 30 to 40 minutes.

8. The method according to claim 1, wherein in the step (3), the process conditions of the homogeneous emulsification are as follows: homogenizing at 20000-25000 rpm under 10-12 MPa for 3-5 min.

9. The method according to claim 1, wherein in the step (4), automatic reciprocating rotary spraying is adopted, the rotation angle is 100-120 degrees, and the pitch angle is 20-30 degrees.

10. The method according to claim 1, wherein the spraying amount in the step (4) is 3 to 5 g/(m)³·h)。

Technical Field

The invention relates to the technical field, in particular to a waste gas deodorization method based on a plant deodorant atomization technology.

Background

With the improvement of living standard of people, the generation amount of various wastes is increased, and most of the wastes are transported to a refuse landfill for landfill treatment except for partial incineration, composting or recycling. The wastes can release a large amount of odor substances in the stacking process, the odor substances comprise hydrogen sulfide, thiols, thioether, ammonia, amines, nitro compounds, hydrocarbons, aldehydes, fatty acids, alcohols, phenols, ketones, vinegar, organic halogen derivatives and the like, the odor substances can pollute air and form malodorous waste gas, and the malodorous waste gas can cause people to be unpleasant and even can affect the respiratory system, the circulatory system, the digestive system, the endocrine system, the nervous system and the like of a human body to damage the health of the human body.

Current methods for deodorizing exhaust gas include perfume masking methods, adsorption methods, ozone oxidation methods, microbiological methods, etc., wherein perfume masking methods are prone to poor human comfort due to the mixing of fragrance and odor; the adsorption method and the microbiological method have requirements on the waste gas treatment environment, and the use cost is high; the ozone concentration in the ozone oxidation method is not easy to control, and is easy to cause human body injury.

Patent application CN111135702A discloses a composite biological filler, VOC exhaust gas deodorization and purification method, which comprises the following steps: 1) carrying out catalytic decomposition and deodorization on the VOC waste gas in a filler for adsorbing the biological enzyme and deodorization composite reagent solution and an aerobic environment; 2) performing one-stage or multi-stage biological purification on the VOC waste gas obtained in the step 1) in a filler for adsorbing biological bacteria liquid. The patent technology uses a large amount of biological enzymes, microbial strains and the like, has certain requirements on equipment, has very high treatment cost and very harsh treatment conditions, and is difficult to popularize and use in a large range.

Disclosure of Invention

The invention aims to provide a waste gas deodorization method based on a plant deodorant atomization technology, which is simple and convenient, low in cost and good in deodorization effect.

In order to achieve the purpose, the invention is realized by the following scheme:

a waste gas deodorization method based on a plant deodorant atomization technology comprises the following specific steps in parts by weight:

(1) firstly, crushing and mixing 20-30 parts of paulownia leaves, 18-22 parts of cinnamomum camphora leaves, 15-18 parts of Chinese ilex leaves, 15-17 parts of pine needles, 12-15 parts of cypress barks, 12-15 parts of sophora fruits, 10-12 parts of shrubalthea barks, 10-12 parts of shaddock peels, 8-10 parts of hyacinth reed roots, 5-7 parts of yaqiancha barks and 5-7 parts of mustard seeds to obtain mixed powder, adding the mixed powder into 350-450 parts of water after steam explosion treatment, performing microwave extraction, and centrifuging to obtain an extracting solution I and residues;

(2) adding the residue into 120-150 parts of tert-butyl alcohol and ethyl ether mixed solution, performing ultrasonic extraction under the condition of a pulsed electric field, centrifuging to obtain a supernatant, and performing rotary evaporation to remove tert-butyl alcohol and ethyl ether to obtain an extracting solution II;

(3) then adding 6-8 parts of polyglycerol-10 myristate into the extracting solution I, slowly adding the extracting solution II at a constant speed while stirring, and homogenizing and emulsifying to obtain the deodorant;

(4) and finally, adding the deodorant into high-pressure atomization equipment, atomizing into 20-30 mu m atomized particles through an atomization nozzle, and directly spraying the atomized particles into the waste gas to realize waste gas deodorization.

