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1.
Norazlina Ab Halim Faradiella Mohd. Kusin Khairul Nizam Mohamed 《International Journal of Environmental Science and Technology》2018,15(4):733-742
This study was carried out to determine the concentration of heavy metals (Cd, Ni, Pb, Cr, Ni and Zn) in ordinary Portland cement (OPC) produced from the co-processing with hazardous waste in comparison with OPC produced using natural raw materials. The results showed that the concentration of heavy metals in cement produced from natural raw material was in the order of Zn > Pb > Cr > Ni > Cu > Cd. Zn and Cd were the highest and the lowest concentrations, respectively, in cements produced from the co-processing activity. The difference between heavy metals concentrations in OPC produced with and without co-processing was found to be statistically significant. The concentration of heavy metals in the cement produced is generally factory dependent. The human risk assessment associated with the heavy metals for non-carcinogenic and carcinogenic risks has been evaluated. The calculated hazard index (HI) and total lifetime cancer risks (LCR) were lower than the acceptable threshold reference values, HI < 1 and LCR < 1 × 10?4, respectively. Thus, it is anticipated that there is no potential of non-carcinogenic and carcinogenic risks for both adult and children. However, the findings indicated that there is a need for regulatory monitoring. The exposure pathway for both non-carcinogenic and carcinogenic risks are both in the order of ingestion > dermal > inhalation. 相似文献
2.
Guanabara Bay (GB) is considered to be one of the most polluted environments of the southern Brazilian coastline. This typical estuarine system is impacted by the heavy discharge of both industrial and domestic waste from the Rio de Janeiro metropolitan area. The mollusc community structure and distribution was investigated between 2000 and 2001, using a three month sampling design of 38 stations, according to austral seasons. Species abundance was aggregated into progressively higher taxa matrices (genus, family, order) and were analysed using multivariate techniques. Mollusc distribution in GB varied significantly in space and time and was probably ruled by the organic enrichment effects of hypoxia and altered redox conditions coupled with prevailing patterns of circulation. Within the sectors of GB an increasing gradient in mollusc diversity and occurrence was observed, ranging from the azoic and impoverished stations in the inner sector to a well-structured community in terms of species composition and abundance inhabiting the outer sector. The non-metric multidimensional scaling (nMDS) and cluster analysis showed similar results when species were aggregated into genera and families, while greater difference occurred at coarser taxonomic identification (order). The literature about taxonomic sufficiency has demonstrated that faunal patterns at different taxonomic levels tend to become similar with increased pollution. In Guanabara Bay, an analysis carried out solely at family level is perfectly adequate to describe the ecophysiological stress. Further aggregation to order level changed the perceived patterns of differences. However, a different taxonomic resolution can be chosen depending on the type of ecological patterns investigated. 相似文献
3.
Le Sénonien du Haut Atlas occidental, Maroc: sédimentologie, analyse séquentielle et paléogéographie
Based on new geological studies of the Senonian series in the southern part of the western High Atlas, Morocco, new insights on stratigraphy and palmogeography are presented. The palæogeography was generally shallow inner neritic with some palæorelief forming small confined basins that were affected by marine incursions under a hot and arid climate. During the Coniacien, a regression occurred caused by pre-Senonien embryonic tectonic phases. In the Campanian, an important regression, due to tectonic movement, caused the eastern sector of Erguita to emerge. During the Maastrichtian, an important Atlantic marine transgression followed pre-Maastrichtian embryonic tectonics and covered the area. 相似文献
4.
H. Md. Azamathulla Yong Chong Cuan Aminuddin Ab. Ghani Chun Kiat Chang 《Arabian Journal of Geosciences》2013,6(9):3469-3480
This study presents gene expression programming (GEP), an extension of genetic programming, as an alternative approach to modeling the suspended sediment load relationship for the three Malaysian rivers. In this study, adaptive neuro-fuzzy inference system (ANFIS), regression model, and GEP approaches were developed to predict suspended load in three Malaysian rivers: Muda River, Langat River, and Kurau River [ANFIS (R 2?=?0.93, root mean square error (RMSE)?=?3.19, and average error (AE)?=?1.12) and regression model (R 2?=?0.63, RMSE?=?13.96, and AE?=?12.69)]. Additionally, the explicit formulations of the developed GEP models are presented (R 2?=?0.88, RMSE?=?5.19, and AE?=?6.5). The performance of the GEP model was found to be acceptable compare to ANFIS and better than the conventional models. 相似文献
5.
The use of data‐driven modelling techniques to deliver improved suspended sediment rating curves has received considerable interest in recent years. Studies indicate an increased level of performance over traditional approaches when such techniques are adopted. However, closer scrutiny reveals that, unlike their traditional counterparts, data‐driven solutions commonly include lagged sediment data as model inputs, and this seriously limits their operational application. In this paper, we argue the need for a greater degree of operational reasoning underpinning data‐driven rating curve solutions and demonstrate how incorrect conclusions about the performance of a data‐driven modelling technique can be reached when the model solution is based upon operationally invalid input combinations. We exemplify the problem through the re‐analysis and augmentation of a recent and typical published study, which uses gene expression programming to model the rating curve. We compare and contrast the previously published solutions, whose inputs negate their operational application, with a range of newly developed and directly comparable traditional and data‐driven solutions, which do have operational value. Results clearly demonstrate that the performance benefits of the published gene expression programming solutions are dependent on the inclusion of operationally limiting, lagged data inputs. Indeed, when operationally inapplicable input combinations are discounted from the models and the analysis is repeated, gene expression programming fails to perform as well as many simpler, more standard multiple linear regression, piecewise linear regression and neural network counterparts. The potential for overstatement of the benefits of the data‐driven paradigm in rating curve studies is thus highlighted. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
6.
