Floristic composition of arid off –shore islands in Abu Dhabi,United Arab Emirates

Data on flora and vegetation of 14 off-shore islands representing different habitat types were studied for investigating floristic composition, vegetation types and correlation with their habitats and ecosystem. The results demonstrate considerable plant distribution and diversity among the islands within the limited spectrum of species; encompassing a total of 47 species, belonging to 43 genera under 24 families. The most representative families were Amaranthaceae (9 species), Fabaceae (4 species), Poaceae (4 species) and Asteraceae and Aizoaceae (3 species each). Fourteen families are represented by only one species. The mangrove species, Avicennia marina, occurs throughout the coast of Abu Dhabi in discontinuous patches and in different water salinities. The studies also seek to underline that dominant species that constitutes the flora of Abu Dhabi are salt tolerant in nature. Compared to other Arabian Peninsula ecosystems, UAE perhaps has a higher coastal: mainland area ratio, which has contributed to a natural dominance of salt tolerant species among the community. The studies show 40% similarity among islands with respect to the species diversity. The floristic composition of the off-shore islands also indicates a need to consider these sites as protected sites.     

Comparison effect of feedstock to inoculum ratios on biogas yields of cafeteria,vegetable, fruit wastes with cattle manure using co-digestion process

Cafeteria, vegetable, fruit, and cattle manure are available year around at low cost and have the potential to complement each other for anaerobic digestion (AD). The objectives of this study were to determine the preferred mixing ratios and effects of feedstock to inoculum ratios for the optimal biogas production. The mesophilic digestion tests were performed with five mixing ratios of CW, VW, FW with CM and five feedstock to inoculum (F/I) ratios using batch anaerobic digesters. Co-digestion of CW, VW, FW with CM was carried out at F/I ratios of 1.0, 2.0, 3.0, 4.0, and 5.0. The results showed that the F/I ratio significantly affected the biogas production rate. Increasing the CW, VW, FW in the CM resulted in an increased methane yield by decreasing the F/I ratios in the reactors from 5.0 to 1.0. The highest biogas yields of 591.3, 432.9, and 450.6 L/kg VS_feed were obtained with CW/CM (50:50), VW/CM (25:75), and FW/CM (25:75) ratios, respectively. At five F/Is tested, after 45 days of AD, the total biogas yields were determined to be 629.74, 552.64, 501.87, 464.66, and 396.04 L and 496.93, 460.02, 420.5, 398.14, and 336.20 L, and 455.03, 382.81, 349.78, 340.95, and 298.53 L, respectively. However, the highest average CH₄ contents obtained at an F/I of 1.0 were 62.14%, 60.72%, and 61.08% that are 5.87%, 9.47%, and 10.17% higher than those obtained at F/I ratio of 5.0 for CW/CM (50:50), VW/CM (25:75), and FW/CM (25:75), respectively.     

Toxicity of acidization fluids used in California oil exploration

There has been considerable public interest regarding the toxicity of chemicals used in hydraulic fracturing, but little is known about its sister technique, acidizing. Little to no research has been done on what the chemicals of acidization are and what impact they could have on humans and the environment. This paper discusses the differences between three acidizing techniques (acid maintenance, matrix acidization, and acid fracturing) and quantifies the amounts of the chemicals used for each. Washington State's Quick Chemical Assessment Tool is used to identify F-graded toxins, which are known carcinogens, mutagens, reproductive toxins, developmental toxins, endocrine disruptors, or high acute toxicity chemicals. The analysis of the present data shows that there have been over 600 instances of acidizing in urbanized Southern and Central California from April 2013 to August 2015. Although most of the chemicals of acidizing are similar to hydraulic fracturing, those used most frequently are different. There are close to 200 specific chemicals used in acidization, with at least 28 of them being F-graded hazardous chemicals. Some are used frequently in the range of 100–1000 kg per treatment, such as hydrofluoric acid, xylene, diethylene glycol, and ethyl benzene. Close to 90 more chemicals are identified using non-specific names as trade secrets or reported with no quantity. Unlike hydraulic fracturing the chemical concentrations in acidizing are high, ranging from 6% to 18%, and the waste returns can be highly acidic, in the range of pH 0–3. With this paper it is hoped that acidization becomes part of the larger discussion on concerns with oil exploration and be evaluated by appropriate authorities.     

Optimum design and evaluation of hybrid solar/wind/diesel power system for Masirah Island

This paper addresses the requirements of electrical energy for an isolated island of Masirah in Oman. The paper studied the possibility of using sources of renewable energy in combination with current diesel power plant on the island to meet the electrical load demand. There are two renewable energy sources used in this study, solar and wind energy. This study aimed to design and evaluate hybrid solar/wind/diesel/battery system in terms of cost and pollution. By using HOMER software, many simulation analyses have been proposed to find and optimize different technologies that contain wind turbine, solar photovoltaic, and diesel in combination with storage batteries for electrical generation. Four different hybrid power systems were proposed, diesel generators only, wind/diesel/battery, PV/diesel/battery, and PV/wind/diesel/battery. The analysis of the results shows that around 75 % could reduce the cost of energy by using PV/wind/diesel hybrid power system. Also, the greenhouse emission could be reduced by around 25 % compared with these by using diesel generators system that currently utilize in the Masirah Island. The solar/wind/diesel hybrid system is techno-economically viable for Masirah Island.     

