A high efficiency liquid fuel atomizer includes an elongated generally tubular member defining a liquid fuel pre-atomization chamber. The wrappable spacer includes a flexible elongate body having oppositely facing inner and outer faces extending along laterally spaced, lengthwise extending edges between opposite ends. In the emotion recognition, the emotion recognition is performed by applying a discriminative weight evaluated using the Gaussian Mixture Model based on minimum classification error to feature vectors of the emotion classified with difficult, thereby enhancing the performance of emotion recognition. The output-purified gas is transferred from the impurities storage region, is optionally passed through a first micrometer sized filter, through a counter-flow heat exchanger, and ultimately up to an output port at room temperature. The first arm is substantially transverse to the vertical support, and may rotates about the vertical support in a horizontal axis. This technique is particularly suited for assembling a multi-piece artificial spinal disk replacement device in situ in order to alleviate discomfort associated with the spinal column.