اسکیــــــــــــــنر جهــــــــــانــــــی

Since the 1970s the annual tonnage produced has increased, although the number employed in the industry has steadily declined. A soft shoal in the bed of a river is due to deposit from a diminution in velocity of flow, produced by a reduction in fall and by a widening of the channel, or to a loss in concentration of the scour of the main current in passing over from one concave bank to the next on the opposite side. A typical solution is to restrict the width of the low-water channel, concentrate all of the flow in it, and also to fix its position so that it is scoured out every year by the floods which follow the deepest part of the bed along the line of the strongest current. Where, however, narrow rocky reefs or other hard shoals stretch across the bottom of a river and present obstacles to the erosion by the current of the soft materials forming the bed of the river above and below, their removal may result in permanent improvement by enabling the river to deepen its bed by natural scour. Often, in the instances where channelization is permitted, boulders may be installed in the bed of the new channel so that water velocity is slowed, and channels may be deliberately curved as well.

The rate of recovery for a stream once it has been dredged is extremely slow, with many streams showing no significant recovery 30 to 40 years after the date of channelization. Another is the fact that channelized streams are almost invariably straightened. It can also increase flooding downstream from the channelized area, as larger volumes of water traveling more rapidly than normal can reach choke points over a shorter period of time than they otherwise would, with a net effect of flood control in one area coming at the expense of greatly aggravated flooding in another. A third reason is flood control, with the idea of giving a stream a sufficiently large and deep channel so that flooding beyond those limits will be minimal or nonexistent, at least on a routine basis. One major reason is to reduce natural erosion; as a natural waterway curves back and forth, it usually deposits sand and gravel on the inside of the corners where the water flows slowly, and cuts sand, gravel, subsoil, and precious topsoil from the outside corners where it flows rapidly due to a change in direction.

One is to make a stream more suitable for navigation or for navigation by larger vessels with deep draughts. The needs of navigation may also require that a stable, continuous, navigable channel is prolonged from the navigable river to deep water at the mouth of the estuary. This data may be sent again if there is a need to re-activate or validate your license. Engineering works to increase the navigability of rivers can only be advantageously undertaken in large rivers with a moderate fall and a fair discharge at their lowest stage, for with a large fall the current presents a great impediment to up-stream navigation, and there are generally great variations in water level, and when the discharge becomes very small in the dry season. There are many tourist places in UAE like theme parks, beach, malls etc. which attract foreigners. Many small rivers, like the Thames above its tidal limit, have been rendered navigable by canalization, and several fairly large rivers have thereby provided a good depth for vessels for considerable distances inland. Emerging technologies in power engineering include the development of smart grids, microgrids, and advanced energy storage systems like lithium-ion batteries and hydrogen fuel cells, which are central to the future of renewable energy integration.

Reliability engineering is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. The reliability function is theoretically defined as the probability of success. Reliability is closely related to availability, which is typically described as the ability of a component or system to function at a specified moment or interval of time. Other engineering skills including system design, installation planning, cellular coverage planners and many others will be needed as well. Price indexes are available for the output of many industries (including expanding coverage of the service sector) and more than 10,000 specific products and product classes. Trees harvested at a younger age produce smaller logs, and these can be turned into lower-value products. Another is to restrict water to a certain area of a stream’s natural bottom lands so that the bulk of such lands can be made available for agriculture. However, leakage detection and control can prevent the issue and can enable you to keep the appliance in good working condition. Professional companies always do the repair with the original parts to offer extended warranty of the appliance to their owners so you should find one that assures you the use of branded products.