A wastewater treatment apparatus having a fixed film media apparatus having insertable high surface area polymer cartridges providing growth surfaces for autotrophic or heterotrophic bacteria and a protective shielding surface which isolates the biofilm from turbulence within the wastewater treatment system. A method of placement of said media apparatus within the aeration and/or clarifier section of the wastewater treatment apparatus.

The purpose of wastewater treatment is generally to remove from the wastewater enough solids to permit the remainder to be discharged to a receiving water source (river, holding pond, urban drainage etc.) without interfering with its proper use and often, within analytical guidelines set by a controlling agency. Wastewater may be treated using physical, chemical or biological processes or a combination of these. The preliminary treatment regimen in most wastewater treatment processes involves a screening procedure to remove coarse materials (paper, sticks, cans etc.) followed by the removal of heavy inorganic particles (sand, pebbles, etc.) by a settlement process.
One common chemical treatment involves the use of ozone. Consider background patents which illustrate, for example, the large number of water purification ozonization techniques such as in U.S. Pat. No. 5,178,755, issued to LaCrosse, that discloses a method for treating wastewater, that has been enhanced by treatment with ultra-violet light and with ozone. In this system, a large amount of ozone is generated and inserted at several points in the effluent flow, including insertion in each of the three clarifiers. This system utilizes large quantities of ozone at a relatively high cost and low efficiency. Furthermore, in this system; water is continually re-circulated based upon a timer and the system does not automatically respond to changes in the influent quality or discharge water from the system based upon water quality parameters.
Another example, U.S. Pat. No. 4,798,669, issued to Bachhofer, et al., discloses an apparatus for mixing the ozone with water which is then trickled over packing material to entrain the ozone within the water being treated. The water is re-circulated through a return branch and mixes with the incoming contaminant water before it enters the treatment system. The re-circulation step is not automatic or self-adjusting based upon water quality parameters. Further ozone contact with the contaminants, after filtration of the effluent, is made by inserting recaptured gas into the effluent stream prior to the effluent being treated by a packed column which trickles the effluent over a packing material. As agitation reduces the capability of water to retain ozone, trickling over packing material may be detrimental to the efficient retention of ozone within the effluent for effective contact with contaminants. See also, U.S. Pat. No. 5,466,374 to Bachhofer et al., U.S. Pat. No. 5,207,993 to Burris, U.S. Pat. No. 3,945,918, issued to Kirk; and U.S. Pat. No. 5,273,664, issued to Schulz for additional configurations used for ozone treatment.
Probably the most commonly used chemical process is chlorine treatment. Like ozone, chlorine is a strong oxidizing agent used to kill bacteria and to slow down the decomposition of the wastewater. Even in systems involving biological treatment of wastewater, chlorine is often added in a penultimate step prior to discharge in order to remove specific organisms which are responsible for infectious diseases including, for example, Shigella Dysenteriae, Salmonella, Escherichia Coli, Klebsiella Pneumoniae, Vibrio Cholerae, Giardia spp., Cryptosporidium spp. and Entamoeba Histolytica. Residual chlorine is neutralized with sulfur dioxide before final discharge.
Nitrogen removal from wastewater can be accomplished through various chemical, physical and biological processes. In contrast to chemical treatments which tend to destroy microorganisms, biological treatment methods use microorganisms, mostly bacteria, in the biological decomposition of wastewaters to stable end products. More microorganisms are produced, and a portion of the waste is converted into carbon dioxide, water and other end products of microbial metabolism.
Nitrogen and nitrogenous compounds are often the focal point for biological wastewater treatment. Biological processes are the most common methods encountered in wastewater treatment due to the low capital costs, low operating costs, and high rates of nitrogen removal. Although nitrogen can be found in wastewater as nitrogenous organic compounds such as proteins and amino acids (Metcalf et al 2003), nitrogen is most commonly found in the forms of ammonia (NH3), ammonium (NH4+), nitrite (NO2−), and nitrate (NO3−). Biological nitrogen removal is achieved by two processes, nitrification and denitrification. The first step in nitrogen removal is biological nitrification, which is the oxidation of ammonium (NH4+) to nitrite (NO2−) and then nitrite is further oxidized to nitrate (NO3−). The second step in nitrogen removal is biological denitrification. Denitrification is a multi-step process that reduces nitrate to nitrogen gas (N2). Nitrogen gas is then released into the atmosphere and thus completes the biological nitrogen removal process from wastewater.
Soluble organic nitrogenous compounds are quickly converted to ammonium through a biological-mediated process. Ammonium is the chemical of interest when nitrogen removal is required in a treatment process. There are many different forms of human activity that generate wastewater with large quantities of ammonium: petrochemical, pharmaceutical, fertilizer and food industries and leachates produced by urban solid waste disposal sites and waste from their agricultural equivalents (pig farms etc.). (Carrera, et al 2003). When present in water, ammonia will dissociate into both ammonium ions (NH4+) and un-ionized ammonia (NH3).NH3+H2O←−→NH4++OH−  Equation 1
The concentration of un-ionized ammonia increase with increasing pH and increasing temperature (Viessman, et al., 2005). Wastewater is slightly alkaline with a pH in the range of 7.0-8.0; therefore ammonium is the dominant species in wastewater.
To remove potentially toxic nitrogenous compounds from wastewater, biological nutrient removal (BNR) is the most common method utilized. BNR for nitrogen is a two step activated sludge process that converts ammonium to nitrogen gas through nitrification and denitrification. Nitrification is the biological oxidation of ammonia to nitrate. It is an aerobic, two step process which proceeds as a result of metabolism by autotrophic, nitrogen-oxidative bacteria species known as Nitrosomas and Nitrobacter. Autotrophic bacteria require oxygen both for respiration and chemical oxidation purposes. As their sources of energy, they utilize inorganic compounds and require either carbon dioxide, bicarbonate or carbonate for their carbon source used in cell synthesis.
Nitrification can be summarized by the following three equations:NH4++1.5O2→NO2−+2H++H2O+biomass energy  Equation 2NO2−+0.5O2→NO3−+biomass energy  Equation 3NH4++2.0O2→NO3−+2H++H2O+biomass energy  Equation 4
The ammonia oxidation shown in Equation 2 is accomplished by the autotroph Nitrosomas. Ammonia serves as an electron donor while molecular oxygen serves as the electron acceptor. Ammonia is oxidized to nitrite (NO2—) in a step-wise process via hydroxylamine (NH2OH) through the use of the enzyme ammonia monoxygenase as seen in Equation 5. Equation 6 illustrates the enzyme hydroxylamine oxidoreductase converting hydroxylamine to nitrite.NH3+O2+2H+→NH2OH+H2O  Equation 5NH2OH+H2O→NO2−+5H+  Equation 6In Equation 3, nitrite is further oxidized to nitrate. This process is carried out by the autotrophic nitrite oxidizing bacteria known as Nitrobacter. Nitrobacter can grow heterotrophically in the presence of acetate, formate or pyruvate and will utilize the enzyme nitrite oxidoreductase for nitrite reduction as seen in Equation 7. (Bitton, 2005).NO2−+0.5O2→NO3−  Equation 7
Nitrification is an energy yielding process and the energy generated is used to assimilate elementary carbon sources like carbon dioxide, bicarbonate and carbonate to meet the carbon requirements for reproduction of the nitrifying bacteria. Being an aerobic process, the oxygen requirement is 4.6 mg O2/mg ammonia for complete oxidation to nitrate. Sufficient alkalinity is also needed as a buffering agent for the nitrous acid, HNO2 (H++NO2−) produced during the nitrification and is consumed at a rate of 15.7 kg CaCO3/kg NH3 oxidized.
Presently there exist a number of types of water purification devices designed to remove nitrogen from wastewater through biological processes. A traditional means involves treating the wastewater with activated sludge. Activated sludge is defined as sewage mixed with bacteria and protozoa that thrive in and multiply in it and lead to its oxidation. Activation reduces the organic pollution that raw sewage otherwise would impose on a body of water to which it is discharged.
Biological nitrogen removal is achieved through the use of either suspended growth treatment or attached growth treatment. Suspended growth is the utilization of a suspended activated sludge containing aerobic autotrophic bacteria for nitrification in an aerated tank and facultative heterotrophic bacteria for denitrification in an anoxic setting. Attached growth is the use of similar bacteria as in a suspended growth reactor, but the bacteria forms a layer of growth, known as a biofilm or fixed film, on a specific fixed film media. Submerging attached growth media in a suspended growth aeration tank, thus combining these technologies, is commonly known as an integrated fixed film activated sludge system (IFAS).
Systems utilizing submerged growth media include floating media and fixed media. Examples of floating media include plastic balls (Stuth U.S. Pat. No. 5,609,754), polyurethane foams (Reimann et al U.S. Pat. No. 4,500,429, Fuchs U.S. Pat. No. 4,415,454 and Reimann U.S. Pat. No. 4,566,971 and polyethylene pellets (Malone U.S. Pat. No. 5,126,042).
Fixed media systems are more varied. Simple systems have been described which have plain flat surfaces. Systems which are designed for having larger exposed surface areas include packed corrugated panels (Volland U.S. Pat. No. 5,545,327, Cox U.S. Pat. No. 6,942,788) or pipes. These are generally aerated systems which use variously positioned air release mechanisms to drive and direct the flow through the media configuration. Another configuration described by Gothreaux (U.S. Pat. No. 6,207,047) involves a porous grid as a support media for bacterial growth and is purported to allow for larger volume wastewater treatment
A number of anaerobic treatment systems have been described which involve a fixed medium which forms a packed bed through which the wastewater is passed. Such systems suffer from the disadvantage of gradually reducing flow rates due to accumulation of solids within the bed. Crawford et al (U.S. Pat. No. 4,676,906 and U.S. Pat. No. 4,780,198) describe a hybrid high rate process which uses a sludge blanket with a filter bed which retains biosolids within the digestor. Aerated fluidized bed or suspended bed systems have also been described (Reimann U.S. Pat. No. 4,566,971).
In what might best be described as a moving fixed media system, U.S. Pat. No. 4,093,539 to Guarino describes a system wherein the media is comprised of a partially submerged rotating contactor located within an aeration tank. The rotation of the media is driven by a supplemental air source.
A major disadvantage encountered with each of the fixed media systems described within the prior art is the exposure of the biofilms to turbulence within the wastewater treatment apparatus. In fact, a number of these systems were designed specifically to expose the media surfaces to turbulence as demonstrated by the rotating media described by Guarino and those wherein aeration is directed over the media such as that described by Volland (U.S. Pat. No. 5,545,327), Cox (U.S. Pat. No. 6,942,788) and Reimann (U.S. Pat. No. 4,566,971). Both forced motion or the bubbling of gases are sources of extreme turbulence. Even in systems where turbulence is not designed-in, exposed media surfaces are subject to fluid motions within the tank due to the pumps used for intertank wastewater exchange. Such turbulence can adversely affect the growth and ultimate thickness of the biofilms by causing these delicate structures to slough off. This loss of biofilms through sloughing off lowers the overall efficiency of the wastewater processing apparatus and creates a further issue of removal of the resulting solids from the wastewater. Since sloughing of the biofilms from fixed film media affects the quality of the effluent, the placement of such systems is generally limited to the aeration section of the wastewater treatment apparatus (4 in FIG. 1). Placement of unprotected media within the clarifier section (6 in FIG. 1) is greatly restricted since, for effluent arising from this section, quality is paramount. In as much as the art consists of various types of fixed film media configurations, it can be appreciated that there is a continuing need for and interest in improvements to these purification systems and their configurations, and in this respect, the present invention addresses these needs and interests.


