Low toxicity, environmentally friendly violet smoke generating compositions and methods of making the same

Abstract

The present invention is directed to a novel, low-toxicity and environmentally-friendly violet smoke generating composition. The composition comprises a mixture of at least one red dye and at least one blue dye, a coolant, an oxidizer, a binder, and a non-sulfur particulate fuel that is also a burn-control agent having two different particle size distributions. Preferably the fuel comprises a mixture of granulated sucrose and sucrose 10.

Claims

1. A low-toxicity violet smoke generating composition, comprising: an oxidizer; a particulate non-sulfur fuel having two different particle size ranges, wherein said fuel comprises a mixture of sucrose 10 having a particle size range of 10 to 100 microns, and granulated sucrose having a particle size range of 300 to 650 microns; a combination of at least one blue dye and at least one red dye, wherein said red dye is selected from the group consisting of 1-(Cyclohexylamino)anthracene-9,10-dione (Solvent Red 168), 1-Isopropylamino-9,10-anthraquinone (Solvent Red 169), and mixtures thereof; a coolant; and a binder.

2. The composition of claim 1, wherein said oxidizer is potassium chlorate.

3. The composition of claim 1, wherein said coolant is selected from the group consisting of sodium bicarbonate, magnesium carbonate, and mixtures thereof.

4. The composition of claim 1, wherein said binder is selected from the group consisting of nitrocellulose, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl ester, polyvinyl ether, and mixtures thereof.

5. The composition of claim 1, wherein said blue dye is selected from the group consisting of: 1-methylamino-4-ethanolaminoanthraquinone; bis[4-(dimethylamino) phenyl]-[4-(phenylamino)naphthalen-1-yl]methanol; 1,4-Bis(butylamino)anthraquinone; 1,4-Bis(isopropylamino)anthraquinone; 1,4-Bis(ethylamino)-9,10-anthraquinone; 1,4-Bis(methylamino)-9,10-anthracenedione; and mixtures thereof.

6. The composition of claim 5, wherein said blue dye is 1-methylamino-4-ethanolaminoanthraquinone (Disperse Blue 3).

7. The composition of claim 1, wherein said composition comprises said oxidizer in an amount of 18 to 35 wt. %, said fuel in an amount of 20 to 50 wt. %, said combination of said dyes in an amount of 27 to 50 wt. %, said coolant in an amount of 8 to 25 wt. %, and said binder in an amount of 1 to 5 wt. %.

8. The composition of claim 1, wherein said oxidizer comprises potassium chlorate in an amount of about 21 wt. %, said red dye comprises 1-Isopropylamino-9,10-anthraquinone (Solvent Red 169) in an amount of about 20.5 wt. %, said blue dye comprises 1-methylamino-4-ethanolaminoanthraquinone (Disperse Blue 3) in an amount of about 14.5 wt. %, said fuel comprises sucrose (10) having a particle size range of 10 to 100 microns in amount of about 14 wt. % and granulated sucrose having a particle size of 350 to 600 microns in an amount of about 14 wt. %, said coolant comprises magnesium carbonate in an amount of about 16 wt. %, and said binder comprises polyvinyl alcohol or nitrocellulose in an amount of about 2 wt. %.

9. A colored smoke-producing pyrotechnic device, comprising a body filled with the composition of claim 1, a first fire starter composition, and an attached squib igniter.

10. The device of claim 9, wherein said composition of claim 1 filling said body is in the form of a solid charge.

11. The device of claim 10, wherein said body is a grenade.

12. The composition of claim 1, wherein said red dye is 1-Isopropylamino-9,10-anthraquinone (Solvent Red 169).

13. A process for producing a low-toxicity violet smoke generating smoke grenade, comprising: mixing in a dry state an oxidizer, a particulate non-sulfur fuel having two different particle size ranges, wherein said fuel comprises a mixture of sucrose 10 having a particle size range of 10 to 100 microns, and granulated sucrose having a particle size range of 300 to 650 microns; a combination of at least one blue dye and at least one red dye, wherein said red dye is selected from the group consisting of 1-(Cyclohexylamino)anthracene-9,10-dione (Solvent Red 168), 1-Isopropylamino-9,10-anthraquinone (Solvent Red 169), and mixtures thereof; a coolant; and a binder to form a loose mixture; loading said mixture into a body as a solid charge; loading an ignition composition into said body; sealing said body; and attaching an igniter to said body to form a smoke grenade.

