[1] A mechanistic model is derived for the rate of fluvial erosion into bedrock by abrasion from uniform size particles that impact the bed during transport in both bed and suspended load. The erosion rate is equated to the product of the impact rate, the mass loss per particle impact, and a bed coverage term. Unlike previous models that consider only bed load, the impact rate is not assumed to...

The textile wastewater samples before treatment processes has been collected and characterized using standard methods, in which COD, color and other contaminations are high and prior to remove before discharge. Feasibility of column adsorption of components contributing COD and color onto activated Neem Leaf Powder using sulphuric acid (a-NLP) from textile wastewater has been studied in this in...

Fries et al. (1999), hereafter referred to as FBW, present interesting experimental data showing that biogenic mounds, formed by the conveyor-belt feeding polychaete Cistenides (Pectinaria) gouldii, can be reshaped into asymmetric bedforms at bed shear stresses below the Shields threshold of sediment movement. The ®nal geometry of the current ripples was found to depend on the spatial density o...

−To obtain highly purified naphthalene, a column crystallizer was employed and operated in the continuous multistage countercurrent fractional mode. The principles and characteristics of the process are introduced. A large amount of experimental work has been done on the crystallization process in a D=50 mm×1,350 mm column. The effects of operation conditions including the composition of feed, ...

Based on a global kinetics of direct dimethyl ether (DME) synthesis process from syngas, a steady-state one-dimensional mathematical model for the bubble column slurry reactor (BCSR) has been established. It was built on the assumption of plug flow of gas phase, sedimentation-dispersion model of catalyst grains and isothermal chamber regardless of reaction heats and rates for the design of an i...

in this paper, experimental data on the drying kinetics of corn in a packed and fluidized bed are presented. experimental research was conducted on a laboratory apparatus. corn was used as a material because of its significance in agriculture and the food industry. an analysis of the influence of the operational parameters (the drying medium velocity i. e. the fluidization number, the drying me...

Carbon dioxide capture is a key issue in climate change mitigation. For decades the removal of carbon dioxide has been an essential step in many industrial processing operations such as the synthesis of ammonia, natural gas purification, and oil refining. In this study, a rotating packed bed has been designed for absorption of carbon dioxide from an air stream. The rotating packed bed is a comp...

In this research, a cold model of internally circulating fluidized bed is investigated. The aim is to find the effects of some of the operating parameters on the performance of the reactor. Experiments were carried out in a glass column (30 mm i.d. and 25 cm height) with a centrally located draft tube (11 mm i.d. and 5 or 7 cm height). The bed was loaded with white silica particles (dp = 0.15 -...

a r t i c l e i n f o Ripples and transverse dunes in areas of abundant sand supply increase in height and spacing as a function of time, grain size, and excess shear velocity. How and why each of these factors influence ripple and transverse dune size, however, is not precisely known. In this paper, the controls on the height and spacing of ripples and transverse dunes in areas of abundant san...

PURPOSE Ultrasonographic (US) criteria on malignant thyroid bed mass have been suggested, including taller than wide shape, loss of echogenic hilum, abnormal vascularity, and microcalcification. The relationship between fine-needle aspiration (FNA) cytology findings and US findings on thyroid bed mass is unknown. We have retrospectively assessed the malignant thyroid bed mass after total thyroi...