Development of titanium dioxide nanoparticles/nanosolution for photocatalytic activity

Biological and chemical contaminants by man-made activities have been serious global issue. Exposure of these contaminants beyond the limits may result in serious environmental and health problem. Therefore, it is important to develop an effective solution that can be easily utilized by mankind. One of the effective ways to overcome this problem is by using titanium dioxide (TiO2). TiO2 is a well-known photocatalyst that widely used for environmental clean-up due to its ability to decompose organic pollutant and kill bacteria. Although it is proven TiO2 has an advantage to solve this concern, its usefulness unfortunately is limited only under UV light irradiation. Therefore, the aim of this work was to investigate the potential of TiO2 that can be activated under visible light by the incorporation of metal ions (Fe, Ag, Zr and Ag-Zr). In this study, sol-gel method was employed for the synthesis of metal ions incorporated TiO2. XRD analysis revealed that all samples content biphasic anatase-brookite TiO2 of size 3 nm to 5 nm. It was found that the incorporation of these metal ions did not change the morphology of TiO2 but the crystallinity and optical properties were affected. The crystallinity of anatase in the biphasic TiO2 was found to be decreased and favored brookite formation. PL analysis showed metal ions incorporation suppressed the recombination of electron-hole pairs while the band gap energy of TiO2 (3.2 eV) was decreased by the incorporation of Fe (2.46 eV) and Ag (2.86 eV). Among this incorporation, Ag-Zr incorporated TiO2 showed highest performance for methyl orange degradation (93%) under fluorescent xxv light irradiation for 10 h. This follows by Zr-TiO2 (82%), Fe-TiO2 (75%) and Ag�TiO2 (43%). Meanwhile, the highest antibacterial performance was exhibited by Ag�TiO2. TEM images showed that E.coli bacterium was killed within 12 h after treated with Ag-TiO2. The results obtained from the fieldwork study established that Ag-Zr incorporation have excellent performances for VOC removal and antibacterial test. The VOC content after treated with Ag-Zr-TiO2 fulfilled the Industry Code of Practice on Indoor Air Quality 2010 which is lower than 3 ppm. In addition, the percentage of microbes also found to be decrease around 45 % within 5 days of monitoring

The development of building assessment criteria framework for sustainable non-residential buildings in Saudi Arabia

To quantify the environmental impacts of building construction, many environmental assessment methods for measuring building performance have been proposed worldwide, such as BREEAM (UK), LEED (US) and Green Star (AU). However, much debate exists about the efficacy of these international assessment tools in measuring building performance outside their country of origin, due to global variations in climate, geography, economics and culture. To address this debate, this study proposes a framework for developing domestic sustainable non-residential building assessment criteria for Saudi Arabia. To create this framework, five major building assessment methods were compared with respect to their application methods, major characteristics and categories. Surveys were conducted with a range of Saudi sustainable construction experts to gain their expertise in reflecting the local context of Saudi Arabian construction. The analytical Hierarchy Process (AHP) method was applied to evaluate survey data. Nine criteria and 36 sub-criteria were defined in this study for inclusion as the most appropriate assessment criteria for sustainable non-residential construction in Saudi Arabia. These criteria include water efficiency and energy efficiency, indoor air quality, materials selection, effective management, land and waste, whole-life cost, quality of service and cultural aspects

Project procurement system selection model (with particular reference to Saudi Arabia)

