A line driver comprising a first transistor (M1), a first amplifier (A1) and a reference resistor (10) for converting an input voltage (Vin) to a first current (i1) through the first transistor (M1). A second current i2=n*i1 flows through a second transistor (M2) which forms a 1:n current mirror with the first transistor (M1). The current i2 flows to a load (6), if so required via a transmission line (TL). The impedance of the load (6) is equal to the characteristic impedance RL of the transmission line (TL). Thus the impedance seen by the line driver is equal to RL. A second transconductance amplifier (A2) counteracts reflected signals in the output signal (Vout) caused by mismatch between the output impedance of the current mirror (M1, M2) and the impedance seen by the line driver.

The invention relates to a line driver, more particularly to a line driver with adaptive output impedance. Such a line driver is known from International Patent Application published under No. WO 95/02931. A line driver is an electronic buffer amplifier designed to have an output impedance matched to the characteristic impedance of a transmission line. Transmission lines are widely used for conveying electric signals. To minimise reflections the source and load impedances of the transmission line should be equal to the characteristic impedance of the transmission line. A standard value for video applications is 75 ohms. A buffer amplifier designed to drive a 75 ohm transmission line should have an output impedance of 75 ohms in order to minimize reflections. The buffer sees a load resistance of 75 ohms, i.e. the impedance of the terminated transmission line.
FIG. 1 shows a first known approach to implement such a buffer. The buffer provides a low-impedance voltage source VS with a series resistor Rs having a value equal to the characteristic impedance of the transmission line TL in order to implement the correct output impedance of the line driver. This type of line driver is often used in digital-to-analog converters (DAC) where the output voltage is controlled by a digital input signal. An disadvantage of this first known structure is that the voltage source VS has to deliver twice the desired output voltage. This becomes a problem where the available supply voltage drops while the signal levels remain unchanged; e.g. a 1.5Vpp output voltage at 3V supply voltage is barely possible.
FIG. 2 shows a second known approach. The voltage source with series resistance is replaced by a current source CS with a parallel resistance Rs. In this structure no voltage is lost, but half of the current delivered by the current source CS is wasted in the parallel resistance Rs. This technique is often used in DACs where the output current is digitally controlled.
It appears that both known solutions are not attractive since either voltage or current is wasted. Therefore it can be appreciated that a line driver with specified output impedance which matches the impedance of a transmission line and which does not require twice the output voltage or twice the output current is desirable.

Line driver with adaptive output impedance


Compositions are described that are useful for removing organic and organometallic substances from substrates, for example, photoresist wafers. Processes are presented that apply a minimum volume of a composition as a coating to the inorganic substrate whereby sufficient heat is added and the organic or organometallic substances are completely removed by rinsing. The compositions and processes may be suitable for removing and, in some instances, completely dissolving photoresists of the positive and negative varieties, and specifically negative dry film photoresist from electronic devices.

Various polymers may be used in the manufacture of electronic devices, including, for instance, photoresists and organic-based dielectrics. Photoresists, for example, may be used throughout semiconductor device fabrication in photolithographic operations. A photoresist may be exposed to actinic radiation through a photomask. Where a positive-acting resist is used, exposure may cause a chemical reaction within the material resulting in a solubility increase in aqueous alkali, allowing it to be dissolved and rinsed away with developer. Where a negative-acting resist is used, cross-linking of the polymer may occur in the exposed regions while leaving unexposed regions unchanged. The unexposed regions may be subject to dissolution and rinsing by a suitable developer chemistry. Following development, a resist mask may be left behind. The design and geometry of the resist mask may depend upon the positive or negative tone of the resist; positive tone resist may match the design of the photomask, while a negative tone resist may provide a pattern that is opposite the photomask design.
Photoresists are used extensively in many applications, including the packaging of microelectronic devices and in manufacturing compound semiconductors.
In wafer level packaging, solder is applied directly to wafers that have completed the fabrication of the microelectronic devices but have not been diced into individual chips. Photoresist is used as the mask to define the placement of the solder on the wafers. After solder is deposited onto the wafer, the photoresist must be removed before the next step in the packaging process can occur. Typically in wafer level packaging, the photoresist is very thick, greater than 10 μm and sometimes as thick as 120 μm. The photoresist can be positive or negative, and can be applied either as a liquid or a dry film. In wafer level packaging, the use of thick dry film negative photoresist is common.
Due to the thickness and cross-linked nature of thick dry film negative photoresist, the removal of this material after solder deposition can be difficult. As a result of requirements for these process flows, immersion cleaning developed so that multiple wafers, typically 25 to 50 at a time, could be processed simultaneously and increase the tool throughput while still accommodating the long process time. The success with this type of processing allowed thick negative films to be successfully incorporated throughout the packaging process. However as wafer feature dimensions continue to be scaled down and the number of processes per wafer increases, the value of the wafer continues to increase. There comes a point when the best way to minimize risk of a bad result due to a process failure, is to process each wafer individually. Current immersion technology does not offer a removal solution with good cleaning characteristics, good compatibility and a process time that would meet practical throughput and cost-of-ownership targets of the industry.
In compound semiconductor processing, positive and negative spin on photoresist are commonly used. For example, for a lift off process, photoresist is applied and patterned, metal is deposited over the top of the pattern and the photoresist is removed, simultaneously removing metal on top of it. Moreover better stripping compositions that are compatible with the permanent wafer materials are needed for removal of the photoresist in a single wafer process.
Additionally, in compound semiconductor processing, patterns are formed in a layer on the substrate surface by patterning a photoresist on the surface and putting the substrate, with the patterned resist into a chamber with a plasma. The plasma can be selected to preferentially etch the open surface relative to the photoresist, thus creating the same pattern as the photoresist in the exposed layer. After the plasma treatment, photoresist as well as post etch residue, often organometallic and/or metal organic in nature, remains on the surface. Removal of the post etch residue at the same time as the remaining photoresist, while still maintaining compatibility with the permanent materials on the wafer surface would help ensure device performance.

Process and composition for removing substances from substrates


A gradient coil for generating a periodically changing read-out gradient in a magnetic resonance imaging apparatus is operated in a series resonant circuit having a capacitor. One of the elements of the series resonant circuit is charged before the beginning of each read-out gradient. The gradient coil can be charged with current, or the capacitor can be charged with voltage. Such operation either avoids or significantly shortens the transient effect which occurs after excitation of the nuclear spins. The use of a series resonant circuit instead of a parallel resonant circuit significantly reduces the voltage load on the gradient amplifier, so that the gradient amplifier can be constructed simpler and more inexpensively.