Provided are a server and a system that are capable of generating road traffic information on traffic congestion in a more appropriate manner, considering actual road traffic conditions. If a vehicle speed V falls below a first reference speed V1 and then exceeds a second reference speed V2 (>V1), then a traffic congestion situation is estimated based on an inference that the vehicle is highly likely to have escaped from traffic congestion. To estimate a traffic congestion situation, it is required that a situation in which the vehicle speed V exceeds the second reference speed V2 continue for a second specified distance or more or for a second specified time T2 or more.

There has been proposed a technical method for generating road traffic information based on probe information. According to the method, if a state in which the speed of a vehicle is equal to or lower than a predetermined value (e.g. 20 km/h) continues, then the road traffic information that includes the positions of the vehicle at the start time point and the end time point, respectively, or the distance of the section is generated (refer to Patent Literature 1).

Road traffic information server and road traffic information system


A distortion compensating device provided in a receiver for compensating distortion which is added to a signal in a transmission path. The signal is generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of a plurality of specified signal points in a signal space diagram. The device includes a signal-point-position averaging circuit for producing an average signal point for each of a plurality of distributions of received signal points in the signal space diagram. A discrimination circuit in the device discriminates the average signal point closest to a received signal point from other average signal points in the signal space diagram.

1. Field of the Invention
The present invention generally relates to a distortion compensating device, and more particularly, to a distortion compensating device in a transmitter or a receiver which can compensate for nonlinear distortion, the nonlinear distortion being caused by a digital signal being distorted in the path from modulation with a matting in the transmitter to demodulation in the receiver.
2. Description of the Related Art
In a digital multiple radio communication, linear modulation such as phase-shift-keying (PSK) modulation and quadrature-amplitude modulation (QAM) is desired to be used for an effective use of frequency. In terrestrial radio communication, a 256QAM system is currently in practical use. In digital mobile communication systems in which a nonlinear modulation is applicable for portability of radio equipment, 4PSK modulation and 16QAM are currently used. To obtain good transmission performance by using such linear modulation systems, it is necessary to produce a high-power transmission signal.
However, when the power of the transmission signal is increased in conventional multiple communication equipment using linear modulation, a nonlinear range in a transmitting-linear amplifier is used. As a result, the transmission signal is distorted and the transmission performance is degraded. Maximum transmission power is determined by a tradeoff with the distortion. Therefore, to obtain a superior transmission performance, a high-efficiency and high-power linear amplifier is required.
On the other hand, in the receiver, to improve carrier to noise ratio (C/N) performance, an RF amplifier having a large gain is commonly used in the front end. However, a high-level signal is applied to the RF amplifier, the RF amplifier is saturated and the received signal is distorted. Therefore, even though the high-level signal is received, the received signal needs to be reduced by an attenuator, etc., and, thus, the high C/N obtained with the high level signal is degraded. Such attenuation of the high-level signal is performed because sufficient transmission performance for the system can be obtained even if the high-level signal is slightly attenuated. However, in the future, for large capacity data transmission, a much better transmutation performance is desired.
At present, several methods of compensating the distortion due to the nonlinear characteristics of the transmitting amplifier are proposed. FIG. 1 shows a block diagram of an example of a transmitter having a conventional distortion compensating function. The transmitter comprises a mapping-and-waveform-shaping circuit 10, a quadrature modulator 20, a transmission stage 30, and an antenna 40. The transmitter is constructed with a quadrature modulation technique, in which a baseband digital signal is divided into an I-channel signal and a Q-channel signal, and the two signals modulate 90xc2x0-phase-shifted carrier signals to produce a modulated signal by combining the two modulated carrier signals. In the quadrature modulation technique, phase and amplitude of the baseband signal is mapped on a quadrature plane referred to a signal space diagram in which the I axis and the Q axis indicate the carrier signal.
In the mapping-and-waveform-shaping circuit 10, the baseband signals which are divided into the I-channel signal and the Q-channel signal are, respectively, converted to signals for being mapped on the signal space diagram constructed with the I axis and the Q axis, and modulating signals are produced through a roll-off filter. In the quadrature modulator 20, carrier signals Lo are respectively modulated by the I-channel and Q-channel signals, and are summed with each other to produce the modulated signal. In the transmission stage 30, the modulated signal is converted to a signal at the RF frequency, and is amplified by the transmitting amplifier to be transmitted through the antenna 40.
FIG. 2 shows a signal space diagram indicating a relationship between the baseband signal and the carrier signal in 16QAM. For example, in 16QAM, to map the I-channel and the Q-channel signals to one of 16 signal points D1 to D16 (hereinafter, referred to as specified signal points) arranged on the quadrature signal space diagram, the I-channel and Q-channel signals are respectively converted to signals, each having 4 levels. In general, by equalizing each intervals between the 4 levels, the 16 signal points are uniformly arranged on the signal space diagram.
In the receiver side, these signal points are discriminated by threshold lines (represented by dashed lines in FIG. 2) drawn among the signal points in the signal space diagram. The conventional threshold lines are drawn at the center between each two signal points taking into account noise which influences each signal point in the same manner. However, by the strong amplification in the transmission stage 30, the uniformly mapped signal points may be distorted, for example, as shown by signal points X1 to X4 in a first quadrant of FIG. 2. In a more specific case, some distorted signal points may fluctuate to another threshold area such as the signal point X3. As a result, the signal point X3 is discriminated to a wrong signal point as an error. To prevent such fault discrimination, there is a conventional mapping method in which opposite characteristics of the distortion characteristics of the amplifier in the transmission stage 30 are previously set with the mapping circuit 10. By using this method, at the output of the amplifier in the transmission stage 30, a signal point arrangement substantially similar to the specified signal point arrangement may be obtained.
FIG. 3 shows a block diagram of another example of a transmitter having a conventional distortion compensating function. The transmitter comprises a mapping-and-waveform-shaping circuit 11, a quadrature modulator 21, a transmission stage 31 and an antenna 41. Each circuit has the same function as that of the circuit in the transmitter shown in FIG. 1. In the transmitter, according to the shape of the baseband signal passed through the roll-off filter, an operational point of the transmitting amplifier in the transmission stage 31 is changed to extend the dynamic range of the transmitting amplifier. Since the carrier signal is modulated by the baseband signal passed through the roll-off filter, the level of the modulated signal is determined by the amplitude of the baseband signal from the roll-off filter. For example, the level of the modulated signal which is modulated by the baseband signal close to the origin in the signal space diagram is low, and the level of the modulated signal which is modulated by the baseband signal at the surrounding signal points is high. A level change of the modulated signal can be known before transmitting the modulated signal because the baseband signal to be transmitted is known. Therefore, by changing the operational point of the transmitting amplifier according to the level of the modulated signal, dynamic range of the amplifier may be increased.
However, the following problems occur in the above-mentioned conventional distortion compensating devices.
In the distortion-compensating device shown in FIG. 1, when the distortion characteristics due to the nonlinearity of the transmitting amplifier in the transmission stage 30 changes, the proper distortion compensation may not be performed with the previously-set opposite characteristics in the mapping-and-waveform-shaping circuit 10. The case where the distortion characteristics of the transmitting amplifier change may be due to a change of the input level applied to the transmitting amplifier, an exchange of the transmitting amplifier, and a temperature increase and aging of the transmitting amplifier. Therefore, the opposite characteristics need to be adapted to such changes. This adaption requires the hardware to be complex. More specifically, to deal with the exchange of the transmitting amplifier, the transmission stage 30 in the RF circuit and the mapping-and-waveform-shaping circuit in the baseband circuit need to be integrated. This may cause complexity of the configuration of the distortion compensating device.
In the distortion compensating device shown in FIG. 3, the waveform-shaping circuit needs to be constructed with a digital signal processing, and an amplifier whose operational point is controllable is required for the transmission stage 31. Therefore, the configuration of the distortion compensating device becomes complex.
Furthermore, in the distortion compensating devices shown in FIGS. 1 and 3, only distortion occurring in the transmitter side is compensated, the distortion occurring in the receiving amplifier in the receiver side cannot be compensated.
It is an object of this invention to provide a distortion compensating device. The distortion compensating device may compensate signal distortion which occurs in a path from modulation in a transmitter to demodulation in a receiver regardless of characteristics of the transmitting and receiving amplifiers. The distortion compensating device is easily constructed with a digital signal processing technique, and is capable of being integrated to a 1-chip IC. Further, by using the distortion compensating device, it is possible to increase transmission power in the transmitter without attenuating a receiving level in the receiver. Therefore, a high system gain in the path from the transmitter to the receiver may be achieved. This permits the disadvantages described above to be eliminated.
The object described above is achieved by a distortion compensating device in a receiver for compensating distortion which is added to a signal in a transmission path, the signal being generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of plural specified signal points in a signal space diagram, the device comprising: a signal-point-position averaging circuit for producing an average signal point for each of a plurality of distributions of received signal points in the signal space diagram; and a discrimination circuit for discriminating the average signal point closest to a received signal point from other average signal points in the signal space diagram.
According to the above distortion compensating device, from a plurality of average signal points produced by the signal-point-position averaging circuit in the receiver, the average signal point closest to the received signal point is discriminated. Therefore, when the received signal point deviates due to the nonlinear distortion of the amplifier, a fault decision for the received signal based on the conventional threshold lines may be decreased.
The object described above is also achieved by a distortion compensating device in a receiver for compensating distortion which is added to a signal in a transmission path, the signal being generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of plural specified signal points in a signal space diagram, the device comprising: a signal-point-position averaging circuit for producing an average signal point for each of a plurality of distributions of received signal points in the signal space diagram; and a discrimination circuit for defining threshold lines in a checkered pattern between the average signal points in the signal space diagram, and for discriminating a received signal point by the threshold lines.
According to the above distortion compensating device, new threshold lines are defined between the average signal points produced from the signal-point-position averaging circuit. The received signal point is discriminated according to the new threshold lines. Therefore, when the received signal point deviates due to the nonlinear distortion of the amplifier, the fault decision for the received signal based on the conventional threshold lines may be decreased.
The object described above is also achieved by a distortion compensating device in a receiver for compensating distortion which is added to a signal in a transmission path, the signal being generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of plural specified signal points in a signal space diagram, the device comprising: a signal-point-position averaging circuit for producing an average signal point for each of a plurality of distributions of received signal points in the signal space diagram; and a discrimination circuit for shifting a received signal point by a distance based on a difference between the specified signal point and the corresponding average signal point in an opposite direction of that from the specified signal point and the corresponding average signal point, and for discriminating a shifted received signal point by threshold lines defined by the specified signal points.
According to the above distortion compensating device, the received signal point is shifted by the distance based on the difference between the specified signal point and the corresponding average signal point in the opposite direction of that from the specified signal point and the corresponding average signal point, and the shifted received signal point is discriminated by the conventional threshold lines defined by the specified signal points. Therefore, by shifting the received signal point, the distortion added to the received signal may be compensated.
The object described above is also achieved by a distortion compensating device in a receiver for compensating distortion which is added to a signal in a transmission path, the signal being generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of plural specified signal points in a signal space diagram, the device comprising: an error-signal generation circuit for generating an error signal indicating a relationship between a corrected received signal point and the corresponding specified signal point in the signal space diagram; an average-error-signal calculating circuit for producing an average error signal by accumulating the latest error signal from the error-signal generation circuit for each received signal supply; a correction circuit for producing the corrected received signal by subtracting the average error signal from a received signal; and a discrimination circuit for discriminating the corrected received signal from the correction circuit.
According to the above distortion compensating device, the received signal point is corrected in the direction of the specified signal point based on an average value of the error signal indicating the relationship between the corrected received signal point and the corresponding specified signal point, and the corrected received signal point is discriminated by the conventional threshold. Therefore, by correcting the received signal point, the distortion added to the received signal may be compensated.
The object described above is also achieved by a distortion compensating device in a receiver for compensating distortion which is added to a signal in a transmission path, the signal being generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of plural specified signal points in a signal space diagram, the device comprising: a distortion-compensated signal calculating circuit for producing a distortion-compensated signal S which is calculated by an equation:
S=Vxe2x88x92xcex12V2xe2x88x92xcex13V3. . .,
where V is a received signal, and xcex1n is a given factor.
According to the above distortion compensating device, as shown in the equation, a distortion component is subtracted from the received signal, and the received signal, after the subtraction, is discriminated by the conventional threshold. Therefore, by the above calculation, the distortion added to the received signal may be compensated.
The object described above is also achieved by a distortion compensating device in a receiver for compensating distortion which is added to a signal in a transmission path, the signal bring generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of plural specified signal points in a signal space diagram, the device comprising: a discrimination circuit for discriminating a received signal according to threshold lines partitioning the signal space diagram into discrimination areas, the threshold lines being defined so that outer side discrimination areas can be wider than inner side discrimination areas.
According to the above distortion compensating device, the threshold lines partitioning the signal space diagram into the plurality of discrimination areas are defined so that the outer side discrimination areas can be wider than the inner side discrimination areas, and the received signal is discriminated by the threshold. More specifically, when the received signal level in the receiver is high, the above type threshold is selected. Therefore, when the received signal point deviates due to the nonlinear distortion of the amplifier, the fault decision for the received signal based on the conventional threshold lines may be decreased. Further, since it is possible to increase transmission power without attenuating the received signal level, this enables a system gain to increase.
The object described above is also achieved by a distortion compensating device in a transmitter for compensating distortion which is to be added to a signal in a transmission path, the signal being generated in a multi-level modulator of a transmitter in which a digital signal is mapped to one of plural specified signal points in a signal space diagram, the device comprising: a variable mapping circuit for changing a mapping pattern of the specified signal points according to a level of a received signal in a receiver.
According to the above distortion compensating device, in modulation of the transmitter, the digital signal is mapped to an outer-shifted signal point when the received signal level in the receiver is high. Therefore, when the signal is distorted by nonlinear characteristics due to the high level of the signal, even if the received signal point in the receiver is deviated by the distortion, a possibility of the fault decision may be decreased. Accordingly, since it is possible to increase transmission power without attenuating the received signal level, this enables the system gain to increase.
The above-mentioned distortion-compensating devices are respectively constructed independent of the characteristics of the transmitting amplifier and the receiving amplifier. Therefore, the device may compensate distortion added in the transmission path from the modulation in the transmitter to the demodulation in the receiver.
Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.


The present disclosure describes a sanding device that has a motor coupled to a base plate for inducing vibration in the base plate. Further, the sanding device has a face plate that is coupled to the base plate, and the face plate has a plurality of sleeves for receiving a respective plurality of columns. The columns rotate and move longitudinally within the sleeves. Further, each column moves independent of the other columns and each column have an abrasive surface on a sanding end for contacting a sanding surface.

Electric sanders, often referred to as sanding blocks or power sanders, are typically used when preparing surfaces for finishing or repairing furniture through abrasion. Typical sanders use abrasive paper, often referred to as sandpaper, to remove undesired surface material. In this regard, the typical sander couples to the sandpaper and moves the sandpaper across the surface in conjunction with a user manually moving the electric sander as well.
There a various types of electric sanders, including vibrating sanders. The vibrating sander usually comprises a flat plate to which the sandpaper is coupled via some type of latch or attachment mechanism. Once attached and the vibrating sander is operating, the vibrating sander moves the plate, thereby moving the sandpaper, in orbital motions, e.g., small circular motions, but not rotational. A user of the vibrating sander then manually moves the sander across the surface via a handle or grip, and the movement of the sandpaper via the plate coupled with movement induced by the user removes material from the surface that is being prepared.
FIG. 1 is an exemplary conventional sanding device 100 that sands even surfaces. The sanding device 100 comprises a motor housing 101 and a sandpaper plate 102. The sandpaper plate 102 is fitted with a piece of sand paper 103. The sandpaper plate 102 creates a flat surface for receiving the sand paper 103. Thus, as a user (not shown) is sanding, the sand paper 103 contacts a surface (not shown) of an object being sanded, and evenly sands the surface it contacts. If the object has an uneven surface with varying elevation anomalies, e.g., the surface has indentations, sporadically placed concavities, depressions, protrusions, bulges, bumps convexities, or adjacent differences in elevation, the sand paper 103 sands only the surface it contacts, regardless of the depth or height of such anomalies in the surface.


A method for controlling regeneration within an after-treatment component of an engine comprises receiving a signal indicative of whether the engine is in an operating state or a non-operating state and detecting, based on the signal, when the engine has departed an operating state and entered a non-operating state. When the engine has departed an operating state and entered a non-operating state, a regeneration event is initiated. The regeneration event comprises causing a stream of air to flow through the after-treatment component and initiating a flow of fuel into the stream of air.

