A basin molding (1), for example a kitchen sink, a washbasin or the like, is made of a composite material having a polymerized cured binder (14) and fillers (16). The basin molding (1) has a visible side (34) and a rear side (36), which is located opposite the visible side (34). Unidirectionally oriented fibers (10) are polymerized into the composite material on, or in the vicinity of, the surface of the rear side (36) of the basin molding (1). A method produces such basin molding (1).

DE 10 2004 055 365 A1 discloses a basin molding made of a composite material comprising a polymerized cured binder and fillers. EP 0 361 101 B1 discloses an associated production method using a molding suitable for kitchen sinks, for example. Basin moldings thus produced have a high optical quality as well as very good functional characteristics, in particular high abrasion resistance and high long-term stability of the visual appearance. By using suitable binders and fillers incorporated therein for the composite material, the appearance of, for instance, natural stone can be duplicated in high quality, while simultaneously improving the functional characteristics of the basin molding.
In particular, basin moldings that have large volumes and/or that deviate from a planar form and extend three dimensionally, such as a kitchen sink, have a weight in excess of 10 kg, for example. In particular during transport but also during installation of the basin moldings, measures must therefore be taken to prevent breakage, which requires a corresponding amount of effort and makes handling difficult.

Basin moulding, for example a kitchen sink, a washbasin or the like, and method for producing such a basin moulding


Systems, methods, and non-transitory computer-readable media can determine a respective embedding for each entity in a set of entities that are accessible through the social networking system, wherein each embedding is learned based at least in part on one or more sessions of connections formed between users and entities of the social networking system. One or more candidate entities that are related to a first entity can be determined based at least in part on the respective embeddings for the candidate entities and the first entity. At least a first candidate entity from the one or more candidate entities can be provided as a recommendation to a user that formed a connection with the first entity.

Today, people often utilize computing devices (or systems) for a wide variety of purposes. Users can use their computing devices to, for example, interact with one another, access content, share content, and create content. In some cases, content items can include postings from members of a social network. The postings may include text and media content items, such as images, videos, and audio. The postings may be published to the social network for consumption by others.
Under conventional approaches, a user may navigate to or be presented with various content items in a social network. The content items can come from pages associated with members of the social network. In some instances, the content items may be of high interest to the user. If the user expresses interest in a particular content item, the social network may attempt, based on the content item, to provide to the user additional content items that would also be of interest to the user. Providing such additional content items can enhance the user experience and may help realize the full potential of the social network. Unfortunately, attempts to provide such additional content items and to maintain a high level of interest from the user often fail. The growing size of social networks can also pose problems with respect to the goal of providing content items of high interest to the user. As available content grows in amount, in theory, the likelihood of finding more content items of high interest to the user should increase. However, in practice, the ability to identify content items of high interest to the user can be complicated by the sheer volume of content.

Systems and methods for recommending pages


An electrical component assembly includes a first electrical component having a PCB mounted therein. The PCB includes a plurality of female sockets. A second electrical component includes a plurality of PCB engagement members and a plurality of pins. The first and second electrical components each include an alignment feature. The first and second electrical components are configured to be aligned and connected by progressively bringing together the first and second electrical components. In a first position, the first and second electrical components are spaced apart a first distance and the alignment features of the first and second electrical components are engaged. In a second position, the first and second electrical components are spaced apart a second distance and the PCB engagement members engage the PCB. In a third position, the first and second electrical components are spaced apart a third distance and the female sockets receive the pins.

Electrical components such as a rectifier/inverter and an inductor box must often be aligned and connected using "blind guidance" due to the geometry of the components and/or the environment in which they are aligned and connected. Further, component tolerance stack-up can lead to frustration in the alignment and connection of such components.

Systems and methods for aligning and connecting electrical components


Herein described is a system and method that tracks the face of a person engaged in a videophone conversation. In addition to performing facial tracking, the invention provides stabilization of facial images that are transmitted during the videophone conversation. The face is tracked by employing one or more algorithms that correlate videophone captured facial images against a stored facial image. The face may be better identified by way of employing one or more voice recognition algorithms. The one or more voice recognition algorithms may correlate utterances of the person engaged in a conversation to one or more stored utterances. The identified utterances are subsequently mapped to a stored facial image. In a representative embodiment, the system used for performing facial tracking and image stabilization comprises an image sensor, a lens, an actuator, and a controller/processor.

As a result of advances in technology, cellular videophones may be used to enhance a phone conversation between two parties. During the conversation, the persons speaking may transmit their headshots as a way to enhance communication between the two parties. In a conversation, however, the relative movement between the lens of a cellular video phone and its user's head may result in one or more erratic movements or a displacement of the headshot image transmitted to the other party. This movement or displacement may occur because of the natural motion of the hand when operating a cellular videophone, for example. In other instances, this movement may be more pronounced when a party in the conversation is inside a moving vehicle such as an automobile, for example. Vehicular bumps and vibrations may contribute to erratic movement, motion, and/or displacement of the transmitted headshot. A party that receives a headshot, which suffers such erratic movement, motion, and/or displacement, may be unable to recognize the person corresponding to the headshot.
The limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.

This patent is subject to a terminal disclaimer.

Method and system of tracking and stabilizing an image transmitted using video telephony


Components for energy storage, in particular to a process for producing a supercapacitor includes a flexible substrate, the process comprising at least the steps of unwinding the flexible substrate from a first roll, spraying a plurality of suspensions comprising micro/nanoparticles suspended in a solvent, the suspension(s) being sprayed by a plurality of nozzles, transporting at least a portion of the flexible substrate at least through a region for deposition of micro/nanoparticles, along a direction of transport of the flexible substrate, the interaction of the deposition region and of the flexible substrate forming an impact region, heating the flexible substrate, during each spraying operation, so as to encourage the complete evaporation of the solvent(s) from the suspensions sprayed onto the flexible substrate.

Supercapacitors generally comprise two porous electrodes impregnated with an electrolyte (an ionic salt in generally organic solution, a quaternary ammonium salt, such as tetraethylammonium tetrafluoroborate in acetonitrile or propylene carbonate, for example). These electrodes are generally separated by an insulating and porous membrane allowing the circulation of the ions of the electrolyte.
The first supercapacitors, known as "EDLCs" (Electrochemical Double Layer Capacitators), are based on a principle equivalent to that of conventional capacitors with polarizable electrodes and an electrolyte acting as dielectric. Their capacity originates from the arrangement of a double layer of ions and of electrons at the electrolyte/electrode interface. Today, supercapacitors combine, for energy storage, a capacitive component resulting from the electrostatic arrangement of the ions close to the electrodes and a pseudocapacitive component due to oxidation/reduction reactions in the capacitor.
The electrostatic component of the energy storage is produced by a nonhomogeneous distribution of the ions of the electrolyte in the vicinity of the surface of each electrode, under the effect of the difference in potential applied between the two electrodes. The electrostatic component of the energy storage confers a potentially high specific power and a very good behavior throughout the charging and discharging cycles.
Materials having a very high ratio of specific surface to volume, having a porosity suited to ion storage at this scale, have been developed in order to increase the capacity of supercapacitors. The methods for manufacturing these materials have been directed towards the use of fullerenes, carbon nanotubes, activated carbon, carbon nanofibers or CNFs and graphene, which are advantageously light, inexpensive and less toxic than the materials commonly used for producing batteries.
Supercapacitors might replace conventional capacitors for applications having a high energy demand, especially having extreme temperatures, vibrations, high accelerations or a high salinity. In these environments, batteries may not operate without their lifetime being greatly restricted (these conditions apply to radars, to motor sports, to electrical avionics and to military applications, for example).
Supercapacitors are mainly applied to systems which require energy peaks over short times (i.e. with high power), of the order of a minute, for phases of acceleration of vehicles in ground transportation (motor vehicles, tramways, buses, "stop and start" devices, in which energy is recovered during the deceleration).
Supercapacitors might also be useful for the management of electricity in onboard systems, for rendering electrical installations secure, for rendering the energy supply of sensitive systems (radio sets, monitoring systems, military field, data centre) secure, in networks of self-contained sensors for applications in monitoring industrial, complex or sensitive sites (hospitals, avionics, offshore platform, oil prospecting, underwater applications) and finally in renewable energies (wind power, recovery of atmospheric electrical energy).
In order to enable an industrial application, the energy density and the power of supercapacitors have to be optimized. Furthermore, the internal resistance of a supercapacitor is currently too high and poorly controlled. The usual supercapacitors are composed of activated carbons with nonhomogeneous and nonoptimized distributions of the size of the pores and use a polymeric binder to ensure the mechanical strength of their structure. This binder increases the internal electrical resistance of the capacitor and disadvantageously increases its weight. Furthermore, this binder breaks down over time and pollutes the electrolyte by degrading the performance of the supercapacitor. The unsuitable porosity also produces a resistance to ion transfer within the active material.
The publication by Bondavalli, P., Delfaure, C., Legagneux, P., Pribat, D., 2013, "Supercapacitor electrode based on mixtures of graphite and carbon nanotubes deposited using a dynamic air-brush deposition technique.", Journal of The Electrochemical Society, 160(4), A601-A606, discloses a process for the deposition of graphene nano/microparticles and of carbon nanotubes by hydrodynamic spraying of a suspension over a support. This process makes it possible to produce supercapacitors achieving high energy and power densities, without use of a polymeric binder, but requires the use of toxic and polluting solvents, such as N-methyl-2-pyrrolidone (NMP) in order to enable the suspension of the nano/microparticles. The solvents used are however suitable for suspending this type of micro/nanoparticles.
The publication by Bondavalli et al. also discloses the production of collectors on surfaces of the order of a cm2. The spraying operation is carried out using a nozzle that sprays a suspension composed of several types of mixed micro/nanoparticles. In order to cover this surface, the substrate is fixed and the spraying jet of a nozzle may be displaced in a plane so as to cover a surface by adjusting the trajectory of the jet so as to have as uniform a deposition as possible of micro/nanoparticles.
The evaporation of toxic solvents such as NMP may be confined to the laboratory during production of small surface areas, for example by carrying out the deposition under a hood. Treatment of the toxic emissions poses a technical challenge if the rate of production of the collectors, electrodes or capacitors is scaled up to the industrial level.
Producing a supercapacitor may require the deposition of several layers of different compositions of micro/nanoparticles. Using the technique disclosed in Bondavalli et al., the nozzle must be changed or cleaned during each of the steps of deposition of different micro/nanoparticles or of layers having different compositions of micro/nanoparticles.
The nozzles are also subject to clogging. The concentrations of micro/nanoparticles may be high during a spraying operation carried out under the conditions described by Bondavalli et al.: clogging poses a maintenance challenge during industrial use of this method for the production of collectors, electrodes or supercapacitors.


