153 research outputs found
Parameter Estimation for the New Weibull Pareto Distribution under Type II Censored Samples
In this paper, parameters estimation under type II censored samples and the corresponding variance covariance matrix for the new WeibullndashPareto distribution are obtained. Nasiru and Luguterah (2015) Results may be considered as a special case from present results. An illustrative example is carried out by using a simulated data
Economic analysis of the international cooperation to face global environmental problems
Because of the doubts about the effectiveness of the Kyoto Protocol, several scholars have asked whether other types of agreements can be designed to achieve large reductions of GHG emissions. Designing a profitable and stable international environmental agreement (IEA) that deals with the shortcomings of Kyoto-type agreement is the main motivation of this work.
One idea would be to focus on technology improvements in order to reduce abatement costs, as this might increase a country's willingness to undertake significant emission reductions. For example, it could be beneficial to supplement a Kyoto-type agreement with technology elements if technological development depends not only on a country's own R&D investment but also on R&D by other countries through cross-country technology spillovers, see for instance, Carraro and Siniscalco (1997). Even with no explicit agreement on emissions, a technology agreement leading to increased R&D in clean technologies, and thus to lower abatement costs, might yield a reduction in emissions. This is the argument behind the proposals of a climate agreement on technology development, see for instance, Barrett (2006).
The aim of the present work is to examine different types of international environmental agreements in order to determine what would be the dominant agreement (at the different levels of marginal damages) with respect to both the total costs of signatories countries and the level of cooperation. The model used in the analysis is a three-stage static model (explained in chapter 2), where the membership game is played in the first stage, the investment game is played in the second stage and finally the emission game is played in the third stage.
Examining the international cooperation on technological development as a supplement to international cooperation on GHG emission reductions, is the main objective of the second chapter where four different types of emission agreements are analyzed. The four agreements share the main aspect that signatories countries act cooperatively in the third stage of the game (emission game). However, the second stage of the game (investment game) differs from one type to another depending on whether signatories are sharing R&D efforts and coordinating their R&D activities or not. In all agreements, it is assumed that effective investment in one country depends on the amount invested in R&D in that country as well as on the investment in R&D undertaken in all countries through technological spillovers.
In the types of agreements that include information exchange (emission agreement with information exchange and emission and R&D agreement with information exchange), the technological spillovers is perfect among signatories, which means that signatories countries avoid the duplication of R&D efforts. However, the technological spillovers is not perfect among signatories in the other two types (emission agreement and emission and R&D agreement without information exchange).
Examining the international cooperation on technological development as an alternative to international cooperation on GHG emission reductions, is the main objective of the third chapter where three different types of technological agreements are analyzed. The three different types of agreements (R&D agreement without information exchange, research joint venture agreement and R&D agreement with information exchange), share the main aspect that signatories countries act non-cooperatively in the third stage of the game (emission game). A comparison between all types of agreements (analyzed in second and third chapters), is also introduced in this chapter.
An extension of the analysis which examines the robustness of the model for the dominant agreements at the high levels of marginal damages, is the main objective of the fourth chapter. The quadratic investment costs and the quadratic environmental damages are the two different assumptions that have been analyzed in this chapter.
Main Conclusions
According to the analysis introduced in this thesis, the main conclusions can be summarized as follows
∙ Cooperating on emissions even if it is accompanied with cooperating on investment without information exchange, is not enough to eliminate countries incentives to act as free-rider.
∙ Sharing R&D investments and avoid duplication of R&D activities is enough to stabilize the grand coalition at the high levels of marginal damages. This result is explained by the asymmetry in the spillovers parameter between signatories and non-signatories. As the agreement, which includes information exchange, implies that signatories fully internalize the spillover effects of their investments in R&D, signatories can eliminate emissions using less resources than non-signatories. The result is that the signatories' investment costs are lower than the non-signatories' investment costs and hence the total costs are also lower. Moreover, there are negative externalities for non-signatories stemming from cooperation, i.e. cooperation increases the total costs of non-signatories. In this framework, if one country abandons the grand coalition, its total costs increase because of the increase in investment costs, which makes the grand coalition stable.