Mapping air quality zones for coastal urban centers

This study presents a new method that incorporates modern air dispersion models allowing local terrain and land–sea breeze effects to be considered along with political and natural boundaries for more accurate mapping of air quality zones (AQZs) for coastal urban centers. This method uses local coastal wind patterns and key urban air pollution sources in each zone to more accurately calculate air pollutant concentration statistics. The new approach distributes virtual air pollution sources within each small grid cell of an area of interest and analyzes a puff dispersion model for a full year’s worth of 1-hr prognostic weather data. The difference of wind patterns in coastal and inland areas creates significantly different skewness (S) and kurtosis (K) statistics for the annually averaged pollutant concentrations at ground level receptor points for each grid cell. Plotting the S-K data highlights grouping of sources predominantly impacted by coastal winds versus inland winds. The application of the new method is demonstrated through a case study for the nation of Kuwait by developing new AQZs to support local air management programs. The zone boundaries established by the S-K method were validated by comparing MM5 and WRF prognostic meteorological weather data used in the air dispersion modeling, a support vector machine classifier was trained to compare results with the graphical classification method, and final zones were compared with data collected from Earth observation satellites to confirm locations of high-exposure-risk areas. The resulting AQZs are more accurate and support efficient management strategies for air quality compliance targets effected by local coastal microclimates.

Implications: A novel method to determine air quality zones in coastal urban areas is introduced using skewness (S) and kurtosis (K) statistics calculated from grid concentrations results of air dispersion models. The method identifies land–sea breeze effects that can be used to manage local air quality in areas of similar microclimates.     

Energy consumption and emission projection for the road transport sector in Malaysia: an application of the LEAP model

This study has attempted to estimate the energy consumption and emission of pollutants namely carbon dioxide (CO₂), carbon monoxide (CO), nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOC) from the road transport sector in Malaysia from the year 2012 till 2040. This was done using the long-range energy alternatives planning (LEAP) model. Estimates of energy consumption and emissions were evaluated and analysed under a business-as-usual scenario and three other alternative fuel policy scenarios of biodiesel vehicles (BIO), natural gas vehicles (NGV) and hybrid electric vehicles (HEV). The aim of this study has been to identify the potential alternative fuel policies that would be effective in reducing the future growth of road transport energy consumption and emission in Malaysia. Results indicate that the NGV scenario contributes towards the highest reduction in road transport energy consumption followed by BIO and HEV. The NGV scenario also achieves highest mitigation of emission of all the four pollutants. In the case of CO₂ emission, BIO scenario attains second highest mitigation, whereas in the event of CO, NOx and NMVOC emission, HEV scenario achieves second highest mitigation.     

Determination of the optimal land use allocation pattern in Nowshahr County,Northern Iran

Regional models of land use change are evaluated as a way of identifying land use pattern based on recent quantitative and probabilistic approaches. Differentiation between models in this area is the result of the approach to the concept of land use and type of indicators used in the modeling process. Since the determination of the optima land use pattern, due to the different uses of land based on the availability of regional capabilities and spatial difference in land use, depends on an integrated model, there must be a model that can assess the existing conditions of the region and present reasonable models of land use according to regional capacities and potentials. In this research, we developed a model to present the Optimal Land Use Allocation Pattern (OLUAP) for maximizing the advantages of change and determining the methods of influencing land use change priorities. This model uses spatial models and analysis, moderates the cost-benefit function, and calculates the allocation priorities of various areas based on regional conditions. The model results show that a wide scope of Nowshahr area is allocated to natural and agricultural uses. At the same time, a limited area has been assigned to urban and industrial uses. In addition, it shows that northern strip of the region due to higher accessibility of services and infrastructures is more suited than other regions to urban and industrial areas, and these two uses have first and second priority, respectively. Besides, according to the man-made environment and the special environmental conditions, the model allocates the central lowlands and southern parts sporadically to agricultural and natural areas as first and second priorities. Since the model is spatial optimization, the suggestions of the model show the OLUAP. Therefore, one can see the optimal condition for each plot and compare it with the existing land use.     

Upgrading of bio-oil from palm kernel shell by catalytic cracking in the presence of HZSM-5

Upgrading of bio-oil extracted from palm kernel shell (PKS) was performed using a lab-scale fixed-bed reactor with HZSM-5 as a catalyst. The catalytic cracking was carried out at optimized conditions: 0.3-MPa pressure, temperature of 500°C, and oil to catalyst ratio of 1:5. One of the challenges in upgrading bio-oil by catalytic cracking is deactivation of catalyst due to coke formation on catalyst surface. To overcome coke deposition, the upgrading process was carried out at 0.3-MPa pressure. Characterization of raw and upgraded bio-oil obtained through catalytic cracking was discussed in detail, indicating improvement in its physical properties. The distribution of products after cracking of bio-oil includes 58.89 wt% of organic liquid product, 15.63 wt% of aqueous fraction, 7.84 wt% of coke, and 17.64 wt% of gases. The degree of deoxygenation and calorific value of organic liquid product is 43.74% and 31.65 MJ/kg respectively. Organic liquid product obtained comprises 17.55% of hydrocarbons within the gasoline range. Hence, HZSM-5 proved its effectiveness for upgrading the bio-oil in a continuous mode.     

Age,Survivorship and Life Expectancy in Near Eastern Fire Salamander, <Emphasis Type="Italic">Salamandra infraimmaculata</Emphasis> (Caudata: Salamandridae)

Populations from different environmental habitats indicate variation in life history traits and these differences are mostly related to longevity, age and size at maturity. In this study, age structure, longevity, survivorship and sexual size dimorphism of Near Eastern fire salamander (Salamandra infraimmaculata) were assessed by means of skeletochronological analysis. Maximum lifespan was recorded to be twelve years in females and eleven years in males and age at maturity was estimated as three and four years for both sexes. Females had significantly larger SVL than that of males, while age structure and mean age did not differ between sexes. Age and body size were positively correlated with each other for both females and males. Since the populations of the Near Eastern fire salamander in Turkey are in decline, the present study which provides preliminary data on life history traits of this species could be helpful for future biological studies.