Dhahran City Research Articles

Energy and Economic Evaluation of Green Roofs for Residential Buildings in Hot-Humid Climates

Green roofs may be considered a passive energy saving technology that also offer benefits like environmental friendliness and enhancement of aesthetic and architectural qualities of buildings. This paper examines the energy and economic viability of the green roof technology in the hot humid climate of Saudi Arabia by considering a modern four bedroom residential building in the city of Dhahran as a case study. The base case and green roof modelling of the selected building has been developed with the help of DesignBuilder software. The base case model has been validated with the help of 3-month measured data about the energy consumption without a green roof installed. The result shows that the energy consumption for the base case is 169 kWh/m2 while the energy consumption due to the application of a green roof on the entire roof surface is 110 kWh/m2. For the three investigated green roof options, energy saving is found to be in the range of 24% to 35%. The economic evaluation based on the net present value (NPV) approach for 40 years with consideration to other environmental advantages indicates that the benefits of the green roof technology are realized towards the end of the life cycle of the building.

Unsteady analysis for solar-powered hybrid storage LiBr-water absorption air-conditioning

Hybrid (cold plus refrigerant) storage design for continuous (24-h a day) solar-powered LiBr-water absorption air-conditioning systems has many advantages. It can improve system performance, reduce collector size, lower storage tank capacity making the system more attractive. This paper analyzes the impact of unsteady solar conditions on operation parameters and system performance of a hybrid storage LiBr-water absorption air-conditioning chiller of 5kW cooling power during a few representative days in summer and winter in Dhahran City, Saudi Arabia. The system consists of flat-plate collector and absorption chiller with hybrid storage tanks (cold and refrigerant) in addition to an excess heat storage tank that might be needed to prevent crystallization. The results indicate that, under constant cooling load constraint, the coefficient of performance is better in winter; however, the required collector area and refrigerant storage tank size are smaller in summer.

The effectiveness of applying dynamic lane assignment at all approaches of signalized intersection

Existing traffic control strategies at signalized intersections aim at the optimization of signal timing parameters while assuming fixed lane assignments to the movements at each approach. Such control results in the waste of time-space resources especially at intersections where significant variations in the demand of turning and through traffic movements occur with time. Such demand variations with fixed space allocation per movement will lead to longer cycle lengths and excessive delays. This study aims to develop a model that integrates the optimization of space allocation (dynamic lane grouping) with the optimization of signal timing parameters for the whole intersection in order to improve its mobility. The effectiveness of dynamic lane grouping is evaluated using collected traffic data at an isolated signalized intersection in Dhahran City, Saudi Arabia. MATLAB environment is utilized to build the model in which the main outputs are the optimal lane group combinations and the optimal signal timing parameters that minimizes average intersection delay. The main input parameters are intersection geometry (mainly number of lanes, and median width) and traffic volumes for all movements. Based on number of lanes at each approach, possible lane group combinations are generated considering the possibility of having shared lanes. A comparison between fixed-lane grouping and dynamic lane grouping strategies in terms of average intersection delay and optimized cycle lengths is presented. It is concluded that operating isolated signalized intersections with controls that consider the optimization of space and time allocations simultaneously can substantially enhance their performance by significantly reducing intersection delay and queue lengths.

Morphological and Chemical Properties of Particulate Matter in the Dammam Metropolitan Region: Dhahran, Khobar, and Dammam, Saudi Arabia

Characteristics of airborne particulate matter (PM) as well as its levels in air samples collected from selected sites within cities of Dhahran, Khobar, and Dammam, in the Eastern Province of Saudi Arabia, are investigated. Concentration levels of the 10 microns’ PM (i.e., PM10) are determined using the gravimetric technique. Morphological and chemical characteristics of the PM collected from the sampling cities are studied using Field-Emission Scanning Electron Microscopy (FESEM), energy dispersive X-ray (EDX), and X-Ray Fluorescence (XRF). Moreover, levels and types of hazardous materials related to these samples are assessed using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). Results revealed that the average concentration levels of PM10 were approximately 177, 380, and 126 μg/m3 in Dhahran, Khobar, and Dammam, respectively. The structure of PM collected in Dhahran was mainly platy and rod-like shaped with a size between 2 and 6 μm, while PM collected in Khobar was mostly irregular in form, with a size range between 2 and 8 μm, and Dammam’s PM was rounded and between 1 and 3 μm in size. Both EDX and XRF results indicate relatively high weight % of C, O, Si, F, and Ca with lower weight % of Na, Mg, and K at the 3 cities. Finally, the study shows that Ba and Zn were the main trace metals associated with the collected PM in the 3 cities.

