The effectiveness of a double-stem injection valve in controlling combustion in a compression-ignition engine

An investigation was made to determine to what extent the rates of combustion in a compression-ignition engine can be controlled by varying the rates of fuel injection. The tests showed that the double-stem valve operated satisfactorily under all normal injection conditions; the rate of injection has a definite effect on the rate of combustion; the engine performance with the double-stem valve was inferior to that obtained with a single-stem valve; and the control of injection rates permitted by an injection valve of two stages of discharge is not sufficient to effect the desired rates of combustion

Efficient data encoder for endoscopic imaging applications

The invention of medical imaging technology revolved the process of diagnosing diseases and opened a new world for better studying inside of the human body. In order to capture images from different human organs, different devices have been developed. Gastro-Endoscopy is an example of a medical imaging device which captures images from human gastrointestinal. With the advancement of technology, the issues regarding such devices started to get rectified. For example, with the invention of swallow-able pill photographer which is called Wireless Capsule Endoscopy (WCE); pain, time, and bleeding risk for patients are radically decreased. The development of such technologies and devices has been increased and the demands for instruments providing better performance are grown along the time. In case ofWCE, the special feature requirements such as a small size (as small as an ordinary pill) and wireless transmission of the captured images dictate restrictions in power consumption and area usage. In this research, the reduction of image encoder hardware cost for endoscopic imaging application has been focused. Several encoding algorithms have been studied and the comparative results are discussed. An efficient data encoder based on Lempel-Ziv-Welch (LZW) algorithm is presented. The encoder is a library-based one where the size of library can be modified by the user, and hence, the output data rate can be controlled according to the bandwidth requirement. The simulation is carried out with several endoscopic images and the results show that a minimum compression ratio of 92.5 % can be achieved with a minimum reconstruction quality of 30 dB. The hardware architecture and implementation result in Field-Programmable Gate Array (FPGA) for the proposed window-based LZW are also presented. A new lossy LZW algorithm is proposed and implemented in FPGA which provides promising results for such an application

A survey of the three-dimensional high Reynolds number transonic wind tunnel

The facilities for aerodynamic testing of airplane models at transonic speeds and high Reynolds numbers are surveyed. The need for high Reynolds number testing is reviewed, using some experimental results. Some approaches to high Reynolds number testing such as the cryogenic wind tunnel, the induction driven wind tunnel, the Ludwieg tube, the Evans clean tunnel and the hydraulic driven wind tunnel are described. The level of development of high Reynolds number testing facilities in Japan is discussed

Space programs summary no. 37-56, volume 1 for the period 1 January to 28 February 1969. Flight projects

Mariner Mars 1969 Project, Mariner Mars 1971 Project, and Viking Project description