text:
|Publication number
|Publication type
|Application number
|Publication date
|May 31, 2005
|Filing date
|May 16, 2003
|Priority date
|May 16, 2003
|Fee status
|Also published as
|Publication number
|Robert J. Lauf, Kimberly K. Anderson, Frederick C. Montgomery
|Original Assignee
|Ut-Battelle, Llc
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (13), Referenced by (21), Classifications (42), Legal Events (6)
|External Links: USPTO, USPTO Assignment, Espacenet
This invention was made with Government support under Contract No. DE-AC05-00OR22725 awarded by the U.S. Department of Energy to UT-Battelle, LLC, and the Government has certain rights in this invention.
This invention relates to the field of optical taggants and more specifically, to materials and methods for tagging explosives and propellants for forensic identification, quality control, and other purposes.
There is an ongoing desire within the law enforcement communities to have a way of recognizing or tracing explosives that have been used in a crime. It will be appreciated that a useful taggant will need to satisfy a number of challenging performance requirements. First, the taggant material must be easily and cheaply dispersed throughout a batch of explosive material using traditional formulating and blending equipment. At the same time, explosives, by their very nature, must be formulated carefully and the industry is understandably reluctant to add materials that might make them unstable or unpredictable. In particular, taggants made from small bits of plastic might be a source of static electricity that could lead to catastrophic detonation during processing, mixing, or loading cartridges. Users will also balk if the performance of the explosive is degraded or if significant costs are added. For the taggant particles to be useful, they must be easily recovered at a crime scene. This means they must first survive and then be detectable (found and collected) at the scene with simple equipment. They must also retain enough of their original distinctive properties to meet the standards of legal evidence. Among other things, this means that the taggant particles must be easily distinguished from other natural or man-made particles such as minerals, cement, fly ash, smelting residues, and the like.
Several methods for tagging sensitive materials such as explosives have been developed. These utilize colored or magnetic particles that can be recovered in the field and then "read" by recognizing some distinguishing characteristic such as the pattern of colored bands or a distinctive spectral response.
Powdered phosphor materials potentially satisfy several of the aforementioned requirements for use as taggants. They are bright (i.e. only a small amount is needed in order to be detected), each material exhibits its own unique optical characteristics that can be easily detected, and they are compatible with common bullet and propellant materials. Some of the best candidate materials are ceramics, and are thus capable of enduring harsh environments with no impact on their optical functionality.
In U.S. Pat. No. 3,772,099, dated Nov. 13, 1973 a fluorescent tagging means for pre-detonation or post-detonation identification of explosives is described. A combination of "spotting" phosphor, which is excitable by ultraviolet radiation to provide a band-type emission and "coding" phosphors, which emit a line-type emission, were added to explosives. All of the phosphors have very small particle sizes and are incorporated into phosphor grains held together by inorganic cement or a binder, and the resulting conglomerate grains are dispersed in the explosive. After an explosion, the phosphor grains can be readily located by the ultraviolet response of the spotting phosphor, and information disclosed by the presence (or absence) of the coding phosphor can then be decoded. The spotting phosphor will also normally provide some additional indicia of information. Further refinements of this tagging system are disclosed in U.S. Pat. No. 3,967,990, dated Jul. 6, 1976.
To inhibit any tendency for the phosphor conglomerate particles to sensitize the explosives, the individual particles were encapsulated in an organic plastic material such as polyethylene and a method for so encapsulating these particles are disclosed in U.S. Pat. No. 3,961,106, dated Jun. 1, 1976. These encapsulated particles can incorporate an anti-static coating, such as amorphous carbon, in order to prevent electrostatic charging thereof, and such a coating is described in U.S. Pat. No. 3,993,838, dated Nov. 23, 1976.
U.S. Pat. No. 3,897,284, dated Jul. 29, 1975, discloses microparticles for tagging of explosives, which particles incorporate a substantial proportion of magnetite that enables the particles to be located by means of magnetic pickup. Ferrite has also been used. More recently, modified tagging particles with strips of color coding material having a layer of magnetite affixed to one side and layers of fluorescent material affixed to both exterior sides, has been developed. In this system, the taggant can be located by visual detection of the luminescent response, or magnetic pickup, or both. Both the ferrite and the magnetite materials are, however, dark colored and absorptive of the radiation which excites the luminescent material, thereby making the particles somewhat difficult to locate after an explosion. Further developments produced similar particles that take advantage of the magnetic properties without diminishing the luminescent response of the materials (U.S. Pat. No. 4,131,064).
Yet, another approach is the development of particles coded with ordered sequences of distinguishable colored segments (U.S. Pat. No. 4,053,433). Other patents employ radioactive isotopes or other hazardous materials as taggants.
The present invention is intended to overcome many of the shortcomings of earlier approaches and simultaneously satisfy more of the desired performance attributes for a robust, flexible taggant system.
Accordingly, it is one object of the present invention to provide a taggant material that is inert and easily blended with explosive materials without degrading stability or explosive performance.
It is another object of the present invention to provide a taggant material that is easily detected after an explosion and displays a unique, traceable combination of physical characteristics.
It is yet another object of the present invention to provide a taggant material that has one or more characteristics that distinguish it from natural or man-made materials of similar size.
It is still yet another object of the present invention to provide a taggant material that is environmentally stable so that it may be recovered after some exposure to the elements without losing its distinctive properties.
It is a further object of the present invention to provide a method of making an inorganic material that fulfills the physical requirements for tagging explosives or other materials of interest.
It is another object of the present invention to provide a method of making an inorganic taggant material in numerous compositional and size variants so that a large number of uniquely identifiable batches may be created.
Further and other objects of the present invention will become apparent from the description contained herein.
In accordance with one aspect of the invention, the foregoing and other objects are achieved by an optical taggant material comprising sintered translucent ceramic beads wherein the beads comprise at least one optically active species in solid solution, whereby the beads have a distinctive optical spectrum. The beads further have a substantially spherical surface with a characteristic diameter greater than about 10 μm and less than about 2 mm whereby this characteristic diameter provides a further distinguishing feature.
In accordance with another aspect of the invention, other objects are achieved by a method for making an optical taggant comprising the steps of: selecting a metal oxide host material being substantially transparent in its pure form; forming a generally spherical hydrous bead of the selected metal oxide by a sol-gel process; incorporating within the bead a dopant comprising at least one optically active metal ion; drying the doped bead; and sintering the bead to form a substantially dense, translucent solid solution having an identifiable optical spectrum owing to the presence of the dopant and an identifiable surface curvature owing to the spherical shape. The bead may optionally be converted to a phosphate or other desired phase by hydrothermal treatment after gelation and prior to sintering.
In the drawings:
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the above-described drawings.
The present invention is designed for the fabrication of small, ceramic microbeads containing at least one optically active dopant in a substantially inert, substantially spherical matrix. These beads can be added to substances such as explosives in order to create a distinctive optical signature that identifies a manufacturer, lot number, etc. in the event of the need for forensic analysis. The beads of the present invention can also be formulated into paints if needed to create distinctive optical signatures for camouflage, decoys, or other countermeasures and can also be applied as a dust to track the movement of personnel, vehicles, etc. These beads can be found at the scene using an ultraviolet source, and after collection, their optical spectrum, diameter, and other physical characteristics form a recognizable, defensible, "fingerprint". The beads are chemically inert and easily blended in batch processes, and are highly stable under normal environmental conditions.
The ceramic beads of the present invention comprise a selected translucent metal oxide host material formed into a substantially spherical hydrous bead of the selected metal oxide having a dopant therein. The dopant comprises at least one optically active species giving the beads a distinctive optical spectrum. The beads further have a substantially spherical surface with a characteristic diameter greater than about 10 μm and less than about 2 mm. This characteristic diameter provides a further distinguishing feature. Some preferred host materials include alumina, zirconia, zirconium phosphate or yttrium aluminum garnet (YAG), other host materials include titanium oxide, hafnium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide and lutetium oxide. All of these materials can be made into generally spherical beads by selected sol-gel processes. YAG is especially suitable for several reasons. First, YAG is a well-known and well-characterized host material for many optical dopants, particularly rare earths. Secondly, when forming YAG from the oxides, it is easily sintered to translucency because of the formation of a transient liquid phase. Thirdly, after sintering, YAG is hard and chemically very stable.