Modeling Monthly Average Temperature of Dhahran City of Saudi-Arabia Using Arima Models

Temperature is the coldness and hotness of the body and its unit is measured in Celsius. The data used for this research work is the average monthly temperature of Dhahran city which is located in the Kingdom of Saudi Arabia. The data range is from 1951 to 2010, and sample data of 1951 to 2008 was used for the estimation to choose the best model and the sample data from 2009 through 2010 was left for the forecast. Different models were tried but ARIMA (2, 1, 1) (0, 1, 1)12 is selected as the best model because of its low sic and aic criteria and also the forecast error, the best model is used for forecasting.

Community pharmacist and primary care physician collaboration: Themissing connection in pharmaceutical care.

Pharmaceutical care (PC) involves the active participation of the pharmacist in the improvement of the quality of life of the patient through the dispensation, counselling, and monitoring of drug therapy. Community pharmacists often encounter patients first, and, for some patients, the pharmacist is their only contact with a healthcare professional. It is easier and quicker for patients to contact a community pharmacist. However, there is a very limited or a total absence of PC services in community pharmacies of the KSA.To describe the inter-professional collaboration between primary care physicians and community pharmacists concerning PC services, a qualitative study was designed using a thorough, in-depth interview carried out in the cities of Dhahran and Dammam of the Eastern province of the Kingdom.

The Integration of Dynamic Lane Grouping Technique and Signal Timing Optimization for Improving the Mobility of Isolated Intersections

Spatial variations in traffic demand degrade intersection performance that can result in the waste of time–space resources. Existing control strategies of intersections assume fixed lane for movement assignment regardless of demand variations. Dynamic lane grouping (DLG) is one of the intelligent transportation systems techniques in which the lane allocation depends mainly on the real-time movement demand. The settings of intersection signal control depend on lane configuration where a demand-responsive lane allocation strategy will help in providing efficient signal operation with lower delays. This paper investigates the benefits of DLG technique in gaining improvements in the performance of isolated signalized intersections. A model that integrates the identification of optimum lane group combination and optimum signal timing parameters is developed. The objective function of the optimization model is based on the minimization of average intersection delay. A case study is conducted on an isolated signalized intersection in Dhahran city, Saudi Arabia. A comparison between the existing operation with fixed lane grouping and the proposed DLG is made in terms of average intersection delay, cycle length, and maximum lane volume-to-capacity ratio. It is concluded that DLG technique achieves significant reduction in average intersection delay that leads to significant improvement in mobility levels of signalized intersections.

Detection of Land Use/Land Cover Changes and Urban Sprawl in Al-Khobar, Saudi Arabia: An Analysis of Multi-Temporal Remote Sensing Data

While several studies examined land use and land cover changes in the central and western parts of Saudi Arabia, this study is the first to use remote sensing data to examine the decadal land cover changes in Saudi Arabia’s eastern coastal city of Al-Khobar between 1990 and 2013. Specifically, it utilized ISODATA classification method to classify Landsat TM, ETM+, and OLI data collected from 1990, 2001, and 2013 and then detected changes in the land cover within the study area. It then measured urban sprawl by calculating the relative Shannon’s entropy index values for the three years. With overall classification accuracies greater than 85%, the results show that urban built-up areas increased by 117% between 1990 and 2001 and 43.51% from 2001 to 2013. Vegetation increased by 110% from 1990 to 2001 and by 52% between 2001 and 2013. The entropy index values of 0.700 (1990), 0.779 (2001), and 0.840 (2013) indicates a high rate of urban sprawl and the city dispersing near the outskirts and towards the neighboring cities of Dhahran and Dammam. Future studies should examine the current challenges faced by the city’s residents due to urban expansion and attempt to find ways to resolve them in the near future.

