Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a single packed extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent in a first extractor for a first time period, at a first extraction temperature and subsequent to the first time period, extracting the aqueous reaction mixture with an organic solvent in a second extractor for a second time period, at a second extraction temperature. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Abstract: A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a sieve tray extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Abstract: A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Abstract: A method for the purification of a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine of formula (I), the method comprising heating a reaction mixture comprising a phenolphthalein compound of formula (II) and a primary arylamine of formula (III) in the presence of an acid catalyst to form a reaction mixture; removing water from the reaction mixture; quenching the reaction mixture with an aqueous alkali solution to form a quenched reaction mixture; extracting the quenched reaction mixture with an aminoaryl compound of formula (IV) to form an organic layer and an extracted aqueous layer comprising a crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound; contacting the extracted aqueous layer with carbon to form a semi-purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound; and mixing the semi-purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound with a solution comprising an alcohol and an acid to form a purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine of formula (I); wherein formulas (I), (II), (III), and (I

Abstract: A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Abstract: Systems and methods are provided to administer a wireless telecommunication network (WTN) having a plurality of cell sites. Network data is received from a data source for a subject cell site. A baseline performance of the subject cell site is determined. Parameters to optimize for the subject cell site based on the baseline performance are identified. An uplink (UL) transmission power of the subject cell site based on a VoLTE drop call rate is adjusted. A downlink (DL) transmission power of a cell specific reference signal (CRS) of the subject cell site is adjusted. A handover operation between the subject cell site and a second cell site is adjusted. A transmission range of the subject cell site is adjusted.

Abstract: Systems and methods are provided to administer a wireless telecommunication network (WTN) having a plurality of cell sites. Network data is received from a data source for a subject cell site. A baseline performance of the subject cell site is determined. Parameters to optimize for the subject cell site based on the baseline performance are identified. Load balancing is performed on the subject cell site by comparing a normalized user equipment (UE) downlink (DL) throughput at a first cellular frequency band to a second cellular frequency band. A cellular coverage of the subject cell site is adjusted based on a voice over LTE (VoLTE) drop call rate for a predetermined time period and a normalized UE DLL throughput. A layer management is performed on the subject cell site.

Abstract: Systems and methods are provided to administer a wireless telecommunication network (WTN) having a plurality of cell sites. Network data is received from a data source for a subject cell site. A baseline performance of the subject cell site is determined. Parameters to optimize for the subject cell site based on the baseline performance are identified. Load balancing is performed on the subject cell site by comparing a normalized user equipment (UE) downlink (DL) throughput at a first cellular frequency band to a second cellular frequency band. A cellular coverage of the subject cell site is adjusted based on a voice over LTE (VoLTE) drop call rate for a predetermined time period and a normalized UE DLL throughput. A layer management is performed on the subject cell site.

Abstract: Systems and methods are provided to administer a wireless telecommunication network (WTN) having a plurality of cell sites. Network data is received from a data source for a subject cell site. A baseline performance of the subject cell site is determined. Parameters to optimize for the subject cell site based on the baseline performance are identified. An uplink (UL) transmission power of the subject cell site based on a VoLTE drop call rate is adjusted. A downlink (DL) transmission power of a cell specific reference signal (CRS) of the subject cell site is adjusted. A handover operation between the subject cell site and a second cell site is adjusted. A transmission range of the subject cell site is adjusted.

Abstract: A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Abstract: The techniques and systems described herein are directed, in part, to optimizing network performance by repeatedly clustering cell sites of the network and optimizing each cluster of cell sites, thereby optimizing performance of a network as a whole. The cell sites may be base stations, radio access networks, and/or other hardware that directly or indirectly exchanges communications with user devices such as mobile telecommunication devices (e.g., user handsets, user hardware, etc.). By optimizing the clusters of cell sites, a service provider (e.g., a telecommunications company, etc.) may improve network performance in less time and/or with less capital resources than attempting to optimize each cell site on an individual basis.