Disclosed is a method for indicating an end of transmitting data frames in order to enable a UTRAN (UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access Network) to assign a common packet channel to another user equipment (UE) in a UE for a CDMA mobile communication system. The UE requests assignment of any one of a number of common packet channels assignable in the UTRAN; the UE is assigned a common packet channel by the UTRAN in response to the to request; the UE sequentially transmits the data frames and their associated control frames over the assigned common packet channel; and the UE transmits at least one control frame, in an appointed field of which a given bit pattern appointed with the UTRAN is registered, in order to inform the UTRAN of an end of data transmission upon completing data transmission through the data frames.

1. Field of the Invention
The present invention relates generally to a common channel communication apparatus and method for a CDMA (Code Division Multiple Access) communication system, and in particular, to an apparatus and method for communicating data over a common packet channel in an asynchronous CDMA communication system.
2. Description of the Related Art
An asynchronous CDMA communication system, such as the UMTS (Universal Mobile Telecommunications System) W-CDMA (Wideband Code Division Multiple Access) communication system, uses a random access channel (RACH) and a common packet channel (CPCH) for an uplink (or reverse) common channel.
FIG. 1 is a diagram for explaining how to transmit and receive a traffic signal over the RACH, which is one of the conventional asynchronous uplink common channels. In FIG. 1, reference numeral 151 indicates a signal transmission procedure of an uplink channel, which can be the RACH. Further, reference numeral 111 indicates an access preamble-acquisition indicator channel (AICH), which is a downlink (or forward) channel. The AICH is a channel over which a UTRAN (UMTS Terrestrial Radio Access Network) receives a signal transmitted from the RACH and responds to the received signal. The signal transmitted by the RACH is called an "access preamble" (AP), which is created by randomly selecting a signature for the RACH.
The RACH selects an access service class (ASC) according to the type of transmission data, and acquires from the UTRAN the right to use a channel using a RACH sub-channel group and an AP defined in the ASC.
In the application and drawings, τX-Y indicates a time period between variables X and Y. For example, the time period between a preamble (P) and an acquisition indicator (AI) would be represented as τP-AI.
Referring to FIG. 1, a user equipment (UE; or a mobile station in CDMA-2000 system) transmits an AP 162 of specific length using the RACH and then awaits a response from the UTRAN (or a base station in the CDMA-2000 system). If there is no response from the UTRAN for a predetermined time (τp-p), the UE increases transmission power by a specific level as represented by 164 and retransmits the AP at the increased transmission power. Upon detecting the AP transmitted over the RACH, the UTRAN transmits a signature 122 of the detected AP over the downlink AICH. After transmitting the AP, the UE determines whether the transmitted signature is detected from the AICH signal that the UTRAN has transmitted in response to the AP. In this case, if the signature used for the AP transmitted over the RACH is detected, the UE determines that the UTRAN has detected the AP, and transmits a message over the uplink access channel.
Otherwise, upon failure to detect the transmitted signature from the AICH signal that the UTRAN has transmitted within a set time τp-p after transmission of the AP 162, the UE judges that the UTRAN has failed to detect the preamble, and retransmits the AP after a lapse of a preset time τp-p. As represented by reference numeral 164, the AP is retransmitted at transmission power increased by ΔP (dB) from the transmission power at which the AP was previously transmitted. The signature used to create the AP is randomly selected from the signatures defined in the ASC selected by the UE. Upon failure to receive the AICH signal using the transmitted signature from the UTRAN after transmission of the AP, the UE changes, after a lapse of a set time, the transmission power and signature of the AP and repeatedly performs the above operation. In the process of transmitting the AP and receiving the AICH signal, if the signature transmitted by the UE itself is received, the UE spreads, after a lapse of a preset time τAP—AI-MSG, a RACH message 170 with a scrambling code for the signature, and transmits the spread RACH message using a predetermined channelization code at a transmission power level corresponding to the preamble to which the UTRAN has responded with the AICH signal (i.e., at initial power for an uplink common channel message).
As described above, by transmitting the AP using the RACH, it is possible for the UTRAN to efficiently detect the AP and to readily set the initial power of an uplink common channel message. However, since the RACH is not power controlled, it is difficult to transmit packet data, which has a long transmission time because the UE has a high data rate or has a large amount of transmission data. In addition, since the channel is allocated through one AP_AICH (Access Preamble-Acquisition Indicator Channel), the UEs that have transmitted the AP using the same signature will use the same channel. In this case, the data transmitted by the different UEs collide with one another, so that the UTRAN cannot receive the data.
To solve this problem, a method for suppressing a collision between the UEs while power controlling the uplink common channel has been proposed for the W-CDMA system. This method is applied to a common packet channel (CPCH). The CPCH enables power control of the uplink common channel, and shows a higher reliability as compared with the RACH in allocating the channel to different UEs. Thus, the CPCH enables the UE to transmit a data channel of a high rate for a predetermined time (from several tens to several hundreds of ms). Further, the CPCH enables the UE to rapidly transmit an uplink transmission message, which is smaller in size than a specific value, to the UTRAN without using a dedicated channel.
In order to establish the dedicated channel, many related control messages are exchanged between the UE and the UTRAN, and a long time is required in transmitting and receiving the control messages. Therefore, exchanging many control messages during the transmission of data of a comparatively small size (several tens to several hundreds of ms) creates a situation where valuable channel resources are allocated to control messages rather than data. The control messages are referred to as overhead. Thus, it is more effective to use the CPCH, when transmitting data of a small size.
However, since several UEs transmit preambles using several signatures in order to acquire the right to use the CPCH, there may occur a collision between the CPCH signals from the UEs. To avoid this phenomenon, a method is needed for allocating to the UEs the right to use the CPCH.
The asynchronous mobile communication system uses a downlink scrambling code to distinguish the UTRANs, and uses an uplink scrambling code to distinguish the UEs. Further, the channels transmitted from the UTRAN are distinguished using an orthogonal variable spreading factor (OVSF) code, and the channels transmitted by the UE are also distinguished using the OVSF code.
Therefore, the information required by the UE to use the CPCH, includes a scrambling code used for a message part of the uplink CPCH channel, an OVSF code used for the message part (UL_DPCCH) of the uplink CPCH, an OVSF code used for a data part (UL_DPDCH) of the uplink CPCH, a maximum data rate of the uplink CPCH, and a channelization code for a downlink dedicated channel (DL_DPCCH) used for power control of the CPCH. The above information is typically required when establishing a dedicated channel between the UTRAN and the UE. Further, the above information (overhead) is transmitted to the UE through transmission of signaling signals before establishment of the dedicated channel. However, since the CPCH is a common channel rather than a dedicated channel, the above information is conventionally represented by a combination of the signatures used in the AP and the CPCH sub-channels to which the sub-channel concept used in the RACH is introduced, in order to allocate the information to the UE.
FIG. 2 shows a signal transmission procedure of the downlink and uplink channel signals according to the prior art. In FIG. 2, in addition to the method used for the RACH for transmitting the AP, a collision detection preamble (CD_P) 217 is used to prevent a collision between CPCH signals from the different UEs.
In FIG. 2, reference numeral 211 indicates an operating procedure of an uplink channel performed when the UE requests allocation of the CPCH, and reference numeral 201 indicates an operating procedure of the UTRAN to allocate the CPCH to the UE. In FIG. 2, the UE transmits an AP 213. For a signature constituting the AP 213, it is possible to use a selected one of the signatures used in the RACH or to use the same signature, and the signature can be distinguished using the different scrambling codes. The signature constituting the AP is selected by the UE based on the above-stated information, as opposed to the method where the RACH randomly selects the signature. That is, to each signature are mapped an OVSF code to be used for the UL_DPCCH, an OVSF code to be used for the UL_DPDCH, an OVSF code to be used for the UL_Scrambling code and DL_DPCCH, the maximum frame number, and a data rate. Therefore, in the UE, selecting one signature is equivalent to selecting four kinds of the information mapped to the corresponding signature. In addition, the UE examines a status of the CPCH channel which can be presently used in the UTRAN to which the UE belongs, through a CPCH status indicator channel (CSICH) transmitted using an ending part of the AP_AICH before transmitting the AP. Thereafter, the UE transmits the AP over the CSICH after selecting the signatures for the channel to be used out of the CPCHs which can be presently used. The AP 213 is transmitted to the UTRAN at initial transmission power set by the UE. In FIG. 2, if there is no response from the UTRAN within a time (τp-p) 212, the LE retransmits the AP represented by AP 215, the higher power level transmission. The number of retransmissions of the AP and the waiting times are set before a process for acquiring the CPCH channel is started, and the LE stops the CPCH channel acquisition process when the retransmission number exceeds a set value.