Thermal analysis and modeling study of an activated carbon solar adsorption icemaker: Dhahran case study

Intermittent adsorption refrigeration systems are suitable for producing ice in remote areas. EES and MATLAB computer programs are exploited to analyze the thermodynamic cycle and to model the system under Dhahran climate conditions, respectively. The results show that the system performance in winter is better than in summer under the climate conditions for the city of Dhahran, Saudi Arabia. For example, the system produces below 3kg in the hot days and more than 5kg of ice per square meter of solar collector in the cold days with solar coefficient of performance (SCOP) that varies between 0.077 and 0.17, respectively.

Radiation modelling and performance evaluations of fixed, single- and double-axis tracking surfaces: a case study for Dhahran city, Saudi Arabia

This work overviews the solar radiation basics and insolation of different surfaces is presented. A complete solar radiation modelling and investigation on the effect of horizontal plate, yearly tilt, monthly tilt, and single-axis and double-axis tracking surface on the insolation are carried out to conduct performance evaluation using the case study in Dhahran city of Saudi Arabia. The increments received by insolation for the yearly tilt, monthly tilt, and single-axis and dual-axis tracking surface with respect to traditional flat-plate collector is estimated. The results show that the yearly optimal tilt angle due to the south is close to the 0.913 time latitude of Dhahran. It is found that the yearly irradiation gains using yearly and monthly optimal tilts relative to flat panel installation are 7% and 14%, respectively. The yearly insulation gains made by single-axis and dual-axis continuous tracking surfaces are 33% and 48%, respectively.

A New Study for Hybrid PV/Wind off-Grid Power Generation Systems with the Comparison of Results from Homer

This article presents the development of a computational model for the sizing optimization of an off-grid hybrid solar wind electric power generation system. The model includes a PV model, wind power model, and a model for the required battery. The developed mathematical model also comprises a model for a diesel generator as an alternative for the storage battery. A simulation code has been developed using MATLAB to solve the mathematical model and simulate the performance of the hybrid system with different configuration for performance analysis and optimal sizing purpose. The mathematical model and the computer code have been developed using a general approach. This approach can be used to simulate, analyze and optimize any hybrid solar/wind/battery/diesel off-grid electric power generation systems. Also, it can be utilized for any remote area in the world depending on the weather data used as input to the developed simulation code. The results obtained via the presently developed model and code have been validated against previously published work and also against that obtained via the widely used software (HOMER). The model is used for the sizing optimization and assessment of a hybrid solar wind system based on the weather conditions for Dhahran city in the eastern province of the Kingdom of Saudi Arabia.

Modeling, simulation and performance evaluation of a community scale PVRO water desalination system operated by fixed and tracking PV panels: A case study for Dhahran city, Saudi Arabia

In this work complete analytical modeling, simulation with experimental verification of photovoltaic system driving reverse osmosis water desalination is presented. In photovoltaic system, solar radiation and PV generation modeling is done and investigation of the effect of fixed and tracking PV panel on the collected insolation and PV power is carried out. In the RO section, complete model of RO membrane is developed that estimates the feed water pressure and permeate flow rate. The developed PV and RO models are validated individually as well as integrated (combined PVRO) by experimental data and show good agreement. By using this validated model the effect of slope and azimuth angle of the PV panel is studied on the permeate flow rate for the whole year. The increments in the clean water flow rate for the yearly tilt, monthly tilt, single and double axis tracking PV panels with respect to traditional flat panel is computed. The estimated results reveal that yearly optimal tilt angle of PV panels due south is close to the 0.913 times latitude of the Dhahran city. Yearly permeate gain with the yearly optimal tilt, monthly optimal tilt of PV panel relative to flat panel installation is 10% and 19% respectively. The optimization of photovoltaic system suggests the adjustment of the PV orientation (tilt angle and azimuth angle) by using a single and dual axis tracking system installations. The yearly permeate gain made by single and double axis continuous tracking PV panels is 43% and 62% respectively. • The detailed and comprehensive modeling of PVRO system is carried out and validated experimentally. • The validated PVRO model is used for permeate prediction with different fixed and tracked PV panels. • The yearly permeate gain made by single axe PV panels is 43% as compared to the flat PV panel PVRO. • The yearly permeate gain made by double axis tracking PV panels is 62% as compared to the flat PV panel PVRO.