The emission of nitrogen oxides, i.e., NOx, particulate matter (PM), and other constituents in exhaust from internal combustion engines, such as compression-ignition engines, is regulated for environmental reasons. Thus, vehicles equipped with compression-ignition engines often include after-treatment components such as particulate filters, catalyzed soot filters and adsorption catalysts for capturing or otherwise removing the regulated constituents from their exhaust streams and/or converting regulated constituents into unregulated constituents that may be permitted to remain in the exhaust streams. For example, catalyst compositions may be provided to convert certain exhaust constituents into non-regulated exhaust gas components. Filter structures that have proven effective in removing the particulate matter from the exhaust gas include ceramic honeycomb wall-flow filters, wound or packed fiber filters, open cell foams, and sintered metal fibers.
In addition to particulates, exhaust from a compression-engine, such as a diesel engine, typically contains NOx, which consists primarily of nitric oxide (NO) and approximately 5 to 20 percent NO2, with greater levels of NO2 being common where oxidation catalysts are present in the exhaust stream. Production of NOx may be particularly problematic when operating lean of stoichiometric as a result of the relatively high levels of oxygen in the exhaust gas stream. Such lean conditions typically exist during cold start conditions. To address this issue, an exhaust after-treatment system may include a NOx adsorber (i.e., a lean NOx trap or LNT). In an LNT, a NOx adsorbent material, such as a zeolite, is disposed so as to trap NO and NO2 molecules.
Once the NOx adsorbent material in an LNT is saturated, the effectiveness of the LNT decreases substantially, and NOx may slip past the LNT. While a NOx-producing engine is operating at sufficiently elevated temperatures, such as at typical, steady-state operating temperatures, after-treatment components positioned downstream from an LNT, such as a selective reduction catalyst component (SRC), can effectively convert the NOx contained in the exhaust stream before release to the atmosphere. Unfortunately, at relatively cool operating temperatures and lean stoichiometry, such as experienced during a cold start-up of the engine, an SRC may not be particularly effective in converting NOx. For this reason, it can be particularly important for an LNT to have sufficient adsorption capacity available when a cold start-up is initiated.
After-treatment components may be maintained either by replacing components or by periodic cleaning or regeneration. To avoid service interruptions, regeneration is generally preferred over replacement of after-treatment components. In a soot collecting component, regeneration may be accomplished by increasing the temperatures of the filter material and/or the collected particulate matter to levels above the combustion temperature of the particulate matter while exposing the particulate matter to available oxygen. Elevating the temperature facilitates consumption of the accumulated soot by allowing the excess oxygen in the exhaust gas to oxidize the particulate matter. Particulate matter may also be oxidized, and thus removed, at lower temperatures by exposing the particulate matter to sufficient concentrations of nitrogen dioxide (NO2). Regeneration in an LNT may be accomplished by exposing the NOx to a hydrocarbon rich environment so as to convert the NOx to H2O and N2. To ensure that an LNT has sufficient adsorption capacity available when a cold start-up is initiated, it may be advantageous to regenerate a LNT prior to initiating a cold startup.
Engine control systems can be used to predict when it may be advantageous to actively facilitate a regeneration event and to effectuate control over the regeneration process. To accomplish this, an engine control system may use a model to deduce (i.e., predict) an accumulation of regulated constituents in the after-treatment component by monitoring properties of the exhaust stream as it flows through the after-treatment component. The control system can use the deduced accumulation data to determine or anticipate when regeneration may be necessary or desirable, to facilitate a regeneration event, and/or to effectuate control over a regeneration process or other remedial measures. In one exemplary model, knowledge of the relationship between accumulation of regulated constituents and various operating parameters enable the extent of NOx loading in an LNT to be estimated. Unfortunately, there are drawbacks associated with the regeneration process. These include the fuel consumption required to regenerate the after-treatment component and exhaust emissions that are created by the regeneration process.
Accordingly, it is desirable to provide an improved system and method for determining when to facilitate active regeneration and for controlling active regeneration of an after-treatment component, with particular applicability to a lean NOx trap and with particular attention to the need for reduced consumption of fuel.

System and method for controlling regeneration within an after-treatment component of a compression-ignition engine


A regioselectively substituted member selected from the group consisting of oligo-saccharide ester and polysaccharide ester is disclosed. The ester has a partial average degree of substitution AS at the C2 position of its anhydroglucose unit of at least 90% relative to the total AS. Also disclosed is a method of producing the regioselectively substituted ester. The method entails reacting in the presence of a catalyst a dissolved or a highly swollen oligo-saccharide or polysaccharide with an esterification reagent.