1. Field of the Invention
The present invention is directed to magnetic resonance imaging (MRI or nuclear magnetic resonance (NMR)) imaging devices operated with a pulse sequence wherein a read-out sequence including at least two relatively-perpendicular gradients are generated per scan for location coding following a spin excitation, wherein the resulting signals are digitized and written in the K-space in a raw data matrix, wherein an image is acquired from the raw data matrix by conducting at least two-dimensional Fourier transformation, and wherein at least one gradient coil is connected with a capacitor to form a series resonant circuit connected to a gradient amplifier, the gradient amplifier being driven according to a predetermined time function.
2. Description of the Prior Art
A method for operating a nuclear magnetic resonance tomography apparatus known as the echo planar imaging (EPI) method is disclosed in European application 0 076 054, corresponding to U.S. Pat. No. 4,509,015. In summary, the echo planar imaging method includes the generation of an RF excitation pulse which is made slice-selective by simultaneously generating a magnetic field gradient in a first direction. A phase coding gradient is generated in a second direction, and a read-out gradient consisting of a gradient pulse sequence changing in polarity from pulse-to-pulse is generated in a third direction. The nuclear magnetic resonance signal acquired under the read-out gradient is phase demodulated, and is conducted through a bandpass filter. The output of the filter is digitized at a sampling rate and for each gradient pulse, is written into a row of a raw data matrix in the k-space. An image matrix is derived from the raw data matrix by two-dimensional Fourier transformation, and an image is produced from the image matrix.
Further details of the echo planar imaging method are discussed below in connection with FIGS. 1-9 to assist in the explanation of a problem associated with that known method to which the improvement disclosed herein is directed.
The basic components of a conventional nuclear magnetic resonance tomography apparatus are shown in FIG. 1. Coils 1-4 generate a static, fundamental magnetic field in which, if the apparatus is used for medical diagnostics, the body of a patient 5 to be examined is situated. Gradient coils are provided for generating independent orthogonal magnetic field components in the x, y and z directions, according to the coordinate system 6. For clarity, only gradient coils 7 and 8 are shown in FIG. 1, which generate the x-gradient in combination with a pair of identical gradient coils disposed on the opposite side of the patient 5. Sets of y-gradient coils (not shown) are disposed parallel to the body 5 above and below the body 5, and sets of z-gradient coils (not shown) are disposed at the head and feet of the body 5 extending transversely relative to the longitudinal axis of the body 5.
The apparatus also includes an RF coil 9 which excites selected nuclei in the body 5 so that nuclear magnetic resonance signals are generated, and also serves to acquire the resulting nuclear magnetic resonance signals.
The coils 1, 2, 3, 4, 7, 8 and 9 bounded by a dot-dash line 9 represent the actual examination instrument. The instrument is operated by an electrical arrangement which includes a fundamental field coils supply 11 for operating the coils 1-4 and a gradient fields coils supply 12 for operating the gradient coils 7 and 8 and the further gradient coils.
Via a switch 19, the RF coil 9 can be connected to an RF transmitter 15, in an excitation mode, or to an amplifier 14 in a signal reception mode. The amplifier 14 and the transmitter 15 are a part of an RF unit 16, which is connected to a process control computer 17. The computer 17 is also connected to the gradient fields coils supply 12. The computer 17 constructs an image from the nuclear magnetic resonance signals, which is portrayed on a display 18.
A number of pulse sequences are known for operating the RF unit 16 and the gradient coils. Methods have prevailed wherein the image generation is based on a two-dimensional or a three-dimensional Fourier transformation. One such method is the aforementioned echo planar imaging method.
A pulse sequence used in the echo planar imaging method is shown in FIGS. 2-6. A radio-frequency excitation pulse RF, shown in FIG. 2, is generated which excites nuclei in a slice of the examination subject which is selected by a slice-selection gradient SS in the z-direction, shown in FIG. 3, and generated simultaneously with the pulse RF. The direction of the gradient SS is subsequently inverted, the negative gradient portion of SS canceling the dephasing of the nuclear spins which was caused by the positive portion of the gradient SS.
After excitation, a phase coding gradient PC and a read-out gradient RO are generated. There are various possibilities for the respective curves of these two gradients. A phase coding gradient PC is shown in FIG. 4 which remains continuously activated during the read-out phase. An alternative phase coding gradient PC' is shown in FIG. 5 which consists of individual pulses ("blips") which are activated upon the occurrence of each polarity change of the read-out gradient RO. Each version of the phase coding gradient is preceded by a dephasing in gradient PCV in the negative y-direction. The read-out gradient RO is activated with a constantly changing polarity, as a result of which the nuclear spins are alternately dephased and rephased, so that a sequence of signals S arises. After a single excitation, so many signals are required that the entire Fourier k-space is scanned, i.e., the existing information is adequate for the reconstruction of a complete tomogram. For this purpose, an extremely rapid switching of the read-out gradient RO with high amplitude is required, which cannot be achieved with square-wave pulses which are usually employed in NMR imaging. A standard solution to this problem is the operation of the gradient coil which generates the gradient RO in a resonant circuit, so that the gradient RO has a sinusoidal shape.
The nuclear magnetic resonant signals S which arise are sampled in the time domain, are digitized, and the numerical values acquired in this manner are entered into a measurement matrix for each read-out pulse. The measurement matrix can be viewed as a measured data space, and in the exemplary two-dimensional embodiment as a measured data plane, in which the signal values are measured on an equidistant network of points. This measured data space is usually referred to in nuclear magnetic resonant tomography as the k-space.
Data identifying the spatial derivation of the signal contributions, which is needed for image generation, is coded in the phase factors, with the relationship between the locus space (i.e., the image) and the k-space being mathematically representable by a two-dimensional Fourier transformation. Each point in the k-space (in this case the k-plane) is therefore representable by the relationship: EQU .intg.(k.sub.x,k.sub.y)=.intg..intg..zeta.(x,y)e.sup.i (.sup.k x.sup.x+k y.sup.y) dxdy, wherein EQU k.sub.x (t)=.gamma..intg..sub.o.sup.t G.sub.x (t')dt',k.sub.y (t)=.gamma..intg..sub.o.sup.t G.sub.y (t')dt',
wherein .gamma. is the gyromagnetic ratio, and .zeta.(x,y) is the spin density distribution taking the relaxation times into consideration.
In FIGS. 8 and 9, the positions of the acquired measured values are schematically illustrated by points on a k-space trajectory in the k-space (k-plane). FIG. 8 shows the case for the continuous gradient PC of FIG. 4, and FIG. 9 shows the case for the gradient PC' shown in FIG. 5 in the form of a series of blips. For the Fourier transformation, the values must lie in an equidistant network of points, which is not the case in the examples shown in FIGS. 8 and 9. The acquired measured values therefore cannot be directly utilized, and an interpolation of the measured values onto an equidistant network of points must be undertaken.
Extremely high gradient amplitudes are needed for location coding of the NMR signals in the EPI method. These high gradient amplitudes must be activated and deactivated in short time intervals (<1 ms), so that the necessary information can be acquired before the NMR signal decays. Due to the inductance and resistance of the gradient coils, these requirements cannot be satisfied in practice with a gradient coil connected directly to a gradient amplifier, because a terminal power of approximately 5 MW would be required.
The above problem can be resolved by connecting the gradient coil with a capacitor to form a parallel resonant circuit, as described in European application 0 227 411 and U.S. Pat. No. 4,628,264. To make parasitic transient effects as short as possible, the resonant capacitor is charged to the required voltage before the actual measuring sequence begins. After the field-generating gradient coil is connected into the circuit, the parallel resonant circuit immediately oscillates at the resonant frequency determined by the capacitor. There is thus substantially no transient effect. The capacitor, however, must be charged to an extremely high voltage (several kV), which requires that the gradient amplifier be capable of handling such voltages.
A series resonant circuit for generating gradient currents for the EPI method is generally described in the article "Whole Body NMR Spiral-Scan Echo Planar Imaging (SEPI) Using Resonant Gradient Coil," Kim et al., Society of Magnetic Resonance in Medicine, 7th Annual Meeting, Book of Abstracts, pg. 1013, however, the manner by which the series resonant circuit disclosed therein is caused to resonate is not discussed.
European application 0 389 666 discloses a gradient coil operated in a series resonant circuit in which the transients is controlled so that the current integral from the time of activation (t=t.sub.0) to a defined time (t=t.sub.1) just becomes zero. The capacitor of the series resonant circuit is thus charged to the necessary voltage without the gradient amplifier having to supply this voltage.
A disadvantage in these known circuits is the relatively long rise time caused by the inductance and resistance of the circuit, as well as by the output voltage of the gradient amplifier. Because the transient effect occurs with a relatively high operating frequency, the frequency-dependent resistance of the gradient coil also has a high value, which significantly lengthens the rise time.

Magnetic resonance imaging apparatus having a resonant circuit for generating gradient fields, and method for operating same


The present invention is an apparatus and method for executing instructions in a system management mode in a processor-based system. The apparatus comprises a memory for storing instruction sequences by which the processor-based system is processed where the memory includes a system management random access memory (SMRAM). The apparatus also comprises a processor having a system address space, that executes the stored instruction sequences. The stored instruction sequences include process steps to cause the processor to: (a) configure the processor to operate in a protected mode while in a system management mode, the processor operating at address greater than one megabyte; (b) invoke a paging feature of the processor; (c) configure the processor to operate in a virtual mode; and (d) process the instruction sequences; wherein the process steps occur upon the receipt of an instruction to process a system management request.