Upon receipt of the AP 215, the UTRAN compares the received AP with the APs received from other UEs. Upon selecting the AP 215, the UTRAN transmits AP_AICH 203 as ACK after a lapse of a time (τp-AI) 202. There are several criteria on which the UTRAN bases its comparison of the received APs to select the AP 215. For example, the criteria may correspond to a case where the CPCH, for which the UE has requested the UTRAN through the AP, is available, or a case where the receiving power of the AP received by the UTRAN satisfies the minimum receiving power requested by the UTRAN. The AP_AICH 203 includes a value of the signature constituting the AP 215 selected by the UTRAN. If the signature transmitted by the UE itself is included in the AP_AICH 203 received after transmitting the AP 215, the UE transmits a collision detection preamble (CD_P) 217 after a lapse of a time (τp-CD—p) 214, a time beginning at the time when AP 215 was originally transmitted. A reason for transmitting the CD_P 217 is to prevent a collision between transmission channels from the various UEs. That is, many UEs belonging to the UTRAN may request the right to use the same CPCH by simultaneously transmitting the same AP to the UTRAN, and as a result, the UEs receiving the same AP_AICH may try to use the same CPCH, thereby causing a collision. Each of the UEs which have simultaneously transmitted the same AP, selects the signature to be used for the CD_P and transmits the CD_P. Upon receipt of the CD_Ps, the UTRAN can select one of the received CD_Ps and respond to the selected CD_P. For example, a criterion for selecting the CD_P can be a receiving power level of the CD_P received from the UTRAN. For the signature constituting the CD_P 217, one of the signatures for the AP can be used, and it can be selected in the same manner as in the RACH. That is, it is possible to randomly select one of the signatures used for the CD_P and transmit the selected signature. Alternatively, only one signature can be used for the CD_P. When there is only one signature used for the CD_P, the UE selects a randomized time point in a specific time period to transmit the CD_P at the selected time point.
Upon receipt of the CD_P 217, the UTRAN compares the received CD_P with the CD_Ps received from other UEs. Upon selecting the CD_P 217, the UTRAN transmits a collision detection indicator channel (CD_ICH) 205 to the UEs after a lapse of a time (τCD—p-CD—I) 206. Upon receipt of the CD_ICH 205 transmitted from the UTRAN, the UEs check whether a value of the signature used for the CD_P transmitted to the UTRAN is included in the CD_ICH 205, and the UE, for which the signature used for the CD_P is included in the CD_ICH 205, transmits a power control preamble (PC_P) 219 after a lapse of a time (τCD—p-PC—p) 216. The PC_P 219 uses an uplink scrambling code determined while the UE determines a signature to be used for the AP, and the same channelization code (OVSF) as a control part (UL_DPCCH) 221 during transmission of the CPCH. The PC_P 219 is comprised of pilot bits, power control command bits, and feedback information bits. The PC_P 219 has a length of 0 or 8 slots. The slot is a basic transmission unit used when the UMTS system transmits over a physical channel, and has a length of 2560 chips when the UMTS system uses a chip rate of 3.84 Mcps (chips per second). When the length of the PC_P 219 is 0 slots, the present radio environment between the UTRAN and the UE is good, so that the CPCH message part can be transmitted at the transmission power at which the CD_P was transmitted, without separate power control. When the PC_P 219 has a length of 8 slots, it is necessary to control transmission power of the CPCH message part.
The AP 215 and the CD_P 217 may use the scrambling codes which have the same initial value but have different start points. For example, the AP can use 0th to 4095th scrambling codes of length 4096, and the CD_P can use 4096th to 8191st scrambling codes of length 4096. The AP and CD_P can use the same part of the scrambling code having the same initial value, and such a method is available when the W-CDMA system separates the signatures used for the uplink common channel into the signatures for the RACH and the signatures for the CPCH. For the scrambling code, the PC_P 219 uses the 0th to 21429th values of the scrambling code having the same initial value as the scrambling code used for AP 215 and CD_P 217. Alternatively, for the scrambling code for the PC_P 219, a different scrambling code can also be used which is mapped one-to-one with the scrambling code used for AP 215 and CD_P 217.
Reference numerals 207 and 209 denote a pilot field and a power control command field of a dedicated physical control channel (DL_DPCCH) out of a downlink dedicated physical channels (DL_DPCHs), respectively. The DL_DPCCH can use either a primary downlink scrambling code for distinguishing the UTRANs or a secondary scrambling code for expanding the capacity of the UTRAN. For a channelization code OVSF to be used for the DL_DPCCH, a channelization code that is determined when the UE selects the signature for the AP is used. The DL_DPCCH is used when the UTRAN performs power control on the PC_P or CPCH message transmitted from the UE. The UTRAN measures receiving power of a pilot field of the PC_P 219 upon receipt of the PC_P 219, and controls transmission power of the uplink transmission channel transmitted by the UE, using the power control command 209. The UE measures power of a DL_DPCCH signal received from the UTRAN to apply a power control command to the power control field of the PC_P 219, and transmits the PC_P to the UTRAN to control transmission power of a downlink channel incoming from the UTRAN.
Reference numerals 221 and 223 denote a control part UL_DPCCH and a data part UL_DPDCH of the CPCH message, respectively. For a scrambling code for spreading the CPCH message of FIG. 2, a scrambling code is used which is identical to the scrambling code used for the PC_P 219. For the used scrambling code, the 0th to 38399th scrambling codes of length 38400 in a unit of 10 ms are used. The scrambling code used for the message of FIG. 2 can be either a scrambling code used for the AP 215 and the CD_P 217, or another scrambling code which is mapped on a one-to-one basis. The channelization code OVSF used for the data part 223 of the CPCH message is determined according to a method previously appointed between the UTRAN and the UE. That is, since the signature to be used for the AP and the OVSF code to be used for the UL_DPDCH are mapped, the OVSF code to be used for the UL_DPDCH is determined by determining the AP signature to be used. For the channelization code used by the control part (UL_DPCCH) 221, a channelization code is used which is identical to the OVSF code used by the PC_P. When the OVSF code to be used for the UL_DPDCH is determined, the channelization code used by the control part (UL_DPCCH) 221 is determined according to an OVSF code tree structure.
Referring to FIG. 2, the prior art enables power control of the channels in order to increase efficiency of the CPCH, which is the uplink common channel, and decreases the chance of a collision between uplink signals from the different UEs, by using the CD_P and the CD_ICH. However, in the prior art, the UE selects all the information for using the CPCH and transmits the selected information to the UTRAN. This selecting method can be performed by combining a signature of the AP, a signature of the CD_P and the CPCH sub-channel, transmitted from the UE. In the prior art, even though the UE requests allocation of the CPCH channel required by the UTRAN by analyzing a status of the CPCH, which is presently used in the UTRAN, by using the CSICH, the fact that the UE previously determines all the information required for transmitting the CPCH and transmits the determined information will result in a limitation of the allocation of resources of the CPCH channel and a delay in acquiring the channel.
The limitations on allocation of the CPCH channel are as follows. Although there exist several available CPCHs in the UTRAN, if the UEs in the UTRAN require the same CPCH, the same AP will be selected. Although the same AP_AICH is received and the CD_P is transmitted again, the UEs which transmitted the non-selected CD_P should start the process for allocating the CPCH from the beginning. In addition, although the CD_P selecting process is performed, many UEs still receive the same CD_ICH, increasing a probability that a collision will occur during uplink transmission of the CPCH. Further, although the CSICH is checked and the UE requests the right to use the CPCH, all of the UEs in the UTRAN which desire to use the CPCH receive the CSICH. Therefore, even though an available channel is required out of the CPCHs, there is a case where several UEs simultaneously request channel allocation. In this case, the UTRAN cannot but allocate the CPCH requested by one of the UEs, even though there are other CPCHs which can be allocated.
With regard to the delay in acquiring the channel, when the case occurs which has been described with reference to the limitations on allocation of the CPCH channel, the UE should repeatedly perform the CPCH allocation request to allocate the desired CPCH channel. When there is used a method for transmitting the CD_P at a given time for a predetermined time using only one signature for the CD_P introduced to reduce the complexity of the system, it is not possible to process the CD_ICH of other UEs while transmitting and processing the CD_ICH of one UE.
In addition, the prior art uses one uplink scrambling code in association with one signature used for the AP. Thus, whenever the CPCH used in the UTRAN increases in number, the uplink scrambling code also increases in number, causing a waste of the resources.
Meanwhile, in order to efficiently transmit packet data using the common channel such as the CPCH channel, a scheduling method for effectively assigning and releasing the channel is required. The scheduling method is used to rapidly release the channel when there is no data on a given uplink channel, and then assign the released channel to another UE, thereby to prevent unnecessary channel access by the UE and a waste of the channel resources.
At present, the maximum length of the packet, which can be transmitted over the CPCH, is broadcasted from the UTRAN to the UE through a parameter NF_max of an RRC (Radio Resource Control) message. In general, the maximum length of the packet that can be transmitted over the CPCH is 64. Therefore, when a frame length of the physical layer is 10 ms and NF_max is set to 64, the UE can transmit the packet data for 640 ms after a success of initial access.
However, since the UTRAN knows only the maximum transmission duration NF_max assigned by itself, the UTRAN reserves (or schedules) a Node B resource for the maximum transmission duration or defers (or rejects) a resource assignment request from another UE, in expectation of data transmission from the UE for 640 ms. In this operation, the UTRAN statically monitors data transmitted from the UE, and thus, it is not possible to effectively guarantee scheduling. That is, even though the UE ends data transmission before expiration of the maximum data transmission duration NF_max, the UTRAN releases the channel after monitoring the corresponding channel until the maximum data duration NF_max expires.
For this reason, the UTRAN increases power of the UE on a false determination that a frame error is occurring from the point where the UE ends data transmission until the point where NF_max expires, thereby causing a waste of the resources. In addition, since the UTRAN cannot rapidly assign the channel to another UE requiring the CPCH, the UE repeats an attempt to access the channel, thus decreasing the overall system stability.

