A method and apparatus is disclosed for detecting the frequency to which a broadcast receiver is tuned. In one embodiment, a sensing unit emits a chirp signal over a range of broadcast bands and monitors the output of the radio receiver to detect the frequency to which the radio receiver is tuned. In another embodiment, a sensing unit demodulates radio signals across a range of frequencies and compares the demodulated signals to observed audio output of the radio receiver.

The increasing use of wide area networks such as the Internet has resulted in an explosion in the provision of on-line services. Computer users can access a vast wealth of information and services by utilizing a wide area network to establish a connection with other computers connected to the network.
The Internet is a global network of millions of computers belonging to various commercial and non-profit entities such as corporations, universities, and research organizations. The computer networks of the Internet are connected by gateways that handle data transfer and conversion of messages from a sending network to the protocols used by a receiving network. The Internets collection of networks and gateways use the TCP/IP protocol. TCP/IP is an acronym for Transport Control Protocol/Internet Protocol, a software protocol developed by the Department of Defense.
Typically, the computers connected to a wide area network such as the Internet are identified as either servers or clients. A server is a computer that stores files that are available to other computers connected to the network. A client is a computer connected to the network that accesses the files and other resources provided by a server. To obtain information from a server, a client computer makes a request for a file or information located on the server using a specified protocol. Upon receipt of a properly formatted request, the server downloads the file to the client computer.
The World Wide Web is a system of Internet servers using specified Internet protocols and supporting specially formatted documents. The HyperText Transfer Protocol (HTTP) is the underlying protocol used by the World Wide Web. HTTP defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands. The other main standard of the World Wide Web is Hyper-Text Markup Language (HTML), which covers how documents and files are formatted and displayed. HTML supports links to other documents, as well as graphics, audio, and video files.
Users access the content contained on the Internet and the World Wide Web with an Internet Browser, which is a software application used to locate and display web pages. Files on a web server are identified by a uniform resource locator. A Uniform Resource Locator ("URL") is the global address of files and other resources on the Internet. The address indicates the protocol being used and specifies the IP address or the domain name where the file or resource is located. Typically, a URL identifies the name of the server and the path to a desired file on the server. For example, a URL for a web server may be constructed as follows: "http://<server>/<filepath>", where <server> identifies the server on which the file is located and <filepath> identifies the path to the file on the server. Thus, with the name of the server and the correct path to a file, a properly formatted URL accesses a desired file on a server connected to the World Wide Web.
As one can imagine, there are myriad documents and files accessible over the Internet. However, as discussed above, retrieving desired information on the Internet requires knowledge of an associated URL. Accordingly, if, for example, a consumer wishes to obtain information about or order a particular company's product on the World Wide Web, she must know the URL (data location) corresponding to that company's web site. Conversely, if a corporation desires the public to visit its web site containing information about its products, it will typically advertise its web site and corresponding URL in television, radio, print or other media. A consumer may then enter this URL, assuming he remembers it, into a browser and access the web site.
When a specific URL or data location is not known, search engines are a way of locating desired information. Typically, a user enters key words or search terms into a search engine, which returns a list of URLs corresponding to web sites or USENET groups where the key words or search terms were found. Often a search engine will return a large list of web sites, through which the user must wade in order to locate the few web sites relevant to his query.
Due in part to the proliferation of commercial web sites consumers have become accustomed to the notion that there is a corresponding web site for the vast majority of products and services being commercially offered. Yet, as described above, access to a particular web site on the Internet, requires knowledge of the actual URL or access to a search engine. This becomes problematic, however, when there is no immediate access to a computer connected to the Internet For example, when a radio listener hears a song on the radio and desires more information about it, he must remember the song title and the artist. Later, the listener can enter the song title or the artist as search terms in a typical search engine. Beyond this method, there are no alternative ways of identifying data locations or URLs based upon an observation of a particular product or event. In light of the foregoing it can be seen that a need exists for alternative methods of identifying URLs or other data locations on a computer network.

Method and apparatus for detecting a radio frequency to which a broadcast receiver is tuned


The disclosure concerns digital telephone sets and, more particularly, those with amplified listening facility and "hands free" telephones. To fulfil the function of the anti-Larsen effect needed in these telephones, there is need for a signal envelope detector which gives a measurement of the mean level of the signal emitted or received on the line. According to the disclosure, the cofidec present in the digital telephones is used to establish an envelope detection system with logarithmic compression. This removes the need to do a logarithmic detection on the analog speech signal. Such a detection would necessitate diodes, upside down with respect to each other, which can be made, particularly, only through bipolar technology. A series/parallel converter, a digital comparator and a counter having a countdown frequency which is far slower than the counting frequency, fulfils the signal envelope detection function.