The present patent application claims the right of priority under 35 U.S.C. xc2xa7119(a)-(d) of German Patent Application Numbers 199 09 786.0, filed Mar. 5, 1999, and 199 51 734.7, filed Oct. 27, 1999.
This invention relates to esters of oligo- and polysaccharides which are regio-selectively substituted, predominantly at the C2 position of the anhydroglucose unit (AGU), and also relates to a method of producing them using enzymes and/or defined salts as catalysts for ester formation. Regioselectively substituted esters of this type have basic properties which are different from those of conventional, randomly functionalised products.
It is known that when oligo- and polysaccharides are subjected to esterification by conventional methods, products are formed which exhibit a random distribution of the esters groups within the AGU and along the chain. This randomness depends on the accessibility to electrons or on the spatial accessibility of the individual hydroxyl groups. Thus in starch, for example, the hydroxyl group in the C6 position is a primary group which is very sterically accessible and which thus exhibits the highest accessibility during heterogeneous reactions in particular. The hydroxyl function of the C2 position forms the basis of the electronic effect of the adjacent glycoside bond and of the electron-attracting properties of the ring oxygen. In homogeneous processes, it has been shown that the C2 position reacts first for this reason. In none of the aforementioned situations, however, is the complete reaction of only one hydroxyl group achieved.
By utilising differences in accessibilities such as these, hydroxyl groups can be selectively blocked with the aid of protective groups, which are generally bulky and can easily be split off, so that regioselective derivatives are formed in subsequent reactions.
Examples of protective groups such as these include triphenylmethyl groups or bulky organosilicon entities such as t-hexyl- or tert-butyl-dimethylsilyl groups.
However, this type of synthesis has the decisive disadvantage that at least two additional reaction steps are necessary due to the introduction of the protective group and the separation thereof. Other disadvantages are the fact that the separation of the protective groups is sometimes incomplete, which means that the cleavage products which are formed thereby, and which are sometimes toxic, have to be removed without leaving a residue, as well as the breakdown of the polysaccharide chain which is possible under the conditions of cleavage and which changes the properties of the product.
When a plurality of reactive centres, e.g. hydroxyl groups, exists in a molecule, enzymes are capable of catalysing direct, selective esterification reactions. In this connection, each enzyme has a certain folded (native) structure which is essential for its specific biocatalytic activity in the physiological medium concerned. It has been shown in numerous publications, however, that many enzymes are also active in organic solvents, i.e. are active irrespective of their native structure, size and function. Enzymes generally exhibit a high activity in nonpolar solvents, whereas only very low activities are found in relatively polar media (Biotechnol. Bioeng. 30 (1987), 81-87). Enzymes are insoluble in the latter organic solvents.
Numerous enzyme-catalysed reactions of this type have already been carried out on low molecular weight mono- and disaccharides in organic solvents (FEMS Microbiol. Rev. 16 (1995), 193-211; J. Prakt. Chem. 335 (1993), 109-127; Synthesis 1992, 895-910; WO 97/36000; WO 95/23871). In these reactions lipases have primarily been used as the enzymes, although esterases and proteases have also been used, and solvents such as tetrahydrofuran, pyridine and N,N-dimethylformamide have been employed. Enzymatic esterifications can also be effected in an aqueous buffer solution. One disadvantage here is that the acylating reagent, which has a character similar to that of a fatty acid, is insoluble in the aqueous buffer solution and can thus only be suspended therein. The substrate which is to be esterified is present in dissolved form (DE-A-34 30 944,1992; JP-A-63191802).
Glucans generally result in the formation of esters at primary hydroxyl groups. In some cases, esterification also occurs at secondary hydroxyl groups (J. am. Chem. Soc. 109 (1987), 3977-3981; Enzyme Microb. Technol. 20 (1997), 225-228). Compounds which comprise electron-attracting groups are generally used for the aforementioned enzymatic esterifications, such as vinyl esters (Biotechnol. Lett. 19 (1997), 511-514) or trihalogenoethyl esters (Tetrahedron 54 (1998), 3971-3982); esterification by a vinyl ester constitutes an irreversible reaction, since the vinyl alcohol which is formed is removed as acetaldehyde from the reaction equilibrium. Other reactive compounds include carboxylic anhydrides and esters of carbonic acid.
Diesters of dicarboxylic acids have also been used for reaction with mono- and disaccharides. In this manner, it has proved possible to synthesise new saccharide-based copolymers, as disclosed in U.S. Pat. No. 5,270,42 1 and U.S. Pat. No. 5,618,933.
In the publications described above, the substrate and the acylating reagent are generally dissolved in an organic solvent, in which the enzyme is then suspended. Enzymatic esterifications cannot be effected on polysaccharides, particularly glucans, by the methods cited above, since the undissolved or unswollen polymer is not accessible to the enzyme or to enzyme catalysis. Polysaccharides can be esterified enzymatically in a heterogeneous phase, however (WO 96/13632, DE-A-34 30 944). These heterogeneous reactions only proceed at the surface of the polymer particles, due to which inhomogeneously esterifed polysaccharide derivatives are formed, i.e. polysaccharide derivatives which comprise a non-uniform distribution of substituents along the polymer chain. Other disadvantages of this method of esterification are that low yields of product are obtained and products are formed which comprise a low degree of selectivity as regards the type of substitution in the anhydroglucose unit.
Conventional heterogeneous esterifications are often conducted in water as a suspension medium (U.S. Pat. No. 5,703,226, 1997). Homogeneous reactions are conducted in organic solvents or in the acylating reagent directly (U.S. Pat. No. 5,714,601, 1998; WO 96/14342). The corresponding carboxylic anhydrides or vinyl esters are generally used as acylating agents. Esterifications or transesterifications of this type are mostly catalysed by alkalies, wherein suitable catalysts include alkali hydroxides, salts of mineral acids or organic amines.
The object of the present invention was to enable esters of oligo- and polysaccharides to be obtained which are homogeneously and regioselectively substituted at the C2 position of the anhydroglucose unit (AGU). Success has now been achieved according to the invention in producing esters of oligo- and polysaccharides which are homogeneously and regioselectively substituted at the C2 position of the AGU. The present invention therefore relates to oligo- and polysaccharide esters which are esterified regioselectively, with ester groups at the C2 position of the AGU preferably amounting to at least 90%, most preferably 90 to 98%, of the total degree of substitution (partial average degree of substitution AS at the C2 position of the AGU with respect to the total AS). The oligo- and polysaccharide esters which are regioselectively substituted at the C2 position and which are particularly preferred according to the invention are esters of starch or starch derivatives, particularly hydroxyethylstarch or hydroxypropylstarch. The present invention also relates to esters, which are regioselectively substituted at the C2 position, of cellulose, cellulose esters or cellulose ethers, particularly of hydroxyethyl cellulose, methyl cellulose, pullulan or maltose. The oligo- and polysaccharide esters according to the invention are obtainable by reaction with esterification reagents from the group comprising vinyl esters, carboxylic anhydrides and trihalogenoethyl esters, as well as lactones, which are described in more detail below in the description of the method. Oligo- and polysaccharide esters which regioselectively substituted at the C2 position and which are particularly preferred according to the invention are 2-O-propionyl-starch, 2-O-butyrylstarch, 2-O-benzoylstarch, 2-O-laurylstarch, 2-O-methoxy-carbonylstarch, 2-O-acryloylstarch and 2-O-methacryloylstarch, most preferably 2-O-acetylstarch. According to the invention, the oligo- and polysaccharides which are regioselectively substituted at the C2 position can be esterified at the remaining OH groups of the AGU with other ester groups which are not identical to the ester groups at the C2 position.
The present invention further relates to a method of producing the compounds according to the invention in the presence of an organic solvent, which method is catalysed by enzyme or salt and is carried out on a dissolved or highly swollen oligo- or polysaccharide.
Starting from the disadvantages of the known methods which were described above, e.g. low yields of product and low degrees of regioselectivity, it has thus proved possible, using catalysis by means of enzymes, to effect the esterification of oligo- and polysaccharides, which are dissolved in organic solvents or which are strongly swollen, regioselectively at the secondary hydroxyl group of the C2 position, and has also proved possible to effect said esterification in combination with the esterification of the primary hydroxyl group of the C6 position of the AGU. The method results in very high product yields, and the partial degrees of substitution can be varied and adjusted over wide limits. Particularly high regioselectivities are achieved with oligo- and polysaccharides which comprise an xcex1-(1,4)-glycoside linkage, particularly starch. However, the method can also be applied to oligo- and polysaccharides which comprise a xcex2-(1,4)-glycoside linkage. Organic solvents which are suitable in principle are those in which the oligo- and polysaccharides which are used exhibit considerable swelling or dissolve, and in which the enzymes used exhibit satisfactory activity. Polar organic solvents such as Dimethyl sulphoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), pyridine and N-methylmorpholine-N-oxide (NMMO) can therefore be used as solvents, as can mixtures of the aforementioned solvents. DMSO is preferred. The enzymes surprisingly exhibit high activity, particularly in DMSO, and products which are esterified strictly regioselectively are obtained in a single-stage reaction. These esters can be converted into regioselectively substituted mixed derivatives, such as esters and ethers, by subsequent, selective reactions.
The esterification can be carried out on polysaccharides, preferably on starch from various natural sources and with wide range of amylose contents and molecular weights, and on starch derivatives, particularly hydroxyethylstarches or hydroxy-propylstarches, and can also be carried out on cellulose, cellulose derivatives, pullulan, pullulan derivatives and oligosaccharides.
Proteases of all types can be used as enzymes. The preferred proteases are serine-, cysteine-, asparagine- and metalloproteases. The proteases are preferably dissolved in a phosphate buffer, or alternatively in a carbonate buffer, within a pH range of 4-9 depending on the enzyme, preferably at pH 7-8, and are subsequently lyophilised. The preferred proteases are proteinase N and subtilisin of Bacillus subtilis, proteinase 2A of Aspergillus oryzae, proteinase 6 of Aspergillus sp., a-chymotrypsin, papain, renin and thermolysin.
Esters of general formula
