Accuracy improvement of tropospheric delay correction models in space geodetic data. Case study: Egypt

The tropospheric delay still remains a limiting factor to the accuracy of space based positioning techniques. The estimation of station positioning, especially height component, which is particularly important for more applications is susceptible to errors in modeling the tropospheric delay due to correlations between the station positioning and residual troposphere delay parameters. As the demand on positioning accuracy and precision has increased, it has begun a necessary of relaying on large external data sets, rather than relatively simple models for treating the tropospheric delay. This method has been possible by advances made in numerical weather models which provide accurate representations of global atmospheric conditions and by advances in computing speed which allow us to perform a large number of computations over a short period of time. The purpose of this work is to develop a new model for estimating the tropospheric delay and then assess the benefits of applying this model at various geographic atmospheric conditions of Egypt. By comparing new model with some common models such as Saastamoinen model, Hopfield model, Niell-MF, Black & Eisner-MF, UNB3 model and Vienna-MF, the results show that, new model for estimation tropospheric delay has an acceptable level of accuracy in describing the dry tropospheric delay in Egypt as it agrees closely with the numerical integration based model. The mean accuracy of this new model has been assessed to be about 9.64 mm with rms 11 mm at an elevation angle of 30° and for an elevation angle of 5°, the mean accuracy is about 83.23 mm with rms 96.42 mm for atmospheric conditions of Egypt

Evaluating Performance of Different Filter Media Stratification for Tertiary Treatment of Wastewater

The use of treated wastewater for agricultural irrigation is one of the methods used to reduce the scarcity of fresh water. In this study, the different filtration media of sand, anthracite, granular activated carbon (GAC) and rice straw with a sub-base of gradual gravel supported each were used. In addition, the filtration efficiency was evaluated according to the treated water quality tests. As such, different filtration rates were parameterized to obtain the best operating conditions after ensuring that treated wastewater meets with the standard specifications for irrigation. The results indicated that the optimal filtration rate is 175 m / day, which achieves the appropriate quality of treated wastewater for the water characteristics examined according to the standard specifications of irrigation water. In addition, rice straw supported by a sand base is considered a practicable filtration media. However, the results of analyses of total solids in water did not match to Egyptian standards when using rice straw with sand as a filtration medium. Therefore, it is recommended to follow the filtration process using rice straw as a filtration medium with another stage of sand filtration to ensure the total solids comply with the standards

Bio-H2 conversion of wastewater via hybrid dark/photo fermentation reactor

Hydrogen energy is a clean source for liveliness betterthan fossil fuel that has hazardous effects on the environmentand atmosphere. Food wastes and organics in the sewage sludgeare a promising sustainable and renewable source for hydrogenproduction where amalgamation of waste treatment and energyproduction would be more than one benefit expressed intreatment of organic pollutants and energy generation.Discovering biohydrogen production from industrialwastewater by dark and photo fermentation was the main aimof this paper. The biogas produced was composed of H2 andCO2, and the maximum H2 content was 25.94%. This ratio wasachieved at batch configuration system and initial pH 6.2 withstarch concentration 15 g/l. Cause of using dark fermentationeffluent (DFE) was used as substrate for A Rhodobactercapsulatus strain and a clostridium culture were cultivated toproduce hydrogen under different light-dark cycles. Acetic andbutyric acids decreased due to first and second photo stages by21.9% and 4.1 % respectively. Maximum hydrogen yield was470.9 ml H2/mol VFAs

Comparative analysis of common full scale reactors for dry anaerobic digestion process

Organic solid wastes are produced with large amount wherever there are human activities. However, improper treated organic wastes made them as sources of diseases. On the other hand, these fractions contain nutrients and energy, so they have also valuable resources. As a result, exploring their potential as an energy source can be accomplish via anaerobic digestion process, in which, organics converted into hydrogen, methane and/or ethanol. Therefore, this manuscript introduces an overview of the common applied types of reactor that can handle these types of wastes in their solid state and recover them in term of biogas, as well as, stabilize the produced digestate to bio-fertilizers by compositing approach. A comparison also listed to demonstrate the optimum operational conditions and expected amount of biogas from each type

Multinomial Logit Utility Model for Tanta City Transportation System considering Ridesharing Mode

Recently, ridesharing has been noticed as an effective and sustainable mode of transport. In which, each passenger carries out a journey that benefits travelers and society greatly, such as reducing travel costs, reducing journey times, relieving road traffic congestions, preserving fuel and reducing air pollution. While the importance and efficiency of ridesharing, ridesharing among travelers has not been commonly utilized. This paper introduces an upgraded disaggregated utility model for a mode choice step in the four-step traffic demand model for transport of passengers in Tanta city - Gharbiya governorate. For the first time, the analysis in this paper includes ridesharing mode in addition to other three common modes; private vehicle, bus, and taxi . The aim of this research is to involve the ridesharing mode and new parameters in the mode choice analysis of the case study. This is done by including additional parameters such as travel cost and comfortable in addition to travel time. Based on surveys, the developed Multinomial logit utility models have been assessed using the McFadden pseudo R2 values. The values demonstrated high compatibility of results with real data as pseudo R2 values ranges between 0.2 and 0.4. In addition, all utility models developed for modes are found to have P-values less than 0.05 indicating the significance of the considered utility characteristics

