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471.
Brian Freeman Bahram Gharabaghi Mohammad Munshed Shah Faisal Meshal Abdullah 《Journal of the Air & Waste Management Association (1995)》2017,67(5):565-581
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. 相似文献
472.
B. Deepanraj M. Srinivas N. Arun G. Sankaranarayanan P. Abdul Salam 《International Journal of Green Energy》2017,14(15):1231-1237
Biofuel blends produced from Jatropha (Jatropha curcas) and Karanja (Pongamia pinnata) oil were evaluated for their combustion properties. Two kinds of blends (regular diesel with Jatropha and Karanja oil) were prepared at 20% volume to the diesel and tested as alternative fuels in single cylinder (vertical), water-cooled, direct injection diesel engine at the rated speed of 1500 rpm. The performance of the engine in terms of thermal efficiency at full load for diesel was 30%. For Jatropha and Karanja biodiesel blends, the thermal efficiencies were 29.0% and 28.6%, respectively. The maximum cylinder pressure and ignition delay for biodiesel fuel blends are very close to that of regular diesel. Prolonged combustion was observed for Karanja oil blend in comparison to Jatropha oil blend. The combustion pattern also reveals the slow burning characteristics of vegetable oils and this study indicates that the blended biofuels have combustion characteristics that are similar to regular diesel fuels. 相似文献
473.
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. 相似文献
474.
475.
T. B. M. Mohd I. U. H. Bhat A. L. Mohmod P. Aditiawati H. P. S. Abdul Khalil 《Journal of Polymers and the Environment》2013,21(2):534-544
This research presents, thermal (TGA, Kinetics, DSC) analysis and FT-IR characterization of two bamboo species viz. Gigantochloa levis and Gigantochloa scortechinii at different position and locations (Internode and node). The internodes and nodes of Gigantochloa levis and Gigantochloa scortechinii exhibited similar thermal stability, observed up to 200 °C. The decomposition of cellulose and hemicelluloses component of the bamboo species occurred between 220 and 390 °C, while the degradation of lignin was observed above 400 °C. The kinetic studies revealed that Gigantochloa levis is more sensitive to degradation as compared to Gigantochloa scortechinii. The FT-IR studies were carried to assign the functional groups available at different positions and locations. 相似文献
476.
With environmental change set to affect the developing world in significant ways, examination of the process of adaptation is increasingly being brought to the fore. Common to all forms of adaptation in rural livelihoods will be a process of change in resource use and the resource rights that will either facilitate or subvert adaptation. This paper looks at Darfur and the repercussions from the multi‐year drought and land degradation that led to forms of adaptation that involved change in relationships between groups over land resources. The analysis looks at how changes in land resource rights relationships have been dealt with historically, as adaptation developed. Approaches involving highly flexible customary institutions were used to effectively manage the change in land resource rights relationships inherent in adaptation, and considerable opportunity existed for positive interaction between customary and statutory law. Initial success at adaptation was followed by interventions by the Sudanese government to manage these relationships for specific objectives that worked against adaptation. This resulted in competition, animosity, confrontation and the subsequent collapse of the institutions, legitimacy, and trust necessary for successful management of land resource rights change. These national policies debilitated the adaptation opportunities and instead led to profoundly negative repercussions in relationships about land in Darfur, eventually becoming a primary driver in the current war. This highlights both the importance of land resource rights relationships to adaptation and how these relationships can be changed (positively and negatively) by specific practices and policies. 相似文献
477.
Temporal changes in Ephemeroptera, Plecoptera and Trichoptera (EPT) abundance were investigated monthly from January to December
2008 at a tropical forest stream of Tupah River (TR) at Gunung Jerai Forest Reserve, Malaysia. A total of 1,689 adult individuals
belong to 16 families of EPT were collected from TR. EPT populations peaked in May, June and December. Mean EPT abundance
was significantly different among months (Kruskal–Wallis test, P < 0.05). Among the three orders, Trichoptera had the most diverse community with eight families reported, followed by Ephemeroptera
(six families) and Plecoptera (two families). The family Baetidae was the most abundant ephemeropteran. Meanwhile, caddisfly
families Hydropsychidae, Leptoceridae and Lepidostomatidae were abundant at TR. However, plecopterans were mainly represented
by Perlidae. There was significant difference in abundance (t = 4.863, P < 0.05) and diversity (t = 7.857, P < 0.05) of EPT adults between dry and wet seasons. Interestingly, abundance of EPT adults was higher in the dry season compared
to the wet season. Consequently, seasonality impact on abundance of EPT adults at TR was obvious. The adult population of
Trichoptera was dominant during the dry season. However, adults of Ephemeroptera were abundant during the wet season. 相似文献
478.
Farrukh Jamil Murni M. Ahmad Suzana Yusup Bawadi Abdullah 《International Journal of Green Energy》2016,13(4):424-429
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. 相似文献
479.
Abdul Shukor Abdul Aziz Latifah Abd Manaf Hasfalina Che Man Nadavala Siva Kumar 《Environmental science and pollution research international》2014,21(13):7996-8005
This paper investigates the adsorption characteristics of palm oil boiler mill fly ash (POFA) derived from an agricultural waste material in removing Cd(II) and Cu(II) from aqueous solution via column studies. The performance of the study is described through the breakthrough curves concept under relevant operating conditions such as column bed depths (1, 1.5, and 2 cm) and influent metal concentrations (5, 10, and 20 mg/L). The Cd(II) and Cu(II) uptake mechanism is particularly bed depth- and concentration-dependant, favoring higher bed depth and lower influent metal concentration. The highest bed capacity of 34.91 mg Cd(II)/g and 21.93 mg Cu(II)/g of POFA was achieved at 20 mg/L of influent metal concentrations, column bed depth of 2 cm, and flow rate of 5 mL/min. The whole breakthrough curve simulation for both metal ions were best described using the Thomas and Yoon–Nelson models, but it is apparent that the initial region of the breakthrough for Cd(II) was better described using the BDST model. The results illustrate that POFA could be utilized effectively for the removal of Cd(II) and Cu(II) ions from aqueous solution in a fixed-bed column system. 相似文献
480.
Ghulam Akhmat Khalid Zaman Tan Shukui Ihtisham Abdul Malik Shamzana Begum Adeel Ahmed 《Environmental science and pollution research international》2014,21(15):9408-9414
The objective of the study is to empirically examine the air pollution, greenhouse gas (GHG) emissions and low birth weight in Pakistan through the cointegration and error correction model over a 36-year time period, i.e., between 1975 and 2012. The study employed the Johansen cointegration technique to estimate the long-run relationship between the variables, while an error correction model was used to determine the short-run dynamics of the system. The study was limited to the following variables, including carbon dioxide emissions, methane emissions, nitrous oxide emissions, GHG emissions, and low birth weight in order to manage robust data analysis. The results reveal that air pollution and GHG emissions significantly affects the low birth weight in Pakistan. In the long run, carbon dioxide emissions act as a strong contributor for low birth weight, as the coefficient value indicates there is a more elastic relationship (i.e., ?1.214, p?0.000) between them, whereas in the short run, this results has been evaporated. Subsequently, in the short run, GHG emissions have a one-to-one corresponding relationship with the low birth weight in Pakistan. Nitrous oxide emissions, both in the short and long run, have a significant and less elastic relationship (i.e., ?0.517 with p?0.001 and ?0.335 with p?0.090). Methane emissions have no significant relationship with the low birth weight in Pakistan. 相似文献