Preferably, in the step (1), the specific method of the steam explosion treatment is as follows: and (3) loading the mixed powder into a blasting cavity of steam blasting equipment, keeping the mixed powder for 1-2 minutes under the condition of 2-3 MPa, and then quickly releasing the pressure.

Preferably, in the step (1), the microwave extraction process conditions are as follows: and (3) irradiating for 5-7 minutes by using 300-500W microwave.

Preferably, in the step (2), the volume ratio of tert-butyl alcohol to ethyl ether in the tert-butyl alcohol-ethyl ether mixture is 1: 2 to 3.

Preferably, in step (2), the pulsed electric field conditions are as follows: the electric field intensity is 30-40 kV/cm, the pulse time is 400-500 mu s, and the pulse frequency is 300-400 Hz.

Preferably, in the step (2), the process conditions of the ultrasonic extraction are as follows: extracting with 400-500W ultrasonic wave for 40-50 min.

Preferably, in the step (3), the adding time of the extracting solution II is 30-40 minutes.

Preferably, in the step (3), the process conditions of the homogeneous emulsification are as follows: homogenizing at 20000-25000 rpm under 10-12 MPa for 3-5 min.

Preferably, in the step (4), automatic reciprocating rotary spraying is adopted, the rotating angle is 100-120 degrees, and the pitching angle is 20-30 degrees.

Preference is given toIn the step (4), the spraying amount is 3-5 g/(m)³·h)。

The invention has the beneficial effects that:

the method takes paulownia leaves, cinnamomum camphora leaves, Chinese ilex leaves, pine needles, cypress bark, sophora fruit, shrubalthea bark, shaddock peel, hyacinth reed root, yaowen bark, mustard seeds and the like as raw materials, respectively obtains water-soluble components and oil-soluble components through two-step extraction, mixes and emulsifies the components to prepare the deodorant, and then the deodorant is atomized and sprayed by high-pressure atomization equipment to realize the deodorization of waste gas. The method is simple and convenient, has low cost and good deodorization effect, and has excellent application and popularization prospects.

The technical core of the invention is that the deodorant takes a plurality of natural plants as raw materials, extracts water-soluble components and oil-soluble components in the raw materials, emulsifies the raw materials to form an oil-in-water structure under the action of polyglycerol-10 myristate, forms small liquid drops under the atomization action of high-pressure atomization equipment, has large specific surface area, has good adsorption effect on odor components in waste gas, removes the odor components through further reaction with the odor components or destroying the stability of the odor components and the like, and realizes the deodorization of the waste gas.

The effects of the natural plants in the invention are as follows: paulownia leaves containing flavonoids containing phenolic hydroxyl groups can be combined with alkaline odor components such as amino groups to realize deodorization; cinnamomum camphora leaf containing Cinnamomum camphora leaf oil, Cinnamomum camphora polyphenol, Cinnamomum camphora leaf flavone, etc.; folium Ilicis Purpureae containing protocatechuic acid, volatile oil, and flavonoids; pine needles containing bioflavonoids, essential oil and the like; cypress bark containing flavonoids, volatile oil, etc.; fructus Sophorae containing isoflavone; cortex Hibisci contains acidic components such as suberic acid and fatty acid, and can react with alkaline odor component; the shaddock peel contains naringin, is a flavanone, and the hydroxyl in the shaddock peel can be combined with odor components to realize deodorization; water hyacinth root containing linoleic acid and other acidic components; hemp is lack of bark and contains essential oil and the like; mustard seed, erucic acid, phenol substance, etc. The invention removes the odor component by the acid-base neutralization and catalytic oxidation reaction of various natural plant components and the odor component, thereby realizing the deodorization of the waste gas.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A waste gas deodorization method based on plant deodorant atomization technology comprises the following specific steps:

(1) crushing and mixing 20g of paulownia leaves, 22g of cinnamomum camphora leaves, 15g of Chinese ilex leaves, 17g of pine needles, 12g of cypress bark, 15g of sophora fruit, 10g of shrubalthea bark, 12g of shaddock peel, 8g of hyacinth reed roots, 7g of yamaowen bark and 5g of mustard seeds to obtain mixed powder, adding 450g of water after steam explosion treatment, performing microwave extraction, and centrifuging to obtain an extracting solution I and residues;

