Akarsular üzerindeki köprülerin menbasında oluşan kabarma miktarının hesabında U. S. Federal Highway Administration ve U. S. Army Corps Of Engineers HEC- 2 yöntemlerinin Türkiye' deki bazı köprüler için karşılaştırılması

TEZ2129Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 1996.Kaynakça (s. 41-43) var.vii, 86 s. ; 30 cm.…Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi Tarafından Desteklenmiştir. Proje No: FBE. 95. E. 158

Modeling nitrate concentrations in a moving bed sequencing batch biofilm reactor using an artificial neural network technique

In this study, the performance data of a moving-bed sequencing batch biofilm reactor (MBSBBR) treating synthetic wastewater were simulated using multi-layer perceptron neural-network technique. Multi-linear regression (MLR) technique is also used for a comparison. The performance of MBSBBR was evaluated using these models for a set of experimental results obtained from a model reactor operated with different cycle times and temperatures. The experimental data were retrieved from a previous reported work. Operational time, temperature, ammonium nitrogen, and pH were used as inputs for modeling, whereas nitrate concentration was the output variable. The results of the models were compared using statistical criteria, such as mean square error, mean absolute error, mean absolute relative error, and determination coefficient (R2). The results showed that the multi-layer perceptron neural-network produced more accurate results than those of MLR, although the latter gave reasonable results

Experimental analysis of stage-discharge relationship in compound channels

Pürüzsüz bir ana yatak ve pürüzlü iki taşkın yatağından oluşan simetrik bileşik kesitli bir deney düzeneği üzerinde, seviye-debi ve seviye-direnç ilişkisini araştırmak amacıyla bir dizi deney yapılmıştır. Çalışmada hem ana yatak akımı hem de taşkın akımı incelenmektedir. Sonuçlar daha önce aynı deney düzeneği üzerinde çalışma yapan diğer araştırmacıların sonuçlarıyla karşılaştırılmaktadır. Her bir durum için seviye-debi ilişkisini veren ve deneysel bulgulara dayanan basit bir üstel regresyon modeli önerilmektedir.A series tests of experiments were conducted concerning stage - discharge and stage-resistance relationships in an symmetric compound channel comprising of one rectangular main channel and two rough floodplain. Both inbank and overbank flow are investigated. The results are compared with the additional data collected from the work of some other researchers who studied at the same flume. A simple power fit regression model is proposed and derived from experimental data for each ease to obtain stage-discharge relationship in open channels

Influence of the mobile main channel bed on the boundary shear stress in a compound channel

Bu çalışmada, bir ana yatak ve bir veya iki adet rijit taşkın yataklarından meydana gelen bileşik kesitli bir deney düzeneği üzerinde "cidar kayma gerilmesi" ve "cidar kayma kuvveti" dağılımları deneysel olarak incelenmiştir. Deneylerde rijit (rigid) ve hareketli (mobile) ana yatak tabanı yapay olarak oluşturulduktan sonra herbir durum için "cidar kayma gerilmesi" dağılımları ayrı ayrı incelenerek bir karşılaştırması yapılmıştır. Aynı zamanda hareketli (mobile) ana yatak tabanının, bileşik kesitli yataktaki momentum transferi, cidar kayma gerilmesi ve cidar kayma kuvveti dağılımları üzerine etkisi irdelenmiştir.In this study, experimental results are presented concerning boundary shear stress and boundary shear force distributions in a compound channel comprising of one river main channel and one or two symmetrically disposed smooth floodplains. A comparison is made between the boundary shear stresses on the main channel bed for channels having rigid or mobile beds of the same geometry. The influence of the mobile main channel bed on the momentum transfer between the main channel and floodplains and on the boundary shear stresses and forces in compound channels were explored

Boundary shear stress analysis in smooth rectangular channels and ducts using neural networks

An artificial neural network (ANN) model was developed to predict boundary shear force distributions in smooth rectangular channels and ducts. Currently the designers often obtain these values with the help of semi-empirical methods. In this paper, as an alternative to these methods, a neural network model is presented. The model was trained and tested using 94 experimental data obtained from the works of best known researchers in this field. The proposed ANN model was found to be superior to existing methods for most of the data sets studied

Contraction and expansion losses through bridge constrictions

The U.S. Federal Highway Administration (FHA) method for computing bridge backwater was modified on the basis of significantly large prototype data (Neely 1966; Bradley 1978). Both the water surface profile and the backwater amount given by the original FHA method, which was developed after extensive laboratory model studies, differed appreciably from those recorded on natural reaches around highway bridges. Although a satisfactory explanation for this discrepancy was not given, most of the design charts of the FHA method were modified according to the prototype data (Bradley 1978). Here, a clear-cut explanation is given, and a modification for the bridge subroutine of the commonly used package program HEC-2 is suggested