A system including at least one automatically controlled process element (1), in particular an automatically controlled process system, having at least one screen (4) for displaying status data or operational data of said process element (1). The display of the screen (4) is temporarily interrupted by a screen saver function and an activating element (5) is provided for remote-control cancellation of the screen saver function. In addition, an activating element (5) for the system is provided.

The present invention relates to a system having at least one process element with at least one screen to display data of the process element, provided with a screen saver function.
Process elements, such as devices, machines, or process facilities that have screens to display state/operational data, are known from the prior art. In order to monitor the often-times automatically controlled activity of these types of process elements, it is known, for example, in the fields of petrochemistry or brewing technology, to monitor these process elements by having operators check the state/operational data displayed on the respective screens, e.g. for fault messages. Often these process elements are positioned throughout expansive areas. If there are fault messages, the operator, for instance, initiates appropriate corrective measures. In order to protect the screens used and elevate their service lives, it is known to deactivate the displays of the screens through screen saver functions after an adjustable time period.
Typically, the operator must interrupt the active screen saver function for each individual screen to be monitored, e.g. by pressing a switch, in order to obtain a renewed display of the state/operational data and be able to determine whether an error-free operating state exists. If a large numbers of screens are positioned throughout an expansive area, the operator may have to expend a significant amount of time for this purpose.
It is already known to cancel the display interruption on the screen, effected by one of the described screen saver functions, for a specific time whenever a fault message occurs, in order to draw attention to the fault message. Typically, however, an interruption of this type, arising from the presence of a fault message, has a time limit imposed, to protect the screen. As a result, the operator must initiate the cancellation of the screen saver function on the respective screen again and again to reliably determine whether a fault message is present.
A control system, having a display unit, for an industrial system is known, e.g., from European Patent Application A-0 389 132. According to the teachings of this reference, for example, the color of the screen display on the display unit is modified according to the state or operational data of a process element. Furthermore, European Patent Application A-0 927 985 teaches a device in which the type and density of advertising output on a television screen is controlled as a function of the dwell time of a person in front of the screen. Finally, it is known from the publication xe2x80x9cFehlerdiagnose mit Bildschirmxe2x80x94Textangabe an Sonder-Werkzeugmaschinen [Error Diagnosis Using Screensxe2x80x94Text Display on Special Machine Tools]xe2x80x9d by Dr. Peter Jung, published in Werkstatt und Betrieb 115 (1982), pp. 365 and 366, to erase the screen display that is associated with faultless operation upon the occurrence of a fault, and to replace it by a fault message.
One object of the present invention is to provide a system having at least one process element with a screen and some form of more advantageous activation element for a system of this type. It is a further object to provide such a system with a feature that allows an operator to cancel the screen saver function of the screen of a process element in a time-saving and comfortable manner.
According to one formulation of the invention, these and other objects are achieved by a system that includes at least one automatically controlled process element having at least one screen to display state or operational data of the process element, the display of the screen being interrupted from time to time by a screen saver function; and an activation element, for remote-controlled cancellation of the screen saver function, having a detection region and activating the display of the screen when a person is detected in the detection region. According to another formulation, the invention provides a system that includes at least one automatically controlled process element; at least one display associated with the process element; screen saver software for the display; and a detector operationally connected to the screen saver software yet physically external to and remote from the process element and the display, wherein the detector controls the screen saver software in accordance with a parameter, other than manual actuation, detected by the detector.
In a system according to the present invention, an activation element for remote-controlled cancellation of the screen saver function of the screen of the process element is provided. In this case, a process element is understood to include, for example, devices, machines, and/or assemblies and, in particular, process systems in, for example, the fields of petrochemistry or brewing technology, which operate essentially automatically.
These types of process elements or process systems are typically sought out at specific intervals by an operator, whereby the screen display, which shows the state/operational data, is examined for fault messages. Whenever fault messages are displayed, suitable measures are taken by the operator, and the system is, for example, switched off until the fault is found and corrected.
The screens, or, stated more generally, the display elements, of these process elements may be implemented as, for example, tube elements or LCD displays. For tube elements, screen savers are known which interrupt the display on the screen after a specific time period. For LCD displays, the background illumination may be switched off after a time delay to preserve the screen.
According to the present invention, an activation element for remote-controlled cancellation of the screen saver function is additionally provided in the system. This element has a detection region and becomes active when a person is detected in the detection region. An operator can therefore, e.g. by entering the area in which the respective process elements are positioned, cause the activation element to be activated and, therefore, the screen saver function of all the associated screens to be cancelled.
In contrast to conventional systems, the cancellation of the screen saver function of the individual screens need therefore no longer be performed at the respective screens.
If multiple screens are provided in the system, it is possible to use one activation element to cancel the screen saver function of multiple screens. In this way, for example, all of the screens which are in the field of view of the operator may be reactivated, so that the operator is able to determine at a glance whether fault messages are present on the screens, i.e. whether faults have arisen with respect to the process elements. The cancellation of the screen saver functions may also occur, for instance, with a time delay, and/or with staggered reactivation, for individual screens or screen groups.
If multiple process elements or an entire process system are to be monitored by the operator, one activation element, for example, may be switched on when the operator enters the processing area. In particular, when the process system operates in an expansive area, multiple activation elements may also be provided. This allows an operator who is traveling on a vehicle, e.g. a bicycle, and seeking out the respective process elements one after another, to pass multiple activation elements, whereby the respective groups of screens are activated by the associated activation element, and the screen saver functions are canceled in groups.
According to the present invention, the activation element is actuated by an operator entering or passing a respective process area. The activation element may therefore be particularly advantageously designed as a floor mat, whereby the remote-controlled activation is triggered when the floor mat is ridden over or stepped upon.
In a further embodiment, the activation element may instead be implemented as a motion sensor and be activated by the appearance of the operator. Alternatively, the activation element may advantageously be implemented as both a floor mat and a motion sensor, in order to achieve particularly reliable activation.
According to a further advantageous embodiment, the activation element can be locked, so that the element is activated only upon input of an appropriate key access by an authorized operator. This key may be implemented as a mechanical key or as an electronic key (for example, by code input).
Particularly advantageous for implementation in a spacious, decentralized process area, the activation element may be connected via a radio connection to the process element(s). Alternatively or additionally, a wire connection may be provided. The activation element can then exchange information signals with the process element(s) via this wired or wireless connection. In particular, communication is thereby enabled with switching elements (e.g., a computer) of the process elements assigned to the screens.
In this case, communication may occur between the activation element and one or more computers which are assigned to the process elements for screen control. The activation element may also be connected to a programmable controller of a process element for screen control.
Advantageously, a deactivation element may be provided, via which the operator can, e.g., reactivate the screen saver functions of the screens upon leaving the process area. A deactivation element of this type may be provided with any or all of the features analogous to those described here and below for the activation element.
The activation element according to the present invention provides, in particular, an especially comfortable cancellation of the screen saver function of the process elements for an operator.

System having a process element with a screen and an activation element for remote-controlled cancellation of a screen saver function


A process is provided in which at least one polyol having a hydroxyl functionality of at least three, preferably four, serves as a polymerization initiator. The polyol initiator is optionally, although preferably, reacted with a catalyst to form a catalyst-initiator complex, which is then used in the polymerization of glycidyl nitrate. The resulting polyfunctional poly(glycidyl nitrate) has a functionality substantially equivalent in number to the hydroxyl functionality of the polyol. The poly(glycidyl nitrate) is cross-linked with at least one aromatic diisocyanate having at least one aromatic ring and two isocyanate moieties bonded directly to the at least one aromatic ring. Examples of the aromatic diisocyanate include toluene diisocyanate, phenylene diisocyanate, and/or methylene di-p-phenylene diisocyanate.