14. The process of claim 13, wherein said mixing is done using a planetary mixer or a fluidized bed mixer.

15. The process of claim 13, wherein each of said loading steps was completed at 1500 to 2500 psi, or about 15,000 lb. dead load.

16. The process of claim 13, wherein said body is a slug weighing between 60 to 65 g.

17. The process of claim 13, wherein said at least one blue dye is 1-methylamino-4-ethanolaminoanthraquinone (Disperse Blue 3), and said at least one red dye is 1-Isopropylamino-9,10-anthraquinone (Solvent Red 169).

18. The process of claim 13, wherein said mixture comprises in dry state said oxidizer in an amount of 18 to 35 wt. %, said fuel in an amount of 20 to 50 wt. %, said combination of said dyes in an amount of 27 to 50 wt. %, said coolant in an amount of 8 to 25 wt. %, and said binder in an amount of 1 to 5 wt. %.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The invention together with other objects, features, aspects, and advantages thereof will be clearly understood from the following in conjunction with the accompanying drawing.

(2) FIG. 1 depicts the burn time of a smoke grenade relative to the amount of incorporated granulated sugar.

SUMMARY OF THE INVENTION

(3) The present invention is directed to a novel, environmentally-friendly and low-toxicity violet smoke generating composition, comprising: a mixture of at least one red dye and at least one blue dye; a coolant, an oxidizer, a binder, and a non-sulfur particulate fuel that is also a burn-control agent having two different particle size distributions.

(4) In a further aspect of the present invention, there is provided a method of producing the violet smoke generating composition and incorporating the composition into a smoke grenade.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

(5) The present invention is directed toward a novel environmentally friendly and low-toxicity violet smoke generating composition including a mixture of blue and red dyes, and a method of manufacturing the novel environmentally-friendly and low-toxicity violet smoke-producing composition of the present invention.

(6) The invention relates to a smoke-producing pyrotechnic composition and more particularly, is related to generally cool-burning, non-toxic and non-corrosive smoke producing compositions, which incorporate:

(7) Oxidizera presently preferred oxidizer is potassium chlorate (KClO.sub.3).

(8) Non-Sulfur Fuela low energy, sugar-based fuel that also minimizes heat and flame produced. Such fuels are free of sulfur and is selected from the group consisting of starch, dextrose, lactose, sucrose, and mixtures thereof.

(9) Dye Mixturea mixture of sublimable and/or evaporative organic coloring substances which produce a violet smoke as a result of the dye undergoing a phase change. Specifically, the dye mixture is a combination of at least one red dye and at least one blue dye, which are less toxic than dyes used previously.

(10) Coolantcoolant prevents excessive decomposition of the dye, and also acts as a buffer for the KClO.sub.3. Suitable coolant is selected from sodium bicarbonate, magnesium carbonate, and the mixtures thereof. Preferably the coolant is magnesium carbonate.

(11) Non-Sugar Bindernitrocellulose or a polymer binder.

(12) Additives (optional)terephthalic acid or stearic acid.

(13) An ideal dye material for this application transforms (sublimes) directly from the solid phase to the gas phase with little or no intermediate liquid phase. The direct transformation to a gas enhances the likelihood of the dye molecules escaping from the solid matrix made of fuel, oxidizer, and dye to the external environment without the dye molecules reaching an undesirably high temperature. Thus, dyes are sought for the composition that have the property of sublimation at increased temperatures and normal pressures.

