Patents by Inventor Natalia V Levit
Natalia V Levit 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).
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Patent number: 11077325Abstract: An article of protective clothing comprising a durable multilayer fabric laminate formed from i) a first flame resistant knitted fabric made from yarns, the fabric having an average fabric modulus of 8 grams-force of greater; ii) a flame-resistant nonwoven fabric having a machine direction and a cross direction, and consisting of a plurality of continuous filaments having a diameter of less than 1000 nm, the filaments in the fabric being substantially oriented parallel with the machine direction and having stretch and recovery in the cross direction; and iii) a second flame resistant knitted fabric made from yarns, the fabric having an average fabric modulus of 8 grams-force of greater; wherein the nonwoven fabric is positioned between and coextensive with the first and second flame-resistant knitted fabrics; the nonwoven fabric being attached to the first knitted fabric by a set of first attachment points, the attachment points defining a first unattached area having a first effective diameter; the nonwovType: GrantFiled: March 10, 2017Date of Patent: August 3, 2021Assignee: DUPONT SAFETY & CONSTRUCTION, INC.Inventor: Natalia V Levit
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Patent number: 9913504Abstract: The present invention relates to a flame resistant thermal liner comprising a nonwoven sheet comprising nanofibers of a synthetic polymer having an limiting oxygen index of at least 21, a mean flow pore of 10 micrometers or less, a thickness air permeability of 25 to 6000 cubic feet per min?micrometers (12 to 2880 cubic meters per square meter per min?micrometers), and an average thickness T1; and a thermally stable flame resistant fabric attached to an outer surface of the nonwoven sheet, the fabric having an average thickness T2; a surface of the thermally stable fabric being in contact with a surface of the nonwoven sheet; wherein T1 and T2 are selected such that the ratio of T1 to T2 is less than 0.75. The invention also relates to a flame resistant composite fabric comprising the flame resistant thermal liner and a garment comprising this flame resistant composite fabric.Type: GrantFiled: October 6, 2015Date of Patent: March 13, 2018Assignee: E I DU PONT DE NEMOURS AND COMPANYInventors: Natalia V Levit, Richard Hall Young
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Publication number: 20170281992Abstract: An article of protective clothing comprising a durable multilayer fabric laminate formed from i) a first flame resistant knitted fabric made from yarns, the fabric having an average fabric modulus of 8 grams-force of greater; ii) a flame-resistant nonwoven fabric having a machine direction and a cross direction, and consisting of a plurality of continuous filaments having a diameter of less than 1000 nm, the filaments in the fabric being substantially oriented parallel with the machine direction and having stretch and recovery in the cross direction; and iii) a second flame resistant knitted fabric made from yarns, the fabric having an average fabric modulus of 8 grams-force of greater; wherein the nonwoven fabric is positioned between and coextensive with the first and second flame-resistant knitted fabrics; the nonwoven fabric being attached to the first knitted fabric by a set of first attachment points, the attachment points defining a first unattached area having a first effective diameter; the nonwovenType: ApplicationFiled: March 10, 2017Publication date: October 5, 2017Inventor: NATALIA V. LEVIT
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Patent number: 9735410Abstract: This invention provides a multi-layer article comprising a first electrode material, a second electrode material, and a porous separator disposed between and in contact with the first and the second electrode materials, wherein the porous separator comprises a nonwoven consisting essentially of a plurality of fibers of a fully aromatic polyimide. Also provided is a method for preparing the multi-layer article, and an electrochemical cell employing the same. A multi-layer article comprising a polyimide nonwoven with enhanced properties is also provided.Type: GrantFiled: November 5, 2014Date of Patent: August 15, 2017Assignee: E I DU PONT DE NEMOURS AND COMPANYInventors: Pankaj Arora, Natalia V Levit
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Publication number: 20160113340Abstract: The present invention relates to a flame resistant thermal liner comprising a nonwoven sheet comprising nanofibers of a synthetic polymer having an limiting oxygen index of at least 21, a mean flow pore of 10 micrometers or less, a thickness air permeability of 25 to 6000 cubic feet per min?micrometers (12 to 2880 cubic meters per square meter per min?micrometers), and an average thickness T1; and a thermally stable flame resistant fabric attached to an outer surface of the nonwoven sheet, the fabric having an average thickness T2; a surface of the thermally stable fabric being in contact with a surface of the nonwoven sheet; wherein T1 and T2 are selected such that the ratio of T1 to T2 is less than 0.75. The invention also relates to a flame resistant composite fabric comprising the flame resistant thermal liner and a garment comprising this flame resistant composite fabric.Type: ApplicationFiled: October 6, 2015Publication date: April 28, 2016Applicant: E I DU PONT DE NEMOURS AND COMPANYInventors: NATALIA V LEVIT, RICHARD HALL YOUNG
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Publication number: 20150125737Abstract: This invention provides a multi-layer article comprising a first electrode material, a second electrode material, and a porous separator disposed between and in contact with the first and the second electrode materials, wherein the porous separator comprises a nonwoven consisting essentially of a plurality of fibers of a fully aromatic polyimide. Also provided is a method for preparing the multi-layer article, and an electrochemical cell employing the same. A multi-layer article comprising a polyimide nonwoven with enhanced properties is also provided.Type: ApplicationFiled: November 5, 2014Publication date: May 7, 2015Inventors: Pankaj Arora, Natalia V. Levit