Apparatus and method for assigning a common packet channel in a CDMA communication system


The invention concerns an optical viewing device which incorporates a spectral filter to partially reduce the intensity or wavelength(s) of light transmitted to a specific region of a specimen which may be a human eye. The reduction in light intensity or wavelength may be variable across the filter and may be accomplished in an intensity-dependent or a wavelength-dependent manner.

1. Field of the Invention
The invention concerns an optical viewing device, such as for example a surgical (stereo) microscope, having an apparatus for partial reduction of the illumination intensity, such as an eclipse filter. An "eclipse filter" is understood to be a spectral filter in an illuminating beam which fully or partially reduces the illumination intensity in a specific light wavelength range.
2. Description of the Related Art
Reduction of the illumination of a specific spatial region of a specimen, by means of a stop, is more frequently being used in a variety of applications so that light sensitive surfaces, of the specimen can be protected from excessively strong radiation. These stops are generally configured to swing into and out of an illuminating beam thereby providing complete and/or partial darkening of the illuminating beam in a specific spatial region which is to be protected from the light.
German Patent Document DE 93 01 448 U, which is incorporated herein by reference, discloses a filter system. The filter system, which includes individual filters possessing different diameters, provides for a partial darkening in specific spatial regions. This darkening is not wavelength-dependent in the visible light region between 400 and 700 nm. In addition, German Patent Document DE 88 08 871 U, which is also incorporated herein by reference, provides a diffusion plate for slit lamp devices which plate creates a preferred direction in the scattering characteristic. Further, U.S. Pat. No. 4,715,704, which is also incorporated herein by reference, describes a light trap having a centrally darkened region.
Although the aforementioned patents have improved the art, various disadvantages remain. First, the reduction in light intensity is accomplished either in binary fashion (i.e., the reduced-light specimen region either appears dark to the user or is visible at full brightness), or there is a graduated filter effect which is not optimized in terms of light color; this can have negative effects on a specimen, for example on a patient's eye. Second, to make the reduced-light region visible in true color to the viewer, it is necessary to remove the stop thereby completely illuminating the specimen; such illumination may damage the specimen. Third, because of the fixed positioning of the stop in the illuminating beam, the shape and/or the attenuated illuminating beam cannot be varied. Fourth, damage to the specimen, for example to the patient's eye, usually does not occur in a similarly hazardous fashion over the entire range of light wavelengths. Rather, damage occurs only in a specific wavelength range, for example from 420 nm to 470 nm (or even up to 495 nm). In addition, below 400 nm, it is unnecessary to filter out all wavelengths.
In light of the aforementioned deficiencies in the prior art, a new apparatus is needed for reducing the intensity of light which is directed toward sensitive regions of a specimen which may be injured by excessively strong radiation.

Optical viewing device having an apparatus for partial reduction of the illumination intensity


Disclosed is a peripheral object detection system to be mounted on a vehicle. The peripheral object detection system includes a peripheral information acquisition device and a detecting range switching mechanism. The peripheral information acquisition device is configured to have, as a detected range, apart of a peripheral space of the vehicle and to acquire distance information to an object that exists in the detected range and is to be detected. The detecting range switching mechanism is configured to switch, toward an area forward or backward of the vehicle, a direction of a detecting range of the peripheral information acquisition device based on forward/backward information that indicates whether the vehicle is moving in a forward direction or in a reverse direction.

1. Field of the Invention
This invention relates to a peripheral object detection system and a haulage vehicle, and especially to a technology that makes it possible to reduce the number of parts and components used in peripheral monitoring surroundings of such a haulage vehicle.
2. Description of the Related Art
In so-called open-pit mining that rock and ore are excavated and delivered at the bottom of a mine, each haulage vehicle (hereinafter called "dump truck") repeats operation that upon completion of loading of excavated rock, it hauls the excavated rock from the excavation site to a dumping site and dumps the excavated rock there, and travels back again to the excavation site. The haulage rate per unit time of rock, which is hauled by each dump truck, is a matter linked directly to the progress of excavation so that the haulage of rock requires each dump truck to travel at high speed. To efficiently haul rocks in bulk out of the excavation site, a plurality of dump trucks travel back and forth many times between the excavation site and the dumping site along a haulage road. It is, accordingly, important to take preventive measures for collision accidents between on-going and on-coming dump trucks themselves.
In excavation work at mines, there is also an outstanding demand for unmanned haulage vehicles (hereinafter called "unmanned dump trucks"), which can perform autonomous traveling without operators on board, with a view to achieving improved safety and lowered mining costs.
As a technology for allowing an unmanned mobile object to perform autonomous traveling, JP2009-175932A is known. This patent document discloses a configuration that forward profile data are acquired as data in a sensor coordinate system by a laser range finder and that based on geometric feature values of data obtained by converting the first-mentioned data from the sensor coordinate system into an orthogonal coordinate system and those of prior data acquired beforehand, a region on a forward side is processed and divided into a travelable area and an untravelable area.
An unmanned dump truck that travels in a mine travels in reverse upon dumping at a dumping site. Measures are, therefore, also important for conforming the area backward of the unmanned dump truck during its backward traveling. In this respect, nothing is taken into consideration in JP2009-175932A. Further, any attempt to apply the technology of JP2009-175932A as a technology for confirming areas forward and backward of the unmanned dump truck requires laser range finders for the confirmation of the areas forward and backward of the unmanned dump truck, so that the problem of higher manufacturing costs for such unmanned dump trucks remains unsolved. Even with a manned haulage vehicle (hereinafter called "the manned dump truck") that travels with an operator onboard, a blind spot is formed in each of forward and backward fields of view. Therefore, the above-described problem also arises in the manned dump truck in much the same way as in the unmanned dump truck.
With the above-described problems in view, the present invention has as objects thereof the provision of a peripheral object detection system, which can perform at lower costs the detection of objects existing in forward and backward peripheries of a vehicle, and a haulage vehicle with the peripheral object detection system mounted thereon.

Peripheral object detection system and haulage vehicle

Hitachi Construction Machinery Co., Ltd.


A method for monitoring an analyzer including a liquid chromatography device (LC) having at least two liquid chromatography (LC) streams, the method including continuously monitoring one or more parameters in measurement data of samples in each of the at least two LC streams, the one or more parameters being independent of an analyte concentration of the respective sample, determining if the one or more monitored parameters show an expected behavior and triggering a response upon detection that the one or more monitored parameters deviate from the expected behavior.

There is growing interest for the implementation of LC devices, often coupled to mass spectrometers (MS) in the clinical laboratory and also in other laboratory settings. The number of published methods, especially for small molecules in therapeutic drug monitoring or drug of abuse testing is increasing.
In particular, there is growing interest in operating analyzers in a random-access mode, i.e., analyzers in which a plurality (potentially a relatively large number) of different assays can be processed in any given measurement period (e.g., during a period of one (work) day or a fraction of a day). This can dramatically increase the number of quality control runs that have to be carried out as, e.g., quality control runs at multiple concentration levels (e.g., two or three concentration levels) have to be carried out in regular intervals for each assay. For instance, typical regulatory standards can require one or more quality control runs per day. This issue of a large number of required quality control runs is further aggravated in systems including multiple LC streams which can be multiplexed to connect to, e.g., a single MS. For these systems, each LC stream might be seen as a separate instrument to be subjected to quality control. Thus, in a system having three or more LC streams connected to an MS, the quality control measurements at each required or desired concentration level for each assay have to be performed three or more times respectively per quality control period.
As a result, an ever longer amount of analyzer time might have to be allocated for quality control runs. Therefore, techniques for reducing the quality control effort while still ensuring that the instrument is properly monitored, particularly for analyzers operating in a random-access mode and having multiple LC streams are desirable.

Techniques for monitoring an analyzer including multiple liquid chromatography streams


An automatic playing apparatus according to the present invention, stores, in an automatic playing pattern data memory, chord, bass, drum data for each of a plurality of intro, normal and ending patterns, and drum data for each of a plurality of fill-in patterns, and reads, when a fill-in is selected via an operation panel, chord data and bass data, stored for an intro, normal, or ending pattern data, and drum data, stored for a fill-in pattern, to perform automatic playing. Further, an automatic playing apparatus according to the present invention includes an automatic playing pattern data memory wherein loud fill-in pattern data and soft fill-in pattern data are stored, sets an intonation value using an intonation dial as the performance is developed, and performs automatic playing based on either loud fill-in pattern data, if the intonation value is equal to or greater than a predetermined value, or based on the soft fill-in pattern data, if the intonation value is smaller than the predetermined value.

1. Field of the Invention
The present invention relates to an automatic playing apparatus that is used in an electronic musical instrument to accomplish automatic playing of designated rhythms, and to an automatic playing apparatus that is used in an electronic musical instrument to accomplish automatic playing in agreement with the performance development (intonation).
2. Description of the Related Art
Conventionally, an electronic keyboard, such as an electronic organ or electronic piano, has a memory wherein automatic playing patterns, including intro, fill-in, normal, and ending, are stored for each rhythm. Switches included on such an electronic keyboard are used to select appropriate automatic playing patterns during the music production process. The keyboard reads the selected patterns from the memory, and inserts corresponding phrases during the performance.
The individual automatic playing patterns comprise data for producing musical tones for chords, bass, and drums. The pattern data stored in the memory therefore include data for chords, bass and drums, while the automatic playing patterns include intro, fill-in, normal and ending.
As a result, when multiple automatic playing patterns are provided for each rhythm, the amount of pattern data is significantly increased and a large memory capacity is required.
Further, if fixed automatic playing patterns are inserted during the production process, rather than inserting phrases corresponding to single-phrase automatic playing patterns that are read from the memory, the performance becomes discontinuous, and a gradual change in the accompaniment that agrees with the intonation of the music performance is not possible.
The inventors of the present invention, therefore, have previously devised an automatic playing apparatus, for which a Japanese Patent Application is in pending (ref., Japanese Unexamined Patent Publication No. 58189/91), that features an intonation dial to be used to control the performance development, intending therewith to provide automatic accompaniment that agrees with the performance development.
With such an automatic playing apparatus that has an intonation dial, however, a fixed fill-in pattern is used when a fill-in is inserted; the apparatus fails, therefore, to adequately provide for performance development.