are preferably used as esterification reagents, wherein R2 preferably denotes a saturated or unsaturated alkyl group comprising 2 to 6 C atoms, or an unsaturated or saturated, branched or unbranched trihalogenoalkane radical comprising 2 to 4 C atoms, particularly vinyl, trihalogenoethyl or alkyl. R1 is preferably an alkyl group comprising 2-18 C atoms, which can be saturated, unsaturated, straight-chain, branched or cyclic and which can optionally be substituted, or an aryl group (which is optionally substituted). R1 is most preferably selected from the group comprising acetyl, propyl, butyryl, vinyl, methacryl, cinnamoyl, pivaloyl and cyclohexyl. When esters of alkenoic acids are used, the double bonds can also be utilised for polymerisation in order to build up network structures. This option also exists when using esters of dicarboxylic acids comprising the R2 radical, such as vinyl adipate, wherein crosslinking can be effected uniformly in the special polysaccharide.
Esterification reagents which are particularly suitable include vinyl acetate, vinyl propionate, vinyl laurate, vinyl butanoate, vinyl stearate, vinyl benzoate, vinyl acrylate, vinyl methacrylate, vinyl crotonate, vinyl pivalate and divinyl pivalate.
Other esterification reagents include carboxylic anhydrides, preferably acetic anhy-dride, propionic anhydride, succinic anhydride and itaconic anhydride, as well as reactive lactones, preferably propiolactone and a-angelicalactone. In the case of carboxylic anhydrides, substitution also occurs at the C6 position of the AGU as well as at the C2 position.
N-isopropylidene compounds of general formula
can also be used as esterification reagents, whereupon the corresponding carboxylic acid esters of the oligo- and polysaccharides are formed. R1 is preferably an alkyl group comprising 2-18 C atoms, which can be saturated, unsaturated, straight-chain, branched or cyclic and which is optionally substituted, or can be an aryl group (which is optionally substituted). R1 is most preferably selected from the group comprising acetyl, propyl, butyryl, vinyl, methacryl, cinnarnoyl, pivaloyl and cyclohexyl.
Particularly suitable esterification reagents from the group comprising N-isopropylidene compounds include N-isopropylidene-O-methyl carbonate, N-isopropylidene-O-ethyl carbonate and N-isopropylidene-O-benzyl carbonate.
The method according to the invention is characterised in that the substrate is dissolved in a polar organic solventxe2x80x94which is DMSO in the case of starchxe2x80x94to which the enzyme and the transesterification reagent are added, and is subsequently incubated. The incubation temperature is between 20xc2x0 C. and 85xc2x0 C., and is preferably within the range from 20 to 45xc2x0 C., particularly in the interval from 35 to 45xc2x0 C. The times of reaction range from 2 to 100 hours, whereupon a conversion of about 50% is achieved with respect to the acylating reagent. Alternatively, the transesterification reagent can be activated by the enzyme in a preceding step. After the reaction is complete, the enzyme is separated by liquid-solid separation (e.g. centrifugation, filtration). The product is isolated by precipitation and is washed and dried. The solvents which remain can be worked-up by distillation and can subsequently be recycled to the esterification process. The enzyme can thus be used in a cyclic process without loss of activity.
When the reaction in the aforementioned system is conducted at a temperature of 40xc2x0 C., chemical esterification also occurs in addition to enzyme-catalysed esterification. This chemical esterification occurs with the production of degrees of substitution ranging from a few percent up to a maximum total degree of substitution corresponding to AS=0.25. This results in the esterification of other hydroxyl groups which are present in the molecule. This chemical esterification can be substantially suppressed if the reaction is conducted at lower temperatures (20-25xc2x0 C.), or is preferably suppressed by conducting the reaction in systems which are almost anhydrous (water content  less than 0.01%).
A partial degree of substitution of up to AS=1.0 at the C2 position of the AGU can be achieved in oligo- and polysaccharides by the method according to the invention. Any desired partial ASxe2x89xa61.0 at the C2 position of the AGU can be achieved via the molar equivalents of acylating reagent which are used (Table 1).
The partial AS in the C2 position of the AGU can also be adjusted via the reaction kinetics as well as via the molar equivalents, i.e. desired AS values xe2x89xa61.0 can be achieved depending on the time at which the reaction is stopped (Table 2).
Verification of the regioselectivity of the enzymatically catalysed esterification reaction was effected on the intact oligo- or polysaccharide by one- and multi-dimensional NMR spectrometry. For this purpose, the remaining free hydroxyl groups were esterified with a suitable carboxylic anhydride, for example with propionic anhydride for saccharide acetates or with acetic anhydride for saccharide benzoates or for other saccharide acylates. These mixed esters are soluble in chloro-form and can be investigated by NMR spectrometry. After evaluating the signals of the AGU protons as hydrocarbons via 1H/1H and 1H/13C correlation, the corresponding acyl groups can be assigned to their position on the AGU with the aid of a 1H/13C multiple bond correlation which is detected using 1H (HMBC technique) (Carbohydr. Res. 224 (1992), 277-283).
In a variant of the method according to the invention, production is effected catalysed by salts only, without further addition of enzyme. Degress of substitution  less than 1.0 at the C2 position are thereby achieved.
As distinct from enzyme catalysis, regioselectivity here is controlled via the state of dissolution of the oligo- and polysaccharides in a polar organic solvent, preferably in DMSO. Interactions between the solvents and the AGU components increase the acidity of the proton of the hydroxyl group in the C2 position of the AGU (J. Am. Chem. Soc. 98 (1976), 4386). By employing a suitable salt as a catalyst, complete esterification of this position can then be effected, wherein it is possible either to employ reaction kinetics control or to control the reaction via the type and amount of catalyst (table 3). The salt is usually present in a concentration of 1-10% by weight, preferably 2-5% by weight, with respect to the starting material.
The method results in higher product yields, and the partial degree of substitution can be adjusted in a defined manner. Suitable solvents for carrying out the method include dimethylsulphoxide (DMSO), N,N-dimethylformamide (DMF) and N,N-dimethyl-acetamide (DMA).
The method can be applied to polysaccharides, preferably to starches with different amylose contents and molecular weights, to starch derivatives such as hydroxy-ethylstarch or hydroxypropylstarch, and to pullulan and pullulan derivatives and oligosaccharides such as cyclodextrin.
Suitable catalysts include salts of inorganic mineral acids, salts of carboxylic acids and carbonates of the alkali and alkaline earth metals. The preferred salts are Na2HPO4, CaHPO4, Na2CO3, MgCO3 (NH4Cl)2CO3, Na2SO2, NH4Cl, NaBr, NaCl and LiCl, as well as sodium citrate. In order to suppress esterification at other hydroxyl groups,; e.g. in the C3 or C6 position, when using salts of weak acids as catalysts, a maximum of only 10 mol % must be used with respect to the weight of oligo- or polysaceharide to be reacted, and at the same time a defined time of reaction must be adhered to.
Esters of general formula
are preferably used as esterification reagents, wherein R2 can denote vinyl, trihalogenoethyl or alkyl for example. Examples of R1 include an alkyl group comprising 2-18 C atoms, which can be saturated, unsaturated, straight-chain, branched or cyclic (and which is optionally substituted), or an aryl group (which is optionally substituted). When esters of alkenoic acids are used, the double bonds can also be utilised for polymerisation in order to build up network structures. This option also exists when using esters of dicarboxylic acids comprising the R2 radical, such as vinyl adipate, wherein crosslinking can be effected uniformly in the special polysaccharide.
Other esterification reagents include carboxylic anhydrides, for example acetic anhydride, propionic anhydride, succinic anhydride and itaconic anhydride, as well as reactive lactones, preferably propiolactone and a-angelicalactone. In the case of carboxylic anhydrides, substitution also occurs at the C6 position of the AGU as well as at the C2 position.
N-isopropylidene compounds of general formula
can also be used as esterification reagents, wherein the corresponding carboxylic acid esters of the oligo- and polysaccharides are formed. Examples of R1 include alkyl groups comprising 2-18 C atoms, which can be saturated, unsaturated, straight-chain, branched or cyclic (and which are optionally substituted), and aryl groups (which are optionally substituted).
The method according to the invention is characterised in that oligo- or poly saccharides are regioselectively esterified at the hydroxyl group of position C2 of the anhydroglucose unit by active esters in polar organic solventsxe2x80x94preferably DMSOxe2x80x94 using salts as catalysts. The reaction temperature is between 20xc2x0 C. and 100xc2x0 C., and is preferably within the range from 30 to 50xc2x0 C. The times of reaction range from 0.5 to 100 hours, depending on the reaction temperature and on the catalyst used. The catalyst is separated by liquid-solid separation (e.g. centrifugation, filtration). Alternatively, a defined amount of water can also be added to the precipitant, in order to dissolve out the catalyst. The resulting ester is isolated by precipitation and is washed and dried.
The solvents which remain can be worked-up by distillation and can subsequently be recycled to the esterification process.
With the method according to the invention, a partial degree of substitution at the C2 position of the AGU of up to AS=1.0 can be achieved according to choice via the reaction kinetics or via the molar equivalents of transesterification reagent used.
Regioselectivity was verified by means of two-dimensional NMR spectrometry. For this purpose, the acylated polysaccharide had to be completely propionylated in the case of acetates, or acetylated in the case of other polysaccharide esters. In this manner, the substitution site can be unambiguously verified by means of multiple bond correlation (Carbohydr. Res. 224 (1992), 277-283).
The products which are obtained by the method according to the invention, e.g. starch acetates, can be decomposed by amylases. At a suitable molecular weight of the starch and when substitution is effected strictly at the C2 position, starch acetates are suitable as blood plasma expanders. 2-O-acetylstarch is particularly suitable for this application. Therefore, the present invention further relates to the use of 2-O-acetylstarch as a blood plasma expander. Moreover, biodegradable plastics can be synthesised from starch acylates. Membranes having a substantially uniform structure can be synthesised by crosslinking processes. Absorbents for different applications can also be produced by treatment to form further derivatives. Starch acetates which have thermoplastic properties can conceivably be used in the pharmaceutical industry as active ingredient retardants.
Regioselectively substituted cyclodextrin esters can be used in the pharmaceutical industry as carriers for pharmaceutical active ingredients. Furthermore, compounds of high molecular weight can be synthesised, in the manner of copolymers, which could be suitable for chromatography (e.g. for the separation of enantiomers).

