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31.
Adsorption onto solid phases plays an important role in the transport of radionuclides and contaminants in the environment. Radionuclides in radioactive waste have been considered to be hazardous pollutants, and their migration with groundwater is strongly affected by sorption on the geologic media. Therefore, the knowledge of radionuclide sorption is of great importance in the management of radioactive wastes. A series of batch sorption experiments were conducted separately to investigate sorption and transport behaviour of cobalt, strontium and caesium on and through marble. Batch-mode kinetic and equilibrium studies have been carried out at different temperatures. Sorption experimental data were analysed by kinetic and isotherm models. Based on the results obtained, it can be concluded that the marble is an economic and efficient retaining material for environmental hazardous migration and/or leakage of some radionuclides. Therefore, this study could be used as a starting point to establish and consider that rock as a reactive barrier around the disposal facilities at the nuclear activity centres. 相似文献
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Ghasempour Zahra Khodaeivandi Sepideh Ahangari Hossein Hamishehkar Hamed Amjadi Sajed Moghaddas Kia Ehsan Ehsani Ali 《Journal of Polymers and the Environment》2022,30(7):2800-2811
Journal of Polymers and the Environment - In this study, composite packaging films were produced from relatively inexpensive materials including Whey protein isolate (WPI) and Persian gum (PG),... 相似文献
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Mahdavian Seyed Mohammadreza Ahmadpour Borazjani Mahmoud Mohammadi Hamid Asgharipour Mohammad Reza Najafi Alamdarlo Hamed 《Environmental science and pollution research international》2022,29(35):52457-52472
Environmental Science and Pollution Research - Iran’s agricultural production has expanded significantly in recent years. Environmental pollution caused by the use of energy and chemical... 相似文献
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Prabu Arulraj Simon Chithambaram Venkatesan Bennet Maria Anto Shanmugan Sengottaiyan Pruncu Catalin Iulian Lamberti Luciano Elsheikh Ammar Hamed Panchal Hitesh Janarthanan Balasundaram 《Environmental science and pollution research international》2022,29(11):15863-15875
Environmental Science and Pollution Research - The unavailability of sunlight during nighttime and cloudy weather condition has limited the usage of solar cookers throughout the day. This study... 相似文献
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Adaptation strategies for maize cultivation under climate change in Iran: irrigation and planting date management 总被引:1,自引:0,他引:1
Rooholla Moradi Alireza Koocheki Mehdi Nassiri Mahallati Hamed Mansoori 《Mitigation and Adaptation Strategies for Global Change》2013,18(2):265-284
Climate change is affecting the productivity of crops and their regional distribution. Strategies to enhance local adaptation capacity are needed to mitigate climate change impacts and to maintain regional stability of food production. The objectives of this study were to simulate the climate change effects on phenological stages, Leaf Area Index (LAI), biomass and grain yield of maize (Zea mays L.) in the future and to explore the possibilities of employing irrigation water and planting dates as adaptation strategies to decrease the climate change impacts on maize production in Khorasan Razavi province, Iran. For this purpose, we employed two types of General Circulation Models ((United Kingdom Met. Office Hadley Center: HadCM3) and (Institute Pierre Simon Laplace: IPCM4)) and three scenarios (A1B, A2 and B1). Long Ashton Research Station-Weather Generator (LARS-WG) was used to produce daily climatic parameters as one stochastic growing season for each projection period. Also, crop growth under projected climate conditions was simulated based on the Cropping System Model (CSM)-CERES-Maize. The results of model evaluation showed that LARS-WG had appropriate prediction for climatic parameters. Time period from cultivation until anthesis and maturity were reduced in majority of scenarios as affected by climate change. The results indicated that the grain yield of maize may be reduced (11 % to 38 %) as affected by climate change based on common planting date in baseline and changed (?61 % to 48 %) in response to different irrigation regimes in the future climate change, under all scenarios and times. In general, earlier planting date (1 May) and decreasing irrigation intervals in the anthesis stage (11 applications) caused higher yield compared with other planting dates due to adaption to high temperature. Based on our findings, it seems that management of irrigation water and planting dates can be beneficial for adaptation of maize to climate change in this region. 相似文献
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B. S. Choudri Mahad Baawain Ahmed Al-Sidairi Hamed Al-Nadabi Khalifa Al-Zeidi 《国际发展与全球生态学杂志》2016,23(5):433-440
The purpose of this study was to determine residents’ perception, knowledge and attitude towards environmental issues and management in the Al-Suwaiq Wilayat (administrative zone) of Al-Batinah North, Sultanate of Oman. For this purpose, a questionnaire was used with questions on issues related to environment and surveyed across 109 households in the Wilayat following a random sampling method in early 2015. The results show that education, health-related infrastructure and unemployment are ranked as most important issues for government attention today and in coming 10 years besides their concern for the environment. Resident’s perceptions on most important environmental issues were concerned about solid-waste pollution, degradation of coastal areas, saltwater intrusion and land degradation. The sources for environmental information, government agencies, local media and schools were regarded as most reliable. Top environmental priorities were suggested to deal with enforcement of regulations, provide effective environmental awareness and education programs. Further, it is suggested that additional studies should be conducted such as ‘State of Environment Reporting’, thereby such reporting, for instance would provide some form of verification of reported behaviour and improved knowledge. 相似文献
38.