Automatic playing apparatus having reduced memory requirements


An inkjet recording medium includes a substrate, an intermediate layer disposed on the substrate, and an ink receiving layer disposed on the intermediate layer. The intermediate layer includes a binder, an inorganic pigment, and a pigment ink fixing agent chosen from divalent salts, multivalent salts, and combinations thereof. The ink receiving layer includes a non-film forming polymer, a binder chosen from any of water dispersible binders or water soluble binders, and a pigment.

The present disclosure relates generally to inkjet recording mediums.
Media suitable for use with inkjet printing often include one or more coating layers formed on a substrate to enhance various properties including printing performance and image quality, to name a couple. For instance, some coating layers may contain a pigment (such as, e.g., silica) that is specifically chosen to enhance ink absorption, while other coating layers may contain another pigment (such as, e.g., alumina) that is specifically chosen to enhance gloss.

Hewlett-Packard Development Company, L.P.


A dispensing device, which may be used with an immunoassay apparatus, includes at least two dispensing pipettes for sucking and discharging liquid; a pipette elevating device for selectively raising and lowering each pipette along an elevating path thereof; a base for holding the pipette elevating device; a base moving device for moving the base; a washing vessel in which each pipette is alternately immersed to be cleaned; and a washing vessel moving device for allowing the washing vessel to selectively move between locations in the elevating paths of the pipettes.

1. Field of the Invention
The invention relates to a dispensing device, and an immunoassay apparatus using the same; and more particularly, to a dispensing device comprising a plurality of dispensing pipettes for sucking and discharging a liquid; a pipette elevating means for raising and lowering each pipette; a base to hold the pipette elevating means; a base moving means for moving the base; and a washing vessel for cleaning each pipette which can be efficiently incorporated into an immunoassay apparatus.
2. Description of the Related Art
Generally, a dispensing device is used by being incorporated in an automatic analyzing apparatus such as an immunoassay apparatus. In the dispensing device, each dispensing pipette is moved to a location over each of specimen, reagent, washing and reaction vessels, which are placed on a table of the automatic analyzing apparatus, so as to suck and discharge the specimen and the reagent to be reacted with each other followed by cleaning.
With the conventional type of dispensing device, each pipette must be moved to the washing vessel to be cleaned for the next dispensing operation each time the dispensing of the specimen or the reagent from the pipette is completed. For the automatic analyzing apparatus including this conventional type dispensing device, there has been a need for a dispensing device capable of accelerating the dispensing operation and the cleaning operation and enabling a large quantity of specimen to be analyzed with high efficiency.

Dispensing device and Immunoassay apparatus using the same


A backup administrator can backup files from a production server on any of a plurality of different bases. In particular, some files can be replicated on a changed-byte basis. In other cases, files can be backed up by replicating updated copies of the entire file, or even byte blocks of the file. Determinations as to how a replication agent will back up a certain file or set of files can be made by a backup administrator, automatically through a predefined logic, or dynamically based on defined criteria. Corresponding agents at the production server can then flag these files as indicated. Thus, at a later point, when the DPM server requests the updates of each file, the production server can either send over copies of the changed file bytes, entire copies of the changed file itself, or even changed blocks of a file, as appropriate.

Background and Relevant Art
As computerized systems have increased in popularity, so have the needs to store and backup electronic files and other communications created by the users and applications associated therewith. In general, computer systems and related devices create files for a variety of reasons, such as in the general case of creating a word processing document in a work setting, as well as creating a file used for more sophisticated database purposes. In addition, many of these documents can include valuable work product, or sensitive information that should be protected.
One will appreciate, therefore, that there are a variety of reasons why an organization will want to backup electronic files on a regular basis, and thereby create a reliable restoration of an originally created file when needed. Generally, some of the challenges facing organizations implementing one or more such backup solutions relate to choices in a particular replication mechanism. That is, there are many ways (i.e., replication mechanisms) to copy data to be protected from a production server volume to a backup storage volume at a backup server, which is where the protected data would reside for recovery purposes. One can appreciate that each replication mechanism carries with it certain advantages and disadvantages.
For example, one conventional replication mechanism involves the production server logging the names of files that have changed on a volume to be protected, and then sending the entire, updated files to a backup volume at the backup server that corresponds to the volume to be protected at the production server. Another, similar mechanism for doing this is for the production server to not only log the name(s) of file(s) that have changed, but also compare the file(s) that have changed at the production server with any corresponding backup copy(ies) of the file(s) at the backup server, and then send to the backup server only the differential, changed bytes.
In particular, the latter mechanism can allow for faster monitoring in part since it may be done without use of a file system filter to monitor changes. Unfortunately, this replication mechanism may involve more resource overhead when comparing a prior copy of the file with an updated version. As such, both of these types of replication mechanism tend to be more effective with smaller files, or with large files that only have a set of the same bytes in a block of bytes that change frequently. Conversely, these replication mechanisms can be very inefficient for very large files, such as database files, particularly files that have sets of several bytes or byte blocks that change with relatively low frequency.
Another conventional replication mechanism involves identifying changes to files, rather than identifying only files that have changed. This mechanism of identifying changes to files typically relies on identifying files (e.g., names, types or locations) that are intended for replication, and identifying only the bytes that have changed in the file between administrator-defined time intervals in between replications. Thus, a backup agent (e.g., a "clone agent" in combination with a "file system filter" at the production server) logs only those changed bytes in the file, and ultimately communicates those changed bytes to the backup storage volume (i.e., "replica volume" on the storage medium). Unfortunately, this replication mechanism still tends to be more cost-effective from a resource expenditure standpoint for very large files or files that change infrequently between replication intervals, but less cost-effective for files that tend to change frequently or are entirely overwritten with each update.
Still another type of replication mechanism, which could be considered a hybrid in some respects of both of the above-discussed replication mechanisms, involves identifying files in terms of "byte blocks." Generally, "byte blocks" comprise fixed size contiguous blocks of bytes, of which there can be many in any given file. For example, a production server (or "file server") can identify files as sets of multiple blocks, where each block contains a plurality of bytes. If any of the bytes change within a given block (i.e., are updated, written to, etc.), the replication mechanism might flag the changed block, and send the entire block to the replica volume at an appropriate time. As such, the replica agent can spend only those resources that may be necessary to identify a changed block of bytes, rather than each changed byte in the file. This can allow a given server to avoid incurring additional overhead even though multiple changes may be made to the same byte block. Nevertheless, while this can provide the replication agent with some resource-expenditure advantages over the aforementioned mechanisms, this mechanism may still be better suited for larger files, such as database files, or files whose byte blocks are changed more than once within the same replication cycle.
Accordingly, an organization that is determining to use a particular replication mechanism for its backup service may need to weigh several considerations. Complicating this is the notion that, even though an organization may make a determination on its present file generation/change needs, such a consideration may nevertheless be inadequate in the future. For example, the organization's determination of a particular replication mechanism will typically be applied to all files to be protected, without regard to indicia that may make the determination more applicable for some files than for others, such as file type, size, location, or the like. Thus, the determination may be based on what the organization feels is best with its current environment, such as the set of most common file types, and/or commonly used applications.
Of course, if the predominant file type(s) and/or application types change(s) at a later point, then it is possible that the initially chosen replication mechanism may need to be replaced. This possibility can make it particularly difficult for the organization, both at the outset when trying to project what replication mechanism will be preferred, as well as at a later point from a resource expenditure perspective if or when needing to change. For example, the organization could insist that the bulk of applications used in the organization use a certain file type and/or application type that is suited to the chosen replication mechanisms, or alternatively commit itself to changing its replication mechanism periodically. Both of these scenarios, of course, can lead to significant cost and resource expenditure problems for the organization.

Automatically determining file replication mechanisms


A diesel engine piston assembly comprises a piston body having a top wall with a combustion bowl formed in the top wall and having a combustion bowl edge, an outer ring belt formed with a plurality of ring grooves including a top ring groove with an upper wall of the top ring groove and a top land portion of the ring belt disposed between the top ring groove and the top wall, a pair of pin bosses with aligned pin bores and a skirt; and a diamond dispersed chromium composite coating applied to at least the top wall, the combustion bowl edge, the top land portion and the upper wall of the top ring groove.

1. Technical Field
This invention relates generally to diesel engines and more particularly to coatings used to protect the various power cylinder components of the power cylinder including the piston.
2. Related Art
Many ways and means exist to protect in-cylinder diesel engine components from deleterious effects of combustion by-products, notably when EGR (exhaust gas recirculation) is used in the engine. Also, it has been proposed to use coatings as joint tribological elements in lieu of bushings and bearings and the like. As examples of the latter, manganese phosphate, DLC (diamond-like-coatings), many variations of PVD (physical vapor deposition)-derived coatings, electroless and electroplated layers.
With widespread use of high pressure diesel engine injection systems (common rail, electronic unit injectors, hydraulic electronic unit injectors) piston bowl rim oxidation/erosion by the torch-like effects from each combusting fuel plume are becoming commonplace. Also, due to late fuel injection timing necessary to preclude NOx formation, instances of liner fuel overspray have been documented. On the other extreme, early or pilot injection might deposit liquid fuel on piston tops that remains unburnt for most of the compression stroke. There are several side effects to these conditions inherent with high pressure diesel injections systems, including: 1) the build-up of carbon deposits on the top land of diesel engine pistons, 2) the deterioration of the oil film at top dead center/top ring reversal point on the liner and 3) piston erosion (pitting) particularly where the plumes from the injectors fire on the top bowl edge of the piston.
Top land carbon build up is historically singled out as the root cause of bore polishing and subsequent lubricant oil control loss. Emissions are then adversely affected.
Liner overspray with fuel dilutes and contaminates the oil film, greatly affecting the ability of the squeeze film to handle the first ring contact load. Fuel overspray also depletes the lubricant TBN reserve and entrains soot into the oil film. The net effect is the formation of a corrosive/abrasive medium which wears out components in intimate contact with the medium. Chemical etching (corrosion) of the liner on the first 20 to 40 mm of the piston travel from TDC not only leads to accelerated local wear, but also leads to higher ring peripheral (OD) face wear.
Local uncontrolled (explosive) deposited fuel burn creates extremely high thermal and mechanical stressing of the piston material. Eventually pitting occurs and will structurally weaken reentrant combustion bowl overhang lip and breakage can occur. Further out towards the piston OD, craters can be dug into the metal substrate. Emissions and overall engine performance are adversely affected. These factors may combine in such a way as to aggravate first ring groove wear in high pressure/high thermal loaded diesel engines.
What has been described thus far are typical problems, to a greater or lesser degree, derived from in-cylinder environment created by emissionized engines having EGR. In addition, the high rate of pressure rise and high peak combustion pressure characteristic of modern diesel engines slap the piston against and excite the liner's vibratory motions, triggering liner cavitation which can be a major problem itself. Skirt coatings (polymer based or graphite impregnated) are expected to help diminish cavitation but they bring additional problems of their own, besides being cumbersome to apply during manufacture.