(14) The dyes, which may be used in this invention corresponding to the color standard FED-STD-595C color chip, are listed by the Society of Dyers and Colorists in dye classification materials according to chemical structure, and include the following:

(15) TABLE-US-00001 TABLE 1 Chemical compositions of dyes suitable for use in in violet smoke-producing compounds of the present invention Cl Name CAS # Trade Name Chemical Name Solvent Red 1 1229-55-6 Anasol Red SG amethoxybenzenazo--naphthol Solvent Red 3 6535-42-8 Anasol Brown DPN 4-(4-ethoxyphenyl)azo-1-naphthol Solvent Red 4 2653-64-7 Anasol Bordeaux DNN 1-(1-Naphthylazo)-2-naphthol Solvent Red 23 85-86-9 Anasol Scarlet Y 1-(4-(Phenyldiazenyl)phenyl)azonaphthalen-2-ol Solvent Red 24 85-83-6 Anasol Red OB 1-((2-Methyl-4-((2-methylphenyl)azo)phenyl)azo)-2- naphthalenol Solvent Red 26 4477-79-6 Anasol Red DTNB 1[[2,5-dimethyl-4-[(2-methylphenyl)azo]phenyl]azo]-2- Naphthalenol Solvent Red 27 1320-06-5 Anasol Red DXXN 1-[[4-[(dimethylphenyl)azo]dimethylphenyl]azo]-2- Naphthalenol Solvent Red 49 509-34-2 Anasol Red RBB 9-(9H)xanthen]-3-one,3,6-bis(diethylamino)- Spiro[isobenzofuran-1(3H) Solvent Red 52 81-39-0 Anasol Red BL 3-Methyl-6-(p-toluidino)-3H-dibenz[f,ij]isoquinoline- 2,7-dione Solvent Red 111 82-38-2 Anasol Red KMA 1-(Methylamino)anthraquinone Solvent Red 135 71902-17-5 Anasol Red GG 8,9,10,11-Tetrachloro-12-phthaloperinone Solvent Red 164 71819-51-7 CA. Solvent Red 164 1-[[2,5-dimethyl-4-[(2-methylphenyl)azo]-phenyl]azo]- 2-naphthol Solvent Red 168 71832-19-4 Abcol red 168 1-(Cyclohexylamino)anthracene-9,10-dione Solvent Red 169 27354-18-3 AMaplast Red PC 1-Isopropylamino-9,10-anthraquinone Solvent Red 179 6829-22-7 Macrolex Red E2G 14H-Benz(4,5)isoquino(2,1-a)perimidin-14-one Solvent Red 207 10114-49-5 Anasol Red CHA 1,5-bis[(3-methylphenyl)amino]anthraquinone Disperse Blue 3 2475-46-9 Anasperse Blue SG 1-methylamino-4-ethanolaminoanthraquinone Solvent Blue 4 6786-83-0 Anasol Blue VBB bis[4-(climethylamino)phenyl]-[4- (phenylamino)naphthalen-1-yl[methanol Solvent Blue 35 17354-14-2 Anasol Brill. Blue MBA 1,4-Bis(butylamino)anthraquinone Solvent Blue 36 14233-37-5 Anasol Brill. Blue MIP 1,4-Bis(isopropylamino)anthraquinone Solvent Blue 59 6994-46-3 Anasol Brill. Blue MEA 1,4-Bis(ethylamino)-9,10-anthraquinone Solvent Blue 78 2475-44-7 Anasol Blue MMA 1,4-Bis(methylamino)-9,10-anthracenedione

(16) The present inventive violet smoke generating composition includes a mixture of at least one red dye and at least one blue dye selected from Table 1. Preferably, the red dye is selected from the group consisting of 1-(Cyclohexylamino)anthracene-9,10-dione (Solvent Red 168); 1-Isopropylamino-9,10-anthraquinone (Solvent Red 169); and mixtures thereof. Preferably the blue dye is 1-methylamino-4-ethanolaminoanthraquinone (Disperse Blue 3). The ratio of the red dye to the blue dye is preferably about 1 to 0.7 by weight. Specifically, in the form of dry weight, the inventive violet smoke generating composition includes at least one red dye in the amount of 15 to 27 wt. % of the mixture, and at least one blue dye in the amount of 12 to 23 wt. % of the mixture. Most preferably, the red dye is Solvent Red 169 and comprises about 20.5 wt. % of the mixture, and the blue dye is Disperse Blue 3 and comprises about 14.5 wt. % of the mixture. These dyes have not previously been used in violet smoke compositions and were subject to toxicology testing to verify that safe sublimated dyes were being generated. Without wish to be bound by theory, small-scale and full-scale testing has demonstrated an acceptable violet color for military smoke signaling.