1. Field of the Invention
This invention relates to a method for making cured poly(glycidyl nitrate) having high stability against de-cure. This invention also relates to the production of solid energetic compositions, such as propellants, explosives, pyrotechnics, and gas generants, comprising poly(glycidyl nitrate) binders.
2. State of the Art
Solid high energy compositions, such as propellants, explosives, pyrotechnics, and gasifiers, or the like, generally comprise solid particulates, such as fuel particles and/or oxidizer particles, dispersed and immobilized in a cured binder matrix.
In recent years, energetic polymers have been developed and evaluated as replacements for inert polymeric binders in cast propellant systems, explosive compositions, and pyrotechnics. The substitution of an energetic polymer for an inert polymer in a typical pressable or extrudable explosive composition generally increases the detonation pressure and detonation velocity of the explosive.
Poly(glycidyl nitrate) (also known as xe2x80x9cPGNxe2x80x9d and xe2x80x9cpolyGLYNxe2x80x9d) has been known and recognized for years as a possible energetic polymer suitable for use in propellants, explosives, gas generants, pyrotechnics, and the like. PGN is commonly synthesized in the industry by preparing a difunctional glycidyl nitrate polymer and curing the PGN with a polyfunctional isocyanate having a functionality of greater than about 2.3 to give urethane cross-linked polymers. Aliphatic polyisocyanates have been selected as the curing agents.
Although glycidyl nitrate prepolymers have a satisfactory shelf life, it is known that conventionally cured PGN inherently de-cures when subjected to elevated temperatures for prolonged periods. If precautions are not taken, over time, cured PGN can de-cure to the point of reverting to a pourable liquid. Accordingly, special care must be taken in the handling and storing of energetic compositions containing cross-linked PGN. The special care required to avoid a de-curing problem has impeded the widespread use of PGN as a binder, despite its attractive energetic properties.
One solution to this de-curing problem has been suggested by N. C. Paul et al., An Improved polyGLYN Binder Through End Group Modification, ICI Explosives (1998). The article indicates the de-curing problem as being caused by the proximity of the terminal hydroxyl groups of the polymer to nitrate ester groups. The authors conclude that the de-curing problem is an inevitable consequence of the end group structure. To overcome this problem, the article describes a two-step process that modifies the end groups by removing the adjacent nitrate esters and replacing the nitrate ester groups with hydroxyl groups by base-catalyzed hydrolysis. Aging tests have shown that this technique is successful in preventing de-cure of the polymer. However, one of the major drawbacks to this solution of PGN de-curing is the decrease of energetic performance. It is estimated that approximately 10 percent of the nitrate esters may be removed from the polymer chain in accordance with this technique. Another drawback is that the extra chemical process steps cause additional expense and chemical waste in production.
Therefore, in one embodiment, the present invention provides a poly(glycidyl nitrate) (PGN) production process that produces cured PGN having desired stability against de-cure without sacrificing nitrate ester moieties in the production process.
The present invention further provides a process for the production of a cured energetic composition wherein the process can yield a cured energetic composition having desirable stability against de-cure without sacrificing nitrate ester moieties in the production process.
In accordance with the purposes of the invention as embodied and broadly described in this document, a process is provided in accordance with a first aspect of the invention in which at least one polyol having a hydroxyl functionality of at least three, preferably four, is provided as a polymerization initiator. The polyol initiator is optionally, although preferably, reacted with a catalyst to form a catalyst-initiator complex, which is then used in the polymerization of glycidyl nitrate. The resulting polyfunctional poly(glycidyl nitrate) has a functionality substantially equivalent in number to the hydroxyl functionality of the polyol. The poly(glycidyl nitrate) is then either cross-linked or combined into an energetic formulation and subjected to cross-linking. Cross-linking is performed with at least one aromatic diisocyanate having at least one aromatic ring and two isocyanate moieties bonded directly to the at least one aromatic ring. Examples of the aromatic diisocyanate include toluene diisocyanate, phenylene diisocyanate, and/or methylene di-p-phenylene diisocyanate.
The selection of an aromatic diisocyanate curative for curing of the polyfunctional PGN imparts a high stability against de-cure, especially at elevated temperatures, while not sacrificing the energetic performance contributed by the nitrate ester moieties of the glycidyl nitrate. Further, by selecting a polyol initiator having a hydroxyl functionality of three or more, cross-linking of the PGN (instead of exclusive chain extension, as in the case of using a difunctional initiator and difunctional curing agent) is attained with an aromatic diisocyanate for enhancing physical properties of the cured binder.
In accordance with another aspect of the invention, a process is provided for the production of a cured energetic composition. The process comprises providing at least one polyol initiator having a hydroxyl functionality of at least three, optionally reacting the polyol initiator with a catalyst to form a catalyst-initiator complex, reacting glycidyl nitrate monomers with the polyol initiator and/or the catalyst-initiator complex to form poly(glycidyl nitrate) having a functionality substantially equal in number to the hydroxyl functionality, preparing an energetic formulation comprising the poly(glycidyl nitrate), and cross-linking the poly(glycidyl nitrate) with at least one aromatic diisocyanate. The diisocyanate has at least one aromatic ring and two exocyclic isocyanate moieties bonded directly to the aromatic ring.
Additional aspects and advantages of the invention will be set forth in the description that follows and in part will be apparent from the description, or may be learned by practice of the invention. The aspects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations pointed out in the appended claims.
Reference will now be made in detail to the presently preferred embodiments and methods of the invention as described below. It should be noted, however, that the invention in its broader aspects is not limited to the specific details, representative devices and methods, and examples described in this section in connection with the preferred embodiments and methods. The invention according to its various aspects is particularly pointed out and distinctly claimed in the attached claims read in view of this specification and appropriate equivalents.
In accordance with one aspect of the invention, a process is provided for the production of poly(glycidyl nitrate). The process comprises providing at least one polyol initiator having a hydroxyl functionality of at least three.
The preferred polyol initiator employed generally has at least three sterically unhindered hydroxyl groups and preferably is a liquid at room temperature. An exemplary liquid triol is glycerin. Examples of solid triols are trimethylol propane ((2-ethyl-2-hydroxymethyl)-1,3-propanediol) and butane triol, which may be dissolved in a suitable solvent, such as methylene chloride. Preferably, the polyol initiator has a hydroxyl functionality of four, i.e., a tetraol. Tetraols useful in forming tetrafunctional polymers according to this invention have the formula:
wherein R1 is nothing or a nonpolar extender, such as an alkylene, or an ether moiety, especially those having a length of not greater than 3 atoms selected from the group consisting of carbon and oxygen, and is preferably saturated; wherein each R2 is the same or different and is either nothing or a nonpolar extender, such as an alkylene, or an ether moiety, especially those having a length of not greater than 3 atoms selected from the group consisting of carbon and oxygen, and is preferably saturated; and wherein each R3 is the same or different and is either nothing or a non-polar extender, such as an alkyl, or an ether moiety, especially those having a length of not greater than 3 atoms selected from the group consisting of carbon and oxygen, and (if present) is preferably saturated, more preferably methylene (xe2x80x94CH2xe2x80x94) or ethylene (xe2x80x94CH2xe2x80x94CH2xe2x80x94).
The tetraol is more preferably diglycerol. Another example of a tetraol is pentaerythritol, which is a solid at room temperature and may be dissolved in, for example, methylene chloride.
The polyol is preferably either a liquid or comprises a solid having a low melting point of not more than 60xc2x0 C. The hydroxyl groups of the polyol are preferably unhindered primary or secondary hydroxyl groups. The molecular weight of the polyol is relatively low, preferably not more than 500, more preferably not more than 300, and most preferably not more than 180.
In accordance with this aspect of the invention, the process optionally but preferably includes reacting the polyol initiator with a catalyst to form a catalyst-initiator complex. The acid catalyst may be used at a low level relative to the hydroxyl groups of the polyol. A much more controlled reaction occurs if the catalyst, such as a Lewis acid, is used at a molar ratio relative to hydroxyl groups of the polyol of less than 1: 1, preferably from about 0.4:1 to about 0.8:1, such as 0.5:1. If a protic acid is used as the catalyst, the ratio of hydrogen ions released by the acid catalyst to the hydroxyl groups of the alcohol is also less than 1:1, preferably 0.4:1 to about 0.8:1, such as 0.5:1. By using a low level of acid catalyst, a greater percentage of the polyol moieties can be incorporated internally within the polymer molecules, cyclic oligomer formation can be suppressed to a level of about 2 to 5% or less, and polydispersity (Mw,Mn) can be kept lower than 2 (as measured by gel permeation chromatography).
When the selection of the catalyst and polyol initiator results in the formation of alkoxide groups in the catalyst-initiator complex, the resulting PGN products are low in functionality. For example, prereacting the polyol and a catalyst, such as boron trifluoride etherate, and then optionally removing diethylether under vacuum conditions can produce a PGN product essentially free of alkoxide groups. If, however, the catalyst and initiator would not form products containing alkoxide groups, such as when boron trifluoride gas is employed instead of boron trifluoride etherate, then the step of removing the potential alkoxide may be avoided.
It is preferred that the catalyst and polyol initiator be prereacted in the absence of any solvent or water and that the polyol initiator be predried, for example, with calcium hydride. It has been found that removing water and solvent during formation of the catalyst-initiator complex increases both the monomer incorporation rate and molecular weight of the polymer and decreases the formation of cyclic oligomers. By suppressing the formation of cyclic oligomers, the functionality of the PGN is made to be substantially equal in number to the functionality of the polyol initiator. Thus, if the functionality of the polyol initiator is three, the functionality in number of the PGN is also preferably about three so that the PGN can be cross-linked with a difunctional isocyanate curative. Although not intending to be limited by any theory, the use of BF3:THF is preferred because it is believed that the THF (tetrahydrofuran) monomers can be incorporated into the polymer without interrupting its functionality through the generation of nonfunctional end groups.
Further in accordance with this aspect of the invention, the process includes reacting glycidyl nitrate with at least one member selected from the group consisting of the polyol initiator and the catalyst-initiator complex to form poly(glycidyl nitrate) having a functionality substantially equal in number to the hydroxyl functionality of the polyol.
The glycidyl nitrate used in the process according to this aspect of the invention is preferably synthesized by nitration of glycerol CH2(OH)CH(OH)CH2(OH) to form dinitroglycerin and ring closure of the dinitroglycerin. Preferably, the nitration is performed with nitric acid, such as 90 weight percent nitric acid, as the nitrating agent. Other nitrating agents, however, may be used, including: mixed acids, such as sulfuric and nitric acids, or acetyl nitrate; nitronium ion salts, such as NO2BF4, NO2ClO4, and/or N2O5; and trifluoroacetic anhydride (TFAA) with ammonium nitrate, nitric acid, and/or Crivello reagents. The molar ratio of nitrating agent to glycerol is preferably in a range of 4:1 to 5:1 for nitric acid.
The nitration of glycerol produces five different compounds: trinitroglycerin (or nitroglycerin), two isomers of mononitroglycerin (xcex1-mononitroglycerin and xcex2-mononitroglycerin), and two isomers of dinitroglycerin (xcex1xe2x80x2-dinitroglycerin and xcex2xe2x80x2-dinitroglycerin).