Coated power cylinder components for diesel engines


A semiconductor integrated circuit memory device, and test method for a memory device are provided in which an external wordline voltage is applied to a wordline of the memory device. A current on the wordline is measured as a result of application of the externally supplied wordline voltage. The measured current is compared to a reference value to determine whether the wordline has a defect, in particular a short-circuit defect. A tester device is connected to the memory device and supplies the external wordline voltage. The current measurement and comparison may be made internally by circuitry on the memory device or externally by circuitry in a tester device.

The present invention is directed to semiconductor devices, and more particularly to testing semiconductor memory devices for defects.
Defects in semiconductor integrated circuit memory devices, such as dynamic random access memory (DRAM) devices, are tested for during production at different stages. Defects in the devices that are detected after completed manufacturing and before integrated circuit packaging are "repaired" by the use of redundant elements. Defects that are detected after packaging lead to rejection of the device.
Currently, defects such as wordline-bitline short-circuits are detected by functional test patterns that compare expected data against actual data. If mismatches occur, the corresponding addresses are stored. A bitmap such as the one shown in FIG. 1 would be identified as a wordline-bitline short either by a redundancy algorithm or by bitmap analysis, and the bitmap shown in FIG. 2 might be recognized as a wordline-wordline short-circuit.
With current testing techniques, the ability to detect a defect depends on the nature of the resistive short. High resistive shorts reduce the signal margin only for the cells on the shorted bitline so that a bitline-oriented failure may be possibly detected. Such a testing technique is not reliable because only a secondary effect is measured. Furthermore, this approach makes defect localization very difficult and requires time consuming analysis techniques to localize a defective wordline because if only a bitline oriented defect is detected, it is not clear from which deactivated wordline the leakage originates.

Test mode for IPP current measurement for wordline defect detection


A method, apparatus, and system are described that provides fully automated network access to remote networked devices. The device and system permits the remote access of a local network without any pre-configuration or administrative burden at the local network. Embodiments as described herein provide a “plug and play” option to insert a device into the local network and provide access to select target devices on the network, even non-routable devices, without first requiring dedicated host software or other administrative privileges or configurations be set at the local network.

A local area network ("LAN") permits the interconnection of computers in a local or limited area. For example, an office or work site may create a computer network that interconnects computers, printers, scanners, and other resources to a single network to provide access by multiple users. The Internet is a large collection of networks that interconnects computers over a larger geographic area. The Internet uses the protocols TCP/IP suite to allow devices on one network to automatically communicate with other devices that may be on the same or remote networks. Each such device is assigned an IP address for each active network interface, which allows network infrastructure components to automatically route traffic between target devices.
Generally, in order to access one device across a network or internet, each available device must be assigned a unique internet protocol ("IP") address to identify the target device. If an address is not unique, the addresses are referred to as non-routable addresses because it is not possible to establish a route (that is, a path through a set of network infrastructure devices) such that traffic from a device on the local network may reach a network interface with the non-routable address on a remote network. This is very common when installing a unique device on a network that automatically assigned an IP address during the installation process. If an administrator just chooses the automatically assigned address, then the same device on different networks will be addressed the same. If more than one network containing this same device is then connected, the two devices are non-routable since their addresses are no longer unique. Alternatively, a target device may be assigned the same IP address as another device if contained in separate private networks, to alleviate the shortage of unique IP addresses available. Such private IP addresses are similarly non-routable if the private networks are later connected. Such non-routable IP addresses lead to greater complexity as administrators seek alternative mechanisms to provide access to remote devices without routable addresses.
Another concern presented by connecting one or more networks through the Internet is the security threat involved. Network administrators may seek to limit access to specific devices on a local network, while still providing remote access to other devices. A network administrator may limit access by developing and deploying network filtering devices or applications that allow them to specify specific address and port combinations that are granted or denied access to or from the remote connection. Although these techniques help reduce security threats, they increase complexity and cost to administrators desiring seamless access to networked devices.
To provide access to or between more than one network that may include the problems identified above, a dedicated device or client software may be installed on the local network that functions as a networked device. This dedicated device or software then acts as a host, assigned with a unique IP address, that all traffic to and from the remote network is automatically routed through the dedicated device or client. However, such a system is generally administratively complex and first requires an administrator to set up the devices on either network, before a connection may be created. Specialized software and/or hardware must be installed at the local network and possibly on each device given access to the remote connection through the dedicated device. Other considerations, such as security credentials must be set and maintained. Accordingly, a significant administrative burden is required to initialize and maintain such a remote system.
Given these challenges, there exists a need for a mechanism to allow simplified and automated access to remote devices using non-routable addresses without the use of dedicated host software and without requiring network administrator privileges on the remote network to set up, maintain or operate the solution.


This disclosure addresses the issue of providing a metallic-ceramic overlay coating that potentially serves as an interface or bond coat layer to provide enhanced oxidation resistance to the underlying superalloy substrate via the formation of a diffusion barrier regime within the supporting base material. Furthermore, the metallic-ceramic coating is expected to limit the growth of a continuous thermally grown oxide (TGO) layer that has been primarily considered to be the principal cause for failure of existing TBC systems. Compositional compatibility of the metallic-ceramic with traditional yttria-stabilized zirconia (YSZ) top coats is provided to further limit debond or spallation of the coating during operational use. A metallic-ceramic architecture is disclosed wherein enhanced oxidation resistance is imparted to the surface of nickel-based superalloy or single crystal metal substrate, with simultaneous integration of the yttria stabilized zirconia (YSZ) within the metallic-ceramic overlayer.