1. Field of the Invention
The invention concerns digital telephone sets, namely telephone sets designed to transmit or receive speech signals, in the form of a digital signal, and not an analog one, on a telephone line.
2. Description of the Prior Art
These sets have an analog-digital and digital-analog conversion integrated circuit, now generally called a "cofidec circuit", interposed between the analog parts of the telephone set (mainly the loudspeaker and the microphone) and the digital parts (designed to be connected to the telephone line).
A cofidec circuit is more precisely a coder-decoder with filtering circuits to limit the band of frequencies transmitted on the line. The coder is a logarithmic (or substantially logarithmic) compression coder, that is, it converts analog signals into digital signals but does so in assigning them an attenuation coefficient that is all the smaller as the amplitude of the signals is great. The reason for this logarithmic compression is the need to improve the signal-to-noise ratio of the small signals. The decoder establishes a reverse digital-analog coding to re-establish the levels of amplitude of the originally emitted signal.
The invention more particularly concerns telephone sets with an amplified listening function (namely sets having a fairly high-powered external loudspeaker so that people in a room can hear the speech signals received). The invention also concerns, especially, telephone sets having a so-called "hands free" function, namely sets that can work without a handset. These sets have, on the body of the set itself and not on a movable handset, firstly an amplified loudspeaker for listening and, secondly, a microphone that is sensitive enough to collect the speech signals emitted by a person who is at a certain distance for example, at a distance of one meter or several meters) from the set.
Sets with amplified listening and, all the more so, "hands free" sets have a problem that is difficult to resolve: this is the problem of removing the "Larsen" effect, namely removing the risk that the circuits of the set will go into oscillation, with the a strident noise being produced in the loudspeaker.
In effect, whenever there is high-powered loudspeaker, there is a risk that the sound signal from the loudspeaker will be re-injected into the microphone, setting up a feedback loop with a gain that may be greater than one. This risk is clearly very high in "hands free" telephones where the microphone (or microphone amplifier) is more sensitive than that of a standard handset.
The general structure of the circuits of a digital telephone set with a "hands free" function is shown in FIG. 1.
The microphone is designated by the reference MIC, the loudspeaker by the reference HP and the telephone line by the reference L.
A cofidec circuit is represented, on the whole, in two parts which are a digital-analog coder COD and a decoder DEC with a conversion function that is complementary to the function of the coder.
An interface circuit IF is interposed between the digital input/output side of the cofidec and the telephone line L. Its function is to apply the signal that is present at a digital output Snm of the cofidec to the telephone line. This signal corresponds to a speech signal emitted by the microphone. It also has the function of receiving, from the line, a signal emitted from the other end of the line, and of applying it to a digital input Enm of the cofidec.
Finally, a circuit ML fulfilling the "hands free" function and, notably, the function of removing the Larsen effect, is interposed between the analog input/output side of the cofidec and the analog elements such as the microphone and the loudspeaker. This circuit is connected, firstly, to an analog input Ean of the cofidec to apply the analog signals coming from the microphone to it and, secondly, to an analog output San of the cofidec to receive analog signals coming from the line and transmit them to the loudspeaker.
The circuit fulfilling the "hands free" functions and, notably, the anti-Larsen function is represented in greater detail in FIG. 2.
It comprises, essentially:
A first variable gain amplifier AMP1, connected on its input side to the microphone MIC and connected on its output side to the analog input Ean of the cofidec;
A second variable gain amplifier AMP2 connected on its input side to the analog output San of the cofidec and connected on its output side to the loudspeaker;
And signal processing circuits designed to analyze the signals emitted by the microphone towards the telephone line and the signals received from the line going to the loudspeaker, to provide for the anti-Larsen effect.
Before giving a detailed explanation of the circuit of FIG. 2, we shall briefly indicate what this circuit should do.
There is a main need, in a telephone conversation, to determine the speaking side and the listening side; For the telephone set of the speaking side, the gain of the microphone has to be increased (i.e. there has to be an increase in the gain of the amplifier AMP1) and the gain of the loudspeaker has to be reduced (i.e. there has to be a reduction in the gain of the amplifier AMP2). For the set of the listening side it is necessary, on the contrary, to increase the gain of the loudspeaker (through action on AMP2) and to reduce the gain of the microphone (through action on AMP1). But, in both cases, the total loop gain of the following chain has to be kept below one: the microphone MIC, the amplifiers, the crosstalk (unwanted or deliberate) which makes a portion of the signal return towards the loudspeaker, and the acoustic coupling between the loudspeaker and the microphone.
Thus, the Larsen effect is prevented at the same time as the microphone and loudspeaker gains are adjusted at each instant, as a function of the conversation in progress.
Another parameter to be taken into consideration is the ambient noise picked up by the microphone. This ambient noise should not be taken for speech and should not put the gain controls into the reverse of the required state.
