सिविल और पर्यावरण इंजीनियरिंग जर्नल

Intermittent water distribution is the key problem of many water authorities in developing countries including Ethiopia. Hence, this research was conducted to carry out the hydraulic modeling of the Aksum town water distribution system which is located in the Central Tigray region of Ethiopia. The objectives of this research were to evaluate the hydraulic performance of the water supply distribution system by assessing the situation of the existing water supply distribution system. Water GEMS V8i software was used as a tool to model the water distribution system. The model can be used to identify the high pressure and low pressure in the junctions and the magnitude of velocity through pipes was used as a base to evaluate the hydraulic performance. Modeling results showed a violation of maximum and minimum pressure and low-velocity requirements. High pressures in the system occurred both during low demand and peak demand have to be identified. The simulation result of the existing system about 38.6% of the junctions was failed to satisfy the allowable pressure and the velocity of about 34.9% was failed out of range during the peak consumption hour. The model performance measures were checked based on the coefficient of determination. In general, it was concluded that the existing water distribution network systems of Aksum town categorized under satisfactory hydraulic performance situation and were not supply adequate water to various demand categories of the town. In the modified system, the network runs hydraulic parameters are radically improved using the Pressure Reducer Valve added in the system to reduce high-pressure impacts on water distribution system. The results of the simulation show that the hydraulic simulation about 43.4% of pipes of diameter from the total water distribution system pipe diameters needed to be upgraded.

Since the 1970s, research projects and field studies have been conducted on different methods for protecting corrosion damage. The methods include alternative reinforcement and slab design, barrier methods, electrochemical methods, and corrosion inhibitors. Each method and its underlying principles are described, performance results of laboratory and/or field trials are reviewed, and systems are evaluated based on the results of the trials. Using performance results from the studies and costs obtained from transportation agencies, an economic analysis is used to estimate the cost of each system over a 75 year economic life using discount rates of 2%, 4%, and 6%. Epoxy-coated reinforcing steel is the most common corrosion protection method used in the United States today. Although controversial in many areas, epoxy-coated reinforcement has performed well in many states, including Kansas, since it was introduced in the early 1970s and is a low-cost backup to many other corrosion protection options. Research on stainless steel reinforcement indicates that it may remain free of corrosion in chloride contaminated for more than 75 years. At a low discount rate (2%), solid stainless steel reinforcement is a cost- effective option compared to other options, but at higher discount rates (4%+), the present value cost of a deck with solid stainless steel is significantly higher than that of an unprotected deck. Stainless steel clad reinforcement is much less expensive than solid stainless steel reinforcement. The performance of stainless steel-clad reinforcement will be similar to that of solid stainless steel bars if the stainless steel coating is continuous and if the black steel core, exposed at the bar ends, is protected so that it does not come into contact with pore solution. The present value of the cost of a bridge deck built with stainless steel-clad reinforcement is significantly lower than the present value for the cost of any other corrosion protection system. This method should be considered for experimental use.

The optimal placement of the actuator for obtaining the best possible reduction in responses was a topic of interest for researchers. Many optimization techniques were used for obtaining the optimal reduction in responses. Placement of more than three actuators in building frame in practice is difficult and cumbersome. As a result, number of actuators to be placed in the frame is generally restricted as three. For optimization problem, involving three actuators, many computational problems are involved, namely, numerical stability, convergence of the solution, possibility of dynamic instability and in some cases, amplification of some response quantities. The above problems are generally encountered in many standard optimization techniques which are used for optimization. Further, some constraints may have to be imposed in the algorithm for floors where actuators cannot be placed for practical reasons. Under such circumstances, optimal placement of actuator is best achieved using the trial or iterative method.

Water is the most domineering diet for living things/Bisaan sagalee mootuu/ means of a vital to alive next to air. Then, the management of this most essential resource for living things is very important. Different traditional water technologies and management practices have used in various parts of the world since time immemorial. The practices are actually dependent on the local situations. Some linked with surface water and others with groundwater extraction and management. A typical example, which has used for long and widely known, called Qanat. Qanat is a traditional water extracting and transporting technique that commonly used in Middle East. However, in Borana community this term knows by the expression called “Finna Marraa Bisaanii ‘the rule of water and grass’. The Indigenous water resources management system of the Borana Community based on Gada system indigenous law of sources of water particularly for Tula-wells and ponds. Tula-Sallan is the permanent source of water in Borana. In Borana, Tula-wells owned by a distinct clan (tribe) and managed by the daily operation of the Tula-wells ‘Abba Herrega’. The Borana indigenous water management systems vary based on categorizations of water sources and Borana traditional livestock watering calendar. In Borana community except river and surface water sources, the remaining water sources have some sort of indigenous rules and regulations followed for anyone to get access to them.

Rwanda Government, via its Ministry of Infrastructure (MININFRA) and authority in charge of Water and Sanitation Corporation (WASAC) has instigated copious initiatives aimed at finding durable ensues to water scantiness in some country districts especially in Bugesera District. To date it lived by 453451 peoples with only 3600 m³/d available from Ngenda Water Treatment Plant (WTP) intents to treat cyohoha Lake. This research is conducted to handle water scantiness issues in Bugesera District with the aid of Gaharwa Lake. For attaining research directs, forms and onsite interrogates have been conducted, and Hazen–Williams equation has been used in designing processes. Therefore, the water treatment plant was designed with an awareness of water quality and quantity, population growth rate. Findings indicated that analyzed water quality parameters were bottled up by low turbidity: 4.2 NTU, Zn: 0.12 mg/L, NO₃: 0.4 mg/L, Manganese: 0.047 mg/L, NH₃-N: 0.04 mg/L, Fe²⁺: 0.61 mg/L, PH: 6.6, Fluoride: 0.11 mg/L, Alkalinity: 2 and Total hardness of 2.6 and water quantity should be 40723.8 m³/d. Additionally, The entire amount necessitated for the proposed Gaharwa WTP is 632,950.1957 USD. Eventually, Gaharwa Lake can be utilized as ensues to water scantiness in the Bugesera district. This research will greatly contribute to the lives of Rwandan people as well as Country Vision.