Regioselectively substituted esters of oligo- and polysaccharides and a method of producing them


A method of forming cutouts in an aircraft fuselage may include forming a first cutout and a second cutout in side-by-side relation to one another in a side region of the fuselage. The method may further include configuring the first cutout and the second cutout such that a direct load path extends along the side region substantially continuously from a lower portion of the side region generally under the first cutout to an upper portion of the side region generally over the second cutout.

Conventional passenger aircraft used in commercial aviation typically include passenger windows mounted along the sides of the aircraft fuselage. The laterally-facing windows are typically arranged in a single row in a window belt that extends between the forward and aft ends on each side of the fuselage. Each window is typically mounted in a window cutout formed in the sides.
During service, the aircraft is subjected to a variety of different loads of different magnitude and orientation. For example, during flight, the weight of the aircraft and the aircraft payload (e.g., passengers, baggage, cargo) are supported by the aircraft wings. During normal cruise flight, the weight of the aircraft and payload cause a bending moment on the fuselage. The bending moment generates an in-plane shear load on each side of the fuselage. The shear load results in tension and compression components of the shear load in the side region and which are oriented at approximately 45 degrees relative to the aircraft longitudinal axis. The shear load passes through the window belt connecting the crown region of the fuselage to the keel region of the fuselage.
Conventional aircraft windows typically have an oval shape and are spaced along the aircraft fuselage at a relatively short pitch distance. The pitch distance between the windows typically corresponds to the distance between the circumferential frames which are typically spaced at approximately 22-24 inches along the interior side of the fuselage skin. The combination of the relatively short pitch distance and the oval shape of conventional aircraft windows results in a discontinuous or contorted load path for the shear loads. In this regard, the oval-shaped windows and the pitch distance prevent the shear load from passing in a straight line between the windows and instead create a discontinuity in the shear load path forcing the shear load to go around each oval-shaped window.
The discontinuous load path results in stress concentrations along the edges of the window cutouts requiring an increase in skin thickness around the cutouts to maintain the stress below the allowable limits of the skin material. The increased skin thickness increases the cost, complexity and production time of the aircraft. In addition, the increase in weight due to the increased skin thickness reduces the payload capacity of the aircraft and increases fuel consumption.
As can be seen, there exists a need in the art for a window cutout having an optimized shape that improves the load path between the window cutouts in the side regions of the fuselage. In addition, there exists a need in the art for an arrangement that optimizes the skin thickness in areas adjacent to the window cutouts.

Method of forming a window cutout in an airframe


A uniaxially-driven controlled biaxial testing fixture includes a base, a first coupler mounted to the base, and a load input drive rack mounted for linear movement with respect to the base. A second coupler and a first specimen grip are both mounted to the load input drive rack. Second, third and fourth specimen grips are also mounted for linear movement with respect to the base. First, second and third drive mechanisms connect the load input drive rack to the second, third and fourth specimen grips. Together the four specimen grips are oriented to provide biaxial application of force to a test specimen.

Biaxial testing apparatus are used to control the load placed along varying axes of a test specimen for testing mechanical properties of metals, plastics, composites, wood, fabrics, elastomers and other materials. Examples of biaxial testing equipment may be found in, for example, U.S. Pat. No. 5,905,205 to Clay, U.S. Pat. No. 5,279,166 to Ward et al. and U.S. Pat. No. 7,204,160 to Sadi et al. The present invention relates to a relatively simple and inexpensive fixture that may be simply attached to a universal load frame capable of only uniaxial deformation in order to provide biaxial deformation at different pre-selected ratios. The different ratios are provided by utilizing different gear sets in the testing fixture.

Uniaxially-driven controlled biaxial testing fixture

The University of Kentucky Research Foundatio


A laser diode comprising a first separate confinement heterostructure and an active region on the first separate confinement heterostructure. A second separate confinement heterostructure is on the active region and one or more epitaxial layers is on the second separate confinement heterostructure. A ridge is formed in the epitaxial layers with a first mesa around the ridge. The first mesa is 0.1 to 0.2 microns above the second confinement heterostructure.

