275 research outputs found
Flood Simulation Models for a River System in a Tropical Region: The Case of Linggi River, Malaysia
Flooding of a river system in a tropical region is predicted using
mathematical simulation models in this study. The proposed models were
categorized as hydrologic model, hydraulic model and sedimentation model.
Two methods of hydrologic models were used to simulate the peak:
streamflow in a river system of a tropical region. The first hydrologic model is the
river model, which is a first order linear autoregressive model, AR(1). The second
hydrologic model is called the basin model which is a deterministic model based on
a linear relationship between rainfall and runoff. The basin model is also described
as a distributed model in which the river basin is divided into a number of
subbasins whereby the rainfall and the runoff at each subbasin is simulated
separately and then combined to get the river basin response. The Linggi River
system in Seremban, Malaysia was used as a case study. The Linggi River system consists of a main river which is called Linggi, and it's six tributaries called the
Batang Penar, Paroi, Temiang Diversion, Temiang, Anak Rasah and Kepayang.
The total catchment area of the Linggi River system up to the point of interest is
127.7 km2. Recorded hydrologic data for the Linggi River basin was used in the
evaluation and testing of the proposed models. Models evaluation involved
calibration, verification and sensitivity analysis. Models testing was implemented
using the Theil's technique. The calculated value of Theil's coefficient was 0.028,
0.17 and 0.01 for the basin model, river model and the hydraulic model
respectively. A computer program was written to especially perform the
calculations of the basin model. This computer program is called BSHYMD
Evaluation of yield and groundwater quality for selected wells in Malaysia
In Malaysia, the use of groundwater can help to meet the increasing water demand. The utilization of the aquifers is currently contributing in water supplies, particularly for the northern states. In this study, quantitative and qualitative assessments were carried out for the groundwater exploitation in the states of Kelantan, Melaka, Terengganu and Perak. The relevant data was acquired from the Department of Mineral and Geoscience, Malaysia. The quantitative assessment mainly included the determination of the use to yield ratio (UTY). The formula was proposed to determine the UTY ratio for aquifers in Malaysia. The proposed formula was applied to determine the maximum UTY ratios for the aquifers located in the states of Kelantan, Melaka, and Terengganu, and were found to be 4.2, 5.2 and 0.6, respectively. This indicated that exploitation of groundwater was beyond the safe limit in the states of Kelantan and Melaka. The qualitative assessment showed that the groundwater is slightly acidic. In addition, the concentrations of iron and manganese were found to be higher than the allowable limits, but the chloride concentration was found within the allowable limit
Groundwater engineering and geotechnique
This book comprises nine chapters designed to cover the syllabus of the subject of Groundwater Hydraulics with some theory and application which is considered important for civil engineers. Post graduate students, and researchers. Many topics covered in this book are useful for undergraduate students doing the Civil Engineering programme. Information on the history of groundwater, the geological formation of aquifers and groundwater utilisation is also included in this book
The Effects of Website Quality on Adoption of E-Government Service: An Empirical Study Applying UTAUT Model Using SEM
In today’s global age, e government services have become the main channel for online communication between the government and its citizens. They aim to provide citizens with more accessible, accurate, real time and high quality services. Therefore, the quality of government websites which provide e services is an essential factor in the successful adoption of e government services by the public. This paper discusses an investigation of the effect of the Website Quality (WQ) factor on the acceptance of using e government services (G2C) in the Kingdom of Saudi Arabia (KSA) by adopting the Unified Theory of Acceptance and Use of Technology (UTAUT) Model. Survey Data collected from 400 respondents were examined using the structural equation modelling (SEM) technique and utilising AMOS tools. This study found that the factors that significantly influenced the Use Behaviour of e government services in KSA (USE) include Performance Expectancy (PE), Effort expectancy (EE), Facilitating Conditions (FC) and Website Quality (WQ), while the construct known Social Influence (SI) did not. Moreover, the results confirm the importance of quality government websites and support systems as one of the main significant and influential factors of e government services adoption. The results of this study can be helpful to Saudi’s governmental sectors to adjust their corporate strategies and plans to advance successful adoption and diffusion of e government services (G2C) in KSA
Study the Performance of Dissolved Air Flotation as Industrial Wastewater Treatment Method