The term "optically active dopant" as used herein, defines any metal ion that is at least partially soluble in the host phase and whose presence in the host modifies the optical properties of the host in a clearly detectable way. Such modification might include the creation of characteristic absorption or emission lines or bands, as well as introduction of fluorescent lines or bands when the doped material is illuminated by UV light. The dopants may be added in any of several convenient ways. This is due partly because of the relatively low concentrations of dopants needed (typically less than 1%). For instance, in the case of a rare earth element (REE) dopant in YAG, the chosen REE can be added in the form of a salt, such as nitrate, directly into the starting broth in substitution for a like amount of the yttrium. Alternatively, the gel beads can be infiltrated with a dilute solution of the selected dopant, after gelation, but before drying and sintering. This step can also be carried out in a hydrothermal process (Parr reactor). Alternatively, the dried or calcined beads may be soaked in a dopant solution followed by another drying step, and then sintering.
One sol-gel method used to make the beads of the present invention is an internal gelation method used by Collins in U.S. Pat. No. 6,602,919, incorporated herein by reference and in U.S. Pat. No. 5,821,186, also incorporated herein by reference. Collin's method uses optimum formulations and conditions for making hydrous zirconium oxide gel beads. There formulations or "broths" are an important aspect of making the hydrous zirconium oxide spherical gel bead. By controlling the broth, it is possible to affect the final characteristics of the gel, such as size, shape, porosity, and density.
Therefore, the key parameters of Collin's method include the following: concentrations of the constituents of the broth; broth stability; reaction temperature; gelation time; completeness of gelation; and the structures and chemical composition of gels formed.
The concentrations of the constituents of the broth are an important factor in making microbeads by the internal gelation process. These constituent concentrations influence the broth stability, gelation times, and types of gels. In Collin's method, a broth for making hydrous zirconium oxide for instance, contains four chemical constituents: an organic base, a complexing agent, a zirconium metal salt, and an acid. The initial concentrations of these constituents in the broth and the order of mixing these chemicals are important. Initially, two separate stock solutions are prepared. One contains the organic base and the complexing agent and the other solution contains the zirconium metal salt solution and the acid. Alternatively, the complexing agent can be added to the zirconium metal salt and acid solution rather than with the organic base solution. The complexing agent can be added to either solution provided the final mole ratio of complexing agent to zirconium is greater than or equal to (≧) 1. The preferred practice of the Collin's method is to use a mole ratio of complexing agent to Zr that is similar to the mole ratio of organic base to Zr. To prepare a broth, these solutions are chilled to less than about 10� C., and preferably near 0� C. before they are mixed.
The organic base is used to help form the gel spherules. In an internal gelation method, the broth is introduced into a heated organic medium to form the gel spherules or beads. Introduction of the broth droplets into a flowing stream of hot organic medium causes decomplexation of the zirconium molecules that are complexed with the complexing agent, which then allows the zirconium to be hydrolyzed. While not wanting to be bound by the following statement, it is believed that this hydrolysis reaction is driven by protonation of the organic base molecules, which effectively removes H+ from the broth. Once the organic base molecules are completely protonated, they decompose and remove more hydrogen ions. For example, one hexamethylenetetramine (HMTA) molecule can remove four hydrogen ions from the broth. The rates at which these reactions occur depend upon the temperature of the broth and upon the concentrations of the constituents. For gelation to occur, the pH of the broth droplets should be at or above the pH of precipitation. Precipitation begins in the pH range of 1 to 3 for hydrous zirconium oxide. Therefore, a preferred organic base is one that protonates and decomposes to remove hydrogen ions and hydrolyzes the reaction. The preferred organic base is HMTA.
The complexing agent is used to complex with the zirconium and allows for stable broths at 0� C. As used herein, "stable broth" is meant to include a broth that stays clear and free of metal gelation or precipitation for a reasonable period of time, preferably ≧1 hour, before gelation is initiated. As discussed, the organic base is used to hydrolyze the zirconium and cause gel formation at higher temperatures. At higher temperatures, the complexing agent also catalyzes the decomposition of protonated organic base molecules resulting in the organic base molecules being a more effective base. However, decomposition only occurs after most of the organic base molecules have been protonated. To provide more control over the final concentrations of the constituents in the broth, a saturated stock solution of about 3.5 M organic base is prepared which also has a complexing agent concentration of about 3.5 M. The amount of the complexing agent does not have to approximate the amount of the organic base, though this type of broth is preferred as it ensures the proper mole ratios as against the amount of zirconium. The preferred complexing agent is urea.
The first stock solution comprises the organic base and the complexing agent. Additionally, since the final broth preferably has both a ratio of organic base to Zr and a ratio of complexing agent to Zr of ≧1, then preferably the first stock solution has a ratio of organic base to complexing agent of about 1:1, although the exact ratio of organic base to complexing agent may vary as desired. The stock solution should be chilled to less than about 10� C. and more preferably to about 0� C., prior to mixing with the second stock solution comprising the zirconium metal salt and the acid. The solution is chilled to avoid premature gelation since the hydrous zirconium oxide will gel as the temperature increases.
The second stock solution used to make the broth of the present invention comprises the zirconium metal salt and the acid. Zirconium metal salts useful in the present invention include any zirconium salt, which is soluble. The zirconium metal salt should provide a sufficient Zr ion concentration in the solution. Examples of these soluble zirconium metal salts include, but are not limited to, zirconyl nitrate, zirconyl chloride and zirconyl tetrachloride.
When water is added to the zirconium metal salt (ZrX), an exothermic reaction occurs with the formation of hydrous zirconium oxide gel and an acid. The types of acids are discussed below. Water acidified with the acid is used to dilute zirconium metal salt to prepare a stable stock solution. When a sufficient amount of acid is added, the hydrolysis reaction is suppressed and gel formation is prevented. As described later, the amount of acid used in a broth is one of the important process parameters for the present invention. The amount of acid used in a broth is a controlling parameter for the gelation process for making hydrous zirconium oxide beads.
In the broth formulations that are described in the present invention, the concentrations of hydrogen ion refer only to the hydrogen ions from the acid that is added to the broth. The acid is added to the broth to help suppress or prevent hydrolysis and gel formation at low temperatures (0� C. to 50� C.). The H+ concentration is important since it helps prevent premature gelation when the complexing agent and organic base are added to the zirconium metal salt solution. A stable broth can be prepared with no addition of acid if the organic base:Zr ratio is 1:1 or less. However, the gelation time for a broth with an organic base:Zr ratio of between about 1 to 1.1 is between about 25 and 30 seconds at 90� C. At lower temperatures, the gelation times are even longer. Any acid may be used, such as hydrochloric acid, nitric acid, sulfuric acid, or phosphoric acid, as long as the acid provides hydrogen ions to help regulate the process. However, in general, the acid selected is dependent upon the zirconium metal salt used, such that the second stock solution comprises a mixture of ZrX and HX, wherein X is F, Cl, Br, I, NO3, HSO4, H2PO4 or HCO3. Nitric acid and, for non-stainless steel systems, hydrochloric acid are the preferred acids. Therefore, in one embodiment, as shown below in Example 1, the zirconium metal salt is zirconyl nitrate and the acid is nitric acid while in another embodiment, the zirconium metal salt is zirconyl chloride and the acid is hydrochloric acid. However, it is understood that the mixture of ZrX/HX is not a required mixture.
When forming the second stock solutions, as with the first stock solution, the solution should be chilled to less than about 10� C. and more preferably to about 0� C., prior to mixing with the first stock solution. Then, when the two solutions are mixed, the final broth will also be chilled to less than approximately 10� C. This is one of the important factors in making a stable broth. In the present invention, the optimum process parameter window for making microbeads of hydrous zirconium oxide includes a broth that is stable for a reasonable period of time at ice bath temperatures near 0� C. Broth formulations that are stable for ≧ about 1 hour are desirable for large-scale preparations. The formulations declared in the optimum process window are therefore stable for ≧1 hour. The broth droplets should be introduced in a hot organic medium before gelation is initiated. Broths that gel in less than one hour could be used if the first stock solution of the organic base and complexing agent and the second stock solution of zirconium metal salt and acid were pumped from separate tanks into a mixing device prior to ejection as droplets into the hot organic medium. The apparatus used to make the gel beads of the present invention is the same apparatus used by Collins' in U.S. Pat. No. 6,602,919 and in U.S. Pat. No. 5,821,186, also shown in FIG. 1.
