Modification and performance of activated carbon for CO2 sequestration in pervious concrete

Concrete is one of the most commonly used material in the construction industry, with a global production of ∼10 billion m3/year. The production of Portland cement, the principal binder in most types of concrete, accounts for ∼ 5–7% of global anthropogenic carbon dioxide (CO2) emissions. Carbon capture and sequestration has been developed as one of several initiatives to help mitigate CO2 emissions associated with cement and concrete production. Pervious concrete, a class of porous concretes, has been developed as a sustainable form of concrete that can be used for a wide range of applications. Its use is considered a ‘Best Management Practice’, recommended by the Environmental Protection Agency (EPA) to reduce storm water runoff, improve storm water quality and contribute to recharge of groundwater supplies. Activated carbon is a well-known adsorbent with a strong affinity for CO2, and its surface chemistry can be further modified to enhance its adsorption capacity. Therefore, this research investigates optimal methods for modifying activated carbon to incorporate within Portland cement-based pervious concrete, in order to enhance its CO2 sequestration capacity and improve its overall sustainability. Two forms of activated carbon (granular and powder) were purchased from Fisher Scientific (UK) and chemically modified using different concentrations of the impregnation agents (NaOH, HCl, CuSO4·5H2O, NH4OH). The CO2 adsorption capacity of the raw and the modified samples was measured using three techniques, which demonstrated that NaOH-modified samples had the highest capacity. A second round of modification was conducted to investigate whether further improvements were possible. A two-step process of modification, first with HCl, followed by NaOH was determined to produce the highest adsorption capacity in this process. Activated carbon modified with this technique was used in three cementitious systems, which were tested in order to determine whether addition of such carbon adversely impacted important properties of the resultant materials. Modified powder activated carbon was used as a partial substitution for cement in cement pastes and pervious concrete, while modified granular activated carbon was used as a partial substitution to fine aggregate in cement mortars and pervious concrete. The investigation revealed that incorporation of small percentages of either form of modified activated carbon did not significantly alter the properties of the tested systems. Therefore, both substitutions were applied in pervious concrete to investigate the performance of modified activated carbon-pervious concrete in terms of CO2 sequestration. The combined presence of the two forms of modified activated carbon had a minor effect on the compressive strength, porosity and permeability of the tested pervious concrete. Importantly, pervious concrete containing modified activated carbon had a higher CO2 sequestration capacity than the control concrete. Furthermore, microstructural analysis showed that modified activated carbon- pervious concrete contained a higher content of calcite than the control concrete. Overall, the addition of modified activated carbon to pervious concrete yielded promising results in terms of CO2 sequestration. Further investigation of the long-term performance of modified activated carbon within pervious concrete systems is essential to realise the potential of this system to reduce atmospheric CO2 levels and improve the sustainability of this essential construction material.Islamic Development Ban

The Arab Gulf countries and the Arab- Israeli conflict;: the linkages and dynamics (1970-2000)

This thesis examines the changing linkages and dynamics of the relationship between the Arab Gulf countries and the Arab-Israeli conflict through the period of 1970-2000. The Arab Gulf countries' level of involvement in supporting the Arabs and Palestinians in the Arab-Israeli conflict diminished throughout the period of study. The thesis explains this diminishing role by discussing the impact of the developments of international struggle for influence in the Gulf as well as the Israeli ambitions and relations to the Gulf region, largely expressed through the Israeli relationship with Iran under the Shah. The thesis shows that the years 1973, 1979 and 1990 formed important turning points for international influence in the region. These turning points influenced on the level of the Arab Gulf countries' involvement in the Arab-Israeli conflict. Throughout the seventies, the Arab Gulf countries played an active role in supporting the Arab side in the Arab-Israeli conflict. The clearest expression of this support was the implementation of the oil embargo against the West during the October 1973 War. The eighties witnessed the birth of the Gulf Cooperation Council (GCC), the formation of which symbolized the emerging security challenges within the Gulf region. These security challenges represented by the Iranian Revolution, the Iran-Iraq war and the Soviet invasion and occupation of Afghanistan exhausted most of the capabilities and efforts of the Arab Gulf countries. Their focus and attention shifted away from the Arab-Israeli conflict, in spite of the serious and dramatic developments in that conflict. The repercussions of the Iraqi invasion of Kuwait in 1990 resulted in a further diminishment of the role of the Arab Gulf countries in backing the Palestinians in the Arab-Israeli conflict. Only after September 2000 and the beginning of the Second Palestinian Intifada did the Arab Gulf countries again play a vital role, by means of financial, political and media support. The thesis explains the linkages between security in the Gulf and the Arab- Israeli conflict. It examines the hypothesis that a reciprocal relationship explaining the level and type of Arab Gulf countries involvement in the Arab-Israeli conflict has existed throughout the period of the study