Treatment of Industrial Oil and Soap Wastewater by Using the Application of Electrocoagulation Process

Electrocoagulation (EC) treatment of oily and soap industrial wastewater was studied in this paper. Operating parameters such as operating time, medium pH, voltage density, and electrode material and chemical oxygen demand (COD) are being investigated in oil and soap removal efficiencies. The maximum efficiency of COD removal is achieved using aluminum electrodes was 96.92%. The performance of EC using aluminum as the electrode exhibited better COD and oil-grease (O&G) removal than the iron electrode. EC is an extremely promising industrial wastewater treatment technique because it is simple, economic and less sludge production technology, especially for oil and soap wastewater. The optimum conditions to achieve high COD removal efficiency of about 96.92% in 30 min was found to be in using initial pH value range 2–3, and a voltage of 20 volts

Evaluation of change detection techniques for monitoring land-cover changes: A case study in new Burg El-Arab area

Accurate information about nature and extent of land cover changes especially in rapidly growing and new industrial cites is essential. New Burg El-Arab city, located to the west of Alexandria, Egypt has developed a new industrial community with a corresponding increase in urbanization and population. The objective of this research is to assess, evaluate and monitor the nature and extent of land cover changes in New Burg El-Arab city through the period from 1990 to 2000 using remotely sensed Landsat multispectral images. Four change detection techniques namely; post-classification, image differencing, image rationing and principal component analysis were applied. The objective is extended to examine the effectiveness of each change detection technique regarding not only the ability to differentiate changed from unchanged areas, but also the ability to classify the changed areas according to the “from-to” identifiers. The results indicated that the post classification change detection technique provided the highest accuracy while the principal component analysis technique gave the least accuracy. It is also found that the soil area has decreased by 37.02% while the urban and vegetation areas have increased by 16.55% and 20.50% respectively through the study period

Factors Affecting Accidents Risks among Truck Drivers In Egypt

Egypt is ranked among the countries with the highest rates of road accidents. According to the American Chamber of Commerce more than 96% of Egypt's goods are transported by trucks and due to their large volume and excessive weight, the severity and number of truck accident fatalities are much higher than other vehicles in Egypt. The present study aims at identifying truck driver's behavior and its influence on crash involvement. Due to the shortage in recording accident data and the inaccurate road accident audit, data was collected from several governorates in Egypt through questionnaire. Questionnaire forms were filled out through personal interviews with truck drivers. The total number of respondents was 643. The final analysis was made on the 615 questionnaires with complete answers. The data was analyzed and logistic regression was applied to accident related data to examine the contributing factors affecting accident occurrence of truck drivers. Results showed that fatigue in terms of driving hours (continuous and total) and lack of sleep, drug use during driving, and driver obesity are the most influencing factors on the occurrence of truck accidents in Egypt. The findings of this research highlight the important role human factors have on the risk of crash involvement amongst Egypt's truck drivers and the need to improve their work conditions

Factors Affecting Accidents Risks among Truck Drivers In Egypt

Egypt is ranked among the countries with the highest rates of road accidents. According to the American Chamber of Commerce more than 96% of Egypt's goods are transported by trucks and due to their large volume and excessive weight, the severity and number of truck accident fatalities are much higher than other vehicles in Egypt. The present study aims at identifying truck driver's behavior and its influence on crash involvement. Due to the shortage in recording accident data and the inaccurate road accident audit, data was collected from several governorates in Egypt through questionnaire. Questionnaire forms were filled out through personal interviews with truck drivers. The total number of respondents was 643. The final analysis was made on the 615 questionnaires with complete answers. The data was analyzed and logistic regression was applied to accident related data to examine the contributing factors affecting accident occurrence of truck drivers. Results showed that fatigue in terms of driving hours (continuous and total) and lack of sleep, drug use during driving, and driver obesity are the most influencing factors on the occurrence of truck accidents in Egypt. The findings of this research highlight the important role human factors have on the risk of crash involvement amongst Egypt's truck drivers and the need to improve their work conditions

Power-Modified Kies-Exponential Distribution: Properties, Classical and Bayesian Inference with an Application to Engineering Data

We introduce here a new distribution called the power-modified Kies-exponential (PMKE) distribution and derive some of its mathematical properties. Its hazard function can be bathtub-shaped, increasing, or decreasing. Its parameters are estimated by seven classical methods. Further, Bayesian estimation, under square error, general entropy, and Linex loss functions are adopted to estimate the parameters. Simulation results are provided to investigate the behavior of these estimators. The estimation methods are sorted, based on partial and overall ranks, to determine the best estimation approach for the model parameters. The proposed distribution can be used to model a real-life turbocharger dataset, as compared with 24 extensions of the exponential distribution