(2) adding the residue into 120g of tert-butyl alcohol ether mixed solution (the volume ratio of tert-butyl alcohol to ether is 1: 3), performing ultrasonic extraction under the condition of a pulsed electric field, centrifuging to obtain a supernatant, and performing rotary evaporation to remove tert-butyl alcohol and ether to obtain an extracting solution II;

(3) then adding 6g of polyglycerol-10 myristate into the extracting solution I, slowly adding the extracting solution II at a constant speed while stirring, homogenizing and emulsifying to obtain the deodorant;

(4) finally, the deodorant is added into high-pressure atomization equipment, atomized into 30-micron atomized particles through an atomization nozzle, and directly sprayed into the waste gas, wherein the spraying amount is 3 g/(m)³H), namely, the deodorization of the exhaust gas can be realized.

In the step (1), the specific method of the steam explosion treatment comprises the following steps: the mixed powder is loaded into a blasting cavity of steam blasting equipment, and the pressure is rapidly released after the mixed powder is kept for 1 minute under the condition of 3 MPa; the process conditions of microwave extraction are as follows: and irradiating the mixture with 500W microwave for 5 minutes.

In the step (2), the pulse electric field conditions are as follows: the electric field intensity is 40kV/cm, the pulse time is 400 mus, and the pulse frequency is 400 Hz; the process conditions of ultrasonic extraction are as follows: ultrasonic extraction at 400W for 50 minutes.

In the step (3), the adding time of the extracting solution II is 30 minutes; the process conditions of homogenizing and emulsifying are as follows: homogenizing at 20000rpm under 12MPa for 5 min.

In the step (4), automatic reciprocating rotary spraying is adopted, the rotating angle is 100 degrees, and the pitching angle is 30 degrees.

Example 2

A waste gas deodorization method based on plant deodorant atomization technology comprises the following specific steps:

(1) firstly, crushing and mixing 30g of paulownia leaves, 18g of cinnamomum camphora leaves, 18g of Chinese ilex leaves, 15g of pine needles, 15g of cypress barks, 12g of sophora fruit, 12g of shrubalthea barks, 10g of shaddock peels, 10g of hyacinth reed roots, 5g of yamaowen barks and 7g of mustard seeds to obtain mixed powder, adding the mixed powder into 350g of water after steam explosion treatment, performing microwave extraction, and centrifuging to obtain an extracting solution I and residues;

(2) adding the residue into 150g of tert-butyl alcohol ether mixed solution (the volume ratio of tert-butyl alcohol to ether is 1: 2), performing ultrasonic extraction under the condition of a pulsed electric field, centrifuging to obtain supernatant, and performing rotary evaporation to remove tert-butyl alcohol and ether to obtain an extracting solution II;

(3) then adding 8g of polyglycerol-10 myristate into the extracting solution I, slowly adding the extracting solution II at a constant speed while stirring, homogenizing and emulsifying to obtain the deodorant;

(4) finally, the deodorant is added into high-pressure atomization equipment, atomized into 20-micron atomized particles through an atomization nozzle, and directly sprayed into the waste gas, wherein the spraying amount is 5 g/(m)³H), namely, the deodorization of the exhaust gas can be realized.

In the step (1), the specific method of the steam explosion treatment comprises the following steps: the mixed powder is loaded into a blasting cavity of steam blasting equipment, and the pressure is rapidly released after the mixed powder is kept for 2 minutes under the condition of 2 MPa; the process conditions of microwave extraction are as follows: and (3) irradiating for 7 minutes by using 300W microwaves.

In the step (2), the pulse electric field conditions are as follows: the electric field intensity is 30kV/cm, the pulse time is 500 mus, and the pulse frequency is 300 Hz; the process conditions of ultrasonic extraction are as follows: ultrasonic extraction at 500W for 40 min.

In the step (3), the adding time of the extracting solution II is 40 minutes; the process conditions of homogenizing and emulsifying are as follows: homogenizing at 25000rpm under 10MPa for 3 min.

In the step (4), automatic reciprocating rotary spraying is adopted, the rotating angle is 120 degrees, and the pitching angle is 20 degrees.