(17) The compositions of the present invention also incorporate at least one binder to provide the desired consistency. A binding agent from the group of the halogen-free thermoplastics can be used for the physical stabilization of the mixture of the pyrotechnic smoke-producing composition. The binding agent is selected from the group consisting of polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl ester, polyvinyl ether, or mixtures thereof. Preferably, the binder is either nitrocellulose or polyvinyl alcohol as they result in a decreased solid residue within the burned grain and produce only a small energy output upon combustion. Nitrocellulose, if applicable, is used in a solution of 6 to 12 wt. % nitrocellulose dissolved in acetone. This is important in avoiding very high-energy outputs, high temperatures, and flames, which render smoke producing compositions dangerous and difficult to handle. Accordingly, no sugar substance is used as a binder, as sugar in excess to the fuel of the present invention may cause insufficient burn and reduce color strength.

(18) The composition of the present invention also includes one or more oxidizer compounds. It is found that potassium chlorate (KClO.sub.3) is an efficient oxidizer and produces good results when coupled with the fuel and previously mentioned nitrogen-rich compounds.

(19) The present invention includes a fuel. The fuel is preferably a relatively low energy fuel similar to the binder. It is also preferred that the fuel produce gaseous reaction products capable of carrying the smoke producing agent into the environment. Preferably the fuel is a sugar. Some suitable fuels include starch, dextrose, and polyhydroxylic compounds such as lactose and sucrose. It has been found that a mixture of fuel, or a mixture of sugars having two distinct particle size distributions effectively controls the burn time of the violet smoke generating composition, which is important to maintain a burn time of between about 50 to about 90 seconds, an acceptable range for M18 smoke grenades. Specifically, the non-sulfur fuel is sucrose comprising a first sugar having a particle size of 300 to 650 microns (granulated), and a second sugar having a particle size of 10 to 100 microns (10). Preferably the first sugar is granulated, and the second sugar is powdered (10). Specifically, in form of dry weight, the inventive violet smoke generating composition includes a first sugar in the amount of 10 to 25 wt. %, and a second sugar in the amount of 10 to 25 wt. %, and most preferably about 14 wt. % granulated sugar and about 14 wt. % 10 sugar.

(20) Other materials may also be added to produce specific desirable results. One suitable material is magnesium carbonate. Magnesium carbonate acts as a buffer, which prevents autocatalytic decomposition of the KClO.sub.3. Magnesium carbonate also functions as a coolant when the smoke-producing composition combusts. Alternatively, sodium bicarbonate can be used. Another useful additive in the present invention is aluminum. In some cases, atomized aluminum can provide additional thermal conductivity within the composition. This results in more uniform heat transfer and ignition of the fuel.

(21) In general, the ingredients of the composition are within the ranges indicated in Table 2:

(22) TABLE-US-00002 TABLE 2 ingredient ranges of the pyrotechnic smoke producing composition of the present invention Percent by Weight Materials (in dry state), % Potassium Chlorate 18 to 35 Sugar (Fuel) 20 to 50 Dye 27 to 50 Magnesium Carbonate 8 to 25 Nitrocellulose 1 to 5

EXAMPLE

(23) A series of mixtures were made using white smoke formulation as a baseline (Table 3), and replacing part or all of the 10 sugar having an average particle size of 60.91 microns, with granulated sugar having an average particle size of 330.82 microns. The amount of 10 to granulated sugar varied between 14:0 and 0:14 percent by weight in the composition while the other components remained constant throughout the experiments with respect to the quantity and lot. A Sympatec HELOS laser diffraction particle size analyzer (Sympatec, Clausthal, Germany) was used to measure particle size of the sugar.