The cyclization of the dinitroglycerin into glycidyl nitrate may be performed in the presence of an inorganic hydroxide, including alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide. Alkaline earth metals, in particular calcium hydroxide, can also be used. Generally, two molar equivalents of cyclizing agent may be used: the first equivalent for neutralizing the nitric acid and the second equivalent for cyclization. Although hydrolysis treatment of the nitrated glycerol solution in an alkaline environment converts the dinitroglycerin isomers into glycidyl nitrate, the two mononitroglycerin isomers and the trinitroglycerin do not cyclize into glycidyl nitrate. Rather, the mononitroglycerin isomers are hydrolyzed, thereby solubilizing in the aqueous phase to facilitate removal, separation, and recovery (e.g., by decanting) from the reaction solution at or below room temperature by decanting or the like. Polymerization of the glycidyl nitrate into PGN can be conducted in the presence of the trinitroglycerin without interference. Thus, the trinitroglycerin does not have to be distilled off or otherwise removed prior to polymerization.
In order to increase the yield of glycidyl nitrate from glycerol, the reaction conditions can be and preferably are selected to drive the synthesis of 1,3-dinitroglycerin. Preferably, the nitration reaction is conducted at a relatively low temperature, preferably not higher than room temperature, more preferably 0 to 25xc2x0 C., and still more preferably 10xc2x0 C. to 20xc2x0 C. The reaction typically takes about 4 hours, more commonly a minimum of about 6 hours, due to the low temperature at which the nitration reaction proceeds. Practice of these conditions can result in a dinitroglycerin concentration of at least 50 mole percent, with trinitroglycerin being present in concentrations of less than 20 mole percent, still more preferably less than about 10 mole percent, to satisfy safety concerns.
The nitration step is preferably conducted in the presence of an acceptable heat sink medium, such as an inert halogenated hydrocarbon, such as methylene chloride, chloroform, and/or dichloroethane.
Although preferred glycidyl nitrate monomers for use in the process according to this aspect of the invention are preferably derived from glycerol, it is to be understood that conventional synthesis routes may also be used within the scope of this invention. Such conventional synthesis routes include, by way of example, the following: the nitration of epichlorohydrin, followed by the recyclization of the nitrated epichlorohydrin with a base; treatment of glycidol with nitrogen pentoxide (N205) in an inert solvent, followed by quenching in an aqueous solution, as described in U.S. Pat. No. 5,136,062; and others.
Polymerization of the glycidyl nitrate occurs as follows:
wherein n is an integer essentially equal to the hydroxyl functionality of a polyol co-initiator and x is an integer representing the repeating units. In the context of this invention, n is at least about 3 and preferably is about 4. The glycidyl nitrate monomer preferably is added to the catalyst-initiator complex reaction mixture at a rate in which the monomer is used up (reacted) essentially as fast as it is added, and the reaction temperature is preferably maintained at a temperature of about 10xc2x0 C. to about 25xc2x0 C.
The polymerization reaction is preferably a cationic polymerization process conducted using a polyol co-initiator and an acid catalyst. The acid catalyst may be selected among protic and Lewis acids known in the art, including BF3:THF, BF3, HBF4, PF5, BF3 etherate, as well as other initiators such as triethoxonium salts, such as triethyloxonium hexafluorophosphate, triethoxonium hexafluoroantimonate, and triethoxonium tetrafluoroborate. (The triethoxonium salts and their use is described in U.S. Pat. No. 6,100,375.) BF3:THF (boron trifluoride tetrahydrofuran) is currently preferred.
The cationic polymerization reaction may be carried out in a suitable organic solvent conducive to the cationic polymerization. Suitable solvents that may be used include nonprotic, nonether, inert solvents, including halogenated hydrocarbon solvents, such as methylene chloride, chloroform, and 1,2-dichloroethane.
The polymerization reaction is preferably conducted in a manner whereby the glycidyl nitrate is combined with the reaction mixture at a rate essentially equivalent to its rate of reaction, so that no effective net concentration of monomer is built up in the reaction mixture. A suitable reaction temperature is, for example, within the range of about 10xc2x0 C. to about 25xc2x0 C., preferably about 11xc2x0 C. to about 17xc2x0 C., and still more preferably about 13xc2x0 C. to about 15xc2x0 C.
A more detailed discussion of a method of polymerizing glycidyl nitrate into poly(glycidyl nitrate) is disclosed in U.S. Pat. No. 5,120,827.
Also in accordance with this aspect of the invention, the process includes cross-linking the poly(glycidyl nitrate) with at least one aromatic diisocyanate, wherein the aromatic diisocyanate has at least one aromatic ring and two isocyanate moieties bonded directly to the aromatic ring.
The aromatic diisocyanate may comprise at least one member selected from the group consisting of toluene diisocyanate, phenylene diisocyanate, and methylene di-p-phenylene isocyanate. In these instances, the hydroxyl functionality of the polyol initiator preferably is four. A presently preferred aromatic diisocyanate comprises toluene diisocyanate, and in presently preferred versions of this process using this diisocyanate, the hydroxyl functionality of the polyol initiator is four. In another presently preferred version of the process, the aromatic diisocyanate comprises toluene diisocyanate and the polyol initiator comprises diglycerol.
In accordance with another aspect of the invention, a process is provided for the production of a cured energetic composition, the process according to this aspect of the invention comprising providing at least one polyol initiator having a hydroxyl functionality of at least three.
In accordance with this aspect of the invention, the process optionally but preferably includes reacting the polyol initiator with a catalyst to form a catalyst-initiator complex. Polyol initiators and catalysts preferred for and suitable for this aspect of the invention include those described above.
The process according to this aspect of the invention further includes reacting glycidyl nitrate with at least one member selected from the group consisting of the polyol initiator and the catalyst-initiator complex to form poly(glycidyl nitrate) having a functionality substantially equal in number to the hydroxyl functionality. This reaction may be and preferably is carried out as described above.
Further in accordance with this aspect of the invention, the process includes cross-linking the poly(glycidyl nitrate) with at least one aromatic diisocyanate, wherein the aromatic diisocyanate has at least one aromatic ring and two isocyanate moieties bonded directly to the at least one aromatic ring. The cross-linking may and preferably is carried out also as described above.
The PGN as obtained through preferred versions of the inventive process can be utilized in explosive compositions without the need for further purification or recrystallization steps. However, after quenching of the PGN with, for example, methanol, it is possible to purify the PGN by removing residual nitroglycerin.
PGN may be used in combination with conventional or novel propellant and solid explosive ingredients as the basis for formulating very high performance insensitive propellant and explosive compositions. Propellant and explosive compositions suitable for use with PGN are disclosed in, for example, U.S. Pat. No. 5,587,553 and U.S. Pat. No. 5,690,868. Techniques for combining PGN into energetic formulations and curing the formulations are well known in the art. Generally, the PGN is mixed with the other ingredients of the explosive composition, including the curative, followed by addition of the cure catalyst. Of course, other sequences for combining ingredients fall within the scope of this invention and would be apparent to those skilled in the art.
Representative explosive materials that can be made with PGN include gun propellants, cast cure explosives, and extrudable explosives. The explosive (or energetic) materials of this invention are preferably not in the form of a foam.
Generally, a gun propellant may comprise about 15 weight percent to about 40 weight percent of binder and plasticizer (at a plasticizer-to-binder weight ratio of, for example, 0:1 to 3:1), 0 to 80 weight percent filler, such as nitramine (e.g., RDX, HMX and/or CL-20), and optionally 0.5 weight percent to 5 weight percent ballistic modifiers.
Cast cure explosives in which PGN may be used generally comprise as ingredients 5 weight percent to 20 weight percent PGN binder and optionally other binders, 0.5 weight percent to 3 weight percent curative, 0.25 weight percent to 2 weight percent cure catalyst, and 20 weight percent to 80 weight percent oxidizer. Exemplary oxidizers include ammonium perchlorate and/or ammonium nitrate.
Typically, formulations for extrudable explosives include 5 weight percent to 35 weight percent PGN and optionally other binders, 0 to 65 weight percent oxidizer, 0 to 90 weight percent explosive filler, 0 to 40 weight percent metal, and 0 to 25 weight percent plasticizers.
PGN may also be used as a binder for composite propellant compositions, including minimum smoke, reduced smoke, and smoke propellants.
Minimum smoke propellants generally include as ingredients the following: 4 weight percent to 30 weight percent binder, 0.5 weight percent to 3 weight percent curative, 0.25 weight percent to 2 weight percent cure catalyst, 0 weight percent to 80 weight percent solid oxidizer, 0 to 50 weight percent energetic solid filler, and 0 to 30 weight percent plasticizer. Other additives, such as 0 to 5 weight percent ballistic modifiers, may also be added.
Typical formulations for reduced smoke propellants generally are similar to minimum smoke propellants. However, if ammonium perchlorate is selected as a component of the oxidizer and/or aluminum or aluminum oxide is selected as a component of the fuel, the ammonium perchlorate, aluminum, and aluminum oxide are used in sufficiently low amounts to retain the desired reduced smoke properties. Generally, aluminum is present in an amount of not more than 3 weight percent for reduced smoke propellants.
Typical formulations for the smokey propellants generally are similar to those of reduced smoke propellants but do not contain undue restrictions on the smoke generating components. Thus, aluminum can be used in concentrations as high as about 22 weight percent (or as limited by combustion efficiency) and the ammonium perchlorate can be used in concentrations as high as 80 weight percent (or as limited by theoretical performance) in smokey propellants.
Methods of preparing energetic compositions are generally known in the art and are set forth in A. Davenas, Solid Rocket Propulsion Technology (1993) and R. Meyer, Explosives (4th ed. 1993).
PGN can be used alone or in combination with other energetic and inert binders, or combinations thereof. Representative inert polymeric binders that can be used in combination with PGN include hydroxyl-terminated polybutadiene (HTPB), butadiene-acrylonitrile-acrylic acid terpolymer (PBAN), poly(propylene glycol) (PPG), poly(ethylene glycol) (PEG), polyesters, polyacrylates, polymethacrylates, cellulose acetate butyrate (CAB), and combinations and copolymers thereof. Representative energetic polymeric binders that can be used in combination with PGN include poly(nitrato methyl methyl oxetane) (polyNMMO), poly(glycidyl azide) (GAP), nitrocellulose (NC), diethyleneglycol-triethyleneglycol-nitraminodiacetic acid terpolymer, poly(bisazidomethyl oxetane) (polyBAMO), poly(azido methyl methyl oxetane) (polyAMMO), poly(nitramino methyl methyl oxetane) (polyNAMMO), copolyBAMO/NMMO, polyBAMO/AMMO, and combinations and copolymers thereof. The binder can optionally be halogenated, such as fluorinated ethylene propylene copolymer, chlorotrifluoroethylene and vinylidene fluoride copolymer, polyvinylidene fluoride, polydifluorochloroethylene, fluorinated polyethers, poly(vinyl chloride) (PVC), polytetrafluoroethylene, and combinations thereof.
Representative oxidizers include ammonium perchlorate (AP), ammonium nitrate (AN), hydroxylammonium nitrate (HAN), ammonium dinitramide (ADN), hydrazinium nitroformate (HNF), and mixtures thereof. The oxidizer may be present as a powder, particles, and/or in other forms.
Representative reactive metals include aluminum, magnesium, boron, titanium, zirconium, and mixtures thereof. These metals may be present as a powder, particles, and/or in other forms.
Energetic fuels (for propellants) or explosive filler (for explosives and pyrotechnics) that can be used in combination with PGN include the following: nitramines such as 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo-[5.5.0.05,903,11]-dodecane (TEX), 1,3,5-trinitro-1,3,5-triaza-cyclohexane (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.05,901]-dodecane (CL-20 or HNIW); 3-nitro-1,2,4-triazol-5-one (NTO); nitroguanidine (NQ), 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), and 1,1-diamino-2,2-dinitroethane (DADNE).
PGN can also be used to prepare high solids (more than about 90% solid ingredients) pressable or extrudable explosives. The pressable or extrudable explosives can also contain one or more inert plasticizers and/or one or more energetic plasticizers. Representative inert plasticizers include dioctyladipate (DOA), isodecylperlargonate (IDP), dioctylphthalate (DOP), dioctylmaleate (DOM), dibutylphthalate (DBP), oleyl nitrile, or combinations thereof. Representative energetic plasticizers include bis(2,2-dinitropropyl)acetal/bis (2,2-dinitropropyl)formal (BDNPF/A), diglycerol tetranitrate (DGTN), trimethylolethanetrinitrate (TMETN), triethyleneglycoldinitrate (TEGDN), diethyleneglycoldinitrate (DEGDN), nitroglycerin (NG), butanetrioltrinitrate (BTTN), alkyl NENAs (nitratoethylnitramine), and combinations thereof.
A list of representative ballistic modifiers include, by way of example, Lewis acids, iron oxide (Fe2O3), bismuth-containing compounds, lead and lead-containing compounds, such as lead salts and organometallic lead compounds.