In general, the molarity of the zirconium in the broth should be in the range of about 0.3 to about 1.0 M. However, the preferred molarity of zirconium in the broth is in the range of about 0.4 M to about 0.8 M. An organic base:H+ mole ratio of ≧0.9 is needed for gelation to occur for a specified gelation time of ≦60 seconds. However, lower ratios may be used if a gelation time of greater than 60 seconds is desired. In these situations, the gels formed with are larger in size due to coalescence.
The amount of the organic base and the complexing agent in the broth will be approximately the same for the reasons previously discussed. These amounts will vary depending on the temperature at which the gel is formed. Higher temperatures permit the use of lower amounts of organic base and complexing agent, and lower temperatures permit the use of higher amounts of organic base and complexing agent. In the present invention, the temperatures at which the gels may be formed range from ambient temperature to about 100� C. These temperature conditions require the concentration of the organic base and the complexing agent to range from about 0.5 M to about 3.5 M. A concentration of about 3.5 M is considered to be the saturation concentration for each of the organic base and the complexing agent. However, in determining the concentration of the organic base and the complexing agent, it is important to remember that the organic base:Zr ratio and the complexing agent:Zr ratio should both be ≧1:1.
The concentration of acid used can range from about 0 M to about 1.2 M. As previously discussed, an acid is not necessary for the formation of the hydrous zirconium oxide gels, but the acid prevents premature gelation when the broth is formed. The acid also permits quicker gelation times by allowing higher organic base:Zr ratios to be employed.
FIG. 1 and
The organic medium reservoir 7 may comprise a stainless steel open-top rectangular container. One or more heating blades 17 may be positioned at the rear of the reservoir to heat the organic medium. A thermocouple 19 may be positioned in the basket at the bottom and near the front of the reservoir and is connected to a temperature controller 21 that is used to control the organic medium temperature. A stirrer 23 with its shaft positioned away from the heating blade or blades 17 (other blades not shown) and its impeller located near the bottom of the reservoir is used to mix and maintain the organic medium at a desired temperature. Occupying most of the front space in the reservoir 7 is a large removable basket 15 that serves as a backup to prevent any spilled gelled spherules from being pumped out of the reservoir to the circulating pump.
The pump 9 is used to pump the hot organic medium from the reservoir 7 through a line to the vertically positioned glass gelation column 11. The flow from the pump 9 is divided into two streams that are controlled by manual valves. The flow of one of the streams may be routed to a position above the center of the top of the gelation column 11. Vertically attached to this line may be a tube whose outlet end is inserted into the entrance of the gelation column. The tube is part of the two-fluid nozzle 5 system that is used to control the size of the droplets. The other hot organic medium stream from the pump 9 is routed to a fitting at the bottom of the gelation column 11 and flows up through a shell 25 that surrounds the gelation column 11. The hot organic medium over-flows at the top of the column, first, into the gelation column 11 and, then, into an overflow cup 27. A large tube 29 is connected to a fitting from the overflow cup 27 to route any overflow back to the hot organic medium reservoir 7. During operation, the flow of organic medium from the heating shell 25 is normally adjusted to provide only a slight overflow.
As shown in
The hot organic medium carrying the droplets from the two-fluid nozzle tube 5 flows directly into the central concurrent flow tube of the jacketed gelation column 11 where it is desirable for the droplets to begin to gel. On exiting the gelation column 11, the gelling spheres flow into a serpentine transport line 13. This line is long enough (about 8-ft.) to allow the gelling spherules to have a total residence time of 25 to 35 seconds to the collection basket 15. The transport time also includes the time the spherules are passing through the gelation column. The gelation column and serpentine transport system are designed to be a siphoning system with a gravity head of about 60-cm for oil temperatures in the range of about 45� to
The collection basket 15 is positioned above the hot organic medium reservoir 7, and is used to collect and separate the gel spherules from the hot organic medium as they exit the serpentine transport line 13. The collected gel spherules are aged by lowering the collection basket 15 into the reservoir 7 for between 15 and 30 minutes, preferably 20 minutes. After aging, the bulk of the organic medium is drained from the gel spherules and the residual organic medium is removed by a series of washing steps to remove the reaction impurities.
Another basket of similar design may also be positioned above the hot oil reservoir to filter the return organic medium from a tube, which is connected to the overflow drain line at the top of the gelation column.
The organic medium may be a one-component solvent or a binary mixture; for example, silicone oils such as Silicon Fluid 200 (Dow Corning, Midland, Mich.) for temperature ranging from ambient temperatures to 100� C.
The following examples illustrate the invention in more detail.
Hydrous zirconium oxide (HZrO) gel beads were made by internal gelation using the technique and apparatus, described above and as shown in FIG. 1 and
Skilled artisans will appreciate that hydrous oxides of other Group IV metals, e.g., Ti may be made by a similar approach (see, for example, Collins, U.S. Pat. No. 5,821,186, the teachings of which are incorporated herein by reference). Furthermore, it is well known that rare earth phosphates are another excellent host material for phosphors and these compounds are also quite stable against environmental degradation. Phosphates may be conveniently made by a modification of the inventive process as shown in the following example, wherein wet hydrous zirconium oxide gel beads formed as described above, then rinsed with an amount of phosphoric acid having a concentration ≦0.5 M for a period of time sufficient to allow the beads to be converted to acid insoluble zirconium monohydrogen phosphate. Next, the beads are mixed with concentrations of phosphoric acid ≧0.5 M and placed in a sealed pressure vessel. Then, the beads are covered with an amount of phosphoric acid sufficient to complete the conversion of the spherules to acid insoluble zirconium monohydrogen phosphate and to prevent the hydrous zirconium oxide from dissolving before the conversion. Finally, the beads are heated in the phosphoric acid to a predetermined temperature up to 100� C. The temperature may be increased from ambient temperature up to 100� C. over time to produce the desired crystallinity. After the desired crystallinity has been formed, the spherules may then be cooled and rinsed to remove unreacted phosphoric acid, and then air dried to a constant temperature.
Wet hydrous zirconium oxide (HZrO) gel beads, made by the method described above, were washed several times in 0.5 M phosphoric acid, allowed to stand about four hours in this solution, then washed several times in 1.0 M phosphoric acid. Hydrothermal conversion was done at 125� C. in 1.0 M phosphoric acid in a closed stainless steel vessel. The conversion step was then repeated several more times, each time increasing the phosphoric acid concentration by 0.5 M until the final treatment was done in 2.5 M phosphoric acid. This material had been dried to form glassy beads. When these dried beads were placed in a 1% Eu nitrate solution, they fractured into concentric shards during rehydration, but absorbed the solution adequately. These fragments were dried and fired in air as in the previous example. Under UV illumination, the particles were very strongly fluorescent (bright red).
An attempt was made to avoid the cracking problem encountered when dried HZrP beads were rehydrated. Using the materials and procedures of the previous example, hydrous zirconia beads were reacted with phosphoric acid and washed. While still wet, the HZrP gel beads were placed overnight in a 1% Eu nitrate solution, then dried for several days and fired in air at 1� C./min to 1000� C. A similar batch was placed overnight in a 1% Ce nitrate solution, dried, and fired in air at 1� C. 1 min to 1000� C.
These batches were designed to make doped HZrO beads directly by coprecipitation. Using the technique described above, zirconium-containing broths were made up using 1 M zirconyl nitrate to which either 1% Eu, Er, or Ce (metals basis) was added as the nitrate. 100 ml of Zr solution, 0.4 g of rare earth nitrate, 14.5 ml of nitric acid, and 70 ml of HMTA/urea stock solution were mixed to form a chilled broth. These broths were injected into hot silicone oil at about 82-86� C. following standard techniques as previously described. The wet beads were aged in the hot oil for about 20 min and then washed in trichloroethylene (TCE) and stored in deionized water.
Wet beads of HZrO:Eu and HZrO:Ce made in the previous example were converted to HZrP by soaking overnight in 0.1 M phosphoric acid, followed by an additional soak for about 4 hours in 1.5 M phosphoric acid. (conversion can also be done in a hydrothermal "Parr reactor" if desired, as discussed in Example 2). The converted beads were washed in deionized water, dried, and fired as in Example 3.
The foregoing examples describe one variant of sol-gel processing normally referred to as internal gelation. It is a fast and easily controlled method for making mono-sized ceramic gel beads, particularly when the composition is substantially a single oxide such as ZrO2. When multiple oxides are involved, it is sometimes found that one cannot conveniently establish conditions under which both metal salts will be stable and then induce conditions where both oxides will precipitate simultaneously. For this situation, other sol-gel methods such as external gelation or water extraction may be employed. All three of the aforementioned sol-gel methods share the common characteristic that the gelation step occurs in a mixture of two immiscible fluids whose surface tension is exploited to create essentially spherical droplets that retain their sphericity upon gelation, drying, and sintering. U.S. Pat. No. 5,420,086 by Brandau et al. describes external gelation processes and chemistries, the teachings of which are incorporated herein by reference. The water extraction method is taught in Arnold et al., U.S. Pat. No. 5,062,993, the entirety of which is incorporated herein by reference.