Increasing the power efficiency of stationary land-based industrial gas turbines will require future turbine inlet temperatures to increase to >1400° C. Cooling air will simultaneously need to be controlled to avoid an increase in NOx emissions. Similarly the concept of ultra low or "zero" emission power generation has focused on an oxy-fuel combustion process in which nitrogen is removed in the combustion air, and replaced with steam, thereby preventing the formation of nitrogen oxides. The exhaust stream of the oxy-fuel process is separated into concentrated CO2 and water. Alternately, hydrogen-fueled combustion turbine systems are conceptually based on a complex cycle composed of a closed Brayton cycle and a Rankine cycle. Hydrogen and oxygen are supplied as the fuel and oxidant respectively to a compressor, and burned in steam. The pressurized steam feed enters a high temperature turbine at 1700° C.
As increased efficiencies are sought in electric power generation, turbine-based power generation systems are increasingly required to operate under extreme conditions. The standard operating environment within a turbine is typically thermally and chemically hostile to materials used to form turbines and turbine components. As higher operating temperatures for gas turbine engines are continuously sought after in order to increase turbine efficiencies, which also increases the thermal and mechanical stresses placed on turbine materials. Therefore, as operating stresses increase, the high temperature durability of the components within the hot gas path of the engine must correspondingly increase. Significant advances in high temperature capabilities have been achieved through the formulation of nickel and cobalt-base superalloys. Nonetheless, when used to form components of the turbine, combustor and augmentor sections of a gas turbine engine, such alloys alone are often susceptible to damage by oxidation and hot corrosion attack, and as a result may not retain adequate mechanical properties. For this reason, these components are often protected by a thermal barrier coating (TBC) system.
In order to successfully achieve long-term operation, higher operating temperature industrial land-based gas turbines will require internal blade cooling, potential utilization of advanced high temperature superalloys, and the incorporation of stable thermal barrier coating (TBC) systems. The following sections provide a brief overview of the current technology base.
Thermal Barrier Coating Systems
Industrial gas turbine engine components must withstand extreme temperatures, thermal cycling, and stress conditions. Current TBC systems consist of four layers, each consisting of different materials with specific properties and functions. These include the superalloy substrate, the bond coat, the thermally grown oxide layer (TGO), and the ceramic top coat.
Superalloy Materials
A superalloy or high performance metallic alloy is an alloy with superior mechanical strength, good surface stability, corrosion resistance, and is a material that can withstand high temperatures without oxidizing or losing mechanical properties. Creep and oxidation resistance are the prime design criteria for use of these materials. Superalloys are iron-, cobalt-, or nickel-based, the latter being suited for aeroengine applications. Many other elements can be present within the superalloy matrix. These include chromium (Cr), molybdenum (Mo), tungsten (W), aluminum (Al), zirconium (Zr), niobium (Ni), rhenium (Re), carbon (C), or silicon (Si).
Superalloys can be used at high temperatures, often in excess of 0.7 of the absolute melting temperature of the alloy. Nickel-based single crystal (SC) superalloys exhibit superior high temperature mechanical strength (at temperature >85% of their melting points), and hot corrosion resistance compared to conventional alloys (M. Kamaraj, "Rafting in single crystal nickel-base superalloys—an overview", Sahana, Vol. 28, Parts 1 &2, February/April 2003, pp. 115-128).
The essential solutes in nickel-based superalloys are aluminum and/or titanium, with a total concentration that is typically less than 10 atomic percent. This generates a two-phase equilibrium microstructure consisting of gamma (γ) and gamma prime (γ). The γ′ phase is largely responsible for elevated temperature strength of the material, and its resistance to creep deformation. The strength of most metals is known to decrease as operating temperature is increased. In contrast, nickel-based superalloys containing the intermetallic γ′ compound are relatively insensitive to temperature.
Additions to commercial nickel-based superalloys include aluminum (Al) and titanium (Ti), chromium (Cr) small quantities of yttrium (Y) boron (B) or zirconium (Zr), and carbide formers C, Cr, Mo, W, Nb, Ta, Ti, and Hf can also be present. Carbides tend to precipitate at grain boundaries and reduce the tendency for grain boundary sliding. Elements such as cobalt (Co), iron (Fe), chromium (Cr), niobium (Nb), tantalum (Ti), molybdenum (Mo), tungsten (W), vanadium (V), titanium (Ti), and aluminum (Al) are known to be solid-solution strengtheners, both in γ and γ′ phases.
Currently nickel-based SC superalloys are identified for the manufacture of critical components as turbine blades, vanes for aircraft, as well as land-based power generation applications. Microstructure, chemical composition, and high temperature mechanical properties are the major factors controlling the performance of SC superalloys.
Bond Coat—Diffusion Barrier Coatings & Overlayer Coatings
TBC systems typically include an environmentally-protective bond coat and a thermal-insulating topcoat, typically referred to as the TBC. Bond coat materials widely used in TBC systems include oxidation-resistant overlay coatings such as MCrAlX (where M is iron, cobalt and/or nickel, and X is yttrium or another rare earth or reactive element) as discussed in U.S. Pat. No. 4,321,310 and U.S. Pat. No. 4,321,311, and oxidation-resistant diffusion coatings such as diffusion aluminides that contain nickel-aluminum (NiAl) intermetallics as discussed in U.S. Pat. No. 5,238,752.
A bond coat is typically applied to the external surface of the superalloy to facilitate growth of a resistant oxide layer. The bond coat is the transition layer onto which the TBC topcoat is applied and adheres. Alumina (α-Al2O3) or an alumina-former is typically selected as a bond coat matrix as alumina offers excellent oxidation protection and has a very low growth rate. The two most widely used types of bond coatings are alumina-based matrices (Al/Al2O3), and MCrAlY where M=Fe and/or Ni. The former is obtained by surface enrichment (i.e., diffusion; see discussion below), while the later is achieved by plasma spray or electron beam physical vapor deposition (EB PVD). With the concept of introducing a diffusion barrier onto the surface of superalloys, the invention of Pt-aluminide coatings resulted. Platinum is typically electroplated to thicknesses of 5-10 μm. In low activity/outward diffusion coatings, the alloying elements present in the substrate (i.e., Ni) will tend to diffuse into the coating layer, to an extent limited by their solubility. In high activity/inward diffusion coatings, elements in solution enter the compound layer being formed, or form precipitates during processing.
In contrast, overlay coatings as opposed to diffusion coatings provide more independence from the substrate alloy, and also have more flexibility in design as compositions can be modified depending on the degradation mechanisms. Typically an overlayer coating as MCrAlY exhibits a two-phase β+γ microstructure. The presence of the γ-phase increases the ductility of the coating, thereby improving thermal fatigue resistance. MCrAlY's when used in land-based gas turbine applications contain nickel or cobalt. Chromium (Cr) is present to provide hot corrosion resistance. The concentration of Cr added is limited with respect to the specific alloy composition, as well as its capability to form Cr-rich phases within the coating. Cobalt (Co) is incorporated into the overlayer coating to provide superior resistance to corrosion. Aluminum (Al) when added in concentrations of 10-12 wt %, enhances oxidation life. Higher concentrations of Al reduce the ductility of the substrate metal. Yttrium (Y) enhances adherence of the oxide layer. The primary role of Y is its reaction with S to prevent sulfur segregation to the oxide layer which is detrimental to scale or coating adhesion. Alternately, addition of silicon (Si) improves cyclic oxidation resistance, but reduces the melting point of the coating. Rhenium (Re) when incorporated into the bond coat overlayer improves isothermal or cyclic oxidation resistance, and thermal cyclic fatigue. Tantalum (Ta) increases oxidation resistance.
In order for a TBC to remain effective throughout the planned life cycle of the component it protects, it is important that the TBC has and maintains a low thermal conductivity throughout the life of the component, including during high temperature excursions. However, the thermal conductivities of TBC materials such as YSZ are known to increase over time when subjected to the operating environment of a gas turbine engine. As a result, TBC's for gas turbine engine components are often deposited to a greater thickness than would otherwise be necessary. Alternatively, internally cooled components such as blades and nozzles must be designed to have higher cooling flow. Both of these solutions are undesirable for reasons relating to cost, component life and engine efficiency. As a result, it can be appreciated that further improvements in TBC technology are desirable, particularly as TBC's are employed to thermally insulate components intended for more demanding engine designs.
Ceramic Top Coat—Thermal Barrier Coating
Top Coat
TBC top coat materials are typically ceramic materials and particularly zirconia (ZrO2) that is partially or fully stabilized by yttria (Y2O3), magnesia (MgO), ceria (CeO2), calcia (CaO), scandia (Sc2O3) or other oxides. Binary yttria-stabilized zirconia (YSZ) is widely used as a TBC top coat material because of its high temperature capability, low thermal conductivity and erosion resistance in comparison to zirconia stabilized by other oxides, e.g., ceria-stabilized zirconia, which exhibits poorer erosion resistance as a result of being relatively soft. YSZ is also preferred as a result of the relative ease with which it can be deposited by plasma spraying, flame spraying and physical vapor deposition (PVD) techniques. In plasma spraying processes, the coating material is typically in the form of a powder that is melted by a plasma as it leaves a spray gun. As a result, a plasma-sprayed TBC is formed by a buildup of molten "splats" and has a microstructure characterized by irregular flattened grains and a degree of inhomogeneity and porosity. TBC's top coats employed in the highest temperature regions of gas turbine engines are often deposited by electron beam physical vapor deposition (EBPVD), which yields a columnar, strain-tolerant grain structure that is able to expand and contract without causing damaging stresses that lead to spallation. Similar columnar microstructures can be produced using other atomic and molecular vapor processes, such as sputtering (e.g., high and low pressure, standard or collimated plume), ion plasma deposition, and all forms of melting and evaporation deposition processes (e.g., cathodic arc, laser melting, etc.).
Current thermal barrier coating (TBC) technology not only limits heat transfer through the coating, but also protects engine components from oxidation and hot corrosion. A 1-200 μm thick TBC coating can reduce temperature from the external surface of the coating to the superalloy interface by up to 200° C. The TBC can reduce the need for blade cooling by about 36% while maintaining identical creep life of the substrate.
During operation, the TBCs are exposed to various thermal and mechanical loads as thermal cycling, high and low cycle fatigue, and high temperature erosion. Due to reliability issues, the thickness of the coatings is limited in most applications to 500 μm. Increasing the coating thickness increases the risk of coating failure and leads to reduced coating life. The failure mechanisms that cause TBC coating spallation differ from traditional thinner coatings. The major reason for traditional TBC failure and coating spallation in gas turbines is considered to typically be related to bond coat oxidation. When the thickness of the thermally grown oxide (TGO) exceeds a certain limit, it induces critical stresses within the coating, which leads to failure. The thermally grown oxide (TGO) is formed by the oxidation of the bond coat layer when temperatures exceed 700° C. leads to the formation of the 1-10 μm thick thermally grown oxide layer. The oxidation results from the ingress of oxygen through the interconnected porosity of the ceramic top coat layer, or alternately through oxygen transport via high oxygen ionic diffusivity within the ZrO2-based ceramic top coat layer. Different chemical components such as sulfur, titanium, and tantalum degrade adhesion between the bond coat and the thermally grown oxide layer, while the addition of silicon and hafnium promote adhesion between the two layers.
Thicker coatings have higher temperature gradients through the coating and thus have higher internal stresses. Although the CTE of the traditionally accepted, commercial, yttria stabilized zirconia (YSZ) coatings is close to that of the substrate material, the CTE difference between the substrate and coating induces stresses at high temperatures at the coating interface. The phase structure of YSZ is not stable above 1250° C. Also the stain tolerance of the coating can be lost rapidly by sintering if too high surface temperatures are allowed. At temperatures >1000° C., YSZ ages via shrinkage and microcrack formation. The addition of 5-15% Y to Zr stabilizes the high temperature crystalline form, thus avoiding phase transitions at the service temperature range. Cerium and/or in combination with yttria has been incorporated as a stabilizer within the zirconia matrix. As an alternate to YSZ, lanthanum-hexaaluminate has been shown to exhibit long-term stability to temperatures of 1400° C. Its composition favors platelet formation which prevents densification of the coating by post-sintering.
Application of Thermal Barrier Coatings on Superalloys
Various methods have been used for depositing ceramic coatings onto metal substrates. These include physical vapor deposition (PVD) and chemical vapor deposition (CVD) processes. Thermal spraying is a process that consists of melting a consumable (powder or wire) and projecting it as a molten particle onto the substrate. Upon impact with the substrate, the molten particle flattens and solidifies. Adhesion is initially mechanical in nature, and after further being subjected to a diffusion heat treatment, adhesion to the underlying substrate alloy is increased. A sprayed coating will have voids and oxide particles. All thermal spraying processes are sight-on-line—that is only the parts that are directly in the line of the spray are coated. Adhesion of the coating is dependent on the cleanliness of the substrate surface, its area (high roughness is desired), and the velocity of the particles. Various thermal spraying techniques include: Flame spraying: An oxyacetylene flame (2700° C.) is used to melt and project the coating fed as a wire or powder. Plasma spraying: An ionized gas plasma (1600° C.) is used to melt and propel the coating (powder). High velocity oxyfuel (HVOF): O2 and H2 are used with a fuel gas as methane to project the coating fed material. Low pressure plasma spraying (LPPS): This is accomplished similar to plasma spraying but done in an inert at low pressure. Vacuum plasma spray (VPS): Similar to plasma spray but done in an inert environment or under vacuum.
The two most widely used techniques for deposition of TBC top coats onto superalloy substrates are air plasma spray (APS) and electron-beam physical vapor deposition (EB PVD), both of which produce distinctively unique microstructures
Impact of Water Vapor on Material Stability
The presence of water vapor in air has been shown to adversely affect the selective oxidation of aluminum in superalloys (i.e., α-Al2O3-formers: PWA 1484, MarM 247, CM 186, Rene N5), by causing more transient oxides as NiO to be formed. Some adverse effects of water vapor on selective oxidation of aluminum do occur even at temperatures as high as 1100° C. Water vapor also causes the α-Al2O3 scale to crack and spall, particularly where the interfacial toughness between the α-Al2O3 scale and superalloy substrate is low.
The major effect of water vapor on superalloys that are chromia-formers (i.e., IN 738; X-40) is enhanced vaporization of Cr2O3, particularly at temperatures >900° C., as well as the formation of transient oxides. These chromia-forming alloys are resistant to cyclic oxidation degradation at 700° C. with no substantial effects of water vapor. These alloys are degraded rather severely at 900° C. This occurs due to cracking and spalling of the Cr2O3 scales which is exacerbated in wet air due to the vaporization of Cr2O3 via the formation of hydrated chromium oxides (CrO2(OH)2).
Considering applications for superalloys in environments containing water vapor, the chromia-formers should not be used at 900° C. or above due to vaporization of Cr2O3. In the case of the alumina-forming superalloys, problems related to the development of the α-Al2O3 scales at low temperatures such as 700° C. needs to be further addressed.
Corrosion of TBC Systems
When EB PVD ceramic-coated superalloys were exposed to sulfates and sintering agents at temperatures of 1204° C. for 16 hrs, penetration of contaminants into the intercolumnar spaces of the coating was identified. In addition, a potentially damaging reaction zone between PVD external (top) layer and the contaminants was clearly identified. Even more dramatic effects were identified after 1000 hrs of isothermal exposure of an EB PVD ceramic-coated matrix to lower temperatures (i.e., 1038° C.).
For the surface-modified PVD ceramics, failure by spallation resulted in the area between the hot zone on the trailing edge of the sample and the flame impingement zone on the leading edge of the sample. Ceramic spallation was accompanied by severe pitting of the bond coat. Where a section was completely removed, the bond coat was significantly depleted of the β-phase near the exposed surface, as well as near the interface with the base alloy. Failure occurred primarily within the thermally grown oxide layer.
A bond coat layer or a combined bond/top coat layer that provides for improved oxidation and corrosion resistance at higher temperature than present systems as well as improved water vapor stability at high temperatures would permit more efficient operation of turbine systems at higher temperature.

