A Co integration Approach Analysis of the Effects of Boiling and Cooling on Some Physical Properties Luffa Sponge Seed

Knowledge of physical properties of seed is pre-requisite for design of handling equipment. This study determined short and long run effects of both boiling and cooling on some physical properties of Luffa Sponge Seed. Three-300g of seed were constantly boiled in separate water pots for 20, 30 and 40minutes and allowed to cool down (12hours, 18hours and 24 hours). 100 randomly selected seeds were selected for different parameter measurements. Data obtained were subjected to summary statistics analysis, generalized linear model (Glm), unit root test, vector autoregression analysis, Johansen co-integration and Granger causality test. Mean sphericity (SPH) decreases with increasing boiling time. Mean SPH ranged between 55.591 and 55.050 (for 30minutes) while mean geometric diameter (GMD) ranged between 5.239 (for 24 hours cooling) and 5.067 (for 12hours cooling). Glm analysis revealed that significant differences exist between the means for both GMD and SPH for the sources of variation. Dickey-Fuller statistics (-3.951 for GMD and -4.666 for SPH) were both significant, GMD and SPH contained unit roots. It was established that higher cooling (18hours and 24hours) and moderate boiling impact optimum seed dimension and sphericity on Luffa and these could help in design of efficient machine for utilization of the seed

Predictions and measurements of residual stress in repair welds in plates

This paper presents the work, from the European Union FP-5 project ELIXIR, on a series of rectangular repair welds in P275 and S690 steels to validate the numerical modelling techniques used in the determination of the residual stresses generated during the repair process. The plates were 1,000 mm by 800 mm with thicknesses of 50 and 100 mm. The repair welds were 50%, 75% and 100% through the plate thickness. The repair welds were modelled using the finite element method to make predictions of the as-welded residual stress distributions. These predictions were compared with surface-strain measurements made on the parent plates during welding and found to be in good agreement. Through-thickness residual stress measurements were obtained from the test plates through, and local to, the weld repairs using the deep hole drilling technique. Comparisons between the measurements and the finite element predictions generally showed good agreement, thus providing confidence in the method