Because of differences in the chemical properties of aluminum and yttrium, it would be easier to make YAG by water extraction, rather than by an internal gelation method. Following the teachings of Arnold U.S. Pat. No. 5,062,993, hydrous alumina and hydrous yttria sols are mixed in the correct stoichiometric amounts (5:3) to yield the target composition of Y3Al5O12 and droplets of this mixed sol are injected into a forming liquid such as 2-ethylhexanol. The forming liquid extracts water from the droplets, causing them to shrink and to form rigid gel beads. These beads may be sintered in air to a desired level of density and translucency by conventional methods.
Using the method outlined in the previous example, the YAG beads are conveniently doped by either of two means. First, small amounts of dopant oxides are included in the starting hydrous oxide sols. Alternatively, the dopant is introduced as a soluble salt in a second infiltration step as discussed in several of the previous examples.
It will be clear that ceramic microbeads made according to any of the foregoing examples are readily distinguished from other natural or artificial oxide particles of comparable size. For example, fly ash from coal combustion may include spherical particles that lie within the claimed size range. However, fly ash is substantially silica glass with large amounts of alkali, alkaline earths, and frequently iron. It is not fluorescent and does not contain significant amounts of rare earths. Fly ash and slag from smelting operations are distinguished by its composition, namely, high levels of transition metals and characteristic nonmetals such as arsenic. Naturally occurring mineral grains do not have the same composition as the inventive particles and are angular, acicular, or plate-like in this size range, rather than spherical.
The ceramic microbeads of the present invention should be sintered to an appropriate density to give them adequate strength and translucency for a particular application. At the same time, it will be appreciated that a small amount of residual porosity in an otherwise substantially dense bead will not normally impair its functionality for the applications described herein. In general, the inventive beads are preferably greater than about 90% of theoretical density and more preferably greater than about 95% of theoretical density.
Translucency, as used herein, is a relative term. Some beads might appear opaque (white or off-white) to the naked eye, yet retain enough translucency to allow for sufficient intensity of the characteristic optical emissions. Skilled artisans will appreciate that the degree of translucency or transparency are related to sintering parameters (time and temperature) in a well-understood way, so that the translucency to meet a specific requirement without undue experimentation can be controlled. In some cases, if the beads are substantially transparent, they could be made in a particular diameter to form a resonant optical cavity at a selected wavelength. In this situation, the beads in a particular batch would preferably be mono-sized and optionally polished by conventional bead polishing methods such as those used for ball bearings.
At the point of end use, a batch might be all the same composition or might include a range of compositions, sizes, and dopants in order to exhibit a distinctive "fingerprint". This is especially useful for coatings, in which a particular blend of microbeads is viewed as a whole rather than as individually recovered beads or bead fragments.
Various mixed oxides could be used in addition to the compositions enumerated above. In particular, it has been previously demonstrated that rare earth aluminum garnets, of the general composition R3Al5O12 where R=Dy, Ho, Y, Er, Tm, Yb, or Lu, can serve as the host matrix for many other dopants (especially other rare earths) and, thereby, provide great latitude for spectral manipulation as described by Lowden et al. in U.S. patent application Ser. No. 09/935,865 filed Aug. 23, 2001, U.S. Publication No. US-2003-0078156-A1, published Apr. 24, 2003, the teachings of which are incorporated herein by reference.
Those skilled in the art can imagine other application scenarios in which it is desirable to tag a person, vehicle, or other article or to determine if a person has passed through a tagged area. For this application, a durable material is needed that is easily dispersed and picked up on tires, shoes, clothing, or the like, yet, is relatively invisible or innocuous to the casual observer. Here, materials at the smaller end of the size range are contemplated (such as 10 μm). These would look like white powder or dust and yet would be reasonably robust, perhaps becoming implanted in shoes, tires, etc. and surviving for some period of time. The beads could also be surreptitiously incorporated into fabric for similar purposes.
It is further understood that the inventive beads may or may not contain a separate "spotting phosphor" in addition to the "coding" phosphor. For explosive tagging, the spotting phosphor is intended to ease location and recovery of forensic evidence and is therefore generally desirable. On the other hand, for clandestine tagging it might be desirable to avoid unwanted detection by either eliminating the spotting phosphor species entirely or using a spotting phosphor that does not fluoresce in the visible range.
Furthermore, the inventive beads can also be incorporated into paints or coatings if desired, in order to impart distinctive optical emission characteristics to a selected object. Applications where such coatings might find use include camouflage, target designation, identify friend or foe, and material tracking or logistics.
It is understood that a batch of nominally spherical particles includes some number of particles that have fractured or split, and furthermore that additional fragmentation of the particles might occur during detonation of the explosive material or through various environmental forces. Nevertheless, even broken spheres normally retain some fraction of their original surface, from which a characteristic diameter or radius of curvature may be ascertained (through microscopic examination, for example).
While several preferred embodiments have been shown and described, and several examples have been specifically delineated, it will be understood that such descriptions are not intended to limit the disclosure, but rather it is intended to cover all modifications and alternate methods falling within the spirit and scope of the invention as defined in the appended claims or their equivalents.
|Cited Patent
|Filing date
|Publication date
|Jun 1, 1970
|Jan 9, 1973
|Mallinckrodt Chemical Works
|Haloapatite phosphors in the form of spherical particles and method of making same
|May 17, 1971
|Nov 13, 1973
|Westinghouse Electric Corp
|Phosphor combination and method, particularly adapted for use with explosives, for providing a distinctive information label
|Sep 18, 1973
|Jul 29, 1975
|Minnesota Mining & Mfg
|Tagging explosives with organic microparticles
|Mar 3, 1975
|Jun 1, 1976
|The United States Of America As Represented By The Secretary Of The Interior
|Method for applying wax or plastic coatings to granular materials
|Mar 3, 1975
|Jul 6, 1976
|The United States Of America As Represented By The Secretary Of The Interior
|Combination of band-type and line-type emission phosphors with explosive
|Mar 3, 1975
|Nov 23, 1976
|The United States Of America As Represented By The Secretary Of The Interior
|Wax or plastic coated phosphor grains
|Feb 19, 1975
|Oct 11, 1977
|Minnesota Mining And Manufacturing Company
|Method of tagging with color-coded microparticles
|Jul 15, 1977
|Dec 26, 1978
|Westinghouse Electric Corp.
|Tagging particles which are easily detected by luminescent response, or magnetic pickup, or both
|Aug 29, 1990
|Nov 5, 1991
|Cooper Power Systems, Inc.
|Process for fabricating doped zinc oxide microsphere gel
|May 6, 1992
|May 30, 1995
|Nukem Gmbh
|Method for producing stabilized zirconium oxide powder
|Jul 29, 1993
|Nov 28, 1995
|Rhone-Poulenc Chimie
|Granular rare earth phosphates having characteristic morphology
|Nov 1, 1996
|Oct 13, 1998
|Lockheed Martin Energy Research Corporation
|Method for preparing hydrous titanium oxide spherules and other gel forms thereof
|Aug 23, 2001
|Apr 24, 2003
|Lowden Richard A.
|Creep resistant refractory with controlled optical emission
|Citing Patent
|Filing date
|Publication date
|Nov 2, 2005
|Aug 14, 2007
|Prime Technology Llc
|Security markers for determining composition of a medium
|Nov 2, 2005
|Feb 10, 2009
|Ncr Corporation
|Security markers for marking a person or property
|Nov 2, 2005
|Mar 10, 2009
|Ncr Corporation
|Security markers for reducing receipt fraud
|Mar 13, 2007
|May 18, 2010
|Smi Holdings, Inc.
|Automatic microparticle mark reader
|Aug 28, 2007
|Nov 9, 2010
|international imagining materials, inc
|Thermal transfer ribbon
|Mar 13, 2007
|Nov 9, 2010
|Smi Holdings, Inc.
|Three-dimensional authentication of microparticle mark
|Dec 18, 2009
|Feb 8, 2011
|Smi Holdings, Inc.
|Automatic microparticle mark reader
|Mar 13, 2007
|Oct 11, 2011
|Smi Holdings, Inc.
|Expression codes for microparticle marks based on signature strings
|Oct 6, 2010
|Jul 17, 2012
|Smi Holdings, Inc.
|Three-dimensional authentication of mircoparticle mark
|Jul 14, 2008
|Jan 29, 2013
|Worcester Polytechnic Institute
|Degradable taggant and method of making and using thereof
|Jun 1, 2011
|Feb 4, 2014
|United States Gypsum Company
|Tagged joint compound and method of identification
|Oct 9, 2008
|Jun 10, 2014
|The Trustees Of Columbia University In The City Of New York
|Friend or foe detection
|Nov 7, 2006
|May 26, 2015
|The University Of North Carolina At Chapel Hill
|Isolated and fixed micro and nano structures and methods thereof
|Dec 2, 2002
|Feb 23, 2006
|Dan Hunt
|Taggants for products and method of taggant identification
|Nov 2, 2005
|Jun 8, 2006
|Ross Gary A
|Security markers for reducing receipt fraud
|Nov 2, 2005
|Jun 22, 2006
|Ross Gary A
|Security markers for determining composition of a medium
|Nov 2, 2005
|Feb 1, 2007
|Ross Gary A
|Security markers for marking a person or property
|Jun 19, 2006
|Mar 1, 2007
|Univ North Carolina
|Nanoparticle fabrication methods, systems, and materials
|Jun 19, 2006
|Dec 16, 2010
|The University Of North Carolina At Chapel Hill
|Nanoparticle fabrication methods, systems, and materials
|May 9, 2008
|Nov 20, 2008
|Mark Brown
|Explosive tagging
|Jul 14, 2008
|Jan 22, 2009
|Christopher R Lambert
|Degradable taggant, and method of making and using thereof
|U.S. Classification
|International Classification
|Cooperative Classification
|European Classification
|May 16, 2003
|Sep 8, 2003
|Oct 17, 2008
|Fee payment
Year of fee payment: 4
|Jan 14, 2013
|Maintenance fee reminder mailed
|May 31, 2013
|Lapse for failure to pay maintenance fees
|Jul 23, 2013
|Expired due to failure to pay maintenance fee
Effective date: 20130531