1. Field of the Invention
The present invention relates generally to memory in microcontroller-based systems, and more particularly to an apparatus and method of executing system management mode services in the virtual mode.
2. Description of the Related Art
Modern computers based on the personal computer architecture may perform power management or other system management functions by employing an operating mode of the Intel x86 family of microprocessors, known as the System Management Mode (SMM). SMM can be used by the system firmware to control product-specific hardware features in a manner which is transparent to the operating system and applications software. SMM may be used, for example, for system management information such as the system configuration or the configuration of a powered-down device, or to invoke a power-saving routine such as a zero-volt suspend function.
The SMM is invoked through an SMI, which typically executes slowly, as compared to the rate of normal code execution. This is because SMIs typically operate below the 1 Megabyte boundary in an uncached memory area. This feature is implemented in order to avoid cache conflict with overlapping memory. During the occurrence of the SMI, the CPU executes in the SMM mode which is exactly like real mode except the segment limits extend to 4 Gbytes rather than just 64 Kbytes for data accesses. Code execution addressability is still limited to only 1 Megabyte. Such an approach results in limited system performance.
One alternate approach involves the transfer of SMI code and data, whenever an SMI is invoked, from a cacheable region above the 1 Megabyte boundary to a cacheable region below the 1 Megabyte boundary. Execution of the SMI will then occur in standard SMM mode, and the SMI code is transferred back to the cacheable region above the 1 Megabyte area upon completion of the SMI. Such an approach takes significant time and therefore results in reduced system performance.
Accordingly, there is a need in the technology for an apparatus and method for overcoming the aforementioned problems. In particular, there is a need for an apparatus and method for efficient and secure execution of system management interrupt service code in a cached area without having to rewrite existing software.

Method and apparatus for providing execution of system management mode services in virtual mode


A method for operating a device for filling a tank for storing fuel as condensed gas for a consumer that can be operated with cryogenically stored fuel. Included is at least one filling line and one extraction line for connecting to a filling device on a gas-station-side. In a first time period for cooling the tank, the condensed gas is introduced into the tank, at least the large part is extracted again in the form of gas via the extraction line, and in a second subsequent time period, the tank is filled with condensed gas at the same time as at least the displaced gas is extracted. In a subsequent third time period, the filling line is closed and the extraction line is maintained open in order to guide the gas from the tank back until the pressure and/or the temperature in the tank is/are lowered to defined values.

The invention relates to a method of operating a device for filling a tank with cryogenically stored fuel, particularly for supplying an internal-combustion engine driving a motor vehicle. With respect to the technical background, reference is made to German patent document DE 10 2004 056 186 A1.
Fuels for driving motor vehicles, such as hydrogen, natural gas or the like, can be stored virtually only in a liquefied form and thus in a highly cooled condition in order to obtain the demanded volumetric and gravimetric storage densities. The intensely cooled liquid hydrogen supply is stored in the vehicle in the boiling or almost boiling condition in a thermally well insulated, pressure-tight tank. The physical density of the boiling hydrogen is maximized by storage at a temperature slightly above the boiling temperature at an ambient pressure, approximately 20 K.
In today's technically implemented storage tanks, hydrogen is typically present at temperatures of approximately 21 K to approximately 27 K, and the corresponding boiling pressures of approximately 2 bar (abs.) to approximately 5 bar (abs.). In the lower part of the storage tank, the boiling hydrogen is present as a denser liquid phase (LH2) and, situated above the latter, as a gaseous phase (GH2). A gaseous as well as a liquid removal of the hydrogen from the storage tank is contemplated and meaningful. As a result of the removal of hydrogen during the operation of the storage device when supplying the internal-combustion engine after a pressure build-up phase, the storage pressure is reduced until the storage tank operating pressure is reached without any targeted heat feed. Because the enthalpy removal is lower when liquid is removed and because of the resulting slower pressure reduction, a removal from the gaseous phase (gas removal) is therefore meaningful.
However, in the case of this cryogenic fuel storage, as a result of the feeding of heat into the fuel tank, a small amount of liquid fuel evaporates continuously. The pressure in the fuel tank therefore increases until the limit value set for the latter—also called the "boil-off" pressure—is reached, and the further evaporating fuel has to be blown off from the fuel tank as so-called boil-off gas. Particularly when no consuming device for the fuel is operative, i.e., particularly when the internal-combustion engine is inoperative, the internal pressure of the tank will rise as a result of the feeding of heat without any removal. For reasons of safety, this pressure has to be limited by the opening of valves. In this case, the boil-off gas is generally released into the environment by way of blow-off pipes in which the above-mentioned valves are provided. The selection of the operating pressure in the fuel tank and of the pressure stroke between the operating pressure and the boil-off pressure, in addition to the amount of the heat feeding, considerably determine the loss-free pressure build-up time.
When fueling a tank for cryogenic liquids whose temperature is above the operating temperature, the excess thermal energy should advantageously be discharged together with the return gas. As a time window, the fueling time is available for this purpose. Heat that cannot be dissipated during fueling is absorbed by the hydrogen and, when the vehicle is not operated by means of hydrogen, results in a pressure rise in the tank.
FIG. 1 shows the state of the art when filling a tank with cryogenically stored fuel at a gas station, in the case of a warm fueling. The warm tank is filled by the gas station by way of liquid hydrogen and is cooled in the process in that the entire fed hydrogen mass is returned to the gas station as heated gaseous hydrogen.
When the tank has reached the required temperature, i.e., LH2 is assumed, the liquid level will rise in the tank. Furthermore, a residual quantity of heated gas is discharged to the gas station. At the end of the fueling, the liquid level in the tank has reached 100%; the fueling is terminated and all tank valves are closed.
At this point in time, however, the tank is not completely cooled throughout. Residual heat is absorbed by the hydrogen; the latter heats up and expands and the pressure in the tank increases as a result. The pressure rise may be so large that no sufficient amounts of gas can be removed even by the response of the boil-off valve and, because of the further pressure rise, an undesirable opening of the safety valve takes place.
Depending on the warm fueling duration and the filling level at the end of the fueling, hydrogen is released into the environment, specifically up to 900 g/h or up to 1 kg/warm fueling. As a result, the emission limit in the operational case (5 g/day), as in the case of a disturbance (60 g/h), is considerably exceeded, and garage parking cannot take place after a warm fueling.
It is therefore an object of the invention to provide a method for operating a device for filling a tank with cryogenically stored fuel which makes it possible to carry out a warm fueling that keeps the pressure rise in the tank so low that no hydrogen has to be blown off by way of the safety valve, thereby increasing the service life of the cryotank.
According to the invention, a method is provided for operating a device for filling a tank for storing fuel as condensed gas, in particular a cryotank, for a consuming device that can be operated with cryogenically stored fuel, in particular an internal-combustion engine of a motor vehicle. The tank includes a filling device for the cryogenically stored fuel. The filling device includes at least one filling line and one removal line, for connecting with a gas-station-side filling device. In this case, the filling operation is controlled such that, in a first time period, for cooling the tank, condensed gas is introduced by way of the filling line into the latter which, for the most part, is removed again as gas by way of the removal line, and that, in a second, subsequent time period, the tank is filled with condensed gas, while removing at least the gas displaced thereby. In a subsequent, third time period, the filling line is closed and the removal line is kept open in order to return gas from the tank to the gas station until the pressure and/or the temperature in the tank have fallen to predetermined values.
As a result, it becomes possible to significantly shorten the fueling time for a warm fueling. Specifically, the warm fueling duration is a function of the actual quantity of heat still present in the system. In this case, the actual tank temperature is taken into consideration. The lowering of the pressure during the third time period—the conditioning—leads to a reduction of the gas quantity to be discharged because the evaporation enthalpy rises considerably at lower pressures. However, in the boiling condition, lower pressure also results in a lower temperature.
This has the result that the temperature difference with respect to the still warm components is greater and the heat is therefore dissipated faster to the hydrogen, which shortens the fueling time.
In addition, the pressure rise in the tank is kept so low that no hydrogen has to be blown-off by way of the safety valve. The service life of the cryotank is thereby increased.
An advantageous embodiment of the process is characterized in that the third time period is followed by a fourth time period, in which the filling line is opened and closed again.
When the pressure or the temperature in the tank have fallen to the required extent, the "fueling" signal is switched away from the vehicle, and the liquid fueling valve is opened for a short time. This has the advantage that the function routine "end of fueling" can thereby easily be triggered on the part of the gas station. Subsequently, the fueling coupling can be released in order to be detached.
Another advantageous embodiment of the method is characterized in that a control device present on the gas station side, particularly a two-position controller or a proportional control element, in the third time period, keeps the pressure in the tank above the ambient pressure but below the tank operating pressure.
In the third time period, in which the conditioning takes place, the gas quantity decreases with the lowering heat feed and thus the pressure in the tank also decreases. Advantageously, a conclusion can be drawn from the occurring pressure with respect to the remaining residual heat quantity in the tank. When the residual heat quantity is reduced to an amount which, in the event of absorption by the hydrogen, will not lead to an excessive rise of the tank pressure and thereby an opening of the safety blow-off valve, the conditioning operation can be concluded by closing the removal valve. This relates to a control device with a proportional control element.
By using a two-position controller as a control element, the pressure in the tank is kept low during the conditioning. The pressure band is situated below the normal operating pressure of the tank, but above the ambient pressure. When the shut-off element of the two-position controller of the gas station is closed, the tank pressure will rise. As the heat feed by the tank falls, the rate of the pressure rise in the tank will also decrease. By analyzing these measured values, a conclusion can be drawn as to the residual amount of heat still present in the system. When the residual amount of heat is reduced to an amount which, when absorbed by the hydrogen, will not lead to an excessive rise of the tank pressure and thereby an opening of the safety blow-off valve, the removal valve can be closed and the conditioning can thereby be terminated.
Thus, in the third time period, the still present amount of heat in the tank system can advantageously be determined by way of the rate of the pressure rise or the existing momentary pressure in the tank, in which case, the removal line is, at the earliest, closed when a subsequent pressure increase, caused by the still present amount of heat in the tank system and by the closed removal line, will remain below the pressure limit value which is provided for the opening of a tank safety blow-off valve.
Further preferred embodiments of the process are characterized in that the fueling operation is terminated at the earliest after the expiration of the third time period by the one-sided or mutual release of fueling elements on the vehicle-side and the gas station-side. A control device, particularly on the gas station-side, is advantageously provided for the described control operations, which control device processes predefined and measured values corresponding to the method steps.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.