The role of the processing circuits of FIG. 2, therefore, is to assess whether the emitted signal and the received signal are a speech signal or a noise signal, to reduce the transmission gain of the weakest of the two signals and to increase the transmission gain of the strongest signal, unless the strongest signal is an ambient noise signal.
The gain transition should therefore be done lightly to prevent sound "clicks" that are audible on the line. The transition should take place quickly when one side starts speaking, and slowly when this side stops speaking. Other problems have to be taken into account (for example, a speaker who interrupts the other one), but these problems are unrelated to the present invention and shall, therefore, not be referred to herein.
The circuits of FIG. 2 therefore include different blocks designed to make the above-mentioned comparisons and assessments.
The basic block is a signal envelope detector that assesses the mean level of the (emitted or received) signal. It receives the signal for which it is desired to assess the level, and it gives a signal that represents the shape of the slow, mean variations of this signal, the fast variations being removed.
A first envelope detector DE1 has an input connected to the microphone to analyze the emitted signal, and a second envelope detector DE2 has an input connected to the analog output of the cofidec to analyze the received signal.
The outputs of the two detectors are applied to the inputs of a comparator COMP that determines the signal having the highest mean level.
Besides, these outputs can each be applied to the input of a detector, DB1 and DB2 respectively, the role of which is to determine whether the analyzed signal is rather a noise signal or rather a speech signal. Without going into the details, the noise detectors DB1 and DB2 detect the peaks of the envelope signal at output of the envelope detectors and compare them with the envelope signal. If the instantaneous envelope becomes greater than a certain quantity at the last peak detected, it is a speech signal. If not, it is related to ambient noise (the particular feature of which is that of being fairly stable).
The outputs of the comparator COMP and the noise detectors DB1 abd DB2 are applied to a control circuit CD which controls the gains of the amplifiers AMP1 and AMP2 as a function of the results of analysis of the signals that are emitted and received.
In the prior art, the envelope detector is made with a circuit such as the one shown in FIG. 3.
It is a logarithmic gain detector, i.e. it gives a signal representing the mean value of the received signal, but with a logarithmic scale. The small signals are more amplified (or less attenuated) than the big ones. This enables an accurate comparison to be made between the emitted and received signal levels, both for the big signals and for the small signals, without the signal-to-noise ratio's being excessively high for the small signals and without any risk of saturation for the big signals.
The prior art logarithmic envelope detector essentially comprises a logarithmic gain amplifier 10 receiving the analog signal, the level of which has to be controlled. This amplifier is followed by a full wave rectifier 12 when the input signal has positive and negative half cycles. The rectifier is followed by a smoothing RC integrator 14, the time constant of which is chosen to make the fast variations in signals disappear and to preserve the slow variations of the envelope.
The output of the detector is taken at the output of the RC integrator.
The logarithmic amplifier is an operational amplifier looped between its output and its input by two diodes in parallel, upside down with respect to each other. Since the diodes have a logarithmic current/voltage curve when they are in direct mode and since, at any instant, at least one of the diodes is in direct mode, the amplifier 10 has a logarithmic amplification coefficient, the amplification being far greater for the small signals than for the big ones.
FIG. 4 shows, as an example, a waveform of an analog signal received at the input of the envelope detector of FIG. 3 (line A). The line B represents the logarithmically compressed signal, at output of the amplifier 10. The range of variation of the signals has been reduced. The amplitude ratio between the small signals and the big ones is considerably smaller than on the line A. The line C represents the signal at output from the rectifier 12. Finally, the line D represents the output signal of the RC integrator 14. The fast variations of the input signal have disappeared. All that remain are the slow variations representing the envelope of the input analog signal or its mean level, but with a logarithmic scale.
In the telephone sets proposed up till now, the circuit of FIG. 1 is made by means of several different integrated circuits. The cofidec is generally made with an integrated circuit using MOS (CMOS or NMOS) technology which lends itself well to the making of conversion and filtering circuits. However, the circuit fulfilling the "hands free" functions is achieved by means of an integrated circuit using bipolar technology.
For, it is not possible to integrate two diodes in parallel and upside down with respect to each other into MOS technology.
Furthermore, whether it is MOS technology or bipolar technology, the circuit of FIG. 3 requires high value capacitances for the smoothing, and these capacitances cannot be integrated.
The present invention proposes a new circuit for telephone sets, enabling the envelope detector (and hence the entire "hands free" function) to be integrated into the same integrated circuit as the cofidecs, even if this integrated circuit is made by means of MOS technology. Another aim of the invention is the elimination of the external capacitances necessary for the signal envelope detection function.