The United States of America as represented by the United States Department of Energy


A geophysics-based method for determining the position of a stationary earth object uses the periodic changes in the gravity vector of the earth caused by the sun- and moon-orbits. Because the local gravity field is highly irregular over a global scale, a model of local tidal accelerations can be compared to actual accelerometer measurements to determine the latitude and longitude of the stationary object.

Historical forms of navigation include pilotage, dead reckoning, celestial navigation, radio navigation, and inertial navigation. Radio navigation relies on radio-frequency sources with known locations, such as Global Positioning System (GPS) satellites or terrestrial airport beacons, to determine where one is relative to where one wants to go. Inertial navigation systems rely on knowing one's initial position, velocity, and attitude and measuring attitude rates and accelerations to provide an estimate of one's position after movement away from the initial position. Integrated systems further improve performance by combining the high-bandwidth motion control of inertial navigation with the long-term position location accuracy of GPS. See M. S. Grewal et al., Global Positioning Systems, Inertial Navigation, and Integration, John Wiley & Sons, New York (2001).
GPS is a satellite-based navigation system that provides continuous positioning and timing information anywhere in the world under all weather conditions. GPS nominally uses at least 24 operational satellites with known relative locations, each satellite in one of six nongeostationary, circular orbits about 2200 km high above the earth. These orbiting satellites continuously broadcast high frequency radio signals to passive receivers on earth. Pseudoranges, or estimated distances from the receiver to the satellites, are computed from the relative time delay of the received signals from several of the satellites. Normally, information is required from four satellites to synchronize the receiver's internal clock with the highly accurate GPS satellite clocks and enable a precise position fix to be determined from the pseudoranges by trilateration. Positioning accuracy for civilian applications is nominally tens of meters. Differential techniques can significantly improve the accuracy of GPS-derived positions by using tandem receivers to simultaneously track the same GPS satellites, thereby enabling submeter-positioning accuracy. GPS has many attractive features, such as inexpensive and light-weight receivers, high positional accuracy in three dimensions, global coverage, all-weather capability, and availability to an unlimited and diverse set of users. However, GPS obviously requires access to the satellite radio signals and such signals may not be available in some locations or may be vulnerable to electronic jamming.
Alternatively, inertial navigation can be used for active position measurement. Inertial navigation systems typically use an inertial measurement unit (IMU) comprising a cluster of sensors to provide full three-axis attitude measurements. For example, the cluster can comprise three accelerometers for measuring acceleration in three directions and three gyroscopes for measuring rotation rate and to provide a reference frame for the accelerometers. The acceleration can be doubly integrated and the rotation rate can be singly integrated by a navigation computer to provide position. The IMU can be a gimbaled system, wherein the sensor cluster is mounted in a gimbal frame to isolate the sensors from external rotations of the host vehicle and keep them level and pointing in a fixed direction via torquing devices. Alternatively, the IMU can be a strapdown system, wherein the sensor cluster is strapped down to the frame of the host vehicle and the measurements are made in reference to the vehicle axes, for example, the roll, pitch, and yaw axes of an airplane in flight.
Inertial navigation systems have some advantages over other forms of navigation, such as GPS. Since IMUs are autonomous, they do not rely on external navigation aids, such as landmarks, celestial objects, or satellites, and they can be used underwater or in underground tunnels. Furthermore, since IMUs are completely on-board the host vehicle, the accelerations and rotation rates can be easily integrated with guidance and control systems and they are inherently stealthy and immune to jamming. However, acquisition, operating, and maintenance costs, system size and weight, and power requirements tend to be higher with IMU systems than with GPS systems. Most importantly, measurement drift, due to the integration of IMU acceleration and rotation rate errors, can cause navigation errors to grow dramatically with time.
There are currently many methods to tracking objects that move relatively fast, such as fixed wing aircraft. However, tracking the movement of objects that move intermittently remains a problem in situations where GPS is passively or actively denied and access to reference beacons is not otherwise available. In particular, IMUs are most useful in situations in which the time duration of the object's motion is sufficiently short such that the accumulated drift error is negligible. IMUs may also be useful in integrated navigation systems in which access to sky or terrestrial reference beacons is available periodically to provide aiding for the IMU, allowing for reinitialization of the IMU position to compensate for the measurement drift. However, without access to these references, even perfect initial location information coupled with a perfect IMU would quickly become useless for locating slow-moving or objects at rest. In particular, there are no systems of any kind that can continuously and reliably monitor the latitude and longitude of an intermittently stationary object without access to external reference beacons or satellites.
The geophysics-based method of present invention overcomes the limitations of conventional navigation systems by analyzing the fundamental properties of earth gravity and spin to obtain a fix on the position of a stationary earth object. The measurement of geophysical phenomenon enables the determination of latitude and longitude without the need for external infrastructure (e.g., satellites needed for GPS) or foreknowledge of how the object moves around or the general area it is in (e.g., as required for inertial navigation systems). Because gravity cannot be shielded and acts at long distances, the geophysics-based method can determine object position in underground and shielded locations. It does not require visual or infrared access to the sky, as in celestial navigation or GPS. It also is immune to RF jamming or magnetic jamming. Nor does the present invention exhibit the time-dependent drift error problems of IMUs.

Geophysics-based method of locating a stationary earth object


A method of controlling a power converter is used to interface to a power grid or supply network operating at a frequency (Fnet) that is nominally fixed (say at 50 Hz, for example) but which can be varied as a way of controlling power imbalanced within the network as a whole. The power converter can include a network bridge that operates in accordance with the pulse width modulation (PWM) strategy having a switching frequency (Fpwm), a nominal switching frequency (Fpwm_nom) and a number of pulses per period (Pulse_Number). The method includes the step of varying the switching frequency (Fpwm) of the PWM strategy in accordance with the time-varying frequency (Fnet) of the supply network to achieve only integer odd harmonics of the time-varying frequency (Fnet) and the step of adjusting the number of pulses per period (Pulse_Number) in accordance with the time-varying frequency (Fnet) of the supply network to maintain a switching frequency (Fpwm) that is less than, or equal to, the nominal switching frequency (Fpwm_nom).