In the last two decades there has been a significant change in the technical and economic conditions prevailing in the construction industry. The traditional methods of procuring projects are now inadequate to cope with these changes. To overcome the shortcomings of the traditional procurement methods, the construction industry has developed a large number of different procurement systems to secure the relationships between contract parties. The proliferation of different procurement systems has created the problem of how to determine the optimum procurement system for any particular project. A systematic approach for selection of the most appropriate system is now needed. Throughout this thesis an investigation has been made of many of the issues related to the successful formulation of a Project Procurement System Selection Model (PPSSM). The knowledge of client needs in the construction industry is essential to the project success. This research has considered the fundamental role played by client needs in the process of procurement selection. The various categories of procurement system that exist in the construction industry are presented in order to address the benefits and drawbacks of each system. A careful investigation of the rules and regulations governing the Saudi construction industry has contributed very significantly to the success of the model building. An examination of the existing models revealed a number of drawbacks which are discussed in detail in this research. A survey was conducted in Saudi Arabia with the aim of testing the PPSSM for effectiveness and efficiency and assisting the governmental agencies to select the most appropriate procurement system to implement their projects. For this purpose, a questionnaire was developed and divided into three major parts: Background information; Data needed to operate PPSSM; and Evaluation of the criteria used for the selection of the procurement system. The results of the first and third parts are generated from 100 responses to the questionnaire mailed to the 110 governmental agencies that represent the population of the study, giving an overall response of (91%). For the second part only thirty senior government agency officers were involved in order to maintain consistency of data needed to operate the PPSSM. The data were analyzed using computer statistical packages: Excel and Statistical Analysis System (SAS). On the basis of the synthesis process of the PPSSM, Saudi public clients have selected "design and build" as the most appropriate procurement system to procure their projects with an overall priority of 0.49. Design and manage, construction management, and management contracting ranked second, third and fourth with priorities of 0.258, 0.140 and 0.106 respectively. The outcome of the study demonstrates the effectiveness of PPSSM in helping the client in the construction industry to choose the right procurement system that best answers his needs and fulfills the project requirements

PROJECT DELIVERY SYSTEM DECISION FRAMEWORK USING THE WEIGHTING FACTORS AND ANALYTIC HIERARCHY PROCESS METHODS

There is a range of contract types and project delivery systems (PDS) that owners can use in executing facilities. Examples include the traditional Design-Bid-Build (DBB) process, Design-Build (DB) and Construction Management-at-Risk (CM-R). A number of owners in Saudi Arabia, particularly governments, prefer some form of competitive bidding (typically the DBB method), and most of the time they insist on it. However, the use of non-traditional delivery systems is increasing, and the system variations are becoming numerous. The selection of project delivery system influences the entire life-cycle of a construction project, from concept through construction into operation and decommissioning. Owners, engineers, contractors, material suppliers and laborers are all affected by the decisions that owners make concerning project delivery systems. Owners need to assess what type of construction services procurement program is best suited to their needs. Selecting a PDS means choosing the best delivery system to carry out a particular project, which is not always an easy and clear decision. The success or failure of a project can depend on the project delivery method, and whether the method is suited to the project. There are many factors and parameters or key considerations, such as cost (budget), time (schedule), quality (level of expertise), risk assessment (responsibility) and safety which determine whether a particular style of PDS is suited to a project. A model is a representation of a real or planned system and can be used as an aid in choosing a PDS. The purpose of this research is to try to develop a project delivery system decision framework (PDSDF) by identifying the factors and parameters that have to be considered in such a model. A survey was conducted to determine the values of factors and key parameters from completed projects. The research attempts to identify patterns of project factors, owner objectives, and project parameters that could best be met by one or another PDS. This model is intended to be very easy for owners to use, while at the same time providing meaningful results that can be used in making a selection of a suitable project delivery system.A weighting factors approach and the analytic hierarchy process (AHP) was used to construct the decision framework. In this process the relative advantages of the three project delivery systems are compared according to each criterion. The relative importance of the criterion is determined on the basis of the owner's needs and project characteristics. The results of comparing the three delivery systems according to each criterion and of determining the order of importance among the criteria were integrated into a model to help the owner reach a decision about which project delivery system he should adopt

Assessment of Energy Systems Using Extended Fuzzy AHP, Fuzzy VIKOR, and TOPSIS Approaches to Manage Non-Cooperative Opinions

Energy systems planning commonly involves the study of supply and demand of power, forecasting the trends of parameters established on economics and technical criteria of models. Numerous measures are needed for the fulfillment of energy system assessment and the investment plans. The higher energy prices which call for diversification of energy systems and managing the resolution of conflicts are the results of high energy demand for growing economies. Due to some challenging problems of fossil fuels, energy production and distribution from alternative sources are getting more attention. This study aimed to reveal the most proper energy systems in Saudi Arabia for investment. Hence, integrated fuzzy AHP (Analytic Hierarchy Process), fuzzy VIKOR (Vlse Kriterijumska Optimizacija Kompromisno Resenje) and TOPSIS (Technique for Order Preferences by Similarity to Idle Solution) methodologies were employed to determine the most eligible energy systems for investment. Eight alternative energy systems were assessed against nine criteria—power generation capacity, efficiency, storability, safety, air pollution, being depletable, net present value, enhanced local economic development, and government support. Data were collected using the Delphi method, a team of three decision-makers (DMs) was established in a heterogeneous manner with the addition of nine domain experts to carry out the analysis. The fuzzy AHP approach was used for clarifying the weight of criteria and fuzzy VIKOR and TOPSIS were utilized for ordering the alternative energy systems according to their investment priority. On the other hand, sensitivity analysis was carried out to determine the priority of investment for energy systems and comparison of them using the weight of group utility and fuzzy DEA (Data Envelopment Analysis) approaches. The results and findings suggested that solar photovoltaic (PV) is the paramount renewable energy system for investment, according to both fuzzy VIKOR and fuzzy TOPSIS approaches. In this context our findings were compared with other works comprehensively.This research was funded by the Deanship of Scientific Research (DSR) at King Abdulaziz University, Jeddah, under grant no. (RG-7-135-38). The authors, therefore, acknowledge with thanks DSR technical and financial support