Method of operating a device for filling a tank with cryogenically stored fuel

Bayerische Motoren Werke Aktiengesellschaft


There is provided a vital information processing apparatus capable of effectively reducing small-amplitude noise and isolated noise without degrading an abrupt change portion in a processing target vital signal. A vital signal detected by a vital signal detector (10) is input from a vital signal input unit (20). A sync signal extractor (25) extracts, e.g., the QRS wave form of an electrocardiogram signal of the input signal and outputs the extracted wave as a sync signal (26). A preprocessor (30) performs predetermined preprocessing for the processing target vital signal, e.g., a K sound signal and outputs the preprocessed signal to median filters (40, 45). Each of the median filters (40, 45) filters the Korotkoff sounds using the QRS signal (26) as the index value and outputs the resultant signal.

The present invention relates to a vital information processing apparatus capable of effectively reducing noise components contained in vital information and, more particularly, to a vital information processing apparatus which can extract each vital signal representing an electrocardiogram, blood pressure, pulse wave, respiration, EEG (electroencephalogram), or the like and has, as a processing target, Korotkoff sounds, blood pressure, electrocardiogram, respiration, an image data signal representing MRI, CT, radioisotope, or the like.
In a vital information processing apparatus for detecting and processing a vital signal, a vital signal to be detected is generally a signal having a very low level and contains a large number of noise components. For this reason, demand has conventionally arisen for effectively reducing the noise components contained in the vital signal prior to processing of vital information.
To reduce the noise components, the following conventional methods are used. The reference waveform of a vital signal is compared with the waveform of a detected signal to extract only signals having high similarity degrees. Alternatively, the feature points of a signal are extracted to detect the generation period of the signal in accordance with the generation period of the feature points, and signal components falling outside the generation period of the signal are eliminated.
In the method of extracting signals having high similarity degrees, all the signals to be processed must be precisely compared with the reference waveform. That is, to make an accurate judgment, a very large volume of information must be processed. This method cannot be used when vital signals are processed in real time. When vital signals are to be forcibly processed in real time, the processing speed of an apparatus must be increased. The apparatus becomes inevitably bulky and expensive as a whole.
In the method of detecting the generation period of the signal and eliminating signals falling outside this generation period, a filter for passing only signals in a signal band using the signal periodicity is arranged, and a signal having a desired frequency is defined as an effective signal using this filter. According to this method, however, a noise signal whose frequency is greatly shifted from the frequency band can be reduced, but a noise component present in the same frequency band as that of the effective signal cannot be reduced.


A structural element having a region of porous silicon or porous silicon oxide, which was obtained from a porization, starting from an edge area of the region, in at least largely crystalline silicon. Relative to the edge area, the crystalline silicon has a crystal orientation that has an orientation that differs from a <100> orientation or from an orientation that is equivalent for reasons of symmetry. This structural element is suited for use in a mass-flow sensor, in a component for the thermal decoupling of sensor and/or actuator structures, or a gas sensor. Furthermore, methods for setting the thermal conductivity of a region of porous silicon or porous silicon oxide of a structural element are described. In particular, in a porization of crystalline silicon, starting from an edge area of the region, the crystalline orientation of the silicon relative to the edge area is selected such that a thermal conductivity comes about along a direction perpendicular to the edge area that differs from, in particular is lower than, the thermal conductivity, that comes about in this direction in an otherwise analogous porization of crystalline silicon having a <100> orientation or an equivalent orientation relative to this edge area.

Porous silicon or porous silicon oxide is used in microsystem technology in particular in the form of a thick layer having poor thermal conductivity, for the thermal decoupling of sensor structures or actuator structures in components such as thermal, chemical or fluid sensors or gas sensors. The quality of the thermal decoupling, and thus the quality of the component, depends to a large degree on the thermal conductivity of the material used for the decoupling. Minimal thermal conductivity measured on oxidized porous silicon having still tenable mechanical stability lie in the range of 0.3 to 0.5 W/mK.
To produce porous silicon or porous silicon oxide, one utilizes an electrochemical reaction between hydrofluoric acid and silicon. In the process, a silicon layer or a silicon wafer is polarized anodically with respect to a hydrofluoric-acid electrolyte, so that a sponge-type structure is produced in the silicon, which has a large inner surface and other chemical and physical properties, such as lower thermal conductivity, than the surrounding bulk silicon.

Structural element having a porous region at least regionally provided with a cover layer and its use as well as method for setting the thermal conductivity of a porous region


In an automotive floor panel assembly (1) comprising a floor panel (1M) stamp-formed of sheet metal and including a longitudinal floor tunnel (2) extending longitudinally in a laterally central part of the floor panel and a lateral floor tunnel (3) extending laterally across the longitudinal floor tunnel, a first reinforcement member (7), which may have a stepped cross section, attached to and extending along a front surface of a front wall (1fw) of the lateral floor tunnel so as to define a closed cross section jointly with the front wall of the lateral floor tunnel. Thereby, a closed cross section is defined jointly by the first reinforcement member and the front wall of the lateral floor tunnel immediately under the front end of the front seats (4) so that the floor panel can be favorably reinforced without limiting the leg rooms of the vehicle occupants of the front seats and without interfering with the space for receiving the fuel tank (10).