Process for making stable cured poly(glycidyl nitrate)


A device that attaches to stringed instruments, preventing the bow from playing over the fingerboard, is disclosed. The device aids in developing proper bow technique, and only restricts movement of the bow over the fingerboard without restricting movement elsewhere between the fingerboard and the bridge.

An almost universal problem exists among beginning orchestral strings players in that while they are developing consistent bowing technique, their arm and bow slide outside of the bowing region and over the fingerboard. Instead of bowing perpendicular to the strings, the bow slides parallel to the strings which creates an unpleasant sound when performing or practicing. Proper technique generally requires the bow to be used on the strings in the area between the bridge and the fingerboard. For many, this stage of learning can last several months and may discourage the player from learning the instrument all together. Beginning orchestral string players turn to aids in many forms to overcome the difficulties of learning a new instrument, so they can competently practice or share their progress with friends or relatives in a pleasant manner.
In the field of the present invention, despite long availability of attaching devices in general, such designs can be large, cumbersome, and can make the experience of playing a stringed instrument unpleasant. Prior designs attach to the sides of the instrument and may cause marks or other damage to the instrument in the course of application or removal. Additionally, other designs can excessively restrict the movement of the bow within the proper playing area between the fingerboard and bridge of the instrument.
Therefore, despite the availability of prior designs, there are still substantial and long-felt unresolved needs for a compact device that aides in developing proper bow technique without unduly restricting movement otherwise.

Device that attaches to stringed instruments preventing the bow from playing over the fingerboard


This invention generally relates to the provision of a vent path during the bonding of silicon wafers and the subsequent encapsulation of the individual devices. A double-sided polished silicon wafer is used for the device wafer. The device wafer includes circuitry, thin membranes and metal interconnections. When bonding a bottom wafer to the device wafer, a vented path exists between the wafers. The venting path includes serpentine shape channel formed by interdigitated fingers and cavities. The cavity and the interdigitated patterns can be etched either together or separately into either wafer. A top wafer has a cavity formed therein. When the top device and bottom wafers are bonded together, the venting path is sealed by dipping the device in a sealing liquid. The serpentine path prevents the sealing liquid from reaching the cavity.

Accelerometers are often packaged by bonding silicon wafers together wherein a first wafer contains a thin membrane supporting a proof mass and two capping wafers, one on top and one at the bottom which have cavities formed therein to accommodate and restrict movement of the proof mass and provide damping during operation of the accelerometer. The bottom wafer also has holes etched through the wafer or channels formed therein extending from opposed sides of the wafer and communicating with the cavity. After the first and the bottom wafer have been bonded together, plasma etching is utilized for freeing and suspending the proof mass. During the etching step, if there were no vent path between bonded wafers the thin membrane ruptures due to the presence of gases trapped during the bonding process. With a vent path, the gases are vented through the channels or through the holes and out of the wafers. The channels must thereafter be sealed to avoid contaminants getting into the cavity. Some prior sealing method may result in the sealing material entering the cavity and obstructing the movement of the proof mass. Thus, there has been a need for a method of making and reliably sealing an accelerometer so that the sealing material does not obstruct the movement of the proof mass.

Method of making and sealing a semiconductor device having an air path therethrough


A satellite antenna for transmitting and receiving an electromagnetic signal has at least one parabolic reflector, a source arm, and a high-power amplifier, in which antenna the high-power amplifier includes a traveling wave tube on the source arm and a high-voltage power supply off the source arm and adapted to supply power to the tube. A satellite mobile telecommunications station includes such a satellite antenna and a storage structure into which the antenna is folded and in which the high-voltage power supply sits.

1. Field of the Invention
The invention relates to the field of satellite transmission antennas, possibly provided with receiving capacity. Such antennas are used in satellite broadcasting systems and they comprise a primary reflector and a source arm generally both connected to a support. The source arm may also be equipped with a secondary reflector.
The invention also relates to a satellite mobile telecommunications station. Satellite mobile telecommunications stations suitable for remote news gathering have recently become available, either transported in flight cases (Swe-Dish Fly-Away terminals, for example) or mounted on a vehicle (Swe-Dish Drive-Away terminals, for example). Such stations also have receiving capacities providing a bidirectional link.
2. Description of the Related Art
The uplink connection from a sender station to the satellite requires a high radiated power level in order for the signal rebroadcast by the satellite to be received and used correctly. To satisfy the required transmission power, in particular under extreme conditions (edge of satellite coverage, poor propagation channel), the sender station transmission system is provided with high-power amplifiers (HPA). Note that receive-only satellite antennas do not suffer from this power problem.
In satellite mobile telecommunications stations, these HPAs are in the form of a single unit combining one or more amplifier components (called active components, for example power transistors or traveling wave tubes (TWT)) and an appropriate power supply to provide the necessary and appropriate electrical power to the active components. These components are bulky and heavy if a power of tens or hundreds of watts is required, the resulting HPA weighing more than ten kilograms. This weight imposes high structural stresses on the elements supporting these components.
The invention also relates to the use of high-power amplifiers (HPA) based on traveling wave tubes (TWT) with a transmission power of at least 100 watts (W). A TWT-based HPA consists of a TWT subsystem and a high-voltage power supply subsystem producing voltages of several kilovolts. Generally designed as a one-piece unit, a TWT-based HPA incorporates a switch-mode power supply unit accepting direct current (DC) voltages (generally in the range 12 volts (V) to 48 V) or alternating current (AC) voltages (generally in the range 90 V to 265 V at 50 hertz (Hz) to 60 Hz) and supplying the high voltage necessary for the TWT to operate correctly.
It is known in the art to use fixed satellite antennas in which the HPAs are installed on the source arm of the antenna. The source arm is then sized appropriately to ensure the stiffness of the assembly and to maintain the centering of the secondary reflector or horn, such sizing sometimes being associated with the use of retaining rods or cables that relieve the source arm of the forces that are applied to it. These satellite antennas quickly become bulky and too heavy for mobile applications, in particular to conform to transportation standards such as those of the International Air Transport Association (IATA).