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Publication number: 20130022858Abstract: This invention relates to separators for batteries and other electrochemical cells, especially lithium-ion batteries, having a shutdown mechanism. The separator is a laminate that contains a nonwoven nanoweb and a porous layer composed of a plurality of thermoplastic particles having particle size smaller than the mean flow pore size of the nanoweb. The shutdown layer melts and starts to flow at a desired temperature, and restricts the ion flow path, resulting in a substantial decrease in ionic conductivity of the separator at the desired shutdown temperature, while leaving the separator intact.Type: ApplicationFiled: January 19, 2012Publication date: January 24, 2013Applicant: E.I. DU PONT DE NEMOURS AND COMPANYInventors: Stephen Mazur, Simon Frisk, Natalia V. Levit
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Publication number: 20130017431Abstract: This invention relates to separators for batteries and other electrochemical cells, especially lithium-ion batteries, having a shutdown mechanism. The separator comprises a nonwoven nanoweb comprising a coating composed of a plurality of thermoplastic particles having particle size larger than the mean flow pore size of the nanoweb. The coating flows at a desired temperature, and restricts the ion flow path, resulting in a substantial decrease in ionic conductivity of the separator at the desired shutdown temperature, while leaving the separator intact.Type: ApplicationFiled: January 19, 2012Publication date: January 17, 2013Applicant: E. I. DU PONT DE NEMOURS AND COMPANYInventors: SIMON FRISK, NATALIA V. LEVIT, PANKAJ ARORA
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Publication number: 20130005940Abstract: A nanoweb that contains a plurality of nanofibers wherein the nanofibers contain a fully aromatic polyimide that is characterized by having a crystallinity index (CI) and a degree of imidization (DOI). The product of the DOI and the CI is between 0.08 and 0.25 or above a lower limit to obtain a desired tensile strength and/or toughness. The nanoweb may for example have a tensile strength per unit basis weight of greater than 15 kg/cm2 per gram per square meter unit of basis weight.Type: ApplicationFiled: June 26, 2012Publication date: January 3, 2013Applicant: E I DU PONT DE NEMOURS AND COMPANYInventors: T. Joseph Dennes, Glen E. Simmonds, Pankaj Arora, Natalia V. Levit
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Patent number: 8025124Abstract: A passive distributed vibration absorber that utilizes multiple discrete mass elements and a viscoelastic layer and that effectively attenuates vibration in modally dense structures excited by a broadband input noise excitation. and is tunable to multiple natural frequencies in such modally dense vibrating structures including low frequencies.Type: GrantFiled: October 31, 2008Date of Patent: September 27, 2011Assignee: E. I. du Pont de Nemours and CompanyInventors: Natalia V Levit, Mark Allan Lamontia, David M Mellen, Joseph A King, Jr., Kathleen Kondylas, Christopher R Fuller
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Publication number: 20090173570Abstract: An acoustically absorbent ceiling tile includes a core of acoustically absorbing material having two major surfaces, and a facing for covering the core on at least one major surface. The facing comprises a porous flash spun plexifilamentary film-fibril sheet having a coherent surface and comprising a plurality of pores having a pore diameter between about 100 nm and about 20,000 nm and a mean pore diameter of less than about 20,000 nm. The facing has highly diffuse reflectance of light, and a reflectance of greater than about 86%. The use of the facing improves the acoustic absorption of ambient sound at frequencies below about 1200 Hz. The facing provides a barrier to moisture and particles including microorganisms so that the ceiling tile is suitable for use in environments in which cleanliness is critical.Type: ApplicationFiled: December 19, 2008Publication date: July 9, 2009Inventors: Natalia V. Levit, Eric W. Teather
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Publication number: 20090173569Abstract: An acoustic absorber includes a core of acoustically absorbing material having two major surfaces, and a facing for covering the core on at least one major surface. The facing comprises a porous flash spun plexifilamentary film-fibril sheet having a coherent surface and comprising a plurality of pores having a pore diameter between about 100 nm and about 20,000 nm and a mean pore diameter of less than about 20,000 nm. The use of the facing improves the acoustic absorption of ambient sound at a frequency below about 1200 Hz. The facing provides a barrier to moisture and particles including microorganisms so that the absorber is suitable for use in environments in which cleanliness is critical.Type: ApplicationFiled: December 19, 2008Publication date: July 9, 2009Inventors: Natalia V. Levit, Eric W. Teather
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Publication number: 20090113843Abstract: A passive distributed vibration absorber that utilizes multiple discrete mass elements and a viscoelastic layer and that effectively attenuates vibration in modally dense structures excited by a broadband input noise excitation and is tunable to multiple natural frequencies in such modally dense vibrating structures including low frequenciesType: ApplicationFiled: October 31, 2008Publication date: May 7, 2009Inventors: Natalia V. Levit, Mark Allan Lamontia, David M. Mellen, Joseph A. King, JR., Kathleen Kondylas, Christopher R. Fuller