Integrated circuit for telephone set with signal envelope detector


A dynamic clock frequency module includes a request evaluation module configured to generate a sum of requests to utilize a system bus from a plurality of modules. A frequency assignment module is configured to calculate a clock frequency for the system bus in response to the requests and adjust the clock frequency between at least two non-zero frequency values. A pulse stretch module is configured to increase a period of time that at least one of the requests is asserted in response to the sum.

Laptop computers, personal digital assistants (PDAs), and other mobile devices often incorporate wireless local area network (WLAN) technology that typically operates using battery power. Therefore, it is important to minimize power dissipation in mobile devices to preserve battery life. Sometimes WLAN circuits are implemented as a system-on-chip (SOC).
Referring now to FIG. 1, an SOC 10 for a wireless network device includes modules 12 that communicate with each other over a system bus 14. The modules 12 include memory modules, processors, host interfaces, peripheral interfaces, local area network (LAN) interfaces, and/or other modules. The wireless network device may communicate with other external devices. For example, the wireless network device may communicate with an external radio frequency (RF) transmitter. Since the modules 12 communicate through a common system bus 14, most of the modules 12 are clocked at the same rate as the system bus 14 or at rates that are derived from the system bus 14 rate.
Only one of the modules 12 is allowed to access the system bus 14 at a given time. Since more than one of the modules 12 may simultaneously attempt to use the system bus 14, a bus arbiter module 16 determines which of the modules 12 has permission to use the system bus 14 at a given time. When one of the modules 12 requires use of the system bus 14, the module 12 requests permission from the bus arbiter module 16. The modules 12 request permission by asserting request signals 18 that are transmitted to the bus arbiter module 16.
Referring now to FIG. 2A, a request signal 26 from a requesting module remains high (or low) when the requesting module does not require use of the system bus 14. When the requesting module requires use of the system bus 14, the requesting module transitions to low (or high). During a write operation, the request signal 26 typically remains asserted until the end of the transaction. The bus arbiter module 16 detects the request signal 26 and instructs a target module to assert an acknowledge signal 28 when the requesting module is free to use the system bus 14.
Once the target module asserts the acknowledge signal 28, the requesting module begins transmitting data to the target module following a single clock cycle delay. At the end of the write transaction, the request signal 26 will transition to high (or low).
Referring now to FIG. 2B, in other bus architectures, the request signal 30 will transition to high (or low) when the acknowledge signal 32 is received. In this case, a last signal 34 is asserted to indicate the end of the transaction.
Referring now to FIG. 2C, during a read transaction, a request signal 36 typically does not remain asserted during the entire transaction. When the requesting module requires use of the system bus 14, the module asserts the request signal 36 by transitioning to low (or high). The bus arbiter module 16 detects the request signal and instructs the target module to assert an acknowledge signal 38. During a read transaction, it typically takes the target module time to retrieve the requested data. Therefore, the acknowledge signal 38 is only asserted for a single clock cycle.
At the end of the clock cycle both the request signal 36 and the acknowledge signal 38 transition to high (or low). This allows other modules 12 in the SOC 10 to use the system bus 14 while the target module retrieves the requested data. The target module asserts a read valid signal 40 to request permission to use the system bus 14. After the bus arbiter module 16 grants permission, the target module begins transmitting data to the requesting module. This is called a split-read process. The read valid signal 40 remains low (or high) while the target module transmits data. The read valid signal 40 transitions to high (or low) when the target module is finished transmitting data to the requesting module.
Power dissipation in an SOC is proportional to the clock frequency. Therefore, power dissipation is minimized by minimizing the clock frequency of the system bus in the SOC. A minimum sufficient clock frequency for an SOC is dependant on the amount of data movement and a number of current computations. Therefore, the minimum clock frequency that sufficiently supports all data traffic will change as the amount of data traffic changes.
In one conventional approach, a clock frequency of an SOC is set to a frequency that is sufficient to handle data traffic in a worst case scenario. However, in this case, power is unnecessarily dissipated when the data traffic in the SOC is lower.

This patent is subject to a terminal disclaimer.

System-on-chip power reduction through dynamic clock frequency


A process for the identification and/or separation of composite signal into its deterministic and noisy components wherein the process uses recursive wavelet transformations to separate the deterministic and noisy components of signals and uses the difference in the properties with regard to degree of correlation and dimensionality of these constituent components as a basis for separation, the said process of identification and/or separation has application in a variety of situations where digitized data is made available via an apparatus which converts the monitored signals.

Detecting and/or separation of the underlying deterministic dynamics from noisy data obtained from complex systems is of considerable importance. Estimating the deterministic content of a monitored digital sequence (usually sequential or time-series) continues to evade satisfactory solution, despite considerable efforts over the years. This problem is central to most measured data and is especially important in applications when data is collected from medical diagnostic and scanning equipment, seismographic instruments, tomography, image analyzers, molecular spectroscopy, chemical reactors/reactions etc. The central problem is, therefore, to identify and/or separate from the composite signal, its deterministic and noise components.

Method and an apparatus for the identification and/or separation of complex composite signals into its deterministic and noisy components

Council of Scientific & Industrial Research


A filter device for a vacuum cleaner includes a casing having a collecting space therein, a suction opening through which air including dust is sucked, formed eccentrically at one side so that sucked air can be rotated and a discharge opening through which purified air is discharged. A filter is installed at an internal space of the casing, for filtering dust from air sucked through the suction opening. A filter cleaning unit is disposed at an outer circumferential surface of the filter, for cleaning the filter by being rotated by a rotation force of air sucked through the suction opening. A rotation restrainer is provided for restraining rotation of the filter cleaning unit when the filter cleaning unit reaches a topmost position. Accordingly, fine dust attached to the filter in cleaning is removed so that a channel of the filter can be prevented from being closed.