Example 3

A waste gas deodorization method based on plant deodorant atomization technology comprises the following specific steps:

(1) firstly, crushing and mixing 25g of paulownia leaves, 20g of cinnamomum camphora leaves, 16g of Chinese ilex leaves, 16g of pine needles, 13g of cypress barks, 14g of sophora fruit, 11g of shrubalthea barks, 11g of shaddock barks, 9g of hyacinth rhizome, 6g of yamaowen barks and 6g of mustard seeds to obtain mixed powder, adding 400g of water after steam explosion treatment, performing microwave extraction, and centrifuging to obtain an extracting solution I and residues;

(2) adding the residue into 135g of tert-butyl alcohol ether mixed solution (the volume ratio of tert-butyl alcohol to ether is 1: 2.5), performing ultrasonic extraction under the condition of a pulsed electric field, centrifuging to obtain a supernatant, and performing rotary evaporation to remove tert-butyl alcohol and ether to obtain an extracting solution II;

(3) then adding 7g of polyglycerol-10 myristate into the extract I, slowly adding the extract II at a constant speed while stirring, homogenizing and emulsifying to obtain deodorant;

(4) finally, the deodorant is added into high-pressure atomization equipment, atomized into 25-micron atomized particles through an atomization nozzle, and directly sprayed into the waste gas, wherein the spraying amount is 4 g/(m)³H), namely, the deodorization of the exhaust gas can be realized.

In the step (1), the specific method of the steam explosion treatment comprises the following steps: the mixed powder is loaded into a blasting cavity of steam blasting equipment, and the pressure is rapidly released after the mixed powder is kept for 2 minutes under the condition of 3 MPa; the process conditions of microwave extraction are as follows: microwave irradiation at 450W for 6 min.

In the step (2), the pulse electric field conditions are as follows: the electric field intensity is 35kV/cm, the pulse time is 450 mus, and the pulse frequency is 350 Hz; the process conditions of ultrasonic extraction are as follows: 500W ultrasonic extraction was carried out for 45 minutes.

In the step (3), the adding time of the extracting solution II is 35 minutes; the process conditions of homogenizing and emulsifying are as follows: homogenizing at 22000rpm under 11MPa for 4 min.

In the step (4), automatic reciprocating rotary spraying is adopted, the rotating angle is 110 degrees, and the pitching angle is 25 degrees.

Comparative example 1

A waste gas deodorization method based on plant deodorant atomization technology comprises the following specific steps:

(1) crushing and mixing 20g of paulownia leaves, 22g of cinnamomum camphora leaves, 15g of Chinese ilex leaves, 17g of pine needles, 12g of cypress bark, 15g of sophora fruit, 10g of shrubalthea bark, 12g of shaddock peel, 8g of hyacinth reed roots, 7g of yamaowen bark and 5g of mustard seeds to obtain mixed powder, adding the mixed powder into 450g of tertiary butanol aqueous solution with the volume concentration of 50% after steam explosion treatment, performing microwave extraction and centrifugation to obtain an extracting solution, thus obtaining the deodorant;

(2) then adding the deodorant into a high-pressure atomization device, atomizing into 30 μm atomized particles by an atomizing nozzle, and directly spraying into the waste gas, wherein the spraying amount is 3 g/(m)³H), namely, the deodorization of the exhaust gas can be realized.

In the step (1), the specific method of the steam explosion treatment comprises the following steps: the mixed powder is loaded into a blasting cavity of steam blasting equipment, and the pressure is rapidly released after the mixed powder is kept for 1 minute under the condition of 3 MPa; the process conditions of microwave extraction are as follows: and irradiating the mixture with 500W microwave for 5 minutes.

In the step (2), automatic reciprocating rotary spraying is adopted, the rotating angle is 100 degrees, and the pitching angle is 30 degrees.

