Preliminary Investigation of the Frictional Response of Reptilian Shed Skin

Developing deterministic surfaces relies on controlling the structure of the rubbing interface so that not only the surface is of optimized topography, but also is able to self-adjust its tribological behaviour according to the evolution of sliding conditions. In seeking inspirations for such designs, many engineers are turning toward the biological world to correlate surface structure to functional behavior of bio-analogues. From a tribological point of view, squamate reptiles offer diverse examples where surface texturing, submicron and nano-scale features, achieve frictional regulation. In this paper, we study the frictional response of shed skin obtained from a snake (Python regius). The study employed a specially designed tribo-acoustic probe capable of measuring the coefficient of friction and detecting the acoustical behavior of the skin in vivo. The results confirm the anisotropy of the frictional response of snakes. The coefficient of friction depends on the direction of sliding: the value in forward motion is lower than that in the backward direction. In addition it is shown that the anisotropy of the frictional response may stem from profile asymmetry of the individual fibril structures present within the ventral scales of the reptil

Performance of the VAX 11/785 data acquisition system at the KFUPMEnergy Research Laboratory

The VAX 785 XSYS data acquisition and analysis system at the Energy Research Laboratory (ERL) of King Fahd University of Petroleum and Minerals has been in use since June 1987. The authors describe features unique to the ERL system and present data on the various aspects of its performance in comparison with other XSYS installations, including data acquisition, sorting, and dumping onto disks and tapes. Results show the effects of data rates and key system parameters on both system deadtime and CPU (central processing unit) time usag

The VAX 11/785 cluster-based data acquisition system at the KFUPMenergy research laboratory

The authors describe the data acquisition and analysis system at the newly established Energy Research Laboratory at King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia. Design considerations for the new system are discussed and both hardware and software components are described. A summary of the current status of the system is given together with a brief account of its performance and an outline of operational experience gained so fa

Performance of the VAX 11/785 data acquisition system at the KFUPMEnergy Research Laboratory

The VAX 785 XSYS data acquisition and analysis system at the Energy Research Laboratory (ERL) of King Fahd University of Petroleum and Minerals has been in use since June 1987. The authors describe features unique to the ERL system and present data on the various aspects of its performance in comparison with other XSYS installations, including data acquisition, sorting, and dumping onto disks and tapes. Results show the effects of data rates and key system parameters on both system deadtime and CPU (central processing unit) time usag

The VAX 11/785 cluster-based data acquisition system at the KFUPMenergy research laboratory

The authors describe the data acquisition and analysis system at the newly established Energy Research Laboratory at King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia. Design considerations for the new system are discussed and both hardware and software components are described. A summary of the current status of the system is given together with a brief account of its performance and an outline of operational experience gained so fa

CAMAC/MBD interface for the VAX data acquisition facility at theKFUPM Energy Research Laboratory

The authors describe the CAMAC/MBD (microprogrammable branch driver) data acquisition interface used with the VAX 11/785 computer system at the Energy Research Laboratory (ERL) of King Fahd University of Petroleum and Minerals, Dhahran, Saudia Arabia. An ERL-developed automatic LAM (look-at-me) multiplexer module is described. Details of a simple and efficient scheme for the acquisition of multiparameter data are highlighted, and performance results are given. The hardware uses fast CAMAC analog-to-digital converter modules with constant conversion time. This has considerably simplified the interface hardware and allowed higher data rates to be acquired at lower values of deadtime in comparison with similar installation

CAMAC/MBD interface for the VAX data acquisition facility at theKFUPM Energy Research Laboratory

The authors describe the CAMAC/MBD (microprogrammable branch driver) data acquisition interface used with the VAX 11/785 computer system at the Energy Research Laboratory (ERL) of King Fahd University of Petroleum and Minerals, Dhahran, Saudia Arabia. An ERL-developed automatic LAM (look-at-me) multiplexer module is described. Details of a simple and efficient scheme for the acquisition of multiparameter data are highlighted, and performance results are given. The hardware uses fast CAMAC analog-to-digital converter modules with constant conversion time. This has considerably simplified the interface hardware and allowed higher data rates to be acquired at lower values of deadtime in comparison with similar installation

Modelling the viability of heat recovery from combined sewers

NoModelling of wastewater temperatures along a sewer pipe using energy balance equations and assuming steady-state conditions was achieved. Modelling error was calculated, by comparing the predicted temperature drop to measured ones in three combined sewers, and was found to have an overall root mean squared error of 0.37 K. Downstream measured wastewater temperature was plotted against modelled values; their line gradients were found to be within the range of 0.9995-1.0012. The ultimate aim of the modelling is to assess the viability of recovering heat from sewer pipes. This is done by evaluating an appropriate location for a heat exchanger within a sewer network that can recover heat without impacting negatively on the downstream wastewater treatment plant (WWTP). Long sewers may prove to be more viable for heat recovery, as heat lost can be reclaimed before wastewater reaching the WWTP