In a moncoque automotive body structure, various body panel members are stamp formed of thin steel plate, and are joined by spot welding or the like so as to form the final body structure. In such a body structure, it is important to ensure an adequate rigidity to the floor panel assembly. For this purpose, it was previously proposed to provide a lateral floor tunnel that extends laterally across the floor panel under the front seats in addition to the more conventional longitudinal floor tunnel (see Japanese patent laid open publication No. 2002-302071. The resulting upward projection in the floor panel having a cross-shape is effective in increasing the rigidity of the floor panel.
However, when a heavy fuel tank is mounted in the recess defined by the lateral floor tunnel, an additional reinforcement is required, and there was some difficulty in preventing such an additional reinforcement from reducing the capacity of the fuel tank and/or the leg rooms of the vehicle occupants.
When a shift lever is mounted on the longitudinal floor tunnel, an added rigidity is required to ensure a favorable feel to the vehicle operator who operates the shift lever, and the cross-shaped floor tunnel was not found to be entirely satisfactory. Therefore, it is necessary to reinforce the part of the longitudinal floor tunnel around the shift lever for the purpose of ensuring the required rigidity. Welding a steel plate having a suitable thickness in a part of the longitudinal floor tunnel provides a required rigidity, but the need for such as added manufacturing step is not desirable from economic view points.


A wafer to be heat-treated is placed in a heat treatment chamber defined by a heat treatment vessel, and the wafer is heat-treated by radiant heat radiated by a heat source. A gas is supplied through a gas passage formed along the outer surface of an inner wall of the heat treatment vessel and having a portion extending near the heat source. The gas heated in the portion of the gas passage extending near the heat source by the heat source is blown toward a substantially central portion of the wafer as complementary heating means for increasing the temperature of the central portion of the wafer.

1. Field of the Invention
The present invention relates to a heat treatment apparatus and a heat treatment method.
2. Description of the Related Art
Various heat treatment apparatuses are employed in a semiconductor device fabricating process for subjecting a semiconductor wafer, i.e., a workpiece, to oxidation, diffusion, CVD (chemical vapor deposition), annealing and such. A representative batch heat treatment apparatus among those known heat treatment apparatus has a vertical reaction tube defining a heat treatment chamber which receives wafer boat holding a plurality of wafers, for example, 150 wafers, at predetermined intervals in a vertical stack, and subjects the plurality of wafers to a heat treatment in an atmosphere of a processing gas.
This known batch heat treatment apparatus is capable of heat-treating a plurality of wafers simultaneously and is satisfactory to some extent. However, since the upper wafers held in an upper portion of the wafer boat and the lower wafers held in a lower portion of the wafer boat are spaced a relatively long distance apart, the upper wafers are brought first into a hot environment in the heat treatment chamber and are taken last out of the hot environment, and operations for loading and unloading the heat treatment chamber need time, it is hard to heat all the wafers evenly by a heat treatment in which the temperature is raised and lowered quickly.
There have been proposed single-wafer heat treatment apparatuses capable of carrying out a heat treatment method requiring rapid heating and rapid cooling suitable for processing wafers of a large diameter and for fabricating miniaturized semiconductor devices. These previously proposed single-wafer heat treatment apparatuses are classified into those of a hot wall type which heat a heat treatment chamber together with a wafer by a heating means disposed outside the heat treatment chamber, and those of a cold wall type which heat only a wafer placed in a heat treatment chamber through a susceptor disposed within the processing chamber.
However, when a wafer is heated by those previously proposed heat treatment apparatus of either the hot wall type or the cold wall type, there is a tendency that the temperature of the central portion of the wafer starts rising later than that of the peripheral portion of the wafer and, consequently, that the surface of the wafer is heated in an irregular temperature distribution while the wafer is being heated to a desired temperature. Particularly, in the heat treatment apparatus of the cold wall type, the irregularity of the temperature distribution in the surface of the wafer is increased even in a heat-treating period after the wafer has been heated to the desired temperature by the process gas of a low temperature applied to the heated wafer. Such an irregular temperature distribution in the surface of the wafer tends to deteriorate the uniformity of heat-treating, such as film formation. Moreover, the process gas adsorbed by the wafer needs time to be heated to a temperature equal to that of the wafer, so that heat treatment apparatus has a tendency to delay the reaction between the processing gas and the wafer, deteriorate the quality of the product and reduce the throughput of the process.

Heat treatment apparatus and heat treatment method


A method and apparatus for repairing isolated chondral defects using allograft implants. Lesions in articular tissue are corrected by forming a recipient socket in the tissue. A donor graft of a size corresponding to the recipient socket is harvested from a partial tissue specimen obtained from allograft material. The donor graft is implanted into the recipient socket.

1. Field of the Invention
The present invention relates to the surgical treatment of isolated articular chondral defects and, more specifically, to methods and instruments for replacement of articular cartilage in the knee using grafts harvested from a partial distal allograft femur or condyle.
2. Description of the Related Art
Methods and apparatus for surgical treatment of isolated articular chondral defects by autograft and allograft transplantation are known. See, for example, U.S. Pat. Nos. 5,919,196, 6,591,581, and 6,592,588, having common assignment with the present application.
FIG. 1 illustrates a prior art procedure for obtaining an allograft hemi-condyle for use in an osteochondral repair procedure. A cadaveric distal femur 10 is cut into two hemi-condylar portions 12 and 14. Disadvantageously, harvesting of bone material from the allograft hemi-condyle leaves significant portions of the hemi-condyle as waste. In addition, hemi-condyles do not provide an intact trochlear region. Repair of defects in the trochlear region requires whole distal femurs, which results in further, significant tissue loss since residual condyles are discarded.
Cutting the distal femur into partial condyles would provide a more efficient use of the distal femur. Reducing the size of the partial condyles also facilitates processing of the allogeneic graft material. Processing of the allogeneic material is facilitated, for example, by increasing available surface area for graft cleaning, and reducing blood and lipid residuals that may impact negatively the viability of chondrocytes, an important factor in procedure outcome.
Accordingly, it would be advantageous to provide a method and system for creating and utilizing partial allograft femurs or condyles in the repair of isolated chondral defects.

Osteochondral repair using plug fashioned from partial distal allograft femur or condyle


Method for operating an apparatus for forming plastic preforms into plastic containers, wherein in a working mode a plurality of forming stations are moved along a predetermined transport path by a movable carrier, wherein these forming stations in each case having blow mould arrangements which in a closed state in each case form cavities, within which the plastic preforms are formed into the plastic containers and the plastic preforms are supplied to these forming stations in order to be formed by supplying a flowable medium to the plastic containers, wherein this forming takes place at least temporarily during the transport of the forming stations along the transport path, and wherein at least temporarily at least components of the blow moulding arrangement are tempered. At least parts of the blow mould are pre-heated in a standstill of the carrier or a movement of the carrier, which is slower with respect to a movement of the carrier in the working mode.