(24) TABLE-US-00003 TABLE 3 Baseline Pyrotechnic Smoke Composition Materials Percent by Weight % KCIO.sub.3 23 Sugar (sucrose, 10X) 14 Terephthalic Acid (TA) 43 Pentaerythritol (PE) 15 MgCO.sub.3 3 Polyacrylic Rubber 2

(25) Typical pyrotechnic mixing procedures were observed when blending components for all mixtures in a Hobart planetary mixer (Hobart Corporation; Troy, Ohio). Acetone was used as the solvent for the polyacrylic rubber binder and as a mixing medium. The polyacrylic rubber was dissolved in a minimum amount of acetone (approximately 500 ml) before being used to wet the other components of the mixture. Acetone was added as needed to wet the other components of the mixture and to achieve the proper consistency for mixing. Mixing was accomplished using an electrically grounded planetary mixer. When sufficient acetone had evaporated leaving the residual material a damp powder, the mixture was removed from the mixing bowl and placed in a tray. The mixture was then transported to a forced air oven and allowed to dry for a minimum of 24 hours at 140 F.

(26) Ten grams of the dried mixture were hand pressed into small aluminum containers using the step-faced ram. The step on the ram had a depth of 0.375 in. and a diameter of 0.35 in. The dimensions of the aluminum container were 1.13 in. inner diameter and 2.21 in. in depth. One gram of the ignition composition given in Table 4 was added to the indentation left by the step-faced ram. The aluminum container was then placed in a Carver Laboratory Press and consolidated with the flat faced ram at 1800 lb. dead load. Based on the dimensions of the container this consolidation force was equivalent to 1800 psi. A container lid with a centered 0.1875 in. diameter port was attached using a sheet metal screw. Initiation was achieved by a small piece of quickmatch (MIL-Q-378B).

(27) TABLE-US-00004 TABLE 4 Ignitions Composition Used in Experiments Materials Percent by Weight % KNO.sub.3 67.35 Ti 11.23 Al 8.16 Si 6.12 S 2.04 C 5.10

(28) Table 5 displays the various sugar ratios in the formulation and burn times for the experiments conducted. A minimum of ten trials was performed for each formulation.

(29) TABLE-US-00005 TABLE 5 Burn Times Resulting from Increasing Percentage of Granulated Sugar Granulated Sugar 10X Confectioners' Average (% Weight) Sugar (% Weight) Burn(s) 0 14 25.05 2 12 26.38 3 11 27.68 4 10 28.33 6 8 30.11 8 6 32.55 9 5 34.14 12 2 37.33 14 0 36.82

(30) Table 5 and FIG. 1 clearly show that when the 10 was replaced with granulated sugar, the burn time was increased by 32% in this experimental configuration. All test items displayed reliable ignition and produced smoke at a rate consistent with the formulation. As evidenced by a R.sup.2 value of 0.9755 in FIG. 1, a linear approximation of the burn time as a function of sugar ratio served as a reasonable model.

Comparative Testing

(31) Violet smoke generating formulations from the small-scale test were prepared in a manner similar to those of the current M18 grenade. These formulations were mixed in 300 g increments using a 2% by weight nitrocellulose binder within a Hobart model A200 planetary mixer (Hobart Corporation; Troy, Ohio). The mix was then pressed at approximately 15,000 lb. dead load in a standard M18 grenade can. Each of the candidate grenades were tested, along with a standard M18 grenade, which uses the sulfur-based formulation under the same environmental conditions. The smoke duration, cloud size, and color were all compared with the standard grenade.

(32) Table 6 shows the violet smoke formulations for the candidate mixes.

(33) TABLE-US-00006 TABLE 6 Violet Smoke Formulations Formulation Formulation Formulation Formulation Violet Smoke Mix No. 1 (%) No. 2 (%) No. 3 (%) No. 4 (%) Disperse Blue 3, DOD-D-51524 12 15 Solvent Red 168 18 Violet dye mix, MIL-DTL-3691 30 Solvent Red 169 15 3 Solvent Violet 47 MIL-DTL-3668 27 Sucrose, 10X powdered, Type 1, 14 14 14 Style C A-A-20135 Sucrose, granulated, Type 1, 14 14 14 28 Style A A-A-20135 Potassium chlorate, MIL-P-150, 21 21 21 21 Grade B, Class 7 Magnesium carbonate, MIL-M- 21 21 21 21 11361, Grade B Nitrocellulose, MIL-DTL-244, +2 +2 +2 +2 Grade D Burn Time(s) 55 60 40 47 , not applicable

(34) Formulation nos. 1 and 2 demonstrated burn times that were within the range of the specification, and they produced a violet-colored smoke cloud that was comparable to that of the current grenade. Formulation nos. 3 and 4 demonstrated a brilliant violet cloud but failed to meet the burn time requirements specified.