Design of hybrid renewable energy system for near zero energy building in Qatar

Environmental development is the fourth pillar of Qatar National Vision 2030, which has been launched to draw a clear roadmap for the future of Qatar. The vision is aiming towards a balance between developmental needs and the protection of Qatar’s natural environment, including land, air and sea. As a contribution to the vision, this thesis is produced. People nowadays have awareness about renewable energy and its benefits. However, renewable energy sources are unpredictable and changeable with climate change. The best solution to overcome these challenges is to combine multiple renewable energy sources in one energy system. Combining multiple RE sources provides reliable system that meets the energy demand. It is very important in designing a hybrid system to optimally size the system components as sufficient enough to meet the load requirements with minimum total costs. In this thesis, an optimal sizing of a hybrid renewable energy system for an existing building is proposed. The aim is to maximize the renewable energy ratio of the building and to minimize the total net present worth of cost as well as CO2 emission. The proposed hybrid renewable energy system (HRES) consists of solar panels, wind turbines and waste energy management plant. Furthermore, a connection to the National grid is provided, where the proposed system can buy and sell from and to the grid. In this study a year collected data are used to calculate hourly power of PV panels, wind turbines and waste boilers for the whole year. Different designs with different combination of renewable energy sources are generated to match the demand of an existing building. The design with low considerable cost and low considerable CO2 emission id considered the optimal solution

The effect of external factors on the students' acceptance of virtual learning.

The rapidly growing popularity of E-Learning has introduced new terms to education, as virtual learning. The success of a virtual learning environment (VLE) depends on a considerable extent of student acceptance and use of such an e-Iearning system. The current study introduces an overview of the Technology Acceptance Model (TAM). Furthermore, it builds a conceptual model to explain the differences between individual students in the level of acceptance and use of a VLE. This model is an extension of TAM. The primary findings of the study show that perceived of peer encouragement (PPE) has direct influence on the students' attitude to use virtual learning. Computer self-efficacy (CSE) and enjoyment (EN) have direct effect on the students' intention to use virtual learning, whilst, the cultural factor (CF) has indirect effects mediated by TAM

Naso-Maxillary extramedullary plasmacytoma: A case report

We report an early case of extramedullary, right maxillary sinus and nasal, plasmacytoma. The patient was a 27 years old female who presented with nasal bleeding and a nasal mass. Imaging studies showed opacities in the nasal cavity and the maxillary sinus but there was no bone involvement.  A biopsy from the nasal mass showed a plasmacytoma. She was investigated to rule out systemic disease. The investigations included; serum electrophoresis, urine analysis for Bence Jones proteins, bone marrow aspirates study and radiological skeletal survey. The results of all investigations were negative. After complete excision of the tumour endoscopically the patient was treated with adjuvant radiotherapy. She remained well, without recurrence or spread of the tumour at 4 years follow up. CTscans pre and postoperatively as well as H&E and Immunohistochemistry slides are presented. To our knowledge, this is the first case to be reported in Sudan.                                                                   &nbsp

On The Mechanism And Behavior Of Plasma

The charged particles’ action of  and fields have three diverse levels of modeling, Starting with the simplest one to the most complicated. In this paper we consider the generalization of Newtonian force law in geometrical term is to describe charged particles’ (plasma) trajectories on electromagnetic fields in the kinetic or microscopic model. Keyword: Gravitational field, Time–dependent Flow, Integral Curves, Exterior Differential Systems, Kinetic Energy

Failure of a geotextile-reinforced embankment using the material point method (MPM)

In a wide spectrum of geotechnical applications, materials undergo large deformations and/or large displacements. On modeling these problems with a Lagrangian finite element method, the mesh can become too distorted and re-meshing is essential. In the past decades, considerable efforts have been made to adopt what is called meshfree methods to mitigate the problems related to mesh distortion. One of these methods is the Material Point Method (MPM) that represents the continuum field as Lagrangian material points (particles), which can move through the fixed background of an Eulerian mesh. In this paper, the tensile membrane is modeled using the coupled FEM-MPM approach which adopts two-dimensional triangular elements for the membrane discretisation which is free to move through a three-dimensional mesh of non-structured tetrahedral elements. Apart from the membrane, the soil is treated with the classical procedure of MPM. To show the potential of the method and the presented membrane scheme, a failure of an embankment with and without geotextile has been presented in this paper. The analyses of failure mechanism and the embankment stability using undrained conditions were investigated to determine the critical embankment height and the corresponding geotextile forces. For the sake of comparison, Plaxis 2D with large deformation formulation is considered as a reference solution