The present invention relates to a method and an apparatus for forming plastic preforms into plastic containers. Such methods and apparatus have been known from the prior art for a long time. In particular, it is known that heated plastic preforms are formed into plastic containers within blow moulds by applying a flowable medium.
In a conventional process, the plastic preforms are formed into the plastic containers by means of a gaseous medium and in particular compressed air. In other processes known from the more recent prior art, the heated plastic preforms are directly applied with a liquid, in particular a product to be filled later, and are thus simultaneously expanded and filled with the liquid and in particular the beverage. The present invention is suitable both for methods in which this forming takes place by means of a gaseous medium, i.e. in particular by means of compressed air, and for methods in which the forming takes place by means of a liquid medium and in particular by means of the beverage to be filled.
Such forming devices usually have a movable, e.g. rotatable carrier on which the forming stations are arranged, wherein during a working process, the plastic preforms are formed into the plastic containers during their transport with this carrier or the forming stations. In some methods it is necessary to temper the respective blow moulds of the forming stations and especially those wall areas which come into contact with the plastic preforms to be expanded.
It is known that the blow moulds are tempered by means of electrical energy, for example by heating, as well as by means of a tempering medium, for example a heated oil. Since the forming stations of many machines are located on a rotating carousel, it is known in the prior art to couple supply lines, for example for electricity but also for liquid, from a stationary area to a rotating area. Such a machine is for example known from the EP 1 776 224 B1. This device describes a carousel-like rotating machine, which has a rotating fluid connection and a rotating power connection on a rotating column, which are connected to a fixed power supply or fluid supply.
When electrical heating means are used in a forming unit or other apparatus for manufacturing containers from a thermoplastic material, a high level of energy is used in particular for pre-tempering, for example heating, of the blow moulds. This is due to the fact that the greatest temperature difference must be overcome during this time period in order to bring the blow mould from an initial temperature to an operating temperature.
Once the blow mould has been brought to a certain target temperature, the blow mould only needs to be kept at this temperature and the temperature differences to be overcome are lower. Accordingly, it is particularly necessary to supply more energy to a machine at the start of commissioning in order to achieve a high heating performance and to reach an operating temperature as quickly as possible.
In the prior art, the blow moulds of all forming stations of the apparatus for forming plastic preforms into plastic containers are usually heated with the same heating elements in all steps. This ensures that heating is only possible with a limited heating performance at the beginning. In addition, the use of electric heating elements requires the most energy at the start, since thereby the greatest temperature differences must be overcome.
Accordingly, in the prior art, it takes a relatively long time to get the blow moulds up to an operating temperature. Valuable working time for preparing the machine is also lost here. In addition, relatively high performances must also be coupled from the stationary area to the rotating area, since a relatively high output is required if all heating elements are to bring the blow moulds to an operating temperature, in particular simultaneously.

Method and apparatus for forming plastic preforms into plastic containers with pre-heating of blow moulds


A method of lithographically transferring a pattern on a light sensitive surface in a multiple exposure process comprises the following steps:    a) providing a mask comprising a first mask pattern area and a second mask pattern area;    b) directing projection light on the mask, thereby producing on the light sensitive surface a first exposed pattern area, which is an image of the first mask pattern area, and a second exposed pattern area, which is an image of the second mask pattern area. The projection light illuminating the first and second mask pattern area has different angular light distributions.    c) repeating step b) using the same mask so that an image of the first mask pattern area is superimposed on the second exposure pattern area.

1. Field of the Invention
The invention generally relates to microlithographic exposure apparatus, and in particular to a method of lithographically transferring a pattern on a light sensitive surface and to an illumination system of such an apparatus.
2. Description of Related Art
Microlithography (also called photolithography or simply lithography) is a technology for the fabrication of integrated circuits, liquid crystal displays and other microstructured devices. The process of microlithography, in conjunction with the process of etching, is used to pattern features in thin film stacks that have been formed on a substrate, for example a silicon wafer. At each layer of the fabrication, the wafer is first coated with a photoresist which is a material that is sensitive to radiation, such as deep ultraviolet (DUV) light. Next, the wafer with the photoresist on top is exposed to projection light in a projection exposure apparatus. The apparatus projects a mask containing a pattern onto the photoresist so that the latter is only exposed at certain locations which are determined by the mask pattern. After the exposure the photoresist is developed to produce an image corresponding to the mask pattern. Then an etch process transfers the pattern into the thin film stacks on the wafer. Finally, the photoresist is removed. Repetition of this process with different masks results in a multi-layered microstructured component.
A projection exposure apparatus typically includes an illumination system for illuminating the mask, a mask stage for aligning the mask, a projection objective and a wafer alignment stage for aligning the wafer coated with the photoresist. The illumination system illuminates a field on the mask that may have the shape of a rectangular or curved slit, for example.
In current projection exposure apparatus a distinction can be made between two different types of apparatus. In one type each target portion on the wafer is irradiated by exposing the entire mask pattern onto the target portion in one go. Such an apparatus is commonly referred to as a wafer stepper. In the other type of apparatus, which is commonly referred to as a step-and-scan apparatus or scanner, each target portion is irradiated by progressively scanning the mask pattern under the projection beam along a scan direction while synchronously moving the substrate parallel or anti-parallel to this direction. The ratio of the velocity of the wafer and the velocity of the mask is equal to the magnification of the projection objective, which is usually smaller than 1, for example 1:4.
It is to be understood that the term "mask" (or reticle) is to be interpreted broadly as a patterning means. Commonly used masks contain transmissive or reflective patterns and may be of the binary, alternating phase-shift, attenuated phase-shift or various hybrid mask type, for example. However, there are also active masks, e.g. masks realized as a programmable mirror array. Also programmable LCD arrays may be used as active masks.
As the technology for manufacturing microstructured devices advances, there are ever increasing demands also on the illumination system. Ideally, the illumination system illuminates each point of the illuminated field on the mask with projection light having a well defined irradiance and angular distribution. The term angular distribution describes how the total light energy of a light bundle, which converges towards a particular point in the mask plane, is distributed among the various directions of the rays that constitute the light bundle.
The angular distribution of the projection light impinging on the mask is usually adapted to the kind of pattern to be projected onto the photoresist. For example, relatively large sized features may require a different angular distribution than small sized features. The most commonly used angular distributions of projection light are referred to as conventional, annular, dipole and quadrupole illumination settings. These terms refer to the irradiance distribution in a pupil plane of the illumination system. With an annular illumination setting, for example, only an annular region is illuminated in the pupil plane. Thus there is only a small range of angles present in the angular distribution of the projection light, and thus all light rays impinge obliquely with similar angles onto the mask.
If a mask pattern to be imaged on the photo resist comprises portions that look very different with respect to structure orientation, density and/or pitches, there is usually no specific angular light distribution that is perfectly suited to image all mask pattern areas with an optimum image quality. For example, if there is a first mask pattern area comprising features that extend along the X direction and a second mask pattern area which comprises features extending to an orthogonal Y direction, a quadrupole or C-quad illumination setting images all features with the same, but sub-optimum image quality. This is because only two poles contribute to the image formation of each feature, whereas the other two poles contribute to background illumination, which results in a reduced contrast. Ideally, the features extending along the X direction would be illuminated exclusively with a Y dipole illumination setting, and the features extending along the Y direction would be illuminated with an X dipole illumination setting.
Such an improved illumination, and hence improved imaging, can be achieved if the pattern is not transferred on the light sensitive surface in one go, but in two (or more) separate exposures using different photo masks. The first mask comprises all features extending along the X direction and is illuminated with a Y dipole illumination setting. The second mask comprises the features extending along the Y direction and is illuminated in a subsequent exposure with an X dipole illumination setting. This approach to distribute the imaging of complex patterns among two separate exposures is usually referred to as "double exposure". If this approach is extended to more than two subsequent exposures, it is referred to as multiple exposure.
Since the mask can be exchanged quickly, the illumination system has to be capable of changing the angular light distribution at mask level quickly, too.
Different means are known in the art to modify the angular distribution of the projection light in the mask plane so as to achieve the desired illumination setting. In the simplest case a stop (diaphragm) comprising one or more apertures is positioned in a pupil plane of the illumination system. Since locations in a pupil plane translate into angles in a Fourier related field plane such as the mask plane, the size, shape and location of the aperture(s) in the pupil plane determines the angular light distribution at mask plane level. However, any change of the illumination setting requires a replacement of the stop. This makes it difficult to finely adjust the illumination setting, because this would require a very large number of stops that have aperture(s) with slightly different sizes, shapes or locations. Furthermore, the use of stops inevitably results in light losses which reduce the throughput of the apparatus.
Many common illumination systems therefore comprise adjustable elements that make it possible, at least to a certain extent, to continuously vary the illumination of the pupil plane.
The most common approach is to use a diffractive optical element that defines the irradiance distribution in the pupil plane. A diffractive optical element can be manufactured such that almost any arbitrary far field irradiance distribution can be produced. Often such diffractive optical elements are realized as computer generated holograms (CGH). For being able to change the irradiance distribution in the pupil plane, a plurality of different diffractive optical elements may be received in an exchange holder so that one of these diffractive optical elements may be inserted quickly into the light path of the projection light. Such an exchange holder may be a linear exchange holder or a turret holder which is capable of rotating around a rotational axis, for example.
The irradiance distribution in the pupil plane defined by the diffractive optical element may be modified additionally with the help of a zoom optical system and a pair of axicon elements. By displacing lenses of the zoom optical system and/or the axicon elements along the optical axis, the irradiance distribution can be modified continuously within certain limits.
However, the exchange of diffractive optical elements and the displacement of lenses and other optical elements along the optical axis is a relatively slow process and may thus limit the throughput of the apparatus.
A more flexible and quicker approach to produce different irradiance distributions in the pupil plane of the illumination system is the use of mirror arrays instead of diffractive optical elements.
In EP 1 262 836 A1 the mirror array is realized as a micro-electromechanical system (MEMS) comprising more than 1000 microscopic mirrors. Each of the mirrors can be tilted in two different planes perpendicular to each other. Thus radiation incident on such a mirror device can be reflected into (substantially) any desired direction of a hemisphere. A condenser lens arranged between the mirror array and the pupil plane translates the reflection angles produced by the mirrors into locations in the pupil plane. This known illumination system makes it possible to illuminate the pupil plane with a plurality of spots, wherein each spot is associated with one particular microscopic mirror and is freely movable across the pupil plane by tilting this mirror.
Similar illumination systems are known from US 2006/0087634 A1, U.S. Pat. No. 7,061,582 B2 and WO 2005/026843 A2.
The illumination system disclosed in WO 2010/006687 A1 uses a mirror array not only to determine the angular, but also the spatial irradiance distribution in the mask plane. To this end the mirror produces spots being so small that different light patterns can be produced on the light entrance facets of the optical integrator. Since these light entrance facets are optically conjugate with the mask plane, a particular light pattern produced on a light entrance facet is directly imaged on the mask plane. This ability to vary the geometry of the field which is illuminated in the mask plane can be used to eliminate the need for adjustable blades in the illumination system. Such blades are used in apparatus of the scanner type at the beginning and the end of each scanning cycle to enlarge or to reduce the illuminated field along the scan direction. It is also described that, at a given instance, different light entrance facets may be illuminated with different light patterns so as to produce a spatial irradiance distribution having a smooth profile.
Also unpublished international patent application PCT/EP2011/000416 discloses an illumination system which is capable to produce at a given instance during a scan process different angular light distributions at different portions on the mask. This is again accomplished by producing different light patterns on the light entrance facets of the optical integrator.
According to unpublished international patent application PCT/EP2010/005317 different angular light distributions at different portions on the mask can be produced with the help of a plurality of modulator units that are arranged in the vicinity of the optical integrator. Each modulator unit is associated with a single optical channel of the optical integrator and variably redistributes, without blocking any light, a spatial and/or angular light distribution of the respective optical channel.
WO 2006/097135 A1 discloses an illumination system which is capable to change very quickly, for example between successive pulses of a pulse train emitted by the light source, the angular light distribution at mask level. This may be accomplished by alternately shielding certain portions of the pupil plane by a rotating diaphragm, by using an LCD transmission filter in the pupil plane or by using the acousto-optic effect in a diffractive optical element, for example. The state of polarization can be changed simultaneously with the angular light distribution with the help of a quickly rotating polarizing element.
US 2008/0013065 A1 discloses an illumination system which is also capable to change very quickly the angular light distributions at mask level. To this end the illumination system comprises a first and a second pupil defining unit each including a diffractive optical element, a zoom optical system and a pair of axicon elements. Projection light is either guided through the first or the second pupil defining unit using suitable light switching components, before it impinges on an optical integrator.
When double (or generally multiple) exposures are performed, overlay errors are a crucial issue. The term overlay error originally related to the registration of adjacent pattern layers in the micro-structured devices. If features that should be arranged one above the other are laterally displaced, this offset is referred to as overlay error. Meanwhile the term overlay error is also used to denote relative displacements of features within a single layer, as this may happen in layers which have been structured in a double exposure process. Many microstructured devices are more sensible to overlay errors within single layers than to overlay errors between adjacent layers. For that reason the overlay error budget within single layers produced in a double exposure process is often particularly small. Exceeding the tight specifications reduces drastically the yield of the manufacturing process. For that reason double exposure is still not as widely used as it could be with regard to the obvious advantages which are associated with illuminating the features with projection light having an optimum angular light distribution.
One significant cause of overlay errors in double exposure processes is associated with the fact that the images of two different masks are superimposed. Then not only alignment errors of the two masks contribute to the overlay error budget, but also manufacturing tolerances that are inevitable when the two masks are fabricated. The fabrication of a mask is a very sophisticated process, and therefore the conditions that prevailed when one mask has been manufactured cannot be perfectly reproduced during the fabrication of the other mask. In other words, even if alignment errors during the second exposure could be reduced to zero, there would still be a significant overlay error because the two masks do not perfectly correspond to one another.

