Nasser A. Al-Azri

The occurrence of algal blooms in Omani coastal waters

Monthly sampling of phytoplankton, chlorophyll a, temperature, salinity and nutrients was carried out in the Sea of Oman and in the Arabian Sea, from 2004 and onwards. In addition to time series data, historical data from 1976 to 2003 were collected from the Ministry of Agriculture and Fisheries Wealth reports. Annual averages of algal blooms occurrence along the coast of Oman showed three major components of seasonal and interannual fluctuations- the seasonal cycle, interannual fluctuations with approximate period of 8 years, and the interannual rising tendency. The dominant algal blooms species comprise both diatoms and dinoflagellates, with obvious dominance of Noctiluca scintillans followed by Cochlodinium polykrikoides and Prorocentrum sp.

Comparative performance analysis of microjet impingement cooling models with different spent-flow schemes

Nomenclature As = surface area of the substrate base, m 2 d = diameter of the nozzle, m H = height of the channel, m h = heat transfer coefficient,W · m−2 · K−1 k = thermal conductivity,W · m−1 · K−1 lx, ly, lz = length, width, and height of the silicon substrate, respectively, m N = number of observation for calculating mean value n = number of jets P = pumping power, W p, Δp = pressure and pressure drop, respectively, Pa Q = volume flow rate, m · s−1 q = heat flux, W · m−2 Rth = thermal resistance, K · W −1 T, ΔT = temperature and temperature rise, respectively, K ts = thickness of the substrate base, m V = velocity vector, m · s−1 x, y, z = orthogonal coordinate system ρ = density, kg · m−3 σ = standard deviation, K

Development of bioclimatic chart for passive building design

The selection of building passive thermal design strategies is based heavily on the local climatic conditions. Identifying the best strategy for a given location can be made using bioclimatic charts. Such charts depend on the atmospheric pressure and are commonly available at sea level. Moreover, manual usage of these charts is cumbersome and time-consuming. In this work, the development of a bioclimatic chart for Muscat, as a case study, is described using Givonis zones in rigorous detail based on typical meteorological year (TMY) data. A generic calculation tool that generates the psychrometric chart for any altitude has been developed using MATLABTM, the procedure described herein, can be imitated on most scripting languages for any location using its atmospheric pressure and TMY data.

Abundance of harmful algal blooms in the coastal waters of Oman: 2006–2011

Over the last decade, the ecosystem of the Sea of Oman and Arabian Sea has been showing signs of rapid and profound changes in terms of phytoplankton diversity and harmful algal bloom outbreaks. Frequent blooms have been on the rise in the coastal waters of Oman causing adverse impacts on marine life. The population dynamics of potentially harmful phytoplankton in relation to environmental parameters was investigated from June 2006 to April 2011. Our studies recorded 24 potentially harmful species. Dinoflagellates Prorocentrum minimum, Scrippsiella trochoidea, Cochlodinium polykrikoides and Noctiluca scintillans were the most abundant species. Diatoms Pseudo-nitzschia seriata, Climacodium frauenfeldianum and Guinardia flaccida were the most abundant, but occurred at low concentrations. Scrippsiella trochoidea and Noctiluca scintillans were reported previously as common phytoplankton in Oman coastal waters; however, Prorocentrum minimum and Cochlodinium polykrikoides are reported for the first time. Here we report their occurrence and persistence in relation to changes in environmental parameters. In addition, the potential long-term implications of changes in phytoplankton species and harmful algal blooms outbreaks on ecological, economic, social and human health impacts will be discussed.

Investigating different diffuse solar radiation models to analyse solar radiation on inclined surfaces in Oman

In this paper, a detailed analysis of the solar radiation on horizontal and tilted surfaces for six locations in Oman is presented. The locations are (from North to South): Majis/Sohar, Sur, Fahud, Masira, Marmul, and Salalah. These locations spread over Oman and cover different types of landscape. The method is validated through the use of measured data. The effect of tilt angle and orientation on the incident solar radiation is presented along with optimum surface tilt angles and directions for maximum solar radiation collection in these six locations. The solar radiation models used in this paper show good agreement with measured data. The results presented in this paper are extremely useful for quick estimation of solar radiation for calculations of buildings’ cooling load and solar collector system performance. This can be easily extended for other locations with similar landscapes and geographical conditions.