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1.
Longer-term environmental studies are increasingly used to better understand contemporary ecosystems conditions and for forecasting their future trajectories. Here, we use radiometric measurements and the characterisation of sediment properties from six mountain and a lowland lake in Central Eastern Europe with the aim to assess temporal and spatial variability in sediment accumulation rates (SARs) in relation to three socio-economic regimes: traditional (1840–1948), socialist (1948–1989) and post-socialist (post-1990). We also set out to determine reference conditions for these lakes i.e. conditions before significant human impact. Our results show a trend of increasing SARs from basal sediments (pre 1840) towards the present at only two sites. This contrasts with findings from Western and Central European lakes where SARs have predominantly increased from 1850 towards the top of cores. We highlight the differential impacts of the traditional, socialist and post-socialist periods on the SARs at these lakes. Lowland and mid-elevations lakes (n = 2) were most markedly impacted by the socialist period of land use regime; lakes from the southern Carpathians (n = 2) were more impacted in the traditional period (transhumance pastoral activities), whereas those from the north (n = 3) in the socialist and post-socialist periods (summer pastoralism). Results from our study show a continuous anthropogenic impact during the entire period considered, even in remote mountain areas. This suggests that a temporal frame of 100–150 years is too short to meaningfully register the reference conditions of these lakes. Furthermore, a predominantly natural state may not have existed for centuries in this region.  相似文献   
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The study focused on Nigeria's polyurethane (PU) production process as a test case. Though it is currently insignificant when viewed from a global perspective, PU production in Nigeria is not eco‐friendly. Traditionally, PU is produced by reacting petro‐based polyol with a poly‐isocyanate, which is made from amines and phosgene and are currently imported into the country. These two materials are detrimental to the human health and environment, indicating that Nigeria's PU industries need to re‐examine their production inputs for environmental compliance. The objective of this study is to review the PU industry for nontoxic reagents that could be sourced locally vis‐à‐vis overcoming sustainable development (greening the economy) challenges in Nigeria. Non‐isocyanate polyurethane (NIPU) is preferred to petro‐polyurethane because, in comparison, NIPU has improved thermal and chemical resistance, porosity and water absorption, and is less toxic. Engaging local resources to produce PU is economically feasible; in addition, NIPU is relatively advantageous to human health and the environment. Aside from being economically feasible, production of NIPU in Nigeria has the propensity to greatly enlarge the growth of the existing PU industry to tremendous heights and contribute to diversifying and improving the overall economy.  相似文献   
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Activated carbon was prepared from coconut shell, an agricultural waste, for the removal of phosphorus from synthetic phosphorus‐containing wastewater. The activated carbon obtained from the coconut shell was characterized using Fourier‐transform infrared (FTIR) spectroscopy. Batch mode experiments were conducted to study the effects of pH, particle size, adsorbent dosage, and sorption time on the adsorptive potential of the prepared activated carbon. Response surface methodology was employed to study the interactions among the variables and to optimize the process conditions for the maximum removal of phosphorus using the coconut shell–based activated carbon (CNS). The characterization results from the FTIR showed the presence of variety of functional groups, such as ?OH, ?NH, C=O, C?H, C?N, CH3, and CH2, which explains the CNS's improved adsorption behavior on the colloidal particles. A maximum performance of 95.22% was obtained for CNS at the optimum conditions of adsorbent dosage = 1,000 milligrams (local variable), pH 2 (local variable), particle size = 0.2 millimeters (local variable), and sorption time = 4.2 hours (global variable).  相似文献   
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Environmental Science and Pollution Research - Globally, disaster risk management (DRM) has gone through a criterion transpose from static to a technology-based proactive approach in managing...  相似文献   
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Housing delivery system, need and demand   总被引:1,自引:0,他引:1  