text: Does anyone know how long this shrine is? Also I hope everyone agrees that the Moonlight weapons are the best weapons in the game. Wow these things are sick, and I only have 2 of them so far. I made it to lvl 6 of the shrine so I was just wondering if I was close. Also if you are thinking about doing this dungeon please do the Casino cheat and get the support skill that evades random encounters. You will definately need it, also dont do this before lvl 50.

subset: commoncrawl


text:
Researchers build Mac mini, iSight-based robot
updated 06:15 pm EDT, Tue September 13, 2005
Mac mini robot
Researchers at the University of Oklahoma have around a Mac mini and iSight camera. The tests were preformed at the Stephenson Research and Technology Center. The group, part of the Artificial Intelligence Research laboratory in Computer Science, was interested in evaluating the Mac Mini because of its small size, built-in wireless and FireWire capabilities. Power is supplied by a 12 Volt 7.2 AH Battery. Tele-operation is achieved using the Mac Mini's built-in wireless capability. After experimenting with the with the robot, the group hopes to write software that will allow it to operate autonomously.


text:
Summer Science Sleuths will not be accepting new applications for the 2014-2015 session.
Summer Science Sleuths at Duke will only host the returning rising 10th graders in 2015 for their third and final year at camp.
Summer Science Sleuths at Duke is a recreational, residential 2-week summer science camp on the campus of Duke University in Durham, N.C. Campers who are selected to attend will receive full tuition and travel scholarships to join us June 14-June 27, 2015.


text:
Ask the Experts
swollen glands on pepi have swollen groin glands(no other swollen glands elsewhere) at this stage around 10 days after exposure. At first i was that scared after exposure but got thinking and then went to hospital. I went on pep after 68 hours after and have taken it...
Response from Robert J. Frascino, M.D.
The Robert James Frascino AIDS Foundation...the groin, as an isolated symptom, are not suggestive of or worrisome for HIV acute retroviral syndrome (ARS). The adenopathy (swollen glands) associated with HIV is generalized. That means it occurs in multiple locations throughout the body.... Read more »
Is a stiff neck a sign of acute HIV infectionHi, 3 weeks ago I received unprotected oral sex from someone i know injects drugs. A few days ago I... Read more »
What exactly do "swollen glands" mean? How soon after a new HIV infection can swollen glands appear?There is a lot of talk about how "swollen glands" are common in HIV'ers at ANY time during... Read more »
Acute HIV Infection... What Is AcuteHIV Infection? Testing for AcuteHIV Infection Risk of Immune Damage Risk of Infecting Others Treating AcuteHIV Infection Pros and Read more »
Acute HIV Infection -- New York City, 2008...diagnoses when HIV-Ab testing alone is used in a high-risk, high-incidence population. 5 Without p-NAAT screening, 9% of the HIV infections documented by the four STD clinics during the screening period would have been missed. However, because... Read more »
U.S. Updates Clinical Guidelines for Prevention and Treatment of Opportunistic Infections Among HIV-Exposed and HIV-Infected Children...HIV-infected children and childrenwho were HIV-exposed through birth to an HIV-infected mother." Dr. Mofenson said. In recent years, HIV infection has increased among adolescents. "We hope that doctors and clinicians make use of these new... Read more »
Hepatitis C Virus Infections Among HIV-Infected Men Who Have Sex With Men: An Expanding Epidemic...of 28 co-infected MSM (25 percent). Of the 28 co-infected men, only five reported any history of injection drug use (IDU). HIV infection, IDU, fisting, and use of gamma hydroxyl butyrate (GHB) were found to be significantly associated with HCV... Read more »
Connect With Others
Similar symptoms to HIV but not HIV
Posted by Redeye77, 1 Reply...diagnose. Maybe it's new STD? Seems like reiters syndrome will fUse many of the same symptoms as acuteHIV infection such as fever, swollen glands, fatigue etc... Maybe for all those people who are experiencing worried well syndrome should look... Read more »
I Dont know WhaT To Do!!!
Posted by salvino, 4 Replies...are done i started getting a sore throat, my mouth is really dry all the time, i have this anal itch from time to time, also swollen glands under my chin and both of my underarms had them but now its only the left one but at first the hurt but... Read more »
Posted by Anonymous, 1 Reply...worsens, a variety of complications start to take over. For many people, the first signs of infection are large lymph nodes or "swollen glands" that may be enlarged for more than 3 months. Other symptoms often experienced months to years before... Read more »
Swollen Glands
Posted by Anonymous, 4 Replies...In early HIV infection, when the lymph nodes are swollen, could it be just one in the neck swollen or would it usually affect the lymph nodes all over Read more »
Related Topics