1.Field of the Invention
The present invention relates to a vacuum cleaner, and more particularly, to a filter device of a vacuum cleaner capable of self-removing dust attached to a filter in operation of a cleaner.
2.Description of the Background Art
In general, a vacuum cleaner is an electronic device for cleaning an indoor space such as a room, an office or the inside of a car and can remove undesired impurities such as dust existing at home or the inside of a car by using a suction force thereof.
FIG. 1 is a perspective view showing a structure of a general vacuum cleaner.
As shown therein, a general vacuum cleaner includes a cleaner main body 1 and a suction head 3 connected to the cleaner main body 1 by a suction hose 5 and an expansion pipe 4, for sucking dust and foreign substances from a floor.
The cleaner main body 1 includes a suction force generating part (not shown) for generating a suction force; and a filter device 6 for collecting dust and foreign substances by a suction force generated from the suction force generating part.
As shown in FIG. 2, the filter device is provided with a knob 8 and detachably attached to the inside of the cleaner main body 1. Thusly, a user can couple the filter device to the cleaner main body 1 or separate it therefrom by using the knob 8, more conveniently.
FIG. 3 is a disassembled perspective view showing a filter device of a conventional vacuum cleaner, and FIG. 4 is a longitudinal sectional view showing a filter device of a conventional vacuum cleaner.
The filter device 6 in accordance with the conventional art includes a casing 11 having a collecting space therein, a suction opening 14 through which air including dust is sucked and a discharge opening 15 through which purified air is discharged; and a filter 13 installed at the internal space of the casing 11, for filtering dust from air sucked through the suction opening 14.
The casing 11 is formed in a cylindrical shape an upper side of which is opened and includes a cover 12 installed for covering an upper surface of the casing 11; a filter supporter 18 positioned at the cover 12 and having a discharge opening 15 formed penetratingly, though which air purified by the filter 13 is discharged outside; a support wall body 16 protruded from an inner lower portion of the casing 11 at a predetermined height; and a pair of blocking plates 17 installed at an upper surface of the support wall body 17 to face each other so that relatively big dust or foreign substances of dust introduced into the casing 11 are prevented from escaping therefrom.
A process for collecting dust in the filter device of the conventional vacuum cleaner will now be described.
When power is applied, a suction force is generated from a suction force generating part (not shown), and dust and foreign substances sucked through the suction head 3 are sucked into the casing 11 through the suction opening 14 via the expansion pipe 4 and the suction hose 5. The dust sucked into the casing 11 is purified by the filter 1 and collected in the casing 11, and only the air purified while passing through the filter 13 is discharged through the discharge opening. Here, relatively heavy dust or foreign substances fall to a gap between the blocking plates 17 by their weights and are collected at the inner lower portion. The support wall body 16 prevents an eddy which may occur in the space under the blocking plate 17 to thereby prevent dust from floating again and being moved to a space above the blocking plate 17. Fine dust or foreign substances which are relatively light in weight are not collected in a space under the blocking plate 17 but float with air and are purified by the filter 13 again.
However, such a conventional vacuum cleaner has a problem in that the filter 13 has to be cleaned or replaced periodically. This is because when the vacuum cleaner is used for a certain period of time, fine dust is attached to the filter 13 of the filter device 6, thereby deteriorating a suction force. That is, since fine dust closes up a close mesh of the filter 13, it is difficult to discharge sucked air and finally a decrease in suction force is caused. Accordingly, if the filter 13 is not periodically cleaned or replaced, a cleaning operation is not performed actively due to the deterioration of the suction force.


The disclosed polar modulation transmitter circuit is configured to generate an output signal having a transmission frequency that minimizes crosstalk effects between different transmission bands (e.g., Bluetooth, GSM, UMTS, etc.). In particular, a polar modulation transceiver circuit, having an amplitude modulated (AM) signal and a phase modulated (PM) signal, comprises a digitally controlled oscillator (DCO) configured to generate a DCO signal having a DCO frequency. The DCO signal is provided to one or more frequency dividers that are configured to selectively divide the DCO signal to generate various lower frequency signals, used to select a sampling rate for a DAC operating on the AM signal and an RF carrier signal frequency, which result in an output signal having a frequency that does not interfere with other RF systems on the same IC (e.g., that falls outside of the downlink frequency of other RF systems). Other systems and methods are also disclosed.

Handheld devices, such as cell phones and PDAs, have made drastic technological advances in the past decade. Today's handheld devices offer users a wide range of functionality. This functionality is enabled in part by handheld devices utilizing increasingly sophisticated RF transmission schemes.
In many modern transceivers, RF transmission schemes have moved from a vector modulation to a polar modulation transmission approach. Polar modulation modulates independently both the magnitude and phase of a signal to be transmitted resulting in a number of possible advantages ranging from power savings to increased transmission bandwidth.

Polar transmitter suitable for monolithic integration in SoCs


In order to carry out foaming of a slag having a high ratio of chromium oxide having values of often above 20% of a non-corrosive melt in an AOD (Argon Oxygen Decarburization) or MRP (Metallurgical Refining Process) converter or CONARC SSt for stainless steel by adding a foam material, according to the invention a previously defined mixture (5) of a metal oxide, iron carrier, carbon and binding material in the form of pellets or briquettes (4) is introduced into the converter, which reacts in a chemically reducing manner under the slag layer (2) due to the high ambient temperature, wherein gaseous carbon monoxide formed in particular by means of the reduction process of the metal oxide with the carbon within the pellets or briquettes (4) induces the slag foaming with the gas bubbles (7) thereof and wherein the specific density of the pellets or briquettes (4) and the resolve time of the reduction process are selected so that optimal bubble formation in respect of size and duration is achieved.