It is possible to convert wind energy to electrical energy by using a wind turbine to drive the rotor of a generator, either directly or by means of a gearbox. The ac frequency that is developed at the stator terminals of the generator (the "stator voltage") is directly proportional to the speed of rotation of the rotor. The voltage at the generator terminals also varies as a function of speed and, depending on the particular type of generator, on the flux level. For optimum energy capture, the speed of rotation of the output shaft of the wind turbine will vary according to the speed of the wind driving the turbine blades. To limit the energy capture at high wind speeds, the speed of rotation of the output shaft is controlled by altering the pitch of the turbine blades. Matching of the variable voltage and frequency of the generator to the nominally fixed voltage and frequency of the supply network can be achieved by using a power converter.
The power converter typically includes a generator bridge, which in normal operation operates as an active rectifier to supply power to a dc link. The generator bridge can have any suitable topology with a series of semiconductor power switching devices fully controlled and regulated using a pulse width modulation (PWM) strategy.
The dc output voltage of the generator bridge is fed to the dc terminals of a network bridge, which in normal operation operates as an active inverter. The principal control for the dc output voltage is achieved by controlling the generator bridge. The network bridge can have any suitable topology with a series of semiconductor power switching devices fully controlled and regulated using a PWM strategy.
The ac output voltage of the network bridge is filtered and supplied to the nominally fixed frequency supply network via a step-up transformer. Protective switchgear can be included to provide a reliable connection to the supply network and to isolate the generator system from the supply network for various operational and non-operational requirements.
The power grid or supply network will operate at a nominally fixed voltage and frequency, although the latter will almost certainly vary between upper and lower limits defined in the various standards and grid codes. Such frequency variations result from power imbalances within the overall network—if load power is in excess of generated power then the frequency will fall and vice versa. Connected equipment, including that covered by the present invention, has to be able to track such frequency changes.
The PWM strategy used in the network bridge will typically operate at a given switching frequency. The mixing between the nominally fixed frequency of the power grid or supply network and the switching frequency of the PWM strategy will cause harmonics in the ac output voltage of the network bridge. In the general case, for a PWM strategy with a switching frequency Fpwm and a nominally fixed frequency of the supply network Fnet then it can be shown that significant harmonics are created at frequencies given by:Fpwm±2N*Fnetparticularly in cases where N=1 and N=2.
If Fpwm is chosen such that:Fpwm=(2M−1)*Fnetwhere M is an integer (i.e., Fpwm is an integer odd multiple of Fnet) then significant harmonics will now appear at:[(2M−1)±2N]*FnetThis means that the significant harmonics are at integer odd multiples of Fnet.
The above equations can also be explained as follows: if the nominally fixed frequency (Fnet) of the supply network is 50 Hz and the switching frequency of the PWM strategy (Fpwm) is 2.5 kHz then significant harmonics are created at 2.3 kHz, 2.4 kHz, 2.6 kHz and 2.7 kHz (i.e., 46, 48, 52 and 54 times the nominally fixed frequency of the supply network).
It is generally accepted that integer odd harmonics are preferable to integer even harmonics such as those mentioned above. This is because the allowable emissions exported into the supply network can be higher for integer odd harmonics than for integer even harmonics. For example, in the widely applied harmonics standard IEEE 519-1992 entitled "IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems" the limits on current distortion for integer even harmonics are restricted to 25% of the limits for integer odd harmonics. Non-integer harmonics (or "interharmonics") are also to be generally avoided because they can cause unwanted disturbances in electrical appliances connected to the supply network. The non-integer harmonics can also interfere with control signals that are sometimes broadcast in the interharmonic region.
One way of making sure that the mixing between the nominally fixed frequency of the power grid or supply network and the switching frequency of the PWM strategy only produces integer odd harmonics in the ac output voltage of the network bridge is to select a particular switching frequency for the PWM strategy. If the nominally fixed frequency (Fnet) of the supply network is 50 Hz then the switching frequency of the PWM strategy (Fpwm) can be set to 2.45 kHz. Significant harmonics are then created at 2.25 kHz, 2.35 kHz, 2.55 kHz and 2.65 kHz (i.e., 45, 47, 51 and 53 times the nominally fixed frequency of the supply network).
However, this solution does not take into account the fact that the nominally fixed frequency of the supply network will vary as result of power imbalances within the overall network. To this extent, the power grid or supply network must to considered to operate at a time-varying frequency even though the upper and lower limits of the variation are typically no more than about ±0.5 Hz and the changes take place gradually over the course of a number of hours or longer. However, in extreme cases, the upper and lower limits of the variation may be as much as ±3.0 Hz.
Even if the switching frequency is allowed to vary according to the time-varying frequency of the power grid or supply network then this can cause problems because the network bridge will typically have a maximum switching frequency that cannot be exceeded for thermal reasons. Extreme variations in the time-varying frequency may therefore result in a switching frequency that is higher than the maximum switching frequency such that the network bridge experiences unacceptably high thermal losses in its semiconductor switching devices.
In some cases, the choice of filter for filtering the ac output voltage of the network bridge can also place limits on the range of allowable switching frequencies for the PWM strategy. This is particularly true for tuned inductor and capacitor (LC) filters.
An improved PWM strategy for a network bridge is therefore needed.

Control methods for pulse width modulation (PWM)


An auxiliary switch for a circuit-breaker includes a casing containing at least one contact blade member mobile under the control of a pivoting and sliding actuator lever between a closed position and an open position. The actuator lever has a lateral actuator pin which projects out of the casing through a slot in the latter. The slot has a localized escape lobe away from its main part and which receives the actuator pin.

1. Field of the Invention
The present invention concerns circuit-breakers.
2. Description of the Prior Art
A circuit-breaker includes a casing containing two spaced contact members electrically connected to respective terminals accessible from outside the casing and a fuse-holder, often called a "holder", that has a housing adapted to accommodate a cartridge fuse, is accessible to the user from outside the casing and is mobile in the casing between two positions, namely a closed position in which the housing extends from one of the two contact members to the other, so that a cartridge fuse in the housing makes an electrical connection between them, and an open position in which the housing is separated from the contact members and lies partly outside the casing, so that the user can insert a cartridge fuse in it or remove a cartridge fuse from it.
French patent application 94 15332 of Dec. 20, 1994 proposes to associate an auxiliary device with the above circuit-breaker, movement of the fuse-holder between its two positions operating the auxiliary device.
To this end cam means are provide on the fuse-holder and the auxiliary device has an operating rod projecting from its casing and inter-engaged with the cam means.
A general object of the present invention is to improve on this arrangement, by applying it to a switch adapted to control the power supply to another circuit, for example an indicator lamp, according to the position (opened or closed) of the fuse-holder of the circuit-breaker.
French patent 2 638 562 describes an auxiliary switch having a casing containing a contact blade member mobile between two positions under the control of a pivoting and sliding actuator lever, namely a closed position in which it is pressed against a fixed contact and an open position in which it is separated from the fixed contact.
However, the actuator lever is operated by a pusher member and there is no mention of associating it with any form of actuator pin.
Thus the above auxiliary switch cannot be easily associated with a circuit-breaker of the kind of interest here, and the latter gives rise to a particular problem any way, in that its fuse-holder has a relatively large range of movement so that the cam means that it incorporates must inter-engage only momentarily, "on the fly", with an auxiliary switch of this kind.
A first more specific object of the present invention consists in an auxiliary switch that meets this two-fold requirement.

Auxiliary switch for circuit-breaker and corresponding circuit-breaker


Vials used for obtaining an aliquot of a biological sample are provided. Also provided are method of using the vials and instruments to obtain an aliquot of a biological sample.

When a liquid-based Pap smear is performed, a biological specimen sample (cellular material) is obtained from the patient, from which a specimen slide is prepared. The specimen slide is then evaluated, e.g., by a cytotechnologist, and typically classified by the cytotechnologist as either "normal" or "abnormal." An abnormal sample normally falls in one of the major categories defined by The Bethesda System for Reporting Cervical/Vaginal Cytologic Diagnosis, which categories include Low-Grade Squamous Intraepithelial Lesions (LSIL), High-Grade Squamous Intraepithelial Lesions (HSIL), Squamous Cell Carcinoma, Adenocarcinoma, Atypical Glandular cells of Undetermined Significance (AGUS), Adenocarcinoma in situ (AIS), and Atypical Squamous Cell (ASC), which can be further sub-divided into Atypical Squamous Cell, cannot exclude HSIL (ASC-H) and Atypical Squamous Cell of Undetermined Significance (ASC-US).
A specific Human Papilloma Virus (HPV) deoxynucleic acid (DNA) test, referred to as the Hybrid Capture II HPV DNA assay, manufactured by Digene Corporation, has been used to determine whether patients, whose Pap smears have been classified as ASC-US, have HPV. Based on the strong correlation between HPV and cervical cancer, it has been recommended that HPV DNA testing be used as a triage test for patients whose Pap smear results are classified as ASC-US.
In the case where a liquid-based Pap smear has been performed, the same sample used to perform the Pap smear analysis can be conveniently used to perform a "reflexive" HPV DNA test, thereby obviating the need for a repeat clinic visit and second Pap smear. In this case, if a slide is positive for ASC-US, an aliquot (e.g., 4 mL) of the fluid sample is removed from the stored vial and sent to a molecular diagnostic laboratory for HPV DNA testing.
Significantly, laboratories that perform HPV DNA tests are weary of molecular contamination—a well-known problem in molecular diagnostic laboratories. Thus, due to the risk of cross-contamination, molecular diagnostic laboratories may not accept aliquots that have been taken from an already processed liquid-based Pap smear for fear of unnecessarily generating false HPV positives.

Vials and apparatus for obtaining an aliquot of a sample