Procesos: revista ecuatoriana de historia. 32 (S0LO LIBROS/Reseñas)

Presenta las reseñas de los siguientes libros: Antonio Annino y Rafael Rojas, La Independencia. Los libros de la patria, México, Centro de Investigación y Docencia Económicas (CIDE)/Fondo de Cultura Económica (FCE), 2008, 244 pp. -- Manuel Espinosa Apolo, Insumisa vecindad. Memoria política del barrio San Roque, Quito, Editorial Tribal/Quito Eterno, 2009, 201 pp. -- Franklin Cepeda Astudillo, Riobamba. Imagen, palabra e historia, Riobamba, Casa de la Cultura Ecuatoriana Benjamín Carrión, Núcleo de Chimborazo, 2001, 286 pp. -- Andrés Guerrero, Administración de poblaciones, ventrililoquia y transescritura. Análilisis históricos: estudios teóricos, Lima-Quito Instituto de Estudios Peruanos (IEP)/Flacso-Ecuador, 2010, 546 pp.

Common black coatings - reflectance and ageing characteristics in the 0.32-14.3 mu m wavelength range

The diffuse and regular reflectances of five optically absorbing coatings frequently used in optical systems, were measured over the 0.32-14.3 mu m wavelength range, before and after exposure to heat and intense optical radiation. The measured coatings included Nextel Velvet Black, an anodised coating and NPL Super Black. The anodised coating exhibited substantial variations in its diffuse and regular reflectance values after thermal and simulated solar ageing. Solar and thermal ageing of the Nextel Velvet Black resulted in increases of its reflectance. However, thermal ageing tended to decrease the reflectance of the other paint samples examined. Thermal and solar ageing of the NPL Super Black resulted in only minor changes in its reflectance characteristics. All measurements are traceable to the UK National Standards.

Improved and optimal dual circular 32-QAM for MB-OFDM

Quadrature Phase Shift Keying (QPSK) and Dual Carrier Modulation (DCM) are currently used as the modulation schemes for Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) in the ECMA-368 defined Ultra-Wideband (UWB) radio platform. ECMA-368 has been chosen as the physical radio platform for many systems including Wireless USB (W-USB), Bluetooth 3.0 and Wireless HDMI; hence ECMA-368 is an important issue to consumer electronics and the users’ experience of these products. To enable the transport of high-rate USB, ECMA-368 offers up to 480 Mb/s instantaneous bit rate to the Medium Access Control (MAC) layer, but depending on radio channel conditions dropped packets unfortunately result in a lower throughput. This paper presents improvement on a high data rate modulation scheme that fits within the configuration of the current standard increasing system throughput by achieving 600 Mb/s (reliable to 3.2 meters) thus maintaining the high rate USB throughput even with a moderate level of dropped packets. The modulation system is termed improved and optimal Dual Circular 32-QAM (DC 32-QAM). The system performance for improved and optimal DC 32-QAM modulation is presented and compared with previous DC 32- QAM, 16-QAM and DCM.