http://ir.lib.ruh.ac.lk/handle/iruor/14381 Thu, 14 May 2026 02:25:52 GMT 2026-05-14T02:25:52Z http://ir.lib.ruh.ac.lk/handle/iruor/15750 Cover page Sun, 01 Oct 2023 00:00:00 GMT http://ir.lib.ruh.ac.lk/handle/iruor/15750 2023-10-01T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/15749 Message of the Editor Rengarasu, Terrance Sun, 01 Oct 2023 00:00:00 GMT http://ir.lib.ruh.ac.lk/handle/iruor/15749 2023-10-01T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/15741 An Investigation on the Shape Factors of Aggregates Dassanayake, D.H.H.P.; Ahilash, N.; Premasiri, A.J.M.S.D.; Jayasekara, H.G.H.N.; Subramaniam, D.N. The aggregate properties such as aggregate size distribution and aggregate shape distribution, affect the mechanical performance of concrete. Although shape of aggregates are computed using various computational methods in researches, it was not clear, which of them define the shape of an aggregate as a whole. This study aims to investigate the shape factors (two-dimensional) in defining the shape of an aggregate. Aggregates of size between 5 – 30 mm diameter were obtained from different batches of aggregate samples that underwent treatment of varied degrees of revolutions in LAAV. Fourteen different shape factors were quantified using image analysis techniques and were tested for ANOVA, regression, principal components and correlation analyses. No shape factor defined the shape of an aggregate individually, while several shape factors were highly correlated. A combination of at least three shape factors is required to define the shape of an aggregate numerically. Sun, 01 Oct 2023 00:00:00 GMT http://ir.lib.ruh.ac.lk/handle/iruor/15741 2023-10-01T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/15740 Impact of Influential Parameters on the Formation of Alternate Bars Meegahakumbura, S.P.S.; Jeiroshan, K.; Rajendran, K.; Mathuwanthy, T.; Dias, D.D. At lower discharge rates, channelized alluvial streams frequently exhibit alternate bars. In this study, bar bed forms were regenerated, and checked the sensitivity of parameters governing the formation process of these peculiar bedforms. Resulted water depth, the number of bars, and bar dimensions were measured by varying flow rate, channel slope, and mean grain size of the bed material. The ratio of Shield number to critical Shield number ranged between 2-11, which agreed with previous research findings. The bar length-to-width ratio of alternate natural bars was compared with modeled outputs, which showed an acceptable resemblance. Results revealed that the highest number of bars could be observed for intermediate discharge values (5 − 8cm3/s) when the bed slopes were maintained between 4.5◦ − 7◦. The formation process of these bedforms was signified once particle Reynold number concentrates towards 20. The bar formation process was curtailed beyond a threshold discharge irrespective of the favorable slope and particle Reynolds number, highlighting the sensitivity of the discharge for this phenomenon. Research outputs can be deployed to predict the possibility of bar formation based on the fluid dynamic and morpho-dynamic characteristics of the desired entity when designing reservoirs, hydropower generating schemes, irrigation water supply systems, etc. Sun, 01 Oct 2023 00:00:00 GMT http://ir.lib.ruh.ac.lk/handle/iruor/15740 2023-10-01T00:00:00Z