This study provides a detailed account of the stepwise development of an empirical equation to estimate the number of lightning casualties in a given region. The factors considered in the development of the formula are; lightning density, population density and urbanization of a given region. The unknown constants of the equation have been evaluated by applying state-wise lightning death records and information on lightning density distribution in USA. The death figure per year due to lightning calculated for Sri Lanka using the empirical equation developed is in good agreement with the same figure reported for the country by actual data collected. The paper also discusses the limitations of the empirical equations that have been developed to calculate lightning density once the isokeraunic level is provided as the input parameter. 相似文献
7.
Petra Hájková Ab Grootjans Mariusz Lamentowicz Eliška Rybníčková Mikuláš Madaras Věra Opravilová Dierk Michaelis Michal Hájek Hans Joosten Lesław Wołejko 《第四纪科学杂志》2012,27(3):233-243
In general, mires develop by autogenic succession from more groundwater‐fed to more rainwater‐fed. This study from a calcareous mire in the West Carpathians (Slovakia) describes a similar development in the Early Holocene, followed by a reverse development in the Middle and Late Holocene. Pollen, macrofossil and testate amoeba analyses show that the site started as a minerotrophic open fen woodland. After 10 700 cal a BP autogenic succession led to the accumulation of at least 1 m of Sphagnum fuscum peat. Around 9000 cal a BP, as climate could no longer sustain a stable water regime, the bog desiccated and a fire broke out. The fire removed part of the peat layer and as a consequence relative water levels rose, leading to the establishment of a wet minerotrophic swamp carr with Thelypteris palustris, Equisetum sp. and Alnus sp. with extremely slow peat accumulation. After 600 cal a BP, rapid peat accumulation with calcareous tufa formation resumed as a result of anthropogenic deforestation and hydrological changes in the catchment and resulting increased groundwater discharge. At present the mire still hosts a wealth of relict and endangered plant and animal species typical of calcareous fens and fen meadows. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
8.
Hazi Md. Azamathulla Aminuddin Ab. Ghani Chun Kiat Chang Zorkeflee Abu Hasan Nor Azazi Zakaria 《洁净——土壤、空气、水》2010,38(10):969-976
In this study, a novel machine learning technique called the support vector machine (SVM) method is proposed as a new predictive model to predict sediment loads in three Malaysian rivers. The SVM is employed without any restriction to an extensive database compiled from measurements in the Muda, Langat, and Kurau rivers. The SVM technique demonstrated a superior performance compared to other traditional sediment‐load methods. The coefficient of determination, 0.958, and the mean square error, 0.0698, of the SVM method are higher than those of the traditional method. The performance of the SVM method demonstrates its predictive capability and the possibility of the generalization of the model to nonlinear problems for river engineering applications. 相似文献
9.
The Adoudounian Basal Series within the western part of the Moroccan Anti-Atlas Mountains was deposited in a varying palæogeographical setting. The first deposits of volcaniclastic and carbonate sediments accumulated in small shallow basins under tectonic control. Then, sedimentation became siliciclastic and volcano-detrital with coastal and deltaic sedimentation in the western area and lagoon-lacustrine in the eastern area. Synsedimentary alkaline volcanism, associated with normal faulting, indicates a within-plate extensional tectonic regime related to rifting, which affected the northern margin of the West African Craton, during Late Neoproterozoic-Early Cambrian times. 相似文献
10.
Dalibor Petković Siti Hafizah Ab Hamid Žarko Ćojbašić Nenad T. Pavlović 《Natural Hazards》2014,74(2):463-475
We present a project management methodology designed for the selection of wind turbines wake effect most influential parameters, who need to run wind farm project for large energy conversion. Very frequently, the managers of these projects are not project management professionals, so they need guidance to have autonomy, using minimal time and documentation resources. Therefore, agile method is adapted to assist the project management. Wind energy poses challenges such as the reduction in the wind speed due to the wake effect by other turbines. If a turbine is within the area of turbulence caused by another turbine, or the area behind another turbine, the wind speed suffers a reduction and, therefore, there is a decrease in the production of electricity. In order to increase the efficiency of a wind farm, analyzing the parameters, which have influence on the wake effect, is one of the focal research areas. To maximize the power produced in a wind farm, it is important to determine and analyze the most influential factors on the wake effects or wake wind speeds since the effect has most influence on the produced power. This procedure is typically called variable selection, and it corresponds to finding a subset of the full set of recorded variables that exhibits good predictive abilities. In this study, architecture for modeling complex systems in function approximation and regression was used, based on using adaptive neuro-fuzzy inference system (ANFIS). Variable searching using the ANFIS network was performed to determine how the five parameters affect the wake wind speed. Our article answers the call for renewing the theoretical bases of wind farm project management in order to overcome the problems that stem from the application of methods based on decision-rationality norms, which bracket the complexity of action and interactions in projects. 相似文献