This paper reviews the past and current housing delivery programmes in Nigeria and analysed the demand and supply issues. The paper examined factors responsible for high housing pricing trends, it state the constraints and challenges in accessing housing. The paper ascertains guiding principles for implementation towards quality housing delivery, and it identifies the various housing delivery mechanisms in current practice and suggests a holistic programme to address the huge housing shortage in Nigeria. The study addresses the problem of housing delivery systems, the supply and the demand issues with a view to inform policy on housing provision structure, want and request towards improving the level of delivery in Nigeria. The methodology adopted for the study includes interviews and analyses of data collected during the field investigations. These investigations were complemented with review of literature. The data required for this study were obtained primarily from secondary source and personal observations. Suggestions were put forward on policy measures that can sustain future planning of housing provision in Nigeria to conform to what is obtain in other part of the world.  相似文献   
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Environmental Science and Pollution Research - Due to the subtle occurrence of environmental polycyclic aromatic hydrocarbon (PAHs) pollution from incinerators, it is seldom considered a...  相似文献   
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The technical properties of three layered cement-bonded boards (CBBs) made from wastepaper and sawdust were investigated. The CBBs were produced at three density levels of 1000, 1200 and 1300 kg/m3 and at four cement/particle ratios of 2.0:1, 2.5:1, 3.0:1 and 3.5:1 on a weight to weight basis. The technical properties evaluated were modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA) and thickness swelling (TS). The MOR values ranged from 4.85 to 11.69 MPa and MOE values ranged from 2.80 to 5.57 GPa. The mean values of WA and TS after 24 h of water soaking of the CBBs ranged from 18.18% to 40.49% and 3.55% to 12.13%, respectively. MOR and MOE of the CBBs increased with increase in board density, but MOR decreased with the increase in cement/particle ratio. On the other hand, WA and TS decreased with increase in board density and cement/particle ratio. CBBs produced from wastepaper and sawdust at cement/particle ratios of 3.0:1 and 3.5:1 are suitable for building construction such as paneling, ceiling and partitioning.  相似文献   
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The effect of spent engine oil on the height, leaf number, leaf area, stem girth, chlorophyll, and moisture contents of Corchorus olitorius grown on 0, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, and 3.0% (v/w oil/soil) oil-contaminated soil was investigated. The engine oil at all concentrations delayed the germination of C. olitorius by 2 days (compared to control) and there was a general significant reduction in all the growth parameters in plants grown on contaminated soil compared to control plants. The highest leaf area of 26.8 cm2 was found in the control plant and least was found in the 0.6% soil (0.11 cm2) after 3 weeks while no values were recorded on the 0.8–3.0% engine-oil-contaminated soil after 5 weeks of experiment. The highest chlorophyll content was also found in the control plant (11.5 mg/l). This showed that spent engine oil has an adverse effect on the growth of C. olitorius plant.  相似文献   
10.
The concept of sustainable development is debatable within the mining context as the fact that mineral resources are non-renewable makes mining inherently unsustainable. The need for a realistic definition of sustainability that can be applied to mining is important, in light of claims by the industry that sustainable development principles underpin aspects of their operations. Furthermore, the socio-economic upliftment that should logically follow the implementation of these principles is not visible in many mining areas. Within the theoretical frameworks of intermediate sustainability, our study aimed to determine the level of sustainability that is appropriate for the mining context. The evaluation of community perspectives within the Rustenburg platinum region in South Africa as a case study, based on qualitative information derived from structured questionnaires and informal interviews brings further clarity. We found out that the environmental and social costs associated with mining were high, while economic benefits to surrounding communities were low. The perceptions of community and corporations were found to contrast sharply: the reality experienced by community members fell well short of the optimistic scenarios presented in the corporate social responsibility reports of the mining companies, which has implications for the mining industry in the area. The Rustenburg region is typical of mining areas, more especially the developing world, and application of a realistic sustainable development concept here can help the mining industry elsewhere to move its operations onto a genuinely more sustainable path.  相似文献   
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