∙ As far as signatories countries invest at the maximum level of R&D investment to eliminate completely the GHG emissions, cooperation in the third stage of the game (emissions) does not affect neither the level of cooperation nor the total costs.
∙ At high levels of marginal damages, it is found that the agreements which include both cooperation on R&D investment and information exchange are the dominant agreements. However, for low values of marginal damages, the dominant agreements are changing according to the different intervals of marginal damages as explained in details in the third chapter.
∙ By examining the robustness of the different assumptions of the model, it is found that both of the assumptions of constant returns to scale of the R&D investment (linear investment costs) and the assumption of linear environmental damages are not critical for achieving the result that grand coalition is stable and profitable, at the high levels of marginal damages
Partial Replacement of Cement by Solid Wastes as New Materials for Green Sustainable Construction Applications
The manufacturing of ordinary Portland cement is an energy-intensive process that results in pollution and CO2 emissions, among other issues. There is a need for an environmentally friendly green concrete substitute. Waste products from a variety of sectors can be recycled and used as a green concrete substitute. This decreases the environmental effects of concrete manufacturing as well as energy consumption. The use of solid waste materials for green building is extremely important now and in the future. Green concrete is also in its infancy in terms of manufacturing and application. Academics must intervene by encouraging business implementation. The aim of this review paper is to raise awareness about the importance of repurposing recycled materials and to highlight new technologies for producing green, sustainable concrete
Bioactive Cytotoxic Agents and Chemokine Production Inhibitors in LPS-Induced Raw264.7 Macrophage Cell Line from Flowers of Crepis Senecioides
Crepis senecioides is one of the endemic plant species found in Libya. The ethanol extract (E) of the flowers was partitioned on silica gel column with dichloromethane affording four compounds. Their structures were elucidated by the physicochemical and spectral data as germanicol acetate (1), 3`,3``butyl, 8`,8``carboxy) di-octyl phethalate (2), taraxasterol (3) and β-sitosterol (4). effect of the tested samples 1 and 2 on the viability of RAW macrophage 264.7 were studied. anti-cancer activity was tested on several human cell lines. Anti-inflammatory effect was also screened. Compound 1 had promising cellular cytotoxicity with IC50 60.26µg/mL on HepG2. Compound 2 had a talented cellular cytotoxicity with IC50 50.18 µg/mL on PC3. Both 1 and 2 exerted alike cytotoxicity with IC50 µg/mL 78.53, 78.14 on PC3 and MCF-7 carcinoma cell lines respectively. The treatment of LPS-stimulated macrophage with 2 led to a highly significant inhibition 45.05% in the nitrite concentration in LPS-stimulated macrophage. Compound 1 had a promising cellular cytotoxicity on HepG2, while 2 exhibited an inhibition on chemokine expression in LPS-induced RAW 264.7 macrophages and had talented cellular cytotoxicity on PC3. Keywords: Crepis senecioide;, Asteraceae; Anti-inflammatory; cytotoxic effect; terpenoids; phethalate derivative
Finite state machines implementation using DNA Techniques
Abstract A finite-state machine (FSM) is an abstract mathematical model of computation used to design both computer programs and sequential logic circuits. Considered as an abstract model of computation, the finite state machine is weak; it has less computational power than some other models of computation such as the Turing machine. This paper overview the finite-state automata based on Deoxyribonucleic Acid (DNA). Such automata uses massive parallel processing offered by molecular approach for computation and exhibits a number of advantages over traditional electronic implementations
Bioactive compounds from Acokanthera oblongifolia
One cardiotonic glycoside, three triterpenes and one steroidal glycoside were isolated from Acokanthera oblongifolia fruits (pericarp) growing in Libya. Their structures were investigated by extensive application of IR, MS, 1DNMR and 2DNMR spectroscopy. The isolated compounds have evidenced in-vitro cytotoxicity on selected human cell lines (A-549, H-1299) when compared to doxorubicin. Keywords: Cardenolide; Acokanthera oblongifolia; antitumor activity; lung carcinoma cell line (A-549, H-1299)
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