Kambiz Haji Hajikolaei Hamed Moradi Gholamreza Vossoughi Mohammad R. Movahhedy 《Journal of Manufacturing Processes》2010,12(2):106-115
Chatter suppression in machining processes results in more material removal rate, high precision and surface quality. In this paper, two control strategies are developed to suppress chatter vibration in the turning process including a worn tool. In the first stage, a sinusoidal spindle speed variation around the mean speed is modulated to disturb the regenerative mechanism. The optimal amplitudes of the speed modulations are found based on a genetic algorithm such that the input energy to the turning process is minimized. In the second stage, to improve the response of the system which is associated with small ripples under the steady state condition, an adaptive controller is designed. In this stage, the provided external force (e.g., by a piezo-actuator) is the input variable. Results are provided for each control strategy. It is shown that if both control approaches are applied simultaneously, chatter vibration is suppressed in less time without any ripples at the steady state condition. 相似文献
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Mohamed Ahmed Reda Hamed 《环境质量管理》2023,32(3):203-208
Due to its simplicity and accurately measuring the flow rate, the venturi system is a special kind of pipe that is widely used in various applied fluid mixtures. One of the venturi system's important applications is ejectors devices that accurately facilitate adding air to water to sustain oxygen demand target levels in many waterworks engineering systems. This study aims to improve venturi system measurement accuracy through experimental investigation and analytical analysis for the venturi system conditional configuration parameters effect on target aeration operational efficiency. In the experiment work, different runs are implemented to characterize the performance of such aerators by describing the impact of venturi characteristics and configurations, including water flow rate, air inlets orifices diameters, inlet velocities, throat lengths, inlet angles, outlets angles, and outlet diameters on aeration efficiency. Results show that the venturi air vent diameter is an important governing parameter for determining aeration performance value. Additionally, an indicated increase in aeration performance with an increasing throat length to its diameter ratio. Meanwhile, the results revealed a varying noted effect of the venturi system characteristics and configurations on aeration performance. Moreover, the equations that relate venturi system configuration and Reynolds numbers with the aeration operational performance are developed to facilitate the target accurate aeration efficiency estimation. 相似文献
40.
Maged M. Hamed 《Environmental Modeling and Assessment》2005,9(4):253-264
The Gulf War in 1991 created an environmental catastrophe, one of the major consequences of which was setting several oil wells on fire in the Arabian Gulf area. The total oil spilled as a result of the damaged wells was about 3.5 × 106 m3. Out of these, 3.3 × 106 m3 of oil was recovered and exported. The rest was left behind as it was not economical to collect. The oil left behind was subject to severe weathering over the past ten years. Soil and subsurface contamination pose a serious risk to the quality of the already scarce fresh groundwater resources in the area which was subject to oil spill in the study region. This paper presents the computer modeling activities carried out towards simulating the transport of the hydrocarbon contamination of the fresh groundwater resources at a study area in the Arabian Gulf region, and predicting the contamination levels at the fresh groundwater lenses in the area in the future, should current contamination levels persist in the soil and groundwater. The modeling activities relied on both semi-analytical and numerical flow and transport models. 相似文献