Satellite transmission antenna and satellite-based mobile telecommunication station


Mapped data of line pressure set to any of high pressure/low pressure regions on the basis of an engine load are stored in a storage section. A determining section 103 determines, on the basis of temperature of the hydraulic oil detected by an ATF temperature sensor 18, whether the mapped data the low pressure region is shifted in an enlarged direction. A state determining section 104 determines whether a throttle valve opening degree TH of the vehicle is totally closed or whether the line pressure is currently set to low line pressure. When the low pressure region is shifted in the enlarged direction and the throttle valve opening degree TH is totally closed or the line pressure is currently set to the low line pressure, a region changing section enlarges the low pressure region of the mapped data stored in the storage section.

Heretofore, in order to heighten fuel economy (gasoline mileage) of a vehicle provided with an automatic transmission, it is known a line pressure control device for an automatic transmission capable of switching line pressure, which is established in a hydraulic control device for the automatic transmission, between two steps including low line pressure and high line pressure (for example, see Japanese Examined Patent Application Publication No. 6-15900 (hereinafter, referred to as "Patent Literature 1") and Japanese Patent Application Publication No. 2002-89680 (hereinafter, referred to as "Patent Literature 2")).
In the line pressure control device for the automatic transmission disclosed in Patent Literature 1, line pressure during shifting of gears is controlled in accordance with temperature of hydraulic oil, detected by an oil temperature sensor, for the automatic transmission. More specifically, it is first determined whether line pressure required during shifting of gears is in a low temperature region, a high temperature region or a shifting region between the low temperature region and high temperature region. Then, in the case where the line pressure required during shifting of gears is particularly in the shifting region, it is processed so that the line pressure to be controlled is caused to change gradually (or linearly) between a line pressure value for low temperature and a line pressure value for high temperature. Since this line pressure control device is configured in this manner, the line pressure is changed gradually. This makes it possible to achieve an effect that gear shift shock can be reduced by controlling line pressure without occurrence of a sudden change in the line pressure.
Further, in the line pressure control device for the automatic transmission disclosed in Patent Literature 2, line pressure is controlled so that, when a throttle valve opening degree is lowered in a stepwise manner, it is determined that line pressure is switched from high pressure to low pressure and start of this switching is delayed by a predetermined period of time since the determination has been made. This line pressure control device is configured in this manner, whereby it is possible to prevent a frictional engagement element from slipping due to a transiently changing state of torque when engine torque is reduced. For that reason, effects that it is possible to avoid gear shift shock and to prevent duration of life of a friction member of the frictional engagement element from being lowered are achieved.
Moreover, in the control of the line pressure, for example, as shown in FIG. 4, it is known that a low line pressure region and a high line pressure region are classified using mapped data on the basis of a throttle valve opening degree of a vehicle (longitudinal axis, a ratio when an effective opening degree of a throttle is divided into eight) and vehicle speed (horizontal axis). In the case of using such mapped data, the low line pressure region is set so that a torque capacity of a clutch (frictional engagement element) does not fall below engine torque at an arbitrary throttle valve opening degree and vehicle speed.

Line pressure control device for automatic transmission


A braking system for a pair of in-line roller skates has a single hand-operated hydraulic actuator which is coupled through a Y coupling to a hydraulic brake assembly on each of the skates for applying braking force simultaneously to opposite sides of a roller on each of the skates. Each hydraulic brake assembly includes a rod extending longitudinally above the rollers to which is connected at least one resilient expander bow, each end of which contacts an engagement caliper. Two engagement calipers are hingedly mounted on the skate housing to apply frictional pressure simultaneously to generally opposite sides of each of the rollers on each of the skates.

The following invention relates to a braking system for roller skates and in particular to a hydraulic braking system for use with roller skates of the in-line variety.
In recent years in-line roller skates have achieved great popularity. Such skates are characterized by a plurality of rollers mounted at the bottom of a shoe or boot where the rollers are situated one behind the other along the directional line of travel of the skate. Thus, the rollers appear to simulate the blade of an ice skate. Such skates are marketed under the brand name ROLLERBLADE.TM..
A problem common to all types of roller skates, including in-line roller skates and skateboards, is the difficulty in slowing down. Thus, various braking systems have been proposed for roller skates and skateboards but none is entirely satisfactory. Conventional braking systems for skateboards which use a foot actuated brake that applies a frictional member against a roller are shown in Waddel U.S. Pat. No. 3,385,608, Sakwa U.S. Pat. No. 3,288,251, and Maurer U.S. Pat. No. 4,003,582. The aforementioned systems use some type of leveraged brake pad bearing directly against a roller or wheel and controlled through a foot actuated mechanical link. While such systems may be practical for skateboards where the user has the ability to shift foot position from one point to another on the skateboard, such a system is not practical for roller skates where the user's feet are encased in special boots.
A hand actuated hydraulic system for a skateboard is proposed in Dungan U.S. Pat. No. 4,295,547. The Dungan system, however, is uniquely adapted for use on skateboards, with side-by-side roller pairs and in order to work properly, requires a special outer stationary brake assist.
What is still needed is a practical hydraulic braking system for use with in-line roller skates.

Hydraulic braking system for in-line roller skates


Articles are provided that include an optical film and an optically clear pressure sensitive adhesive layer on at least one outer surface of the optical film. Additionally, articles are provided that include a pressure sensitive adhesive layer that resists bubble formation when adhered to an outgassing substrate. The pressure sensitive adhesive layer in the various articles contain a (meth)acrylate block copolymer.

Pressure sensitive adhesives have significant commercial applications. While a variety of pressure sensitive adhesive compositions are known, not all such compositions are suitable for use in optical applications where optical clarity is desired. In such applications, it is often desirable that the pressure sensitive adhesive remains optically clear during the manufacture and lifetime of the optical component or product.
The stability, clarity, bond strength, or a combination thereof of some known pressure sensitive adhesives can be adversely affected when used in combination with some optical films or other substrates. For example, substrates that contain polycarbonates or poly(methyl methacrylates) are known to outgas (i.e., release a gaseous material) under certain environmental conditions (e.g., elevated temperature or humidity) resulting in the formation of bubbles in adjacent layers such as an adhesive layer. The bubbles can result in a weakening of the adhesive bond between the outgassing substrate and another layer to which it is laminated. Delamination and bubbling in the adhesive layer of an optical component or product is usually undesirable. Even in non-optical applications, bubbling and delamination in the adhesive layer can be undesirable.

(Meth)acrylate block copolymer pressure sensitive adhesives


A system and method for providing a scalable spoken dialog system are disclosed. The method comprises receiving information which may be internal to the system or external to the system and dynamically modifying at least one module within a spoken dialog system according to the received information. The modules may be one or more of an automatic speech recognition, natural language understanding, dialog management and text-to-speech module or engine. Dynamically modifying the module may improve hardware performance or improve a specific caller's speech processing accuracy, for example. The modification of the modules or hardware may also be based on an application or a task, or based on a current portion of a dialog.

1. Field of the Invention
The present invention relates to spoken dialog systems and more specifically to a system and method for dynamically adjusting components within a spoken dialog system according to network loads and other requirements to reduce hardware requirements.
2. Introduction
Any spoken dialog system, for example, to automate a call center, must operate on one or more compute devices such as a server. When a company desires to implement a spoken dialog system, one component of planning and implementing the system is a prediction of the number of calls that the system should be able to manage simultaneously. As the number of predicted calls increases, then more computer resources must be purchased and deployed to manage the load. The hardware costs of implementing such as system may make implementation of a spoken dialog system unaffordable.
Hardware costs in the initial acquisition and maintenance of a dialog system are an important consideration when planning call center automation with voice-enabled services. One common practice is to plan for assumed peak loads in terms of simultaneous users. Each user or caller into the system may be assigned a port. Hardware planning based on being able to manage peak loads is not cost efficient given that the average load might be significantly lower than the expected peak load.
What is needed in the art is a method for improving the efficiency of the use of computer resources when implementing a spoken dialog system.

System and method of dynamically modifying a spoken dialog system to reduce hardware requirements


A Fatigue Performance Test induces a traffic analogous, 60 cycle, stress-strain environment into a road pavement cross section through a rolling cyclic fatigue platform. Data from the encounter dynamic reveals where strain build-up is occurring well before external, visually detectable evidence of fatigue failure is present in the pavement sample from cracks or permanent deformation. Responsive tuning of the embedded, sensor firmware establishes a baseline status for the sample whereupon incoming data gathered during the stress-strain encounter dynamic reveals details of fatigue build-up.