1. Field of the Invention
This invention relates to laser diodes, and more particularly to nitride based semiconductor laser diodes and methods for fabricating same.
2. Description of the Related Art
A laser is a device that produces a beam of coherent light as a result of stimulated emission. Light beams produced by lasers can have high energy because of their single wavelength, frequency, and coherence. A number of materials are capable of producing a lasing effect and include certain high-purity crystals (such as ruby), semiconductors, certain types of glass, certain gasses including carbon dioxide, helium, argon and neon, and certain plasmas.
More recently there has been increased interest in lasers made of semiconductor materials. These devices typically have a smaller size, lower cost, and have other related advantages typically associated with semiconductor devices. Semiconductor lasers are similar to other lasers in that the emitted radiation has spacial and temporal coherence, and like other lasers, semiconductor lasers produce a beam of light that is highly monochromatic (i.e., of narrow bandwidth) and is highly directional. Overall, semiconductor lasers provide very efficient systems that are easily modulated by modulating the current directed across the devices. Additionally, because semiconductor lasers have very short photon lifetimes, they can be used to produce high-frequency modulation.
One type of semiconductor laser diode is referred to as an edge emitting laser where the stimulated emission is from the side surface or edge of the laser diode. These devices typically have epitaxial layers in the form of waveguiding or reflective elements (cladding layers) with a light generating active region between the reflective elements. Additional layers can be included between the reflective elements to form a laser cavity. The edges of the laser diode can be cleaved during manufacturing to form edge reflective surfaces or facets. A total reflectivity (TR) material can cover one edge, and an anti reflectivity (AR) material can cover the opposite edge. Light from the active region is reflected between the edges and within the cavity by the reflective elements, with stimulated emission emitting from the edge with the AR material. After application of the TR and AR materials, the individual laser diodes can be separated.
A known characteristic of laser diodes (and light emitting diodes) is that the frequency of radiation that can be produced by the particular laser diode is related to the bandgap of the particular semiconductor material. Smaller bandgaps produce lower energy, shorter wavelength photons, while wider bandgaps produce higher energy, shorter wavelength photons. One semiconductor material commonly used for lasers is indium gallium aluminum phosphide (InGaAlP), which has a bandgap that is generally dependent upon the mole of atomic fraction of each element present. This material, regardless of the different element atomic fraction, produces only light in the red portion of the visible spectrum, i.e., about 600 to 700 nanometers (nm).
Laser diodes that produce shorter wavelengths not only produce different colors of radiation, but offer other advantages. For example, laser diodes, and in particular edge emitting laser diodes, can be used with optical storage and memory devices (e.g. compact disks (CD) digital video disks (DVD), high definition (HD) DVDs, and Blue Ray DVDs). Their shorter wavelength enables the storage and memory devices to hold proportionally more information. For example, an optical storage device storing information using blue light can hold approximately 32 times the amount of information as one using red light, using the same storage space. There are also applications for shorter wavelength laser in medical systems and projection displays. This has generated interest in Group-III nitride material for use in laser diodes, and in particular gallium nitride (GaN). GaN can produce light in the blue and ultra violet (UV) frequency spectrums because of its relatively high bandgap (3.36 eV at room temperature). This interest has resulted in developments related to the structure and fabrication of Group-III nitride based laser diodes [For example see U.S. Pat. Nos. 5,592,501 and 5,838,706 to Edmond et al].
Group-III nitride laser diodes can require relatively high threshold currents and voltages to reach laser radiation because of optical and electrical inefficiencies. These elevated current and voltage levels can result in heat being generated during laser diode operation. In certain applications, laser diodes are driven by a pulsed signal that results in pulsed laser light being emitted from the laser diode. The heat generated within the laser diode typically does not present a problem during pulsed laser diode operation because the laser diode has the opportunity to cool during the lows of the signal. For other important applications, however, it can be desirable to drive the laser diode with a continuous wave (CW). CW operation is particularly applicable to operation with optical storage devices that can require a continuous light source for data storage and retrieval. Driving many current Group-III based laser diodes with a CW having the threshold current and voltage necessary for laser emission can result in heating that can damage or destroy the laser diode. Heat sinks or other cooling methods/devices can be employed to reduce operating heat within these laser diodes, but the methods/devices can increase the cost and complexity of the devices and can require additional space.

Group-III nitride based laser diode and method for fabricating same


The present invention relates to a light emitting metallic compound of Chemical Formula 1 and an organic electroluminescence device including the compound. In the Chemical Formula 1, M is selected from Ir, Pt, Rh, Re, and Os, m is 2, provided that m is 1 when M is Pt. X is a N or P atom, Y is S, O, or Se, and Z is SiR5R6, CR5R6, PR5, S, SO2, carbonyl, or NR5, and L2 is represented by Chemical Formulae 2, 3, or 4. R1, R2, R3, R4, R5, R6, R7, and R8 are the same or different, and are selected from hydrogen, a C1 to C20 alkyl, an aryl, a cycloalkyl, a halogen, a linear or branched substituent including at least one halogen, a linear or branched substituent including at least one heteroatom, carbonyl, vinyl, and acetylenyl, or may form a cycle, and R9 is hydrogen, a C1 to C20 alkyl excluding an aromatic cyclic substituent, a cycloalkyl, a halogen, a linear or branched substituent including at least one halogen; or a linear or branched substituent including at least one heteroatom.

An electroluminescence device (EL device) is a self-light emitting display device having such merits as a wide viewing angle and excellent contrast as well as a quick response time.
EL devices are classified into an inorganic EL device and an organic EL device in accordance with a material used for a light emitting layer. The organic EL device has merits of improved luminance, driving voltage, response speed, and multi-colorfying property compared to an inorganic EL device.
An organic EL device is generally composed of an anode on a substrate, a hole transport layer on the anode, and a light emitting layer, an electron transport layer (ETL), and a cathode sequentially positioned thereon. The hole transport layer, light emitting layer, and electron transport layer (ETL) are organic films that are composed of organic compounds.
The organic EL device having the above structure is operated as follows.
When a voltage is applied to a space between the anode and the cathode, the holes are injected from the anode to the light emitting layer through the hole transport layer. Meanwhile, when the electrons are injected from the cathode into the light emitting layer through the electron transport layer (ETL), carriers are recombined in the region of the light emitting layer to thereby produce excitons. The state of the excitons is changed from an exited state to a base state, and the change in the state of the excitons makes the molecules of the light emitting layer emit light to thereby form an image.
Materials for forming a light emitting layer are divided into fluorescent materials using singlet excitons and phosphorescent materials using triplet excitons according to the light emitting mechanism. Phosphorescent materials generally include organic/inorganic compound structures including transition element atoms. The transition element atoms change triplet excitons, which used to be impossible to transition, into excitons that are possible to transition, causing them to emit phosphorescent light. Since the phosphorescent materials can use triplet excitons having a generation probability of 75%, higher luminous efficiency can be achieved than with fluorescent materials using singlet excitons having a generation probability of 25%.
Among light emitting materials using the triplet excitons are phosphorescent materials including iridium and platinum compounds (Sergey Lamansky et al. Inorg. Chem., 40, 1704-1711, 2001, and Sergey Lamansky et al., J. Am. Chem. Soc., 123, 4304-4312, 2001). For blue light emitting materials, Ir compounds based on (4,6-F2ppy)2Irpic or a fluorinated ppy ligand structure have been developed (Vladimir V. Grushin et al., Chem. Commun., 1494-1495, 2001). The (4,6-F2ppy)2Irpic, however, has shortcomings that it emits light in a sky blue region and its large shoulder peaks increase a y value in color purity coordinates. Researchers are studying red and green light emitting materials, but there still remains great demand to develop highly efficient phosphorescent materials having a long lifespan.

Metallic compound and organic electroluminescence device comprising the same

Industry-University Cooperation Foundation, Hanyang University


In a Digital Rights Management (DRM) system, cryptographic keys for decrypting distributed assets (such as audio or video media) are distributed using an offline (e.g., non-Internet) method for distribution of the key generation process, with an implicit authorization to use the distributed key generation process. This is used to update an asset key for use by a client such as a media player when a key formula for generating the key for decrypting an asset has been compromised, such as by hackers.