text:
Search the Collection
Sitter in 1 portrait
by Dawson & Sons
Melbourne Inman(1873-1951), Billiards champion
Sitter in 1 portrait
Melbourne Inman; Florence Inman (née Ambler)
by Dawson & Sons
bromide print, circa 1907
NPG x21184
Tell us moreback to top
Can you tell us more about this person? Spotted an error, something missing, or do you know anything that we don't know? If you have any information to share please complete the form below


text:
A great crowd learning about mason bees
People come form near and far to learn about mason bees.
The interest is high when gardeners bring in their nests. Every nest tells a story.
Here is Margriet – owner of Beediverse doing a seminar.
A 'thank you' to Lidy from Amsterdam Nursery for photos.
I live in Mission BC, how do I find out about Bee workshops close to my area?
Thank you
We will be posting any workshops we hear about on our blog.
Name *
Email *
Notify me of follow-up comments by email.
Notify me of new posts by email.
Enter your email address to subscribe to this blog and receive notifications of new posts by email.
Join 91 other subscribers
Copyright © 2015 Beediverse Official Blog
Powered by WordPress and Oxygen


text:
Bradley Cooper denies 'secretly marrying' to Suki Waterhouse
Bradley Cooper has denied his secret marriage to Suki Waterhouse after the couple was recently spotted wearing wedding rings.
Speaking at the LA premiere of 'Guardians of the Galaxy', the 39-year-old actor said that one knew when they take a picture and it becomes a negative image as it was his father's ring and he was not married, the Mirror reported.
The 'Hangover' actor said that the photographer's original shot taken was reversed when printed, which lead to a confusion.
The couple has been together for 18 months.
(Posted on 27-07-2014)
Share This Page:
Free Yearly Horoscope: Select your zodiac sign
Pisces | Aquarius | Capricorn | Sagittarius | Scorpio | Libra | Virgo | Leo | Cancer | Gemini | Taurus | Aries


text:
Welcome and thank you for your interest in the
Candy Crocker School Of Dance. In business since 1977, we are proud to be known as a "Tyler Tradition."
Whether you are a beginner or an aspiring professional, our studio is sure to offer a class you will enjoy. We offer Ballet, Pointe, Tap, Jazz, Jazz Technique, Hip Hop, and A Specialized Preschool Program. Each year our students perform in Christmas Shows, Dance Competitions, and our Annual Dance Production.
Please look around our site and feel free to drop in at the studio any time. We are always happy to welcome new people as our Dance Tradition Continues.
Summer Dance Camp Schedule
Recital 2015 will be Saturday, May 16th
Act I: 2 P.M., Act II: 7 P.M., Caldwell Auditorium
- Junior Camp (entering grades K-2) $80
June 8th through 11th (10-1:00)
- Senior Camp (entering grades 9-12) $90
June 15th through 18th (10-2:30)
- Preteen Camp (entering grades 3-5) $85
June 22nd through 25th (10-1:30)
- Teen Camp (entering grades 6-8) $85
July 6th through 9th (10-2:00)
- Junior Camp (entering grades K-2) $80
July 13th through 16th (10-1:00)
See the Classes page for information on the Preschool Dance Schedule.
Company Auditions
- Company Audition Rehearsals (3rd and up)
July 17th 5:00 P.M. & July 18th 10:00 A.M.
- Company Audition Day
July 25th 10:00 A.M.
Fall Schedule/Registration
Our Fall Schedule is not published because of the changes likely to occur during registration. I would rather schedule your child's class in person or over the phone.
- Fall registration for returning students will be Monday, July 13th-Tuesday, July 14th (5-7)
- Fall registration for new students will be Wednesday, July 15th-Thursday, July 16th (5-7)
- Fall classes begin Monday, August 17th


text:
@1612690 Disco
@899895 Multi-room house
@889498 Cave adventure
@884273 Racetrack
@854553 Small House
@1124896 School
@655046 Mixed house
@1720011 3D House
@1859120 My Tribe House
@887587 Large House
Free Tribe House codes by BeuysaWatch
©2012-2015 Beuysa
Is there any Micegirl tribe house codes?
oooh awesome
These wont work on micegirl
I need Micegirl ones please.
Heromice ones needed
Thank you!!!
Do you have some for MiceGirl? I have over 1K cheese and the editor won't let me create.
None r working..
Cheesemice ones?
Micegirl codes needed
i need Micegirl ones :3
Thank you for the codes!
not found
I need some cool tribe houses for heromice
None are working for me. They all say they don't exist
so CUte <3 my tribe is the multi-room ^^
thank you for the code ^^
How do you create a tribe house?
using it.
Thank you !! my tribemates are really enjoying your maps
the disco is probs the best
thanks for these codes, it's reaaaaally useful.
None of them work for me D: It keeps saying they don't exist DDD:
the school didn`t work for me
How did you do that video-screen thing in the Multi-room house? It's amazing!
Great rooms, btw!
Great rooms, btw!
Ohhh, I love the Racetrack, Cave Adventure, Disco and the 3D House!


text:
Got it!
We'll remember your season preference for the rest of your visit.
You are viewing reviews from a season you previously selected.
Show all reviews
No reviews are available for the season you selected.
A very disappointing B & B with very cramped conditions. Breakfast was a 'do it yourself' affair, working from within a 'wardrobe' - not entirely satisfactory.


text:
App Description
Addition Tables help children with the memorization of the essential combinations in addition!
Children can practice individual addition sets, such as 8+1, 8+5, 8+3, 8+9, etc. The child can fill out the cards in any order they choose.
In a subtle way, the app keeps track of the child's progress, so parents and teachers can review their activity. Children can cycle through as many table cards as they choose in a random fashion.
This activity is a time-tested method of reinforcing the basic addition combinations and is used in Montessori classrooms around the world! This app was co-developed and approved my an AMI certified Montessori teacher with over 40 years experience in the field!
Thanks for supporting Mobile Montessori!
App Changes
- February 13, 2013 Initial release
- October 10, 2013 Price increase: $2.99 -> $3.99
- July 18, 2014 Price decrease: $3.99 -> $2.99
- July 16, 2015 Price increase: $2.99 -> $4.99
- July 29, 2015 Price decrease: $4.99 -> $1.99


text: Elizabeth Howard | IBDB: The official source for Broadway Information IBDB: The official source for Broadway Information Official Broadway League sites: - sites - broadway.org broadwayleague.com broadwayfanclub.com kidsnightonbroadway.com stagespecs.org tonyawards.com Quick Search For: In This Category: All Show People/Org. Theatre Season Elizabeth Howard Performer Female Productions ProductionsDate of ProductionsThe Rat[Play, Original] Performer: Elizabeth Howard [Andre]Feb 10, 1925 - May 1925 Find out where Elizabeth Howard and are credited together © 2001-2015, The Broadway League, All Rights Reserved. (Copyright and Disclaimer)


