Abstract:
The present invention relates to a polyurethane prepared from a mixture comprising: (a) at least one polyethylene glycol; (b) at least one di-isocyanate; (c) at least one polydialkyl siloxane diol; and (d) at least one diol of formula (I) wherein n is an integer from 1 to 25; wherein the polyethylene glycol, di-isocyanate, polydialkyl siloxane diol and diol are reacted under substantially anhydrous conditions. Further aspects of the invention relate to a process for preparing a polyurethane. The invention also relates to a process for preparing a polyurethane xerogel in the form of a molded article, said process comprising the steps of: (i) preparing a reaction mixture comprising at least one polyethylene glycol, at least one di-isocyanate, at least one polydialkyl siloxane diol and at least one diol of formula I as described above; (ii) reacting the reaction mixture formed in step (i) under substantially anhydrous conditions to form a polyurethane xerogel; and (iii) injection molding the polyurethane xerogel to form a molded article.
Abstract:
Processes for preparation of fatty acid alkyl esters are described herein. The processes include contacting fatty acid glycerides with alcohols in the presence of a catalyst separating the reaction products from the catalyst, and separating the fatty acid alkyl esters from the reaction products. The catalyst includes a metal from Group VIB of the Periodic Table and an element from Group VA of the Periodic Table.
Abstract:
A septic field dosing system is described which utilizes a self starting true siphon to deliver a dose of septic tank effluent into a conventional septic field. The precision siphon unit not only eliminates the need for electrical services to the septic tank, thereby eliminating the need for pumps and solenoid operated valves and switches at the septic tank, but also contains the effluent handling equipment in a small unit. For example, the drawdown of the septic tank is used to entirely control the operation of the dosing siphon. Further, the dimensional configuration of the precision siphon operates within the boundaries of the draw down to deliver a proper size dose to the septic field. While a typical septic tank can hold of the order of a thousand or more gallons, the precision siphon can easily fit into a five gallon bucket.
Abstract:
Metabolic auxotroph of Vibrio cholerae 0139 synonym Bengal which has a mutation in its hem A gene and which is not capable of synthesizing aminolevulinic acid (ALA) de novo and which is obtained from a parent strain originally isolated from a patient's coproculture having all the identifying characteristics of Vibrio cholerae 0139 synonym Bengal is described. In this strain the hem A gene is mutated by inserting a kanamycin resistant gene cassette. Another metabolic auxotroph of Vibrio cholerae 01 E1 Tor where the hem A gene is mutated by a frame shift mutation is disclosed. Methods of producing the strains are disclosed.
Abstract:
The present invention relates to a method of using non-macrogelled polymer-solvent combinations to form devices, in particular medical devices and/or cosmetic devices, more specifically contact lenses. The method of using polymer solvent combinations is suitable for forming useful 3D dimensionally stable structures which may include curved surfaces, which may be significantly different to those curved surfaces achieved by using simple meniscus effects.
Abstract:
Processes for preparation of fatty acid alkyl esters are described herein. The processes include contacting fatty acid glycerides with alcohols in the presence of a catalyst separating the reaction products from the catalyst, and separating the fatty acid alkyl esters from the reaction products. The catalyst includes a metal from Group VIB of the Periodic Table, a metal from Group IIIA of the Periodic Table, and an element from Group VA of the Periodic Table.
Abstract:
A septic field dosing system is described which utilizes a self starting true siphon to deliver a dose of septic tank effluent into a conventional septic field. The precision siphon unit described by present invention not only eliminates the need for electrical services to the septic tank, thereby eliminating the need for pumps and solenoid operated valves and switches at the septic tank, but also contains the effluent handling equipment in a small unit which uses the available features of the septic tank to assist in the performance of its operations. For example, the drawdown of the septic tank which is now determined by the configuration of the siphon unit is used to entirely control the operation of the dosing siphon. Further, the dimensional configuration of the precision siphon taught by the invention operates within the boundaries of the draw down to deliver a proper size dose to the septic field. While a typical septic tank can hold of the order of a thousand or more gallons, the precision siphon can easily fit into a five gallon bucket.
Abstract:
A process for the non-oxidative conversion of methane simultaneously with the conversion of an organic oxygenate, represented by a general formula: CnH2n+1OCmH2m+1, wherein C, H and O are carbon, hydrogen and oxygen elements, respectively; n is an integer having a value between 1 and 4; and m is an integer having a value between zero and 4, to C2+ hydrocarbons, particularly to gasoline range C6–C10 hydrocarbons and hydrogen, using a bifunctional pentasil zeolite catalyst, having strong acid and dehydrogenation functions, at a temperature below 700° C. is disclosed. In this process the moles of methane converted per mole of oxygenate converted is above 1.0, depending upon the process conditions.
Abstract translation:一种用于通过有机含氧化合物的转化同时进行甲烷的非氧化转化的方法,其由以下通式表示:C n H 2n + 1 C m 其中C,H和O分别为碳,氢和氧元素; n是1到4之间的整数; 并且m是具有0至4之间的值的整数,至C 2 + C 2烃,特别是汽油范围C 6 -C 10烃 和在低于700℃的温度下使用具有强酸和脱氢功能的双官能pentasil沸石催化剂的氢。 在这个过程中,转化的每摩尔含氧化合物转化的甲烷的摩尔数大于1.0,这取决于工艺条件。
Abstract:
An improved process for the production of ethylene by non-catalytic oxidative cracking of ethane or ethane rich C.sub.2 -C.sub.4 paraffins with high conversion, selectivity and productivity, operating in a most energy efficient and safe manner requiring little or no external energy, in an empty tubular reactor, wherein the exothermic oxidative conversion of ethane or ethane rich C.sub.2 -C.sub.4 paraffins is coupled with the endothermic hydrocarbon cracking reactions by carrying out both the exothermic and endothermic reactions simultaneously in the reactor so that the heat produced in the exothermic reactions is used instantly in the endothermic reactions and thereby making the overall process mildly exothermic, near thermo-neutral or mildly endothermic, which comprises passing a preheated gaseous feed comprising of ethane or ethane rich C.sub.2 -C.sub.4 paraffins, oxygen and steam through an empty tubular reactor operated at the effective temperature, pressure, space velocity and hydrocarbon/O.sub.2 and hydrocarbon/steam mole ratios in the feed, is provided.
Abstract translation:一种改进的乙烯生产工艺,通过非催化氧化裂解乙烷或富含乙烷的富C2-C4链烷烃,具有高转化率,选择性和生产率,以最节能和安全的方式运行,需要很少或没有外部能量,在空的 其中乙烷或富含乙烷的C2-C4链烷烃的放热氧化转化通过在反应器中同时进行放热和吸热反应与吸热烃裂解反应相结合,使得在放热反应中产生的热量立即使用 在吸热反应中,从而使整个过程温和地放热,接近热中性或温和吸热,其包括使包含乙烷或富乙烷的C2-C4链烷烃的氧气和蒸汽的预热气态进料通过在 有效的温度,压力,空间速度和烃/ O 2和烃/蒸汽 提供饲料中的摩尔比。
Abstract:
Novel devices for the controlled release of active materials especially pharmaceutical are formed from at least two interpenetrating pieces. The male piece is water swellable and swells to disengage the female piece. The female piece is preferably formed from a thermoplastic, e.g. LDPE or from a soluble material such as gelatin which is rendered impermeable by an external coating of a hydrophobic material such as PVC. The devices find particular application as oral dosage forms for use in man.