Patents by Inventor Ravi Chandran

Ravi Chandran has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6911139
    Abstract: The disclosure relates to a process for forming a deposit on the surface of a metallic or conductive surface. The process employs an electrolytic process to deposit a silicate containing coating or film upon a metallic or conductive surface.
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: June 28, 2005
    Assignee: Elisha Holding LLC
    Inventors: Robert L. Heimann, Branko Popov, Bruce Flint, Nancy G. Heimann, Ravi Chandran, William M. Dalton
  • Publication number: 20050131678
    Abstract: An apparatus and method for suppressing noise is presented. The apparatus may utilize a filter bank of bandpass filters to split the input noisy speech-containing signal into separate frequency bands. To determine whether the input signal contains speech, DTMF tones or silence, a joint voice activity & DTMF activity detector (JVADAD) may be used. The overall average noise-to-signal ratio (NSR) of the input signal is estimated in the overall NSR estimator, which estimates the average noisy signal power in the input signal during speech activity and the average noise power during silence. Two indirect power measures are performed for each band, measuring a short-term power and a long-term power. The power estimation processes are adapted based on the signal activity indicated by the JVADAD. A NSR adapter adapts the NSR for each frequency band based on the long-term and short-term power measures, the overall NSR and the signal activity indicated by the JVADAD. The NSR adaptation may then be performed.
    Type: Application
    Filed: January 28, 2005
    Publication date: June 16, 2005
    Inventors: Ravi Chandran, Danniel Marchok, Bruce Dunne
  • Publication number: 20050120924
    Abstract: A gasifier system and process comprises a pulse combustion device in communication with a fluid channel for producing a gas stream having heat or fuel value. The pulse combustion device is operated under sub-stoichiometric conditions such that combustion and steam reforming both occur in the fluid channel. The pulse combustion device also produces a pulsating combustion product stream and an acoustic pressure wave. The acoustic pressure wave serves to cause agglomeration of particles contained within the combustion stream for easy removal. In one embodiment, a sulfur capturing agent is injected into the fluid channel for not only removing sulfur from the combustion product stream but for also facilitating particle agglomeration. Ultimately, a gas stream containing hydrogen is produced that may be used in various processes, such as in the production of electricity.
    Type: Application
    Filed: December 21, 2004
    Publication date: June 9, 2005
    Inventors: Ravi Chandran, Momtaz Mansour
  • Publication number: 20050125802
    Abstract: A virtual multithreading hardware mechanism provides multi-threading on a single-threaded processor. Thread switches are triggered by user-defined triggers. Synchronous triggers may be defined in the form of special trigger instructions. Asynchronous triggers may be defined via special marking instructions that identify an asynchronous trigger condition. The asynchronous trigger condition may be based on a plurality of atomic processor events. Minimal context information, such as only an instruction pointer address, is maintained by the hardware upon a thread switch. In contrast to traditional simultaneous multithreading schemes, the virtual multithreading hardware provides thread switches that are transparent to an operating system and that may be performed without operating system intervention.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 9, 2005
    Inventors: Perry Wang, Hong Wang, John Shen, Ashok Seshadri, Anthony Mah, William Greene, Ravi Chandran, Piyush Desai, Steve Liao
  • Patent number: 6890957
    Abstract: The present invention is directed to a liquid formulation of metformin or its pharmaceutically acceptable salts thereof. The liquid pharmaceutical composition comprises a therapeutically effective amount of metformin or its pharmaceutically acceptable salt, in a liquid carrier, which may also include a sweetener that does not increase the blood glucose level of a subject after ingestion thereof. In one embodiment, it may also include alkyl hydroxyethylcellulose, and/or a polyhydroxy alcohol. In another embodiment, the carrier may contain a sweetener, mineral acid, and bicarbonate salt maintained at a pH of 4.0 to 9.0. It is useful for treating hyperglycemia and diabetes.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: May 10, 2005
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Ravi Chandran, Ashish Gogia
  • Patent number: 6866896
    Abstract: An electroless or electrolytic process for treating metallic surfaces is disclosed. The disclosed process exposes the metallic surface to a first medium comprising at least one silicate, and then to a second medium comprising colloidal silica (additional processing steps can be employed before, between and after exposure to the first and second mediums). The first and second mediums can be electrolytic or electroless.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: March 15, 2005
    Assignee: Elisha Holding LLC
    Inventors: Robert L. Heimann, Bruce Flint, Ravi Chandran, Jonathan L. Bass, James S. Falcone, Jr.
  • Publication number: 20050050759
    Abstract: Disclosed is a pulsed dryer and a pulsed drying system. The dryer includes a pulse combustor fluid dynamically coupled to a drying chamber. The pulsed dryer can be any suitable type of dryer, for example a pulsed spray dryer or a pulsed fluid bed dryer. The pulse combustor can fire the dried fines or employ auxiliary fuel such as natural gas, propane, etc. The system can include a steam or heat transfer fluid thermal circuit for providing heat to the drying chamber and optionally for cooling the pulse combustor flue gases prior to flow into the drying chamber. The disclosed dryers and systems can be advantageously utilized for wet feedstock in general and in particular for drying biomass or other organic type feedstock.