The invention concerns a method for producing foamed slag on a stainless steel melt in an AOD (argon oxygen decarburization) or MRP (metallurgical refining process) converter or CONARC SSt for stainless steel by adding a foaming material.
During refining in a converter for producing stainless steel, a slag forms which has a high content of metal oxides, especially chromium oxide. The concentration of the chromium oxide during the refining phase often reaches values exceeding 20%, which greatly increases the viscosity of the slag. The slag is usually very hard just before the reduction.
The process metallurgy of these types of slags constitutes the following successively occurring partial reactions:{O2}=2[O] thermal dissociation of the oxygen  (1)2[Cr]+3[O]=(Cr2O3) chromium oxidation in the melt  (2)(Cr2O3)+3[C]=2[Cr]+3{CO} chromium oxide reduction at the slag/metal phase boundary  (3)
Reaction (3) is fundamentally important for the production of stainless steel, because chromium oxide is the most important component in the foamed slag production. However, this reaction takes place to a very limited extent in the conventional process. The reason for this is the high viscosity of the slag. All current converter processes reduce the slag only in the following step, in the so-called reduction, and the process for this is normally carried out with silicon in the form of ferrosilicon.
If, however, the slag viscosity is suitable for foaming, the reduction process (Eq. 3) is made possible by the gaseous CO formed in the refining process itself and by the iron oxide reduction of the foaming material, which is added to the melt in the form of pellets or briquettes at a specific time. The principal components of the material are iron oxide carriers, e.g., scale, then carbon and a ballast material, which defines a systematic placement of the briquette in the melt.
The reduction process in this type of briquette then proceeds by the following principle:(Fe2O3)+3[C]=2[Fe]+3{CO} chromium oxidation in the melt  (4)
The crucial factors for the formation of the foamed slag are thus the constituents of the added foaming material and the slag viscosity, which in turn depends on the composition and the temperature of the molten slag. Above all the viscosity defines a phase region of the molten slag in which foam formation is possible. Therefore, it is important to control the slag basicity, which is responsible for the viscosity, so that the gas bubbles that are formed are forced to stay temporarily in the slag layer. In this regard, the limestone added to control the slag basicity constitutes a further source of gas, since the thermal dissociation of this material releases CO according to the following equation:(CaCO3)=(CaO)+{CO}  (5)
The phenomenon of bubble formation involves a process that utilizes the mechanical force of the reacting gas bubbles to produce a new surface region in the slag. The buoyant forces on the gas bubbles transiently split the slag surface and saturate the whole slag layer to produce the foam. When there is a protracted gas stream from the reacting substances, the number of accumulating bubbles grows with the growing foam. As a result, the height of the foam layer increases with increasing amount of gas; it is directly proportional to the amount of the foaming material.
An important factor in this type of mechanism is the optimal placement of the reactants to obtain a maximum foaming effect. Optimal placement occurs in the boundary region between the slag layer and the liquid metal.
The document JP 1 116018 A describes a method for increasing the efficiency of the blowing process in steelmaking in a converter by adding a mixture, wherein slag formation and foaming is prevented.
DE 195 18 343 A1 describes a method for increasing the effectiveness of the smelting reduction of oxidic metal carriers and improving the thermal efficiency of the charged fuels in the smelting production process.
DE 10 2008 032975 A1 describes a method for producing a foamed slag on stainless steel melts in an electric arc furnace.
Slag foaming has not been used so far in the production of stainless steel. Nowadays only dusts are added as compressed pellets or briquettes for the purpose of realizing cooling effects. Since the reducing element, namely, carbon, and the ballast material are not present in the briquettes, these remain effective only unreduced in the slag zone.
In DE 10 2007 006 529 A1, in the production of a foamed slag on a high-chromium steel melt, the metal oxides, mainly chromium oxide, that are present in the slag are additionally reduced by the briquettes and/or pellets floating near the melt/slag phase boundary, such that the reaction gases that are produced support the foaming of the slag. To this end, the briquettes or pellets charged to the electric arc furnace consist of a well-defined mixture of an iron carrier as the ballast material, carbon or carbon as the reducing agent, and a binder.

Method for foamed slag generation of a non-corrosive melt in a converter


A filter is disclosed for treating a gaseous stream to remove therefrom undesirable components, especially from exhaust gases of engines, and particularly from internal combustion engines, such as, for example, Diesel engines and the like. The filter includes a filter body or element having a plurality of inlet and outlet channels, with the inlet channels being separated from the outlet channels by walls or partitions to provide reaction chambers. The filter body is made a high-temperature-resistant, sintering material, and can be made of metal wire or metal chips which are compacted and subsequently sintered.