Characteristics of organic compounds in aerosol particulate matter from Dhahran city, Saudi Arabia

Organic chemical pollutants in atmospheric particulate matter (PM) have a potential toxicity hazard resulting in human responses that vary from no discernible effect to premature death. The formation and sources of PM also affect air quality of metropolitan areas as well as climate change. The new developments and industrial activities in the Middle East, especially Saudi Arabia, are expected to contribute to the natural, regional, and anthropogenic input sources of organic matter (OM). Here we report the occurrence, concentrations and sources of organic tracers, including n-alkanes, polycyclic aromatic hydrocarbons (PAHs), plasticizers, and petroleum biomarkers, in ambient atmospheric PM from the city of Dhahran, Saudi Arabia. The major compounds were unresolved complex mixtures (UCM) of branched and cyclic hydrocarbons (489±296ngm−3), plasticizers (131±119ngm−3 for phenyl phosphates, 87±42ngm−3 for phthalates), n-alkanes (73±53ngm−3), hopane biomarkers (11±8ngm−3), n-alkanones (6.7±6.3ngm−3), PAHs (2.0±2.1ngm−3), n-alkanols (1.2±1.2ngm−3), sterane biomarkers (0.4±0.3ngm−3), and sterols (0.5±0.4ngm−3). Obviously, UCM and plasticizers were the major components (56±9% and 26±10% of the total extracts, respectively) in the PM of Dhahran, which might have adverse public health effects. The major sources of this OM are emissions from industrial factories north of the city, plastics and biomass burning, and petroleum product combustion (traffic/refining).

Global solar radiation in Northeastern Saudi Arabia

This paper presents the actual global solar radiation on a horizontal surface along with the prevailing meteorological conditions encountered during the measurement period from 1 January–31 December, for one complete year, in the Arabian Gulf Coast near the city of Dhahran. High resolution, real time solar radiation and meteorological data were collected, and processed. Hourly, daily, and monthly statistics of solar radiation was made from the one-minute averaged recorded values. The highest measured daily, and monthly mean solar radiation were found to be 351 and 328 W/m −2, respectively. The highest one-minute averaged solar radiation values up to 1183 W/m −2 were observed in the summer season, from May–September. The highest hourly solar radiation value was recorded as 1053 W/m −2 in the middle of June. Beside the global solar radiation measurements, the main observed meteorological parameters were temperature, pressure, wind speed, precipitation, and relative humidity. On the other hand, the estimation of daily and monthly mean global solar radiation was performed based upon two empirical formulas which relate the solar radiation to the sunshine duration, relative humidity, maximum temperature, the latitude of the monitoring location, sunset hour and declination angles. The agreement between the measured and estimated solar radiation values was found to be satisfactory. Nevertheless, the empirical formula under-estimates the solar radiation values during summer, and over-estimates during winter.

Characterizing Urban Storm Runoff Quality in Dhahran City in Saudi Arabia

The need to increase the water supply of the Kingdom of Saudi Arabia to keep up with the industrial and agricultural development cannot be overemphasized. Several ways exist to enhance the available supplies. One such method is the utilization of storm runoff from urban areas after appropriate treatment. In this study, the possibility of using urban runoff for industrial, irrigation, and other municipal uses after appropriate treatment is investigated. To achieve this, a representative urban watershed in the city of Dhahran was used and the runoff quantity and quality were determined over a four-year study period. The quality parameters considered were suspended solids (SS), total dissolved solids (TDS), alkalinity, hardness, chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), nitrite plus nitrate, phosphorous (P), chlorine (Cl), sulfate, grease and oil, coliforms, and heavy metals. The data obtained on the quantity and quality of the runoff in this city were further analyzed and the levels of treatment required for the various types of uses have been determined. The study showed that SS, COD, and coliforms were the major pollutants. Accordingly, the most feasible alternative is to convert the storm-drainage network to a sedimentation and temporary storage reservoir. If disinfected, the runoff water can be used for restricted irrigation.