Method of lithographically transferring a pattern on a light sensitive surface and illumination system of a microlithographic projection exposure apparatus


A lean signal processing method, a bearing monitoring unit and a wheel monitoring unit using the lean signal processing method are presented that are especially suitable for embedded systems. The invention is based on the basic inventive idea of digitally adjusting measured signals that are to be analyzed in different frequency bands to thereby enable to have a single common analogue front end and a single common digital spectrum analyzer back end. This will save analogue components and relax the need for memory in addition to a lean signal processing.

In the field of rolling element bearings, it is known to attach one or more sensors to measure one or more physical parameters and transduce these physical parameters into electrical signals to thereby monitor the condition of the bearing. One such example is to monitor a wheel bearing of vehicle, such as a truck or a truck trailer. To be able to retrofit a truck or truck trailer with wheel bearing monitoring, it is known to mount a monitoring unit to the wheel rim. Wheel monitoring apparatuses that are mounted on a wheel rim has to be particularly light and robust in order, on the one hand, to avoid an imbalance of the wheel as a result of the weight of the wheel monitoring unit and, on the other hand, to ensure a long service life despite the extreme conditions to which the wheel monitoring unit is exposed to during operation. There seems to be room for improvements.


Nontoxic, biodegradable injection-molded, plastic shotshell components, and method of manufacturing same, the components having a fused degradation composition comprising as its active ingredients polycaprolactone, amide stearate and vegetable oil, the latter two enhancing the degradation activity of the polycaprolactone and imparting injection-moldability thereto.