    Type: Application
    Filed: August 11, 2004
    Publication date: March 10, 2005
    Inventors: Ravi Chandran, Momtaz Mansour
  • Patent number: 6839666
    Abstract: The spectral shape of a communication signal is preserved by filtering it into a selected number of frequency band signals representing a selected number of the frequency bands. A calculator generates a plurality of initial gain signals having initial gain values for altering the gain of the frequency band signals. Each initial gain signal corresponds to one of the frequency band signals. Each initial gain value is derived from a measurement of the power of at least a portion of one of the frequency band signals. The calculator also generates a plurality of modified gain signals having modified gain values. Each modified gain signal corresponds to at least one of the frequency band signals and each modified gain value is derived from one or more functions of at least two of the initial gain values. The frequency band signals are altered in response to the modified gain signals to generate weighted frequency band signals which are combined to generate an improved communication signal.
    Type: Grant
    Filed: December 11, 2002
    Date of Patent: January 4, 2005
    Assignee: Tellabs Operations, Inc.
    Inventors: Ravi Chandran, Bruce E. Dunne, Daniel J. Marchok
  • Publication number: 20040265202
    Abstract: The present invention is directed to a process for treating, reducing, and/or stabilizing various wastes or flue gases. In one embodiment, the process is directed to treatment of alkali bearing wastes that include nitrate and/or nitrite-rich wastes. Optionally, the disclosed method can be utilized for treatment of hazardous wastes, including radioactive hazardous waste compounds. In general, the present invention includes processing a waste or gaseous stream with the addition of suitable carbon-containing additives to treat and reduce nitrogen-containing compounds in the waste. Additives may be gaseous, liquid or solid reduction-promoting agents, catalysts, and the like. The reaction products obtained from the process of the invention include mainly alkali carbonate, nitrogen, hydrogen, carbon monoxide and carbon dioxide.
    Type: Application
    Filed: April 21, 2004
    Publication date: December 30, 2004
    Applicant: Manufacturing and Technology Conversion, International, Inc.
    Inventors: Ravi Chandran, Momtaz N. Mansour
  • Patent number: 6832565
    Abstract: A gasifier system and process comprises a pulse combustion device in communication with a fluid channel for producing a gas stream having heat or fuel value. The pulse combustion device is operated under sub-stoichiometric conditions such that combustion and steam reforming both occur in the fluid channel. The pulse combustion device also produces a pulsating combustion product stream and an acoustic pressure wave. The acoustic pressure wave serves to cause agglomeration of particles contained within the combustion stream for easy removal. In one embodiment, a sulfur capturing agent is injected into the fluid channel for not only removing sulfur from the combustion product stream but for also facilitating particle agglomeration. Ultimately, a gas stream containing hydrogen is produced that may be used in various processes, such as in the production of electricity.
    Type: Grant
    Filed: May 22, 2003
    Date of Patent: December 21, 2004
    Assignee: Manufacturing & Technology Conversion, Inc.
    Inventors: Ravi Chandran, Momtaz N. Mansour
  • Publication number: 20040222105
    Abstract: The disclosure relates to treating a silicate medium and using the treated medium for improving the surface of metallic or electrically conductive materials. The treated medium provides a silicate medium having a defined degree of polymerization and predetermined quantities of the desired silicate polymer. The treated silicate medium can be employed in an electroless or electrolytic process.
    Type: Application
    Filed: April 23, 2004
    Publication date: November 11, 2004
    Inventors: Robert L. Heimann, Wayne L. Soucie, Jonathan L. Bass, Ravi Chandran, Nancy G. Heimann
  • Publication number: 20040188262
    Abstract: An electroless or electrolytic process for treating metallic surfaces is disclosed. The disclosed process exposes the metallic surface to a first medium comprising at least one silicate, and then to a second medium comprising colloidal silica (additional processing steps can be employed before, between and after exposure to the first and second mediums). The first and second mediums can be electrolytic or electroless.
    Type: Application
    Filed: April 15, 2004
    Publication date: September 30, 2004
    Inventors: Robert L. Heimann, Bruce Flint, Ravi Chandran, Jonathan L. Bass, James S. Falcone
  • Publication number: 20040182000
    Abstract: Various processes and systems are disclosed for converting carbonaceous materials into a product gas stream. For instance, the product gas stream may be endothermically converted to a gas through a steam reforming process. The present invention is directed to various methods and systems for increasing throughput and efficiency of the system. Further, the present invention is also directed to sulfur removal methods and systems from a gas stream.
    Type: Application
    Filed: September 10, 2003
    Publication date: September 23, 2004
    Inventors: Momtaz N. Mansour, Ravi Chandran
  • Publication number: 20040184484
    Abstract: A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are generated using at least one timing signal. At least one of the predetermined number of bins includes a pilot tone sub-symbol having a frequency corresponding to the clock signal. The communications system also includes a receiver for receiving the OFDM/DMT symbols from the transmission medium. The receiver demodulates the received symbols using at least one timing signal. The receiver has a first pilot tone search mode of operation in which the receiver adjusts its timing signal to scan the frequency range of the predetermined number of bins looking for the pilot tone sub-symbol and identifies the bin including the pilot tone sub-symbol.