This research aimed to study the removal efficiency of oilpollutant from industrial wastewater by dissolved-air flotation (DAF)with and without chemical coagulants. The sample test of wastewater isdischarged from Daura Refinery. The performance of dissolved airflotation for example saturation pressure and recycle ratio were studied.The industrial wastewater treated by DAF is carried out with two typesof chemical coagulants: Alum and Polyacrylamid. The treatment methodof wastewater by DAF with and without chemical coagulants and theireffect on the removal efficiency of oil, results were obtained at differentparameters such as saturation pressure (2,5-5.5atm) and recycle ratio(20-50). It has been found the oil removal efficiency (R %) increases withincrease in recycle ratio (R.R) and saturation pressure (P). Themaximum oil removal efficiency in DAF unit without coagulants is foundto be equal to 60%, while with polyacrylamide coagulants is equal to 94,90 %, while with alum coagulants is equal to 89, 82 % and withcombination of alum+ polyacrylamide coagulants is equal to 98.96,95.5 % for initial oil concentration (Co) 50, 200 ppm respectively. Theexperimental results were indicated the removal efficiency of oil by usingpolyacrylamide as alone is more effective than adding alum butcombination of them, resulted improvement in removal efficiency. Theexperimental results of DAF process with coagulants are expressed indevelop general empirical correlation by chemical cad in computerprogram
Innovation in prediction planning for anterior open bite correction
This study applies recent advances in 3D virtual imaging for application in the prediction planning of dentofacial
deformities. Stereo-photogrammetry has been used to create virtual and physical models, which are creatively combined in
planning the surgical correction of anterior open bite. The application of these novel methods is demonstrated through the surgical
correction of a case
Adaptation techniques in optical wireless communications
The need for high-speed local area networks to meet the recent developments
in multimedia and video transmission applications has recently focused interest
on optical wireless communication. Optical wireless systems boast some
advantages over radio frequency (RF) systems, including a large unregulated
spectrum, freedom from fading, confidentiality and immunity against
interference from electrical devices. They can satisfy the dual need for mobility
and broadband networking. However, optical wireless links are not without
flaws. They are affected by background noise (artificial and natural light
sources) and suffer from multipath dispersion. The former can degrade the
signal-to-noise ratio, while the latter restricts the maximum transmission rate
available.
The aim of this thesis is to investigate a number of techniques to overcome
these drawbacks and design a robust high-speed indoor optical wireless system
with full mobility. Beam delay and power adaptation in a multi-spot diffusing
system is proposed in order to increase the received optical signal, reduce the
delay spread and enable the system to operate at higher data rates. The thesis
proposes employing angle diversity receivers and imaging diversity receivers as
in order to reduce background noise components. Moreover, the work
introduces and designs a high-speed fully adaptive optical wireless system that
employs beam delay, angle and power adaptation in a multi-spot diffusing
configuration and investigates the robustness of the link design in a realistic
indoor office. Furthermore, a new adaptive optical wireless system based on a
finite vocabulary of stored holograms is introduced. This method can effectively
optimise the spots’ locations and reduce the design complexity of an adaptive
optical wireless system. A fast adaptation approach based on a divide-andconquer
methodology is proposed and integrated with the system to reduce the
time required to identify the optimum hologram. The trade-off between complexity and performance enhancement of the adaptive finite holograms
methods compared with the original beam power and angle adaptation is
investigated
The effects of website quality on adoption of e-government service : an empirical study applying UTAUT model using SEM
In today’s global age, e-government services have become the main channel for online communication between the government and its citizens. They aim to provide citizens with more accessible, accurate, real-time and high quality services. Therefore, the quality of government websites which provide e-services is an essential factor in the successful adoption of e-government services by the public. This paper discusses an investigation of the effect of the Website Quality (WQ) factor on the acceptance of using e-government services (G2C) in the Kingdom of Saudi Arabia (KSA) by adopting the Unified Theory of Acceptance and Use of Technology (UTAUT) Model. Survey Data collected from 400 respondents were examined using the structural equation modelling (SEM) technique and utilising AMOS tools. This study found that the factors that significantly influenced the Use Behaviour of e-government services in KSA (USE) include Performance Expectancy (PE), Effort expectancy (EE), Facilitating Conditions (FC) and Website Quality (WQ), while the construct known Social Influence (SI) did not. Moreover, the results confirm the importance of quality government websites and support systems as one of the main significant and influential factors of e-government services adoption. The results of this study can be helpful to Saudi’s governmental sectors to adjust their corporate strategies and plans to advance successful adoption and diffusion of e-government services (G2C) in KSA.<br /
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