Repair and maintenance of the civil infrastructure, including roads and highways of the United States present great technical and financial challenges. The American Association of State Highway Transportation Officials (AASHTO) issued a bottom line report in 2010 stating that $160 billion a year must be spent to maintain infrastructure; however, only about $80 billion is being spent. The result is a rapidly failing infrastructure. New methods of maintaining existing roads and new methods of constructing roads that would extend the useful life for the same budget dollar are needed to meet the challenges of addressing our failing infrastructure.
In the United States alone there are approximately 4.4 million center lane miles of asphalt concrete, with a center lane comprising a 24 foot wide pavement surface having a lane in each direction. Asphalt concrete paving surfaces are typically prepared by heating aggregate to 400° F., and applying liquid asphalt (e.g., by spraying into a pug mill or drum coating) to yield a mixture of 95% aggregate and 5% asphalt. If a temperature of approximately 350° F. is maintained for the mixture, it is considered hot mix asphalt and does not stick to itself as long as the temperature is maintained. The hot mix asphalt is typically placed in a transfer truck, which hauls it to the job site, where it is placed on either a gravel road base or onto an old road surface that has been previously primed. A paving apparatus receives the hot mix asphalt from the transfer truck and spreads it out uniformly across the base surface, and as the material progressively cools below 250° F. degrees it is compacted with a roller. The hot mix asphalt is rolled to a uniform density, and after approximately one to three days of cooling and aging the surface can be opened to traffic.
After such asphalt pavement has been in place for several years, the pavement progressively ages. Water works its way into the pavement. It begins to lose its integrity on the surface, causing aggregate at the surface of the pavement to be lost. The pavement surface roughens as aggregate is lost, and cracks begin to form. Conventional pavement repair techniques at this stage in the deterioration process include: pouring hot rubber asphalt into the cracks, using cold patch (a polymer-modified cold mix asphalt that can be applied to a damaged road surface, e.g., placed in a pothole, under ambient temperature conditions using hand tools). Another technique for repairing pavement exhibiting minimal damage involves application of a liquid asphalt emulsion to the pavement surface so as to provide a degree of waterproofing to slow the aging process, or, for surfaces exhibiting more deterioration, application of a thin layer of a slurry of aggregate and asphalt emulsion over the top of the pavement.
Preparing and installing hot asphalt pavement involves running aggregate through a heat tube (typically at around 400° F.) where moisture is driven off to prevent boil over when the rock contacts molten asphalt. The aggregate is added to asphalt, optionally containing a rubber polymer. The aggregate is sent through a mill having high velocity tines that rolls the aggregate through a spray of asphalt. The resulting mixture of aggregate with baked-on asphalt typically comprises 95% aggregate and 5% asphalt (optionally with rubber polymer). The mixture exits the mill at about 350° F. and is transported into waiting trucks (e.g., a belly dump truck) which are driven to the job site. New pavement is laid down over an earthen base covered with gravel that has been graded and compacted. Typically, the new road is not laid in a single pass. Instead, a first 2-3 inch lift of loose hot asphalt is laid down and partially compacted, and then a second lift is laid over the first and compacted, The temperature of the asphalt concrete pavement at this stage is typically about 140° F. Additional lifts can be added as desired, e.g., to a depth of approximately 12 inches, depending upon the expected usage conditions for the road (heavy or light transportation, the velocity of traffic, desired lifetime). Primer or additional material is typically not put between layers of lift in new construction, as the fresh pavement exhibits good adherence to itself in new construction. New construction design typically never requires any primer or additional material between the subsequent lifts.
After approximately fifteen years of exposure to the elements, it becomes cost prohibitive to attempt to maintain asphalt pavement via conventional cold patching, waterproofing, and slurry techniques. The conventional approach at this stage in the deterioration of the pavement typically involves priming the damages surface and applying a layer of hot mix asphalt. For pavement too deteriorated for application priming and application of a layer of hot mix asphalt, a cold-in-place recycling process can be employed. In cold-in-place recycling, typically the topmost 2 to 5 inches of the damaged road surface are pulverized down to a specific aggregate size and mixed with an asphalt emulsion, and then re-installed to pave the same road from which the old paving material has been removed.
Existing pavement (asphalt or concrete) is typically repaired by use of an overlay, e.g., a mixture of aggregate and asphalt such as described above for new road construction. In the case of repaving over the top of rigid concrete, some type of primer is typically applied, e.g., as a spray resulting in application of approximately 10 gallons of primer per 1,000 square feet of pavement. The primer can be an asphalt emulsion that provides a tacky surface for the new overlay. A single layer of overlay can be applied, or multiple layers, typically two or more.
Cracks and stresses in a repaired underlying road bed will quickly imprint themselves on new overlays of paving material, due to the malleability of the new asphalt under rolling loads. As the underlying road bed undergoes expansion and contraction under ambient condition, cracks can be telegraphed up through as much as three inches of overlying asphalt. A conventional method for achieving some resistance to the telegraphing of old defects in the underlying road bed is to put down a hot tack coat of asphalt, lay a polypropylene mat (similar in appearance to spun-bond polypropylene, typically ¼-½ inches in thickness, available as Petromat® from Nilex, Inc. of Centennial, Colo.) over the hot tack coat of asphalt, followed by a layer of new hot asphalt concrete which is then compacted over the existing surface. This will inhibit the rate of telegraphing of cracks to a limited extent, such that instead of taking place from 6 months to 2 years after repair, the cracks do not telegraph for from to 1 year to 3 years after repair. This telegraphing phenomenon by the defects in an existing aged roadbed manifest surface defects in a new pavement overlay about three times sooner than is common to a fresh asphalt concrete pavement placed on a compacted earthen and gravel base; as is the practice in new construction.
Deterioration mechanisms of new highways have been investigated over a 20 year life cycle. Overlays are typically applied between the twelfth and fifteenth year. Typically, no significant deterioration is observed over the first five years of a well-built highway. Within the first five years, cracks or potholes typically do not appear unless there is acute damage to the pavement, or loose material underneath the pavement. After the first five years, physical symptoms of deterioration are observed, including lateral and longitudinal cracks due to shrinkage of the pavement mass through the loss of binder and embrittlement of the asphalt. Cracks ultimately result in creation of a pothole. Ravelling is a mechanism wherein the effects of exposure to water and sun break down the adhesion between the rock on the top surface of the pavement and the underlying aggregate, such that small and then larger rock is released from the pavement. A stress fracture is where the pavement, for one reason or another, may not have been thick enough to withstand exposure to an extremely heavy load, moisture, or poor compaction underneath. When combined with shrinkage of the asphalt itself as it goes through heating and cooling cycles, and application of oxidative stress, stress fractures can also result. Stress fractures are characterized by extending in different directions (unlike the lateral or longitudinal cracking as described above).
The macro-texture of a pavement refers to the visible roughness of the pavement surface as a whole. The primary function of the macro-texture is to help maintain adequate skid resistance to vehicles travelling at high speeds. It also provides paths for water to escape which helps to prevent wheels of motor vehicles from hydroplaning. This optionally may be accomplished through cutting or forming grooves in existing or new pavements. Micro-textures refer to the roughness of the surface of the individual stones within the asphalt concrete pavement. It is the fine texture that occurs on chippings and other exposed parts of the surfacing. For concrete pavement this is usually the sand and fine aggregates present at the surface layer and for asphalt it is usually associated with the type of aggregates used. Micro-texture creates frictional properties for vehicles travelling at low speeds. The wet skid resistant nature of a road is dependent on the interaction of the tire and the combined macro-texture and micro-texture of the road surface.
Conventional repair of shallow surface fissures and raveling uses various methods. Re-saturants are materials that soften old asphalt. They are typically mixed with an emulsion and sprayed onto the surface of the old pavement. The material penetrates into the uppermost 20 or 30 mils of the pavement and softens the asphalt, imparting flexibility. Thermally fluidized hot asphalt can also be sprayed directly onto the surface, which hardens and provides waterproofing. A fog seal is typically sprayed on the surface, and can be provided with a sand blotter to improve the friction coefficient. In a chip seal, a rubberized emulsion can also be sprayed onto the aged pavement, and then stone is broadcast into the rubberized emulsion which then hardens, bonding the stone. Slurry seal employs a cold aggregate/asphalt mixture prepared in a pug mill and placed on the aged pavement surface, but is applied in a much thinner layer, e.g., 0.25-0.75 inches. Once the pavement surface is repaired, any safety markings can be repainted.
The Federal Highway Administration, through the National Academy of Sciences, has done research into pavement durability. A 20-year long-term paving program (LTPP) was initiated in 1984 in an attempt to understand the failure mechanisms of paving. At the end of the 20-year program and after five years of data analysis, better ways have been developed for measuring pavement failure, the most noteworthy being the Strategic Highway Research Program (SHRP) grading system. The SHRP system can be used to determine the physical qualities of an asphalt product and its potential for long-term service. Subsequently, mechanical testing was developed to determine when the ductility and flexibility of the pavement was diminished, which correlates with end of its useful life as well as the chemical changes in the asphalt itself over time were studied. The presence of carboxylates and sulfoxides that are generated over the life of the pavement cross-section was discovered to be associated with asphalt embrittlement. This discovery now enables prediction of useful life. Accelerated weathering chambers also can be employed to determine the rate of formation of these telltale carboxylates and sulfoxides in a new binder system, binder/aggregate combination, or other paving material thereby predicting an expected useful life. In terms of the chemistry of deterioration, study data indicate that asphalt pavement fails because it becomes brittle. Embrittlement leads to mass loss, which leads to shrinkage, which produces cracks. Cracks become potholes, the pavement stops flexing, and aggregate becomes dislodged.