Biodegradation is the degradation and assimilation of organic polymers and other compounds by the action of living organisms. With a few notable exceptions, synthetic plastics are resistant to microbiological degradation, but naturally occurring polymers are susceptible to breakdown by fungi and bacteria. Biological degradation of polymers is facilitated by linearity of the polymer chains and by low molecular weights (below 1,000). These conclusions are supported by laboratory tests in which polymer samples are exposed to mixtures of known micro-organisms and by soil burial tests. Applications for biodegradable plastics in agriculture include slow release urea-formaldehyde fertilizers and degradable containers and matrices for the sustained release of pesticides and herbicides. Absorbable sutures are prominent examples of surgical applications for biodegradable plastics. Absorbable plastics have also been developed for use in orthopedic surgery in the form of screws, pins and plates.
Polycaprolactone polymer systems belong to the family of polymer of cyclic esters. In early 1930, the pioneering work in the area of polymerization was started by W. H. Carruthers.
In late 1950 and the early 1960's, Union Carbide Corporation recognized the usefulness of the above polymer systems and their applications in the molding, coating, fiber, film, and others. Their work resulted in various types of polymer systems and the economically feasible manufacturing systems for the manufacture of these polymer systems. E. F. Cox and F. Hostettler, of Union Carbide, received a number of patents in this field (U.S. Pat. Nos. 3,021,309-3,021,317).
In the late 1960's, in order to overcome a problem faced in the regeneration of forests by bare root planting methods, the U.S. government contacted Union Carbide Corporation to develop biodegradable plastic containers for use in lieu of previously used containers, which were manufactured of non-degradable plastic and surrounded the root systems of the seedlings, to the detriment of their growth. Union Carbide obtained a number of patents, as indicated below, which were directed to this problem. They were:
______________________________________ 3,844,987 3,923,729 3,850,862 3,921,333 3,850,863 3,929,937 3,852,913 3,931,068 3,867,324 3,932,319 3,919,163 ______________________________________
Each of these patents were related to the biodegradable feature of polycaprolactone. None of these patents contain any suggestion which would lead to the solution of the problems which we confronted in our attempts to develop a shotshell component.
Because of the great resistance of most plastics to environmental degradation, new needs for readily degradable plastics continue to arise. Also, known needs continue to increase or expand, merely because of the continually increased use of plastics by the public. One of the most recently publicized needs for readily degradable plastic is currently being stressed by environmental groups, because of the littering problem created by shotgun shells discharged by hunters. Thus, a need for plastic shotshell components, such as wads, shot-cups, and casings, has received much attention of late. When the hunting is conducted on land, such components rest upon the upper surface of the ground and present an unsightly view. When the shotguns are discharged over water, they tend to float and present other problems in addition to unsightliness. Our invention is directed toward overcoming this problem.
In addition to the need for overcoming the littering problem, there is a need to overcome a related problem, namely the problem created by the toxicity of the material from which shotshell components may be made. As a consequence, our attention was also directed toward the need to provide shotshell components which are nontoxic and will degrade within a reasonable length of time.
Although the above problems are of serious consequence, we also had an additional problem in mind, while seeking to overcome littering and toxicity. This additional problem was the need to provide an improved performance in the shot patterns of shotshells. This related need has arisen as a result of numerous states enacting laws which require the use of steel shot, instead of lead shot, in waterfowl hunting. The underlying reason for this requirement is that it has been well established that spent lead shot, which collect at the bottom of water bodies such as sloughs, become ingested by ducks and geese, which causes their deaths via lead poisoning. Although steel shot have been fairly well accepted, numerous complaints have arisen about their effectiveness, because of their lighter weight, as compared to lead shot. It is well established that steel shot carry a lesser impact upon striking the target because of such lighter weight and, as a consequence, there are many more wounded and unrecovered birds which would have been killed, if struck by the same number of lead shot. It is clear, therefore, that, if satisfactory and equal results are to be obtained in the use of steel shot, an improved pattern performance is necessary. Thus, while we were seeking to overcome toxicity and littering, we also sought to improve the pattern performance of steel shot by providing an improved shotshell component, such as a shot-cup which moves outwardly from the shotshell with the shot upon firing of the shotshell.
As indicated above, it is recognized that we need nontoxicity and rapid degradability, if we are to solve the littering and poisoning problems. The experience of the trade to date has been that polyethylene, particularly linear polyethylene, has been the most suitable plastic for use in the manufacture of shotshell components, such as casings, wads, and shot-cups. The reason for this is that polyethylene has the most suitable engineering properties and provides the most satisfying ballistic data. It has been previously known that polycaprolactone ##STR1## is nontoxic and is the most rapidly degrading plastic available, particularly in cold and wet climates and in water bodies. It appears that polycaprolactone components potentially will degrade rapidly, even in water bodies, such as fresh lakes, seas and other bodies of waters. Its use, however, has been prohibited, because its engineering properties are such that it alone cannot be used, since it has serious rigidity limitations at higher temperatures. Also, commercially available polycaprolactone systems did not yield trouble-free injection-molding processes for the molding of shotgun shell components. We reasoned that, if these two adverse aspects of polycaprolactone could be overcome, perhaps we could arrive at a suitable biodegradable shotshell component which would solve at least one of the above problems, namely littering.
Blending of polyethylene with polycaprolactone, however, is not feasible because the wide differences in their melting temperatures precludes injection-molding of an alloy or blend thereof. If the shot-cup is made of a polymer system consisting of linear polyethylene and the terpolymer, ethylene vinyl acetate carbon monoxide, it is photodegradable, but its degradability is very slow in wet and dark climates, and is not a suitable choice for the aforementioned environment as the degradable plastic.
The reason that polycaprolactone alone has heretofore been considered to be incapable of being injection-molded was that serious difficulty was experienced in obtaining the release of the shotshell components from the mold. We concluded that, if we could somehow modify polycaprolactone so as to obtain a satisfactory release of the parts from the mold, then we would have made progress toward overcoming at least one of its two adverse ammunition characteristics. In an effort to ameliorate this problem, we decided to follow two separate routes.
The first route we followed was to compound and repelletize the polycaprolactone polymer system, after incorporating a release additive package. We found, however, that although this appeared to ameliorate the problem, it lowers the molecular weight of the polycaprolactone polymer system to a substantial extent, and resulted in even further lowering the high temperature rigidity of this material. In view thereof, we felt compelled to discontinue following this approach.
The second route which we followed was to surface-coat the polycaprolactone polymer with liquid and solid lubricants to function as the releasing additive package. By doing so, we avoided the relatively extreme heating and cooling which was associated with the compounding and repelletizing procedure referred to above and, as a consequence, we saved the polycaprolactone from degrading further to yield maximum high temperature rigidity rating for the shotgun shell applications. We have apparently solved the problem in a much more satisfactory manner. We tried calcium stearate, zinc stearate, aluminum zinc stearate, aluminum stearate, and various fatty acid esters and fatty alcohol esters as elements of release additive packages. Although they functioned to a limited extent, none of these release additive packages functioned to a satisfactory degree. We found, however, that a combination of vegetable oil and fatty acid ester amides function in a highly satisfactory manner, if used advisedly, so that the polycaprolactone polymer system becomes readily capable of being injection-molded into the desired shotshell components.
A suitable shotshell component must perform adequately within the range of 150.degree. F. to -20.degree. F. Pure polycaprolactone shotshell components do not yield satisfactory ballistic performance at 150.degree. F. In an effort to ameliorate the high temperature rigidity problem, we chose two routes. The first route was to produce an alloy of polycaprolactone with rigid biochemically degradable plastics. In doing so, we worked with hydroxypropylcellulose, cellulose acetate, lactic acid polymers, and starch-based polymer systems. The hydroxypropylcellulose and starch-polymer system deteriorated the desired properties, and the polymer system became weaker than the initial polycaprolactone. The cellulose acetate and polylactic acid polymers did yield some improvement in that the high temperature rigidity of the system improved for the shotshell application, but simultaneously the low temperature limitations of the initial polycaprolactone increased. Work is being continued in this area.
The second route which we followed in seeking to ameliorate the high temperature rigidity problem was to rigidize and reinforce the polycaprolactone with inorganic fillers and organic fibers, such as cotton flock, talc, calcium carbonate, silica, clay and combinations thereof, and others. This approach failed to meet aforementioned shotgun shell performance, and the work in this area has been terminated.
A third approach is being practiced in a further effort to ameliorate the high temperature rigidity problem of the polycaprolactone polymer system. This approach is based upon a combination of the two above approaches, in which we seek to develop a suitable alloy.
Some notable alloying materials which we have explored, and the results of which are listed, is set forth hereinbelow:
(1) The alloying of various grades of starch-based polymer system, with no positive results. PA0 (2) The alloying of polycaprolactone with terpolymers, with no positive results. PA0 (3) The alloying of polycaprolactone with polylactide polymer systems, with positive results in terms of improvement of high temperature rigidity, but not satisfactory enough to meet total performance requirements. PA0 (1) Union Carbide Chemicals and Plastics Co., Inc., 39 Old Ridgebury Road, Danbury, Conn. 06817-0001, Telephone 1-800-223-0537. PA0 (2) Solvay Polymers, Inc., Technical Center, 1230 Battleground Road, P.O. Box 1000, Deer Park, Tex. 77536. PA0 (3) Daicel Chemical, 1 Tepo-Cho Sakai, Osaka-Pref, Osaka, 590, JAPAN, Telephone 81-6-722-273111.
In all, we have tested 10-15 different materials in combination with polycaprolactone and the alloys thereof, in our efforts to develop a suitable polycaprolactone polymer. To date, the best we have found is the polymer system described and claimed herein.

Injection-modulable, polycaprolactone-based, biodegradable plastic articles such as shotshell components, and method of manufacturing same