text:
Tag Archive
VIDEO: Mike Scott Playing Basketball On Plastic Hoop
Proof that Mike Scott would win the plastic basketball hoop dunk contest: »
Hawks Season In Review: Mike Scott
Note: We use stats per 36 minutes instead of stats per game on the graphics. The reason behind that is stats per 36 tell a more complete story of how a player did while he was on the court, as opposed to per game stats which averages a player's stats based on the number... »
Hawks Season Review: Top 5 Games of 2013-14
The Hawks were no strangers to close games this season, with 30 of their 82 games decided by 5 or fewer points, and also had some dominating performances sprinkled in along the way, so choosing the Top 5 games of this season was a difficult task. These are my personal choices, but these were... »
Hawks Players Thank Fans In Tweets
There's no doubt Hawks players were bummed after a tough Game 7 loss to the Pacers in the playoffs, but they took time to thank fans for their support all season via Twitter: Proud of my Team. Fought hard all season with no excuses and we had a chance to advance in playoffs. We... »
10 Memorable Moments From the Hawks vs. Pacers Series
The series didn't end the way the Atlanta Hawks wanted it to, but there were many memorable moments along the way against the Pacers. We put together 10 of our favorites: 10) Korver's Deep Three The Pacers made a furious second half rally in Game 5 to cut what was a 30-point deficit down... »
Hawks Go Cold as Pacers Win Game 7, Series
The Hawks (3-4) went cold at the wrong time and were eliminated by the Pacers (4-3) in Game 7 as Atlanta shot just 30.4 percent from the field in the 92-80 loss. Paul George was magnificent for Indiana with 30 points, 11 rebounds, three assists, and two steals as he set the tone for the... »
Hawks Players Tweet Excitement After Game 5 Win
There was plenty of Twitter buzz going around Monday night during and after the Atlanta Hawks' 107-97 Game 5 win over the Indiana Pacers. More to come on that on the Hawks Blog later, but here's what the players had to say: Great win! Bench was the difference. @mikescott aka Migue was on fire.... »
Hawks Take 3-2 Series Lead With Win In Indiana
The Hawks (3-2) got a 107-97 victory on the road against the Pacers (2-3) thanks to a dominant 41-19 second quarter performance led by Mike Scott and Shelvin Mack. The Hawks trailed after the first quarter by one, but Scott's 17 points and Mack's 13 off the bench in the second quarter lifted them to a... »
Mike Scott and Shelvin Mack Catch Fire in the Second Quarter
After trailing 21-20 after the first quarter — with six turnovers — the Hawks exploded in the second quarter, out-scoring the Pacers 41-19 behind 30 combined points from Mike Scott and Shelvin Mack off the bench. Mack tied the game at 21 after splitting a pair of free throws on the first possession for the Hawks,... »
Game 5 Scouting Report: Hawks vs. Pacers
The Indiana Pacers did what they had to do in getting a split in Atlanta to regain home-court advantage. Their Game 4 win, particularly the second half of it, was a display of grit and will, as the team many thought to be the best in the NBA through the first half of the... »


text:
Best of News
Councillor Denzil Minnan-Wong, speaks to the media after a morning... News PhotoCanada,City,Discus,Flood,Government,Horizontal,Hotel,Mayor,Meeting,Morning,Occupation,Office,Politics,Rain,Social Issues,Talking,The Media,Toronto,Torrential RainPhotographer Rick MadonikCollection: Toronto Star 2013 Toronto StarTORONTO, ON - MAY 29: Councillor Denzil Minnan-Wong, speaks to the media after a morning meeting with city staff in the Mayor's office (Mayor was not present) to discus the overnight rain and flooding issues. Minnan-Wong is Chair of Public Works and Infrastructure committee.Toronto Mayor Rob Ford arrives at City Hall office just after noon on Wednesday, May 29, 2013. Mayor Rob Ford is currently facing allegations that he was recorded on a cellphone video smoking crack cocaine and making offensive remarks. (Rick Madonik/Toronto Star via Getty Images)


text:
|The role of exocentric reference frames in the perception of visual direction
|Pelz, Jeff; Hayhoe, Mary
|One classic piece of evidence for an efference copy signal of eye position is that a small, positive afterimage viewed in darkness is perceived to move with the eye. When a small stationary reference point is visible the afterimage appears to move relative to the reference point. However, this is true only when the afterimage is localized to a small area. We have observed that when an extended afterimage of a complex scene is generated by a brief, bright flash it does not appear to move, even with large changes in eye position. When subjects were instructed to maintain their direction of gaze, we observed small saccades (typically < 1 deg) and slow drift movements often totalling more than 10 deg over a 30 sec period. When the instructions were to simply inspect the extended afterimage, subjects made larger saccades (up to 5 deg) which were not accompanied by afterimage movement. The smaller movements observed under the first instructions are greater than those observed in the dark or with small afterimages. When a visible reference is present with these large afterimages, the afterimage appears stationary, while the reference point appears to move. Eye position was monitored following the generation of such afterimages. In general, the perceived motion of the stationary reference point was in a direction opposite to the motion of the eye. Similar drift movements of smaller magnitude were observed with localized afterimages, but the motion was attributed to the afterimage. This suggests that with whole scene afterimages, extraretinal information about slow movements and small to moderate saccades is absent or suppressed, and that stationarity is assigned to the complex scene. This indicates a perceptual disposition to rely on visual information (when it is available) for maintaining constancy of visual direction, despite substantial changes in eye position. We found that changes in gaze as large as 13 deg produced no change in reported position of the large scene afterimage. When a small, stationary reference light was present it appeared to move in the afterimage scene in a way consistent with the recorded eye movements. When observers attempted to maintain their direction of gaze, most of the eye movements were slow drift, with occasional small saccades. When the instruction to hold gaze was relaxed, larger saccades up to about 5 deg were observed which were not accompanied by afterimage movement.
|RIT community members may access full-text via RIT Libraries licensed databases: http://library.rit.edu/databases/
|Record URI:
|Publishers URL:
An open access version of this file is not available. Check "Publisher URL" field for access


text:
Waiting for Godot
Waiting for Godot is an absurdist play by Samuel Beckett, in which two characters, Vladimir and Estragon, wait endlessly and in vain for the arrival of someone named Godot. Godot's absence, as well as numerous other aspects of the play, have led to many interpretations since the play's 1953 premiere. It was voted "the most significant English language play of the 20th century". Waiting for Godot is Beckett's translation of his own original French version, ...... more on Wikipedia
Waiting for Godot is listed on...
- 73
- of 778
Waiting for Godot is #73 on
Books That Changed My Life
The most life changing books, ranked by the wisdom of the crowd of hundreds of people. If you are looking for books that will change your life, these have the themes, characters an...read more
- 6
- of 45
Waiting for Godot is #6 on
The Best Absurdist Fiction Novels
List of the best absurdist fiction novels from various time periods with the title and the author's name listed next to images of the novel's jacket sleeve. Absurdist fiction began...read more
- 20
- of 317
Waiting for Godot is #20 on
Great Books of the Western World
Compiled by Encyclopedia Britannica, this is a list of the great books of the western world. It is our western canon gathered into a single package of 60 volumes. Initially compile...read more
- 11
- of 51
Waiting for Godot is #11 on
The Best Existentialism Books
List of best books about Existentialism, including jacket cover images when available. All these popular books on Existentialism are sorted by popularity, so the highest rated book...read more


text:
From the Lords to Lebanon, Labour misses Robin CookDavid Clark: His wisdom and moral leadership would have been a crucial counter to a narrow Blairite agenda.
On Hampstead Heath I feel the pain of warNorman Johnson: Here's me. My family. My friends. All of us healthy and looking great. Not a care in the world. Then, far away in Lebanon: a lot of people who are not so lucky. Dead, even.


