Abstract: The construction system includes a composition that includes Portland cement, nano-TiO2, and slag cement. The composition may also include water. The composition is cured via a CO2 curing process to produce a self-cleaning photocatalytic composite with lower carbon footprint and may be more economically manufactured than known cement-based photocatalytic composites. The unveiled synergistic effect of using slag cement and applying a CO2 curing process may reduce the porosity of the material and reduce the penetration of the pollutants that will accumulate in the surface. Thus, pollutants will be more exposed to UV light and decompose the pollutants in a greater rate. The construction system is self-cleaning in that water, such as from rainfall, may effectively clean the cured composition to reset the sequestering capabilities for the construction system to continue to remove toxic gases for the atmosphere.

Abstract: A method for the detection of noise and speech segments in a digital audio input signal, the input signal being divided into a plurality of frames including a first stage in which a first classification of a frame as noise is performed if the mean energy value for this frame and the previous N frames is not greater than a first energy threshold, N>1, a second stage in which for each frame that has not been classified as noise in the first stage it is decided if the frame is classified as noise or as speech based on combining at least a first criterion of spectral similarity of the frame with acoustic noise and speech models, a second criterion of analysis of the energy of the frame and a third criterion of duration, and of using a state machine for detecting the beginning of a segment as an accumulation of a determined number of consecutive frames with acoustic similarity greater than a first threshold and for detecting the end of the segment; a third stage in which the classification as speech or as noise