Sediment Entry Investigation at the 30 Degree Water Intake Installed at a Trapezoidal Channel
2 Abstract: A major problem which most of lateral intakes are faced with is sedimentation and sediment delivery. This process causes many problems such as reduction flow discharge capacity in irrigation canals as well as threatening of blockage of water during low water flow. Therefore it is the main goal of engineer to design an intake with higher flow discharge and low sediment delivery. Since most of lateral intakes are installed at trapezoidal which has not received the same attention as intake from rectangular canals, it is the main goal of this study to investigate sediment delivery to an intake from trapezoidal canal. In this study, sediment tests carried out for different hydraulic conditions at a 30 degree water intake installed at main channel with inclined bank. From analysis of these it was found that the flow patterns at the upstream of the intake has been modified in such a way that more water from surface layers are diverted. Therefore less suspended sediment enters the intake. Also it was found that in all tests the amount of sediment enters the intake reaches its minimum value at Froude Number between o.35 to o.4. In low flow depth because of the effect of bed roughness over strength of secondary current, the suspended sediment enters the intake is lower compare to the higher flow depth for the same conditions.
Control of sediment entry into an intake canal by using submerged vanes
River flow which is entering into an intake canal carries lot of sediment due to centrifugal action at river-intake junction and results in various problems. The present work aims to control sediment entry into an intake canal by modifying flow pattern using submerged vanes. Experiments are conducted in a 57.5 cm wide rectangular laboratory model filled with sediment, d50=0.28mm, for a constant discharge of 0.025m3/s and flow depth (H) of 8cm. A rigid bed trapezoidal channel (side slopes, 1H: 1V) of bed width 15 cm, diverting at an angle of 45° from river model is used as an intake channel. Submerged vanes of width 0.18H and 1mm thick are arranged in single and double rows at a spacing (Vs) of 8cm and 12cm. The angle of attack (θ) of vane with respect to flow direction in river model varies as 15°, 300 and 450. A total of seven vanes are arranged as a crest of wave with a central vane height of 0.625 H and decreasing gradually to 0.438H on either side. In single row vane arrangement, for ‘Vs’=8 cm and ‘θ’...
The Human Rights Act and Parliamentary Democracy
The Human Rights Act 1998 is the culmination of an aggressive campaign for the incorporation into domestic law of the European Convention on Human Rights, a campaign in which the judges joined forces with other political activists. Variously described as 'brilliant';' 'a masterly exposition of the parliamentary draftsman's art';2 and even 'a thing of intellectual beauty',3 the Act has also been greeted as an 'ingenious compromise' between the 'maximalists' and 'minimalists', the former supporting a judicial power to invalidate legislation, as is the case in Canada.4 But although it is purported to reconcile in 'subtle' form the protection of human rights with the sovereignty of Parliament (a claim even more credible after an important but unsung Commons amendment), the Act also represents an unprecedented transfer of political power from the executive and legislature to the judiciary, and a fundamental re-structuring of our 'political constitution'.s As such it is unquestionably the most significant formal redistribution of political power in this country since 1911,6 and perhaps since 1688 when the Bill of Rights proclaimed loudly that proceedings in Parliament ought not to be questioned or impeached in any court or any other place. In the words of Baroness Williams of Crosby, we have crossed our 'constitutional Rubicon',7 at least to the extent that the courts may now declare a statute incompatible with Convention rights. The enactment of the Human Rights Act 1998 was marked by an unusually high quality of debate, particularly in the House of Lords, with powerful performances by the Lord Chancellor and Lord Lester of Herne Hill. The performance of the latter on one occasion was too much for Lord Campbell of Alloway, unaccustomed it seems to cerebral rather than ceremonial contributions in their Lordships' House. Lord Campbell was heard to protest (in a manner dubbed 'offensive' by Lord Ackner)8 about 'these escoteric lectures on law at this time of night', having 'never heard anything like this after dinner' in the 18 years he had been in the Lords.9 He had better get used to it: the law and the lawyers are about to dominate all the debates, at all times of the day and night, before and after every meal time. Indeed in the Second Reading Debate on this Bill in the House of Lords 'full of