The present invention relates to a filter for treating gases to remove undesirable components therefrom, especially from exhaust gases of engines, and particularly internal combustion engines, such as, for example, Diesel engines, and the like. The filter includes a filter body or element having a plurality of inlet and outlet channels, with the inlet channels being separated from the outlet channels by means of walls or partitions which define reaction chambers.
With respect to removal of, for example, soot and the like deleterious substances from exhaust gases, particularly in reference to Diesel engines, soot filters made of ceramic material are known. In such applications, the soot filter is generally positioned in the exhaust duct or pipe system of the internal combustion engine and downstream of the exhaust manifold.
The hot gases emanating from the engine flow into the inlet channels of the filter body or element, pass through the porous filter walls which surround the inlet channels, and they are subsequently emitted by means of the respective outlet channels.
Due to high temperature conditions, the soot, i.e., carbonaceous matter, is converted in the filter walls into gaseous matter and ash, and these are emitted together with the exhaust gas from the exhaust duct.
A particular detriment of ceramic filters resides in their particular porosity, especially the pore size distribution and the spherical pore configuration, which determines separation of soot but also limits soot separation. A substantial change of the porosity is precluded, however, by the special structural characteristics of the ceramic material.
Ceramic filters have other drawbacks. They are particularly sensitive to rapid changes in temperature, localized over-heating by exhaust gases due to poor thermal conductivity, and against shocks and blows or the like impact stresses. This means that the filter body must be exteriorly surrounded by a material which is protecting or insulating with respect to temperature and shock, generally stone wool, and this insulating material, in turn, is enclosed by a housing. Thus, the known soot filters occupy a considerable space and in consideration of oftentimes experienced limited space availability, problems are experienced in the engine compartment of a motor vehicle.
The drawbacks of ceramic filters are also apparent in any recycling, when such filters are coated with catalytically acting or active metals, such as, for example, platinum, rhodium, vanadium and palladium. These metals need then to be recovered with laborious methods during requisite recycling from the ceramic body. In addition, the serviceable life of such ceramic bodies is limited due to stresses, and this problem represents a considerable cost factor which needs to be addressed during manufacture and ultimate sale of such ceramic bodies.
Also known are exhaust gas catalysts which by catalytic action remove further deleterious components such as, for example, carbon monoxides, hydrocarbons, and nitric oxides from the exhaust gas. For this purpose one uses, for example, filters with coatings of platinum, rhodium, vanadium, and other catalytically acting materials. Such filters which are based on ceramic materials, however, are expensive and, furthermore, sensitive to operating conditions.


A semiconductor device having a crystalline semiconductor film with production of a cavity suppressed and a manufacturing method thereof. A manufacturing method of a semiconductor device according to the invention comprises the steps of forming an amorphous silicon film on a substrate having an insulating surface, adding a metal element such as Ni for promoting crystallization to the amorphous silicon film, applying heat treatment to crystallize the amorphous silicon film, so that a crystalline silicon film is formed on the substrate, removing a silicon oxide film formed on the surface of the crystalline silicon film due to the heat treatment by a solution containing organic solvent and fluoride, and irradiating laser light or strong light to the crystalline silicon film.

1. Field of the Invention
The present invention relates to a semiconductor device and a manufacturing method thereof, and in particular, relates to a semiconductor device in which a cavity (a hole, an opening, a pore, and the like) is prevented from being produced at a crystalline semiconductor film and a manufacturing method thereof.
2. Description of the Related Art
When an amorphous silicon film is added with a metal such as Ni and heat treatment is applied thereto, a crystalline silicon film can be formed at low temperature in short time. Subsequently, a natural oxide film that is formed incidentally on the crystalline silicon film due to the heat treatment is removed by using diluted hydrofluoric acid. As the crystalline silicon film at this stage has many crystal defects, electromagnetic energy is supplied to the crystalline silicon film in the subsequent step. Consequently, a high-quality crystalline silicon film with few crystal defects can be obtained. Laser light such as excimer laser light typifies the electromagnetic energy as a specific example. A crystalline silicon film manufactured by this method can be used for manufacturing an electronic device such as a high-performance thin film transistor (TFT).

Semiconductor device and manufacturing method thereof

Semiconductor Energy Laboratory Co., Ltd.


The present invention relates to substances which can be used as cosmetic ingredients, especially for skin whitening and as cosmetic agents against signs of ageing skin. The present invention also relates to the use of such substances for the manufacture of a medicament for the treatment of disorders related to the pigmentation of the skin. The invention furthermore relates to specific substances.

EP 1 437 117 A1 (Cognis France) discloses sinapic acid (=3,5,-dimethoxy-4-hydroxycinnamic acid, =(3,5-dimethoxy-4-hydroxy-phenly)-3-prop-2-enoic acid, =sinapinic acid) and its derivatives as cosmetic ingredients. The derivatives are referenced in claim 15 and in paragraph [0025]: the derivatives obtained according to this paragraph are all derivatives via the acid function of sinapic acid. Derivatives via the 4-Hydroxygroup of the phenyl group or via the alkylene group adjacent to the acid group are not disclosed. EP 1 437 117 also cites the problem of instability for sinapic acid and proposes as solution a microencapsulation.
JP 64-013017 (Pola Chemical Industries) discloses derivatives of 3,5-dimethoxy-4-hydroxycinnamic acid. All the derivatives disclosed are derivatives via the acid function of the sinapic acid. No derivatives of the 4-hydroxygroup or the alkylene group are described.
JP 2004175778 A (Sogo Pharmaceutical Co) discloses cinnamic acid derivatives as cosmetic ingredient. All derivatives disclosed carry a specific group (2) or (3) on the acid moiety of the cinnamic acid. These substances are not encompassed by the substances according to the present invention.
WO 03/027055 A (Pacific Corporation) discloses thymyl or carvacryl esters of 3,4,5-trimethoxy phenyl acetate, 3,4,5-trimethoxy cinnamate or 3,4,5-trimethoxyhydrocinnamate and their use as whitening compositions.
Aim of the invention was to provide substances which can be effectively used for the manufacture of or in cosmetic compositions and which are especially suitable as skin whitener and/or as cosmetic agents against the signs of skin ageing. Of special interest was to provide substances which are chemically stable and can thus be easily incorporated into cosmetic compositions. In addition it is desired that these substances do not, or only to a much lower extent than products known in the market, cause an irritation of the skin onto which it is applied. A further aim of the invention was to provide substances for the manufacture of a medicament for the treatment of disorders related to the pigmentation of the skin. The invention furthermore relates to specific substances.