    Type: Application
    Filed: March 29, 2004
    Publication date: September 23, 2004
    Inventors: Daniel J. Marchok, Samir Kapoor, Ravi Chandran
  • Patent number: 6771590
    Abstract: A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are generated using at least one timing signal. At least one of the predetermined number of bins includes a pilot tone sub-symbol having a frequency corresponding to the clock signal. The communications system also includes a receiver for receiving the OFDM/DMT symbols from the transmission medium. The receiver demodulates the received symbols using at least one timing signal. The receiver has a first pilot tone search mode of operation in which the receiver adjusts its timing signal to scan the frequency range of the predetermined number of bins looking for the pilot tone sub-symbol and identifies the bin including the pilot tone sub-symbol.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: August 3, 2004
    Assignee: Tellabs Operations, Inc.
    Inventors: Daniel J. Marchok, Samir Kapoor, Ravi Chandran
  • Patent number: 6766292
    Abstract: In order to enhance the quality of a communication signal comprising speech signal components due to speech and noise signal components due to noise, a filter divides the communication signal into a plurality of frequency band signals representing the speech signal components and the noise signal components in a plurality of frequency bands. A calculator generates a plurality of weighting signals having weighting values corresponding to the frequency band signals. The weighting values represent at least approximations of the normalized powers of the noise signal components in the frequency band signals. The frequency band signals are altered in response to the weighting signals to generate weighted frequency band signals which are combined to generate a communication signal with enhanced quality.
    Type: Grant
    Filed: March 28, 2000
    Date of Patent: July 20, 2004
    Assignee: Tellabs Operations, Inc.
    Inventors: Ravi Chandran, Bruce E. Dunne, Daniel J. Marchok
  • Publication number: 20040120360
    Abstract: A method for switching multi-rate communications is described. The method includes filling a first set of p timeslots with p sets of data from a first data collection of a first type, where the first data collection includes m sets of data and p is less than m. The method also includes loading at least one overflow timeslot with at least one overflow set of data from the first data collection, where the overflow set of data exceeds a size of the first set of p timeslots.
    Type: Application
    Filed: December 11, 2003
    Publication date: June 24, 2004
    Inventors: Terrence J. Tanis, Ravi Chandran, Daniel J. Marchok
  • Publication number: 20040079087
    Abstract: A novel process and apparatus for power generation from biomass and other carbonaceous feedstocks are provided. The process integrates a pulse combustor steam reformer with a gas turbine to generate electricity such that (i) efficiency is higher than those of conventional and current advanced power systems, (ii) emissions are lower than those proposed in the new environmental regulations, and (iii) performance is comparable to that of combined cycle, even though a bottoming cycle is not included here. The pulse combustor steam reformer generates a hydrogen-rich, medium-Btu fuel gas that is fired in a gas turbine to generate electricity. The apparatus may be configured to produce only power or combined heat and power.
    Type: Application
    Filed: December 4, 2003
    Publication date: April 29, 2004
    Inventors: Ravi Chandran, Momtaz N. Mansour
  • Publication number: 20040031450
    Abstract: A gasifier system and process comprises a pulse combustion device in communication with a fluid channel for producing a gas stream having heat or fuel value. The pulse combustion device is operated under sub-stoichiometric conditions such that combustion and steam reforming both occur in the fluid channel. The pulse combustion device also produces a pulsating combustion product stream and an acoustic pressure wave. The acoustic pressure wave serves to cause agglomeration of particles contained within the combustion stream for easy removal. In one embodiment, a sulfur capturing agent is injected into the fluid channel for not only removing sulfur from the combustion product stream but for also facilitating particle agglomeration. Ultimately, a gas stream containing hydrogen is produced that may be used in various processes, such as in the production of electricity.
    Type: Application
    Filed: May 22, 2003
    Publication date: February 19, 2004
    Applicant: Manufacturing & Technology Conversion, Inc.
    Inventors: Ravi Chandran, Momtaz N. Mansour
  • Patent number: 6671667
    Abstract: In order to enhance the quality of a communication signal derived from speech and noise, the likelihood that the communication signals result from at least some speech is determined. A calculator calculates a first power signal representing the power of at least a portion of the communication signals estimated over a first time period and calculates a second power signal representing the power of at least a portion of the communication signals estimated over a second time period longer than the first time period. The calculator also generates a comparison signal having a value related to the likelihood that the portion of the communication signals result from at least some speech by comparing a first expression involving the first power signal with a second expression involving the second power signal.
    Type: Grant
    Filed: March 28, 2000
    Date of Patent: December 30, 2003
    Assignee: Tellabs Operations, Inc.
    Inventors: Ravi Chandran, Bruce E. Dunne, Daniel J. Marchok