Full Scale Production

(35) For full-scale production the ingredients were mixed using a Glatt fluidized air bed mixer, with a polyvinyl alcohol (PVA) binder in a water solution. Specifically, the ingredients were weighed to 0.1 g of the desired amount. The sugar, dye, magnesium carbonate, and potassium chlorate were added to the bowl of the Glatt mixer. After 5 minutes of the mixing, the binder was added to the Glatt mixer bowl via spray for 15 minutes. The mixing operation produced powder and small granules of the smoke composition. The powder was either stored or taken to the pressing operation immediately.

(36) The formulations prepared in the Glatt mixer were then pressed and loaded as follows: Press 1: 100 g of smoke composition at 15,000 lb. dead load; Press 2: 100 g of smoke composition at 15,000 lb. dead load; and Press 3: 100 g of smoke composition and 5 g of an ignition composition at 15,000 lb. dead load.

(37) Five grenades were produced for this phase of testing, and were loaded in the same manner as the standard M18 grenades. Four slugs were pressed at about 5500 lb. maximum and reconsolidated at 8500500 lb. Each slug was approximately 65 g. The grenades were loaded in the following order: smoke slug, smoke slug, starter patch, smoke slug, starter patch, and smoke slug. The loading was completed at 1500 to 2500 psi, preferably 2300 psi.

(38) To produce a brighter violet cloud, the percentage of red dye was increased. Table 7 shows the formulation of the five grenades. Two 1000 g batches of formulation were produced. The mix was pressed into 65 g slugs, instead of 60 g, to extend the burn times.

(39) TABLE-US-00007 TABLE 7 Primary Violet Smoke Formulation Material Amount (%) Amount (g) Solvent Red 169 20.5 205.0 Disperse Blue 3 14.5 145.0 Potassium chlorate 21.0 210.0 Magnesium carbonate 16.0 160.0 Sugar, 10X 14.0 140.0 Sugar, granulated 14.0 140.0 PVA (BMS CEL 06325) 2.0 333.0

(40) The grenades produced with Table 7 contained 260 g of primary violet smoke formulation each, and had an average burn time of 48.8 s. No flaming occurred during this test.

(41) The production and testing of a second violet smoke formulation was also executed. Table 8 shows the second formulation of the grenades. Two 1000 g batches of smoke formulation were made. These batches were also pressed into 65 g.

(42) TABLE-US-00008 TABLE 8 Second Violet Smoke Formulation Material Amount (%) Amount (g) Solvent Red 168 20.5 205.0 Disperse Blue 3 14.5 145.0 Potassium chlorate 21.0 210.0 Magnesium carbonate 16.0 160.0 Sugar, 10X 14.0 140.0 Sugar, granulated 14.0 140.0 PVA (BMS CEL 06325) 2.0 333.0

(43) The grenades produced with the second violet smoke formulation listed in Table 8 contained 260 g of alternate violet smoke formulation each and had an average burn time of 46.0 s.

(44) An alternative formulation was also made:

(45) TABLE-US-00009 TABLE 9 Alternate Violet Smoke Formulation Material Amount (%) Amount (g) Solvent Red 168 20.5 61.5 Disperse Blue 3 14.5 43.5 Potassium chlorate 21.0 63.0 Magnesium carbonate 16.0 48.0 Sugar, 10X 7.0 21.0 Sugar, granulated 21.0 63.0 Nitrocellulose binder 2.0 6.0 Total 102.0 300.0

(46) Five grenades with this formulation were mixed and pressed in the Glatt mixer and added to the M18 grenade starter-patch configuration. Specifically, the smoke formulations contained a nitrocellulose binder, which was prepared by wet-mixing in acetone. The compositions were dried overnight before being pressed as follows: Press 1: 100 g of smoke composition at 15,000 lb. dead load; Press 2: 100 g of smoke composition at 15,000 lb. dead load; and Press 3: 100 g of smoke composition and 5 g of an ignition composition at 15,000 lb. dead load.

(47) The average burn time for the alternate violet smoke formulation was 46.0 s.

(48) The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.