text:
Anton Blidh
Mölnlycke Sweden
Eligible for draft:
6th round (180th overall), 2013
184 lbs.
Prospect Talent Score
Probability of Success
2010-11: Anton Blidh played for Frolunda's U18 team and skated for Goteborg 1 in the 2011 TV-Pucken tournament for high school age players in Sweden. In 12 games with Frolunda he had 2 goals with 1 assist and had 8 penalty minutes. He made one playoff appearance and had no points with 25 penalty minutes. Blidh scored 2 goals with 4 assists and had 6 penalty minutes in eight TV-Pucken games.
2011-12: Blidh stepped into a full-time role for the Frolunda U18 team in his second season. Playing 38 games during the regular season, he scored 13 goals with 19 assists and was +11 with 28 penalty minutes. Frolunda was the top team in the South Division and reached the playoff semifinals, falling 4-3 to eventual champion Rogle BK. Blindh scored 2 goals with 4 penalty minutes and had an even plus/minus in four playoff games.
2012-13:Blidh played 49 games for Frolunda's U20 team as a 17-year-old and represented Sweden at the 2013 U18 World Junior Championship. He scored 17 goals with 10 assists and was +13 with 80 penalty minutes in 43 regular season games as Frolunda was the SuperElit league's top team. Frolunda reached the playoff semifinals and Blidh scored 1 goal with 2 assists and was +2 in six playoff games. Skating for Sweden, which finished fifth at the U18 WJC, he scored 1 goal and was +1 in five games. He also played 11 games for Frolunda's U18 team (including three playoff games) and scored 6 goals with 5 assists and was +3 with 14 penalty minutes. Ranked 100th amongst European skaters in Central Scouting's final rankings, Blidh was selected by Boston in the sixth round (180th overall) of the 2013 NHL Draft.
2013-14: Blidh skated in 24 regular season games for Frolunda in his first pro season in Sweden — splitting the year between the SHL and Allsvenskan club Karlskrona — and was one of the top scorers for the Frolunda U20 team. He had 5 assists and and even plus/minus with 2 penalty minutes, averaging 11:15 minutes of ice time in SHL play. Frolunda finished second to league champion Skelleftea in the regular season before falling to Linkopings in a seven-game first round playoff series. Blidh scored 1 goal with 2 assists and was +2 in six playoff games. In 11 Allsvenskan games for Karlskrona he scored 1 goal with 1 assist and was -2 with 6 penalty minutes. Bildh scored 11 goals with 14 assists and was +15 with 20 penalty minutes in 27 SuperElit league games with the Frolunda U20 team.
Talent Analysis
Blidh is a strong skater and has the projectable frame of a strong two-way forward. He has been a consistent scorer at the junior level but is viewed as more of a forechecking, three-zone type of player at the pro level. He plays an aggressive, responsible style defensively that is rare amongst young prospects.
Blidh is seeing steady ice time in his second SHL season with Frolunda in 2014-15 and skated for Sweden in the 2015 World Juniors; impressing scouts with his speed and activeness inside the play. He has scored five goals for Frolunda but it has been his play away from the puck — particularly on the forecheck and in his own zone — that has kept him in the lineup. Drafted in 2013, he has yet to sign a contract with Boston and must be signed by June 2015 or he would re-enter the NHL Draft. Long-term he projects as a physical, two-way lower line forward similar in style to former Bruin P.J. Axelsson.


text:
Please Visit our Site Sponsors
|What a Powerstroke is for, Towing and Hauling FAQs, How To's, What do you pull, 5ers
|Thread Tools
|Display Modes
Questions about Towing weight, size, and what the truck can handle.
Hey Family, Sorry i have not been around in a while. Life got the better of me. Got some new toys so ive been hanging out in the Kawasaki and Raptor forms and i havent had time or money to put into the PSD. But.... now me and Mama are talking about a Toy hauler and i have questions. I Know Ford Says i can tow 12,500lbs with tow behind and 12,800 fifth wheel. My Baby is a 2002 4x4 crew cab Long Bed. I'm interested in knowing what people like more. my debate is losing the Bed space. I have 3 full size ATV's. (for those who are asking they are Honda 400EX, Kawasaki KFX 700, and Yamaha Raptor, all stock... right now) So i know if i get a 5ther i'm going to lose my bed for another atv. so that is a concern, also i have heard that pulling behind is not as smooth or easy as the 5ther. Now i have towed a 5ther before with my uncles Old F450 with the 460, and i liked it a lot. I'm also intrested in hearing form Toy hauler owners, what you bought, why you went with what you went with. I'm looking for a 25 to 30 foot 5th wheel and maybe a 20 to 25 foot tow behind. also what else would you recommend for the rig to tow in the 10000lb range. Any info would be very helpful. There also might be a RZR or a 4th ATV in the future so i need to keep that in mind too. RIght now i have a Little single axle 10 foot flat bed that i tow the atvs with and i almost cant tell its behind me unless were going up a hill. Thanks for the help.
not an expert with toyhaulers but i would just buy a big enough one to put your toys in there and get the fifth wheel. reasons ease of manuverablity, rides smoother going down road, better load displacement on pickup. ohter things you need for tow rig quality brake controller and air bags would make it nice but no necessary. i've never had bags on my pickups but always wanted a set and will be getting some for my tow rig in the future. other wised your mods look good for tow rig
If you want to stay 10k lb and below, you're not going to get a big fifth wheel, much less a toy hauler. You'd be more in the range of a bumper pull.
yeah i kinda figured that, i just want to stay legal, i know i cant go giant toy hauler but i think i can get into a 30 foot or below 5ther and still stay within 12,500lbs
I've had 4 bumper pull trailers and two fifth wheels. The fifth wheels tow better on the freeway. I used friction and sway hitches on the bumper pulls . Look at the equalizer hitch, best sway control inder $1k. Having the truck bed is so nice. Every garage model I've had wont fit all the toys so I stay clear, but they are nice. Look at load capability of trailer. Higher quality handles more weight. Three axles better than two, eight lugs better than six. If you get a two axle trailer, look for 8 lugs versus 6. 6 lugs equal 6k axles 8 lug equals 7k axles. Also water and drain tanks, the bigger the better.
yeah were looking at pull thru 5ther's with no pop outs. looks like i can get into a fun runner 32' but they only come with 60 gal water, and i want at least 100 gal. Looked at come of Forest Rivers last night on their website, i think i can get into a sand storm stealth or wolf pack. Its just hard finding one under 35 feet.
Forest river good quality, wolf pack and fun runner tie for lowest quality on the business, but doesn't mean they don't fit the bill. Sometimes you don't need the extra quality. On my 5th toyhauler and can't say enough about weekend warrior. Quality for the price. Raptor 3018 great bumper pull that can haul weight, spendy though. Raptors good but all garage models
yeah i'm trying to stay away from garage models. if i only had 2 atvs i would consider it but i have 3. If i have to get a bumper pull then i will. I was looking at Attitudes last night and they are much lighter then the forest rivers but they can't haul as much weight. Its tough finding the right one. I may just go with a used weekend warrior if i can find one not priced super high.
|Thread Tools
|Display Modes
Linear Mode


text:
Posted: August 12, 2014|
A YOXALL businessman has been jailed for six years, after he admitted sexually abusing two girls aged two and seven.
Scott Cordner joined with another man, Robert Dunn, to target the toddler, in an attack which took place at a house in Staffordshire.
The 42-year-old, of Ferrers Road, also made and downloaded indecent images of children – continuing to stockpile pictures on his computer even when he was released on bail, Stafford Crown Court was told on Friday.
Judge Mark Eades told the two men, who exchanged messages about their child sex fantasies in an internet chat room: "You both have a dark secret – you are both attracted to young girls. It's easy to hide that secret in the privacy of your own home, behind your computer. It seems harmless, but it's not. Some of the disgusting conversations you two had on the internet have been read out – horrible conversations about horrible acts.
"The trouble with it is that it can lead to the execution of these acts."
The pair's relationship began by sharing messages of a sexual nature about each other's wives, prosecutor Nicholas Cartwright said. They then moved on to exchange messages about sexual activity against children, before planning to abuse a very young girl.
He said the conversations started out as 'fantasy'.
The pair were discovered when Cordner's wife used her husband's computer in January of this year.
Laura Pitman, defending, said: "He was a man of previous good character and a businessman. wHe appeared to have everything you could hope for, but he then disturbed not only his own life, but his wife's."