Comparative example 2

A waste gas deodorization method based on plant deodorant atomization technology comprises the following specific steps:

(1) crushing and mixing 20g of paulownia leaves, 22g of cinnamomum camphora leaves, 15g of Chinese ilex leaves, 17g of pine needles, 12g of cypress bark, 10g of shrubalthea bark, 12g of pomelo peel, 8g of hyacinth reed rhizome and 5g of mustard seeds to obtain mixed powder, adding the mixed powder into 450g of water after steam explosion treatment, performing microwave extraction, and centrifuging to obtain an extracting solution I and residues;

(2) adding the residue into 120g of tert-butyl alcohol ether mixed solution (the volume ratio of tert-butyl alcohol to ether is 1: 3), performing ultrasonic extraction under the condition of a pulsed electric field, centrifuging to obtain a supernatant, and performing rotary evaporation to remove tert-butyl alcohol and ether to obtain an extracting solution II;

(3) then adding 6g of polyglycerol-10 myristate into the extracting solution I, slowly adding the extracting solution II at a constant speed while stirring, homogenizing and emulsifying to obtain the deodorant;

(4) finally, the deodorant is added into high-pressure atomization equipment, atomized into 30-micron atomized particles through an atomization nozzle, and directly sprayed into the waste gas, wherein the spraying amount is 3 g/(m)³H), namely, the deodorization of the exhaust gas can be realized.

In the step (1), the specific method of the steam explosion treatment comprises the following steps: the mixed powder is loaded into a blasting cavity of steam blasting equipment, and the pressure is rapidly released after the mixed powder is kept for 1 minute under the condition of 3 MPa; the process conditions of microwave extraction are as follows: and irradiating the mixture with 500W microwave for 5 minutes.

In the step (2), the pulse electric field conditions are as follows: the electric field intensity is 40kV/cm, the pulse time is 400 mus, and the pulse frequency is 400 Hz; the process conditions of ultrasonic extraction are as follows: ultrasonic extraction at 400W for 50 minutes.

In the step (3), the adding time of the extracting solution II is 30 minutes; the process conditions of homogenizing and emulsifying are as follows: homogenizing at 20000rpm under 12MPa for 5 min.

In the step (4), automatic reciprocating rotary spraying is adopted, the rotating angle is 100 degrees, and the pitching angle is 30 degrees.

Test examples

The methods of examples 1 to 3 and comparative examples 1 and 2 were used to deodorize waste gas in a landfill site (each treatment was carried out separately at a relatively long interval) for 6 hours, and the waste gas before deodorization contained: ammonia gas 20.34mg/m³Hydrogen sulfide 5.31. mu.g/m³Methyl mercaptan 4.63. mu.g/m³(ii) a The contents of each odor component in the deodorized exhaust gas are shown in Table 1.

The method is characterized in that the ammonia content is detected by adopting HJ533-2009 'Nashi reagent spectrophotometry for measuring ammonia in ambient air and waste gas', the hydrogen sulfide content is detected by GB/T11742-89 'methylene blue spectrophotometry for measuring hydrogen sulfide in ambient air', and the methanethiol content is detected by HJ1078-2019 'air bag sampling-preconcentration/gas chromatography-mass spectrometry for measuring 8 sulfur-containing organic compounds such as fixed pollution source waste gas methanethiol and the like'.

TABLE 1 content of each component of the exhaust gas after deodorization treatment

	Ammonia gas (mg/m)3)	Hydrogen sulfide (. mu.g/m)3)	Methyl mercaptan (. mu.g/m)3)
				Example 1	0.78	0.42	0.31
Example 2	0.76	0.41	0.29
				Example 3	0.72	0.38	0.27
Comparative example 1	2.18	1.63	1.59
				Comparative example 2	3.65	2.35	2.33

As can be seen from table 1, after the exhaust gas is deodorized by the methods of examples 1 to 3, the contents of odor components such as ammonia, hydrogen sulfide, and methyl mercaptan in the exhaust gas are all significantly reduced, and the exhaust gas has a good deodorizing effect.

The comparative example 1 directly uses the tertiary butanol aqueous solution for one-step extraction when preparing the deodorant, and the comparative example 2 omits the pagodatree pod and the numb bark when preparing the deodorant, the deodorization effect is obviously poor, which shows that the plant components of the invention cooperate with each other, and the full extraction of the water-soluble component and the oil-soluble component is combined, thereby realizing the full deodorization of the waste gas.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.