Ethyl 1-benzyl-1,2,3,3a,4,10b-hexa-hydro-pyrrolo-[2',3':3,4]pyrrolo-[1,2-a]benzimidazole-2-carboxyl-ate.

The title mol-ecule, C(22)H(23)N(3)O(2), was obtained via an intra-molecular cyclo-addition of an azomethine ylide and an alkene tethered by a benzimidazole unit. The benzoimidazole unit is essentially planar, with an r.m.s. deviation of 0.0087 Å from the nine constituent atoms. It has a cis fusion of the two pyrrolidine rings as well as a cis ester appendage. The two pyrrolidine rings rings have envelope conformations. The crystal packing is stabilized by aromatic π-π stacking of parallel benzimidazole ring systems, with a centroid-to-centroid distance of 3.518 (6) Å. Weak inter-molecular C-H⋯O contacts may also play a role in the stability of the packing

Ka-Band HTS System User Uplink SNIR Probability Models

Ka-band High-throughput-satellite (HTS) systems reuse frequency bands in spot beams for much higher system capacity and better spectrum efficiency. They however are prone to intra-system co-color interference and so suffer from the channel signal-to-noise-plus-interference ratio (SNIR) degradation. This chapter presents the development of the uplink SNIR probability models for Ka-band spot beam HTS systems. The models are applicable to different Ka-band propagation channel conditions of statistical significance. Its use of collective representation to model traffic variation of co-color beams captures the statistics of traffic variation and allows feasibility and variety of use case representation. The analytical approach complements known studies and fills in the blank of the use cases of urban and mobile users. The models can be used for system design performance estimation and prediction. It features computation time and memory savings in numerical implementation

The foreclosure crisis in 2008: predatory lending or household overreaching?

At least early in the financial crisis, the high rate of foreclosures seemed to be due more to households' overreaching than to predatory lending. A disproportionate number of those being foreclosed on were well-educated, well-off and relatively young people.Foreclosure ; Mortgage loans ; Housing - Finance