Deterioration of asphalt binder is generally associated with asphalt beyond the first 100 microns covering the rock surface. An asphalt layer on aggregate at depths within 100 microns of the asphalt/rock interface was found by the 20 year LTDP study to have not experienced the presence of sulfoxides and carboxylates that are associated with embrittlement. Therefore the properties of that asphalt were similar to those of virgin asphalt initially placed on the rock. While not wishing to be bound by theory, it is believed that the tight bond of the asphalt within the first 100 microns of the rock surface exhibited a high degree of intimacy. This intimacy inhibits the movement of scavenging oxidizers into the asphalt structure, thereby minimizing deterioration. Accordingly, it is believed that in an aged paving material averaging 95% aggregate and 5% asphalt, a 100 micron layer of good asphalt surrounds each aggregate particle, with embrittled asphalt in between. It is this "embrittlement zone" where ductility is lost and failure takes place. Air gaps in the cross-section of the pavement can allow water and air to gain access to the asphalt rock interface. Over a period of time, the asphalt goes from being flexible to becoming brittle. The chemistries associated with the embrittlement are related to the formation of sulfoxide or hydroxyl groups, and typically there is a loss of a hydrogen atom on the carbon (oxidation) which causes the key molecular structures to become shorter, thereby less flexible. Once that happens, the pavement becomes inflexible, cracks open up, the pavement loses mass, and rolling loads break up the pavement, causing cracking, potholes, running, raveling, and block cracking, each resulting in a loss of the pavement integrity.
The conventional methods for repair of surface defects inclusive of rejuvenators and fog seals typically do not exhibit a desirable lifespan. The most durable conventional repair, a slurry seal or a chip seal, may last only 7 or 8 years. An analysis of pavement failure mechanisms provides an explanation for the poor lifespan observed for new asphalt pavement and subsequent repairs. The primary factor is that the repairs do not remedy the underlying embrittlement of the asphalt binder deep within the pavement cross-section. The embrittlement results from the scissioning of the polymer chains present in the asphalt under the influence of free radicals associated principally with water. Water penetrates the pavement, and sunlight and traffic over the pavement surface provides energy for reaction with oxygen and other pavement components, yielding sulfoxide and carboxylase reaction products and reduced polymer chain length through reaction with the resulting free radicals. Loss of polymeric molecular weight impacts the ability of the pavement to stretch and flex. A secondary failure mechanism is loss of rock itself due to hydrolytic attack of the asphalt-rock interface. Rocks typically comprise metal oxides (e.g., calcium oxide, silicon dioxide, lithium oxide, potassium oxide, sodium oxide). Hydroxide groups can form upon exposure to water, resulting in oxidative reactions that impair the adhesion of asphalt to the rock surface, a process referred to as stripping.
Loss of waterproofing typically is a top down mechanism. The asphalt breaks down from exposure to heavy load and the sun, causing water to penetrate between the asphalt and rock. The asphalt can lose its hydrophobicity, with paraffinic components being broken down into more hydrophilic components, which in turn accelerate the process of water adsorption. Ravelling occurs, resulting in a loss of macrotexture. Ultimately, the microtexture of the surface is lost due to abrasion of tires across the surface rubbing off the asphalt and polishing the rock surface, whereby the coefficient of friction drops to unacceptable levels. Typically, a brand new pavement will have a coefficient of friction of between 0.6 and 0.7. Over time, loss of microtexture and ultimately macrotexture results in the coefficient of friction dropping to below about 0.35, at which point the pavement becomes inherently unsafe in terms of steer resistance in the presence of water. Even if a pavement surface doesn't have raveling or cracking, it can still be unsafe to drive on due to loss of adequate surface texture. Microtexture and macrotexture mechanisms function at different speeds. Typically, up to about 45 mph the microtexture controls stopping distance. Between 45 and 50 the macrotexture begins to have a greater effect on stopping distance, and above 50 mph the macrotexture is the principal determining factor in stopping distance.
A method of repairing pavement utilizing electromagnetic radiation (energy) of wavelengths, e.g., of from 1-5 mm (terahertz range) is disclosed in U.S. Pat. Nos. 8,992,118, 9,169,606, 9,074,328, 9,347,187, 9,481,967, 9,127,413, 9,057,163, 9,551,114, and U.S. Pat. No. 9,551,117, the contents of which are hereby incorporated by reference herein in their entirety.
For example, in one method for repairing an asphalt pavement, a surface of a damaged asphalt pavement comprising aged asphalt is prepared by filling in deviations from a uniform surface plane with dry aggregate and compacting the dry aggregate; a reactive asphalt emulsion is applied to the prepared surface, whereby the reactive emulsion penetrates into cracks and crevices in the damaged asphalt pavement and into areas filled with the dry aggregate, wherein the reactive asphalt emulsion comprises butyl rubber, a diene modified asphalt, and an environmentally hardened bioresin, and wherein the reactive asphalt emulsion contains no perfluorocarbons or less than 1% perfluorocarbons as volatile components; and an emitter is passed over the prepared pavement, wherein the emitter generates electromagnetic radiation having a wavelength of from 2-5 mm the radiation penetrating into the pavement to a depth of at least 2 inches, wherein a temperature differential throughout a top two inches of pavement is 100° F. or less, wherein a highest temperature in the top two inches of pavement does not exceed 300° F., and wherein a minimum temperature in the top two inches of pavement is at least 200° F., whereby voids and interstices in the damaged pavement are disturbed without dehydrogenation of the asphalt, and whereby oligomers present in the aged asphalt are linked together into longer polymer chains, whereby ductility of the aged asphalt is improved. Useful in such methods is an emitter system comprising: a structural frame; and one or more emitter panels situated within the structural frame and pointing downward, wherein the metal frame is insulated with a layer of a high-density ceramic, wherein each emitter panel comprises a serpentine wire positioned between the high-density ceramic and a sheet of a micaceous material exhibiting biaxial birefringence, wherein each emitter panels is configured such that, in use, energy generated by each emitter panel passes through the sheet of micaceous material and impinges on an asphalt pavement, wherein each emitter panel is configured to produce energy with a power density of from 3 to 15 W/in2.
In a similar method utilizing terahertz energy, a surface of a damaged asphalt pavement comprising aged asphalt is prepared by filling in deviations from a uniform surface plane with dry aggregate and compacting the dry aggregate; applying a reactive asphalt emulsion to the prepared surface, whereby the reactive emulsion penetrates into cracks and crevices in the damaged asphalt pavement and into areas filled with the dry aggregate, wherein the reactive asphalt emulsion comprises butyl rubber, a diene modified asphalt, and an environmentally hardened bioresin, and wherein the reactive asphalt emulsion contains no perfluorocarbons or less than 1% perfluorocarbons as volatile components; and an emitter is passed over the prepared pavement, wherein the emitter generates electromagnetic radiation having a wavelength of from about 2 microns to 1 millimeter, the radiation penetrating into the pavement to a depth of at least 2 inches, wherein a temperature differential throughout a top two inches of pavement is 100° F. or less, wherein a highest temperature in the top two inches of pavement does not exceed 300° F., and wherein a minimum temperature in the top two inches of pavement is at least 200° F., whereby voids and interstices in the damaged pavement are disturbed without dehydrogenation of the asphalt, and whereby oligomers present in the aged asphalt are linked together into longer polymer chains, whereby ductility of the aged asphalt is improved.
In a similar method utilizing terahertz radiation, an emitter is passed over an aged asphalt pavement, wherein the emitter generates electromagnetic radiation having a wavelength of from 20 microns to 1 mm or from 1 mm to 5 mm, the radiation penetrating into the pavement to a depth of at least 2 inches, wherein a temperature differential throughout a top two inches of pavement is 100° F. or less, wherein a highest temperature in the top two inches of pavement does not exceed 300° F., and wherein a minimum temperature in the top two inches of pavement is at least 200° F., whereby voids and interstices in the damaged pavement are disturbed without dehydrogenation of the asphalt, and whereby oligomers present in the aged asphalt are linked together into longer polymer chains, whereby ductility of the asphalt is improved; allowing the pavement to cool to below 190° F.; and a compacting roller is applied to the asphalt pavement to minimize voids and surface irregularities, wherein the asphalt is at a temperature no lower than 150° F.
An emitter unit suitable for use in generating terahertz radiation for repairing asphalt pavement can comprise at least one emitter panel, the emitter panel comprising: a frame having a high-density ceramic liner; a sheet of a micaceous material exhibiting biaxial birefringence; and a serpentine wire positioned between the high-density ceramic liner and the sheet of the micaceous material, wherein the emitter panel is configured to emit electromagnetic radiation at a wavelength of from about 2 microns to 1 millimeter and a power density of from 0.47 to 2.33 W/cm2 or from 133 to 664 (fflbf/min)/in2.
Accordingly, there are a variety of mechanisms by which asphalt pavement can be damaged, and there are a variety of methods available for repairing damaged pavement, some of them more successful than others in preserving and extending the useful life of the pavement. It is known that for pavement that is timely and properly maintained, and repaired in the early stages of deterioration, the typical useful life can be extended out to 19 or 20 years. However, in the current economic environment, the conventional approach to road maintenance is to fix the most often travelled pavement first, and then repair, as budgets allow, progressively the better pavement, such that a useful life closer to 12 or 13 years is typically observed.

Rolling cyclic fatigue test platform for determining asphalt ductility