Use of derivatives of sinapinic acid and compositions comprising such derivatives


A separation system for separating a feed stream comprising propylene and propane and a method for separating such feed stream. The separation system includes a distillation column for producing a light stream comprising propylene and a heavy stream comprising propane; a reboiler for reboiling a part of the first heavy stream to produce a boiled heavy stream; a condenser for cooling the light stream to produce a condensed light stream; and an absorption refrigerator for receiving water and providing chilled water, for receiving hot water from a waste heat source and providing a cooled hot water and for receiving cooling water and providing a heated cooling water. The absorption refrigerator is arranged such that the cooling of the water and the hot water occurs by the cooling water. The condenser is arranged such that the cooling of the light stream occurs by the chilled water from the absorption refrigerator.

Separation of propylene (propene) from propane is well-known, as described in Zimmermann, H. and Walzl, R., 2009, Ethylene. Ullmann's Encyclopedia of Industrial Chemistry. Propylene fractionation separates propylene as a chemical-grade overhead product (typically 93-95 wt % min.) or more frequently as polymer-grade propylene (≥98 wt %) from propane. Separation to polymer grade propylene requires typically 150-230 stages and a reflux ratio of 20 because of the close boiling points of propylene and propane. One of the basic processes applied for this difficult separation task is operating polymer-grade fractionators at ca 1800 kPa, with cooling water in the overhead condenser and hot quench water in the reboiler. In the case of naphtha cracking and where sufficient waste heat is available from the hot quench water cycle this is the most economic process.
The condenser should operate at the lowest pressure that can be achieved by the cooling water, since a lower pressure leads to lowering of the cost. The cooling water typically has a temperature of 20-30° C. An example of a known separation system for separating a feed stream comprising propylene and propane is illustrated in FIG. 1.
In the example of FIG. 1, 20 t/h of liquid C3 product 101, containing 5% wt propane and 95% wt propylene, is fed to stage 78 of a distillation column C-101, which has 160 stages and a diameter of 4 meter. The pressure drop over the column C-101 is 1.3 bar. A reboiler H-101 has a duty of 18.8 MWth and produces 235 t/h of vapor 103. The distillation column C-101 produces 215 t/h of vapor 104 at the top that is condensed against cooling water in a condenser H-102, which is sent to vessel V-101. In the vessel V-101, 196 t/h of the condensed vapor is pumped back as a reflux 109 and 19 t/h of 99% pure propylene is produced as a product stream 111. The heat from the condenser H-102 is rejected to cooling water having a temperature of 20-30° C. In this case, the condenser H-102 operates at a pressure of 16 bara. The column is operated at a vapor velocity of 79% of the flooding velocity. The high pressure of the condenser H-102 makes the distillation more difficult, requiring a large amount of reflux. To accommodate the high vapor and liquid flows in the column as a result of the large amount of reflux, the column diameter needs to be large in order to avoid flooding of the column.
Thus, for operating at a vapor velocity of 79% of the flooding velocity using cooling water of 20-30° C. as in this example, the condenser pressure becomes 16 bara, which limits the amount of the liquid C3 product 101 fed to stage 78 of the distillation column C-101 to 20 t/h.
One known way of decreasing the pressure of the condenser is the use of a compressor for the vapor from the distillation column. FIG. 2 illustrates a separation system for separating a feed stream comprising propylene and propane, wherein a compressor is used. In the example of FIG. 2, the vapor 204 comes out from the distillation column C-201 at 9 bara and is compressed by K-201 to obtain a compressed vapor 205 of 14 bara. This compressed vapor 205 is fed to a heat exchanger H-201. In the heat exchanger H-201, the compressed vapor 205 provides heat to reboil liquid 202 from the distillation column C-201 to obtain 203. The compressed vapor 205 is condensed to obtain a stream 206. The stream 206 is then sent to a vessel V-201, where one part 208 of the stream 206 is pumped back as a reflux and one part 210 of the stream 206 is taken from the system as the propylene product stream. The disadvantage of this system is that it requires a compressor to work. The compressor requires high value energy, such as electricity (motor drive), or high pressure stream (steam turbine drive) to function.

System and method for separation of propylene and propane