Abstract: A system initiates multiple instances of a concurrent computing process, establishes a communication channel among the multiple instances, initiates execution of a computational job on the multiple instances, detects an interrupt request on one of the multiple instances, and terminates execution of the computational job while maintaining communication among the multiple instances via the communication channel.

Abstract: The present invention provides a method and system for exception handling in an executable process executing in a concurrent computing environment. The present invention allows a user to interrupt the executable process at any stage of the computation without disconnecting the communication channel among the instances of the executable process. Additionally, the present invention also allows interrupting the concurrent computing process at any stage when an error occurs in the executable process or the communication channel without terminating the communication among the instances of the executable process. Upon notification of an interrupt request, each of the instances of the executable process in the concurrent computing environment flushes any pending incoming messages to return itself to a previous known state while maintaining the communication channel between the instances of the executable process.

Abstract: A process for producing a photochromic glass which will exhibit a brown coloration in its darkened state without a degradation in the photochromic properties of the glass taking place. The process includes the steps of forming a batch of specified components which include tin or a tin compound and subjecting the resultant batch to a series of glass-forming steps so as to develop photochromic properties in a glass article formed from the molten batch.The invention also provides a photochromic glass having silver halide crystals and tin dispersed throughout the glass, the glass having in its darkened state a brown coloration which is described in accordance with the Hunter L,a,b, Color Scale System by the rectangular region having corners defined by the (a,b) co-ordinates: (5,1), (1,5), (12,16) and (16,12), the 1/2 OD FT of the glass being 120 seconds or less.

Abstract: Fast-response alumino-phosphate photochromic glasses having silver halide crystals dispersed throughout the glass consisting essentially of, in weight percentages:SiO.sub.2 : 8.5 to 25%, Al.sub.2 O.sub.3 : 13 to 36.5%, P.sub.2 O.sub.5 : 7.5 to 33.5%, B.sub.2 O.sub.3 : 7 to 28%; R.sub.2 O: 7 to 20.5%, R'O:0 to 21%, TiO.sub.2 : 0 to 6%, ZrO.sub.2 : 0 to 10%, PbO:0 to 8%,Where R.sub.2 O represents at least one of Na.sub.2 O, K.sub.2 O and Li.sub.2 O, the maximum content of Li.sub.O being 5%; and R'O represents at least one of MgO,CaO,SrO and BaO, within the following individual limits: MgO: 0 to 4%, CaO: 0 to 6.5%, SrO: 0 to 10%, BaO: 0 to 21%; the amount of SiO.sub.2 is not less than 16% when the B.sub.2 O.sub.3 content is less than 8%; and the silver content of the glass, expressed as Ag.sub.2 O, is not less than 0.05% by weight.Such glasses in which Al.sub.2 O.sub.3 is the largest constituent are preferred for ophthalmic purposes, but it is also possible for either B.sub.2 O.sub.3 or P.sub.2 O.sub.

Abstract: Fast-response photochromic boron-free aluminophosphate glasses which have silver halide crystals dispersed throughout the glass comprise, in weight percentages:______________________________________ SiO.sub.2 10 to 17% Al.sub.2 O.sub.3 20 to 29% P.sub.2 O.sub.5 30 to 40% R.sub.2 O 8.5 to 17% R'O 4 to 18% ______________________________________Where R.sub.2 O represents Na.sub.2 O and/or K.sub.2 O; R'O represents CaO and/or BaO, the CaO content being at least 4% if BaO is absent and being from 0 to 7% if BaO is present, while the BaO content is from 0 to 18%; the total of SiO.sub.2 + Al.sub.2 O.sub.3 + P.sub.2 O.sub.5 amounting to not less than 69% by weight of the glass. Preferably the total of SiO.sub.2 + P.sub.2 O.sub.5 + Al.sub.2 O.sub.3 is not less than 72% by weight of the glass. The silver content of the glass, expressed as Ag.sub.2 O, is preferably not less than 0.05%. Refractive index n.sub.D can be corrected to the standard ophthalmic value of 1.523 by additions of TiO.sub.2, ZrO.sub.2 and/or PbO.