The development of sustainable assessment method for Saudi Arabia built environment

Our built environment is responsible for some of the most serious global and local en- vironmental change. The construction industry therefore faces pressure to increase the sustainability of its practices re ected in the development of stringent regulations and sustainability assessment methods, designed to mitigate such negative impacts. How- ever, the well-established methods (e.g. BREEAM, LEED, SBTool, and CASBEE) have not originally been designed to suit developing countries (including Saudi Arabia). This study therefore proposes to customize an adapted Saudi Environmental Assessment Method (SEAM). This study to begin with investigates the most important and globally widespread environmental assessment methods: BREEAM, LEED, SBTool, and CAS- BEE. It identifes areas of convergence and distinction in order to enable the consolida- tion of environmental criteria into new potential schemes. As sustainable and ecological context are usually regarded as multi-dimensional, scientific evidence proposes that a technique based on consensus is most appropriate for the establishment of inclusive and efficient building environmental assessment schemes. Therefore, a consensus based ap- proach is used to deliver: (a) applicable assessment categories and criteria for the Saudi Arabia context and (b) its weighting system. Hence, the Delphi technique and Ana- lytic Hierarchy Process (AHP) are selected and conducted in four successive systematic consultation rounds, involving world leading experts in the domain of environmental and sustainable assessment schemes, as well as professionals and highly-informed local experts from academia, government and industry. These two stages resulted in the development of SEAM criteria and its weighting system

Optimal Design and Analysis of Grid-Connected Solar Photovoltaic Systems

Many countries consider utilizing renewable energy sources such as solar photovoltaic (PV), wind, and biomass to boost their potential for more clean and sustainable development and to gain revenues by export. In this thesis, a top-down approach of solar PV planning and optimization methodology is developed to enable high-performance at minimum costs. The first problem evaluates renewable resources and prioritizes their importance towards sustainable power generation. In the second problem, possible sites for solar PV potential are examined. In the third problem, optimal design of a grid-connected solar PV system is performed using HOMER software. A techno-economic feasibility of different system configurations including seven designs of tracking systems is conducted. In the fourth and the final problem, the optimal tilt and azimuth angles for maximum solar power generation are found. Using a detailed estimation model coded in MATLAB software, the solar irradiation on a tilted angle was estimated using a ground measurement of solar irradiation on a horizontal surface. A case study for Saudi Arabia is conducted. The results of our prioritization study show solar PV followed by concentrated solar power are the most favorable technologies followed by wind energy. Using a real climatology and legislation data, such as roads, mountains, and protected areas, land suitability is determined via AHP-GIS model. The overlaid result suitability map shows that 16% (300,000 km2) of the study area is promising for deploying utility-size PV power plants in the north and northwest of Saudi Arabia. The optimal PV system design for Makkah, Saudi Arabia shows that the two-axis tracker can produce 34% more power than the fixed system. Horizontal tracker with continuous adjustment shows the highest net present cost (NPC) and the highest levelized cost of energy (LCOE), with a high penetration of solar energy to the grid. At different tilt and azimuth angles, the solar irradiation, potential power, and system revenue were calculated for 18 cities in Saudi Arabia. For Riyadh city (high suitable site), the monthly adjustment increases the harvested solar energy by 4%. It is recommended to adjust the tilt angle five times per year to achieve near-optimal results and minimize the cost associated with workforce or solar trackers for monthly adjustments. The proposed work can be exploited by decision-makers in the solar energy area for optimal design and analysis of grid-connected solar photovoltaic systems