Many media distribution systems require the digital media ("content" or "asset") such as video or audio that they distribute to be encrypted with a cryptographic key using an associated cipher process to prevent playback by unauthorized media players. The system for managing these cryptographic keys is called a Digital Rights Management (DRM) system. Many DRM systems involve a client software component (DRM module) in the media players and a server software component (DRM server) that distributes the keys to the client.
Cryptography is the traditional method of protecting data in transit across a computer network. In its typical application, cryptography protects communications (messages) between two mutually trusting parties from thievery or hackers by attack on the data in transit. However, for many digital file transfer applications (e.g. for the transfer of audio or video content), instead the party that receives the content (i.e., the receiving party) might try to break the DRM encryption that the party that supplied the content (i.e., the distributing party) applied to the content. Thus in this case the receiver is not a trusted party per se, but the point is to protect the distributor who owns the content from its misuse by the receiving party. In addition, with the proliferation of network penetration attacks, a third party may well obtain access to the receiving party's computer and thus to the protected content.
In many DRM systems now in use, the weakest link in security is not the encrypted data (message) but rather cryptographic key management and handling. As well known, modern cryptographic systems use keys which are strings of digital values for both encryption and decryption purposes. For instance, one of the more successful DRM systems, which distributes music online, requires that the receiving party's computer to maintain the unencrypted key for each piece of encrypted music in a "key bag" (repository) that is itself encrypted.
This approach has disadvantages. By encrypting the key bag instead of the keys contained in the key bag, this exposes the keys to a potential attack. Similarly to play a piece of content the receiving party's computer must decrypt the entire key bag, retrieve the key for a particular piece of content, and decrypt the content with the retrieved key.
This approach also disadvantageously allows different devices to use different formats for their key bags. The use of different key bag formats for different devices further exposes the keys to penetration when the content is transferred between devices.
Most current DRM systems encrypt content with a "content key" that is applied to an encryption algorithm (process) such AES, triple DES, or RC4. These are well known encryption systems. Typically these are symmetric key systems, that is the same key is used for encryption and decryption. With this method, the entire content is encrypted with a single content key. Normally of course it is relatively easy for users to share the encrypted files in an unauthorized fashion. However without the content key, such shared files are useless. In cases where the content key is discovered, for instance by hackers or other unauthorized users, the content key is often published and made available to the public. This substantially reduces security of the system and allows unauthorized downloading and successful decryption of the content without permission, which is extremely undesirable to the owner of the content. Usually the attackers or hackers share the discovering process, in addition to the keys themselves, and as a result even more keys are discovered and published in a public database. The less experienced users who may not be able to use the discovery process can then access the database, which is often provided in a website, to see if the content key for their particular piece of content, for instance a particular piece of music or video, is published and in turn break the copy protection on material that they have obtained without paying for. This type of attack, also known as a dictionary attack, has been found to be successful.
It is well known that an attack can discover the content key associated with each piece of content. Specifically, the content key typically remains available during play in the memory of the playback device (which is a computer or for instance digital music or video player), or even longer when the end user pauses during play. Specific DRM implementations protect against this "pause attack" already have been implemented.
This dictionary attack is becoming more harmful to owners of the distributed digital content, especially since there are only a few currently available commercially successful systems for distribution of videos and audio. Since there are only a few such systems, hackers, by focusing on the content available via those systems and publishing the content keys, have made unauthorized use of the content even easier.
In a typical DRM system, the pieces of encrypted digital content are maintained on a central server by the content owner or operator of the service. Users then download to their computer via the Internet particular pieces of content such as a song or a video program. The downloaded material is typically downloaded in encrypted form and the content key is transmitted also, often in a separate transmission. This is done for some form of payment. The user can then play the content by decrypting it on his computer or player. This process is transparent to the user if he has purchased an unauthorized piece of digital content since the key accompanies the downloaded file and software installed on the user's computer decrypts the file. It is also possible for the user to download the digital file to a media player. Typically this second download is also performed in the encrypted state and then the decryption occurs upon playback in the player. Again this is transparent for properly purchased content. It is generally been found best if the decryption only occurs upon playback, for security reasons. Of course if the content key has been compromised as described above, that is published, anyone can access the song and transfers of the encrypted files to unauthorized users is easily accomplished and they can then apply the decryption key even though not authorized to do so.
In a typical scenario, a client computer downloads a piece of media (content or asset) to be played from a media distribution server, and the client also contacts a remote license server which provides the DRM license containing the specific cryptographic keys (content or asset key) required to decrypt the content. The DRM module has the necessary machine code instructions in order to open the license file and then decrypt the content or asset for the player, even without a network (e.g., Internet) connection.
So DRM systems are constantly being reverse engineered by attackers (hackers). In some types of attacks, a critical piece of data used in the content decryption process may be published by an attacker. This piece of data may allow an unauthorized party to utilize the DRM module and the license on the machine to perform unauthorized tasks (such as playing the content on a device that is not allowed by the license).
The DRM provider may want to upgrade the DRM module in the client media player to introduce new features or in reaction to security vulnerabilities or attacks on the client DRM module. There are multiple known routes for a DRM module to obtain an update on a computer system. Some methods require the system being upgraded to have Internet connectivity (using a remote loader, or installer program with online registration) and some do not (using a standalone pre-downloaded installer, or installation via a USB drive or an optical media disk).

Method and apparatus for key distribution with implicit offline authorization


A polymeric laminate for use in polymeric films, and packaging material and packages made therefrom, that is roughened or knurled to produce a series of nicks or cuts over substantially the entire surface area of the laminate, producing an easy-opening feature. The laminate may be a multilayer, polymeric structure that may comprise an oriented polypropylene, polyethylene terephthalate, or a biaxially oriented nylon. The packaging material of the invention may contain a sealant film, either a single layer or multilayer film, and may also comprise an intermediate layer of foil.

This invention relates to the field of polymeric films, and packages made therefrom, for packaging a variety of products, particularly food. More particularly, the invention relates to a method of achieving an easy-opening package made from a polymeric film.
Generally, polymeric or thermoplastic materials are difficult to tear because the materials are flexible and are usually comprised of randomly dispersed, long chains of molecules having relatively strong covalent carbon-to-carbon bonds.
One method of easing tearing is generally to stretch or orient the thermoplastic materials as they are being cast or blown. Stretching lines up the molecular chains in the stretched direction so that if tearing occurs in that direction, it takes place through weaker non-carbon-to-carbon bonds. This method has limited effectiveness because not all polymers can be readily oriented. Also, only a certain amount of molecules can be aligned, and, despite the stretching, tearing may still not be easy and reliable. Orienting also requires special manufacturing efforts and care.
A more effective method of creating an easy-opening tear is to notch the seal of the package to initiate the tear. Notches may be created on the seal during the sealing operations by use of a seal jaw. Alternatively, notches may be created in the bag, at seal or otherwise, by use of a blade or another sharp device, during manufacture or packaging.
A significant problem with bags or films having a notch is that the notch is not precisely located or is disturbed during manufacture, packaging, transportation or general handling.
Another method of forming a tear line, widely used for single layer films, is to employ a star wheel to form a line of intermittent perforations in the films. Perforations are unsuitable for multilayer laminates for many reasons. One such reason is that perforations in the film allow product-environment exchanges which defeat a purpose of using multilayer films, i.e., to protect an interiorly contained product by combining gas barrier properties of one material with moisture barrier properties of another.
A third prior art method of imparting an easy tear opening to a laminate structure is the use of a tear tape or string. The tear tape or string is undesirable because it can result in structures being opened when the tear tape or string is ripped or otherwise disturbed during manufacture, packaging, transportation or handling.
A fourth prior art method of imparting an easy tear opening to a laminate structure is through the use of laser scoring. Laser scoring, however, requires the use of specialized equipment, and therefore, leads to increased costs of manufacture.
An alternative to the above four methods of producing an easy-opening effect is to "roughen," "knurl" or "knick" a designated area of film to create the easy-opening effect.
"Roughening or "knurling" the surface of a polymeric film may be done by various methods. The roughening can be formed by rotating a round abrasive such as a grindstone or wire brush, or other instrument having bristles, and putting the rotating instrument into contact with the film. Alternatively, a flat instrument having a roughened or grainy surface, such as for example a grain-containing sheet material, can be put into contact with the polymeric film.
The following patents and or publications, which teach easy-opening features of the type discussed above, are cited as references:
U.S. Pat. No. 2,703,764, to Vogt, discloses a thermoplastic tape with a weakened embrittled edge to facilitate tearing along the edge.
U.S. Pat. No. 3,608,815, to Bunch, teaches a pattern of porelike punctures over a fold line on the edge of a formed package.
U.S. Pat. No. 4,543,279, to Kai, teaches a film with an easy-opening feature of a plurality of random cuts or scratches formed along the edges of a film.
U.S. Pat. No. 5,141,795, also to Kai, teaches a pouch or package with an easy-opening feature of a multiplicity of through cuts formed in the edge portion of the package, wherein the through cuts are partly or wholly closed with the heat seal layer.
U.S. Pat. No. 4,778,058, to Yamazaki, teaches an easy-opening feature of a surface roughened portion of a film or pouch, wherein the surface roughened portion is positioned at and around the folded portion and at an external surface of the pouch.
European Patent Application No. 0 596 747 A1 teaches an easy-opening feature of a plurality of rows of linearly extending, laterally spaced slits formed parallel to and inwardly adjacent a side of the film.
It has now been found that an effective and practical method of creating an easy-opening package made of polymeric or flexible materials is to roughen or knurl the entire surface of the structure by applying a series of overall nicks or minute cuts over substantially the entire area of the outer layer of the structure.
The method of the invention creates an effective easy-opening package that has decreased costs of production over prior art methods. Since the entire surface area of the package is roughened or knurled, the easy-opening feature does not need to be registered to printing, or to the shape or structure of the final package, resulting in manufacturing efficiencies. This contrasts with prior art packages having easy-opening features, in which the easy opening feature is fixed in a particular location with relation to the printing or to the shape or structure of the finished package.
The method of the invention also creates a packaging material or package that does not have notches or tear strips but is rather a smooth surface. Thus, the laminate and packaging material of the invention avoid the problem of tearing or ripping during manufacture, packaging, transportation or general handling, that is common in the prior art.

Easy-opening flexible packaging laminates and packaging materials made therefrom


An electronic price label (EPL) mounting device and method which allows an EPL to be mounted on a shelf at a number of viewing angles. The device includes a first portion coupled to the shelf, and a second portion which retains the EPL and which is rotatably coupled to the first portion. The device may additionally include a retainer for securing a sign to the second portion.

The present invention relates to electronic price label (EPL) systems, and more specifically to an EPL mounting device and method.
EPL systems typically include a plurality of EPLs for each merchandise item in a store. EPLs include displays which display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. EPL systems typically obtain their prices from the POS server's PLU file. A store may contain thousands of EPLs to display the prices of the merchandise items. The EPLs are coupled to a central server from where information about the EPLs is typically maintained in an EPL data file. The EPL data file contains EPL identification information, and EPL merchandise item information.
Customers find difficulty in viewing typical EPLs for two reasons. First, typical EPLs employ liquid crystal displays (LCDs), due to their low cost. However, LCDs must be viewed head-on. Reading difficulty increases as viewing angles increase. Second, typical EPLs have traditionally been mounted to shelf edges at a single orientation requiring removal and replacement if the shelf height changed. Otherwise, customers find difficulty in viewing items on the lowest and highest of shelves. Variance of customer heights complicates the problem.
Another problem associated with traditional EPL mounting methods is that they do not always facilitate mounting of store specific paper signage or other promotional fixtures.
Therefore, it would be desirable to provide an EPL mounting device and method which is capable of solving these mounting problems.

Electronic price label mounting device and method