High performance of a simple design, two effect solar distillation unit

Under a passive mode of operation, a transient analysis of a new, simple design, two effect solar distillation unit is presented. The unit consists mainly of a single sloped basin solar still of a shutter fashion type reflector, purging its vapor to a second effect still connected at the shaded side of the first effect still. Based on the energy balance for the different components of the two effects distillation unit, the hourly variation in the unit energies, temperatures, productivity, and efficiency was obtained. The effects of some design, operational, and environmental parameters on the distillation unit productivity are presented. On the basis of the numerical computations, it was observed that the unit first to the second effects volume ratio, the solar intensity, the base and side wall insulation, and the initial temperature of the basin water significantly influence the unit's productivity. The daily productivity increases to as high as 10.7 kg/m 2.d, for the proposed unit under the climatic conditions of the city of Dhahran, Saudi Arabia. The proposed distillation unit is simple, passive and adds no design, operation or maintenance complexities over the conventional single effect basin solar still.

Generation of representative weather—Year data for Saudi Arabia

In recent years, the computation of load and energy requirement in buildings, energy conservation studies in buildings, and the design of solar systems are not accomplished using long-term averages of weather data as inputs, but preferably with data-sets representative of the climatological features of the site that are generated for this purpose. Such data-sets are the test reference year, typical meteorological year and weather year for energy calculations. In this paper, the basis, the selection procedure and the use of each of these data-sets are discussed. Also, an attempt is made to generate typical weather years for the cities of Dhahran, Riyadh, Jeddah, Khamis-Mushayt and Hail, using the standard meteorological data obtained by measurements by the Meteorology and Environmental Protection Administration.

STORMWATER HARVESTING IN THE URBAN WATERSHEDS OF ARID ZONES1

ABSTRACT: A representative city in an arid zone, such as the Kingdom of Saudi Arabia, is instrumented to determine the quantity and quality of storm runoff with a view to investigating the possibility of using it for industrial and agricultural purposes after appropriate treatments. In an urban watershed in the City of Dhahran, Saudi Arabia, quantity and quality of storm runoff had been monitored for the past six years, and the average annual runoff that can be harvested was determined. The quality of runoff is well within the range of possible reuse schemes, most notably for restricted irrigation. Treatment schemes for the harvested water are proposed.

A computer study for estimation of seasonal energy consumption and selection of air-conditioner in six Saudi Arabian cities

A computer model was developed to simulate the building cooling load and the seasonal energy consumption of standard residential sized central air-conditioning systems. The model was first validated by comparing the predicted cooling energy consumption against the metered energy of a 100 m 2 residence. The model predicts within 10% of the metered value. The validated model was next used to compute the cooling load and seasonal energy consumption for similar 100 m 2 residences in six cities located in different climatic zones of Saudi Arabia. Simulations showed that the cities of Dhahran and Riyadh required a 17.6 kW system to satisfy the cooling load through the year, whereas the defined residences in the cities of Taif, Hail, Jeddah and Gizan required a 14.1 kW system. Our analysis showed that the selected residence in Gizan would consume 23,100 kWh annually, while a comparable residence located in Dhahran, having a more severe summer, required only 21,500 kWh. This difference may be explained by analysis of the weather data which revealed that Gizan required year-round cooling, whereas Dhahran needed cooling for only 283 days during the year. Investigation showed that, by selecting the next smaller capacity air-conditioning unit for each location than required to satisfy the load for 100% of the time, the annual power consumption may be reduced, on an average, by 10%, with about 7% of the hours during the cooling season when the air-conditioning load may not be satisfied.