Simulation of brittle damage for fracture process of endodontically treated tooth

The mechanics of brittle damage in porcelain of an endodontically treated maxilla incisor tooth was simulated using finite element method (FEM). For this purpose a very complex composite structure of endodontically treated tooth is simulated under transverse loading. Three dimensional (3D) model of human maxilla incisor tooth root was developed based on Computed Tomography (CT) scan images. Crown, core cement, resin core, dental post, post cement and dentin were created using SolidWorks software, and then the model was imported into ABAQUS-6.9EF software for nonlinear behavior analysis. This study utilizes finite element method to simulate onset and propagation of crack in ceramic layer (porcelain) by the cause of both tension and compression loading related to complexity of the geometry of tooth implant. The simulation has been done using brittle damaged model available in ABAQUS/Explicit in quasi-static load condition. The load-displacement response of whole structure is measured from the top of porcelain by controlling displacement on a rigid rod. Crack initiated at the top of porcelain bellow the location of the rod caused by tension damage at equivalent load of 590 N. Damage in porcelain accounts for up to 63% reduction of whole structure stiffness from the undamaged state. The failure process in porcelain layer can be described by an exponential rate of fracture energy dissipation. This study demonstrated that the proposed finite element model and analysis procedure can be use to predict the nonlinear behavior of tooth implant

The impact of crude oil price volatility on selected Asian emerging economies

This paper empirically investigates the impact of oil price volatility on six major emerging economies of Asia, namely China, India, Indonesia, Malaysia, Philippines and Thailand. Following Andersen et al. (2004) quarterly oil price volatility is measured by using the realized volatility (RV). For China, according to the VAR analysis along with the Granger causality test, generalized impulse response functions and generalized variance decompositions, it can be inferred that oil price volatility impacts output growth in the short run. For India oil price volatility impacts both GDP growth and inflation. In Philippines oil price volatility impacts inflation. For the Indonesian economy oil price volatility impacts both GDP growth and inflation before and after the Asian financial crisis. In Malaysia oil price volatility impacts GDP growth, while there is a very little feedback from the opposite side. For Thailand, oil price volatility impacts output growth for the whole studied period. However, after the Asian financial crisis the impact seems to disappear. It seems that oil subsidization of the Thai Government by introduction of the oil fund plays a significant role in improving economic performance by lessening the adverse effect of oil price volatility on macroeconomic indicators

Economic Growth with Coal, Oil and Renewable Energy Consumption in China: Prospects for Fuel Substitution

We examine the relationship between Chinese aggregate production and consumption of three main energy commodities: coal, oil and renewable energy. Both autoregressive distributed lag (ARDL) and vector error correction modeling (VECM) show that Chinese growth is led by all three energy sources. Economic growth also causes coal, oil and renewables consumption, but with negative own-price effects for coal and oil and a strong possibility of fuel substitution through positive cross-price effects. The results further show coal consumption causing pollution, while renewable energy consumption reduces emissions. No significant causation on emissions is found for oil. Hence, making coal both absolutely and relatively expensive compared to oil and renewable energy encourages shifting from coal to oil and renewable energy, thereby improving economic and environmental sustainability

Determinants of Renewable Energy Adoption in China and India: A Comparative Analysis

This article examines the dynamic relationships among output, carbon emission and renewable energy generation of India and China during the period 1972 to 2011 using a multivariate vector error correction model (VECM). The results for India reveal unidirectional short-run causality from carbon emission to renewable energy generation and from renewable energy generation to output, whereas in the long run, the variables have bidirectional causality. Causalities in China give a rather different scenario, with a short-run unidirectional causality from output to renewable energy and from carbon emission to renewable energy generation. In the long run, for China, unidirectional causality is found from output to renewable energy generation, while bidirectional causality is found between carbon emission and renewable energy generation

A philosophical context for methods to estimate origin-destination trip matrices using link counts.

This paper creates a philosophical structure for classifying methods which estimate origin-destination matrices using link counts. It is claimed that the motivation for doing so is to help real-life transport planners use matrix estimation methods effectively, especially in terms of trading-off observational data with prior subjective input (typically referred to as 'professional judgement'). The paper lists a number of applications that require such methods, differentiating between relatively simple and highly complex applications. It is argued that a sound philosophical perspective is particularly important for estimating trip matrices in the latter type of application. As a result of this argument, a classification structure is built up through using concepts of realism, subjectivity, empiricism and rationalism. Emphasis is put on the fact that, in typical transport planning applications, none of these concepts is useful in its extreme form. The structure is then used to make a review of methods for estimating trip matrices using link counts, covering material published over the past 30 years. The paper concludes by making recommendations, both philosophical and methodological, concerning both practical applications and further research

Does the institutional quality matter for renewable energy promotion in the OECD economies?

This study examines the effect of institutional quality on renewable energy promotion in the OECD economies. The study employs annual data from 1980 to 2014 on 18 OECD economies. The robust panel unit root tests show that all the considered variables have a similar order of integration, indicating that they are nonstationary at their levels but stationary at the first-order differences. The panel cointegration test with structural breaks and cross-section dependence confirms a long-run equilibrium association between institutional quality, renewable energy consumption, and control variables. The analysis of long-run estimations displays that better institutional quality makes a unique and substantial contribution to promoting renewable energy consumption. Overall, the study findings offer important policy implications highlighting the importance of institutional quality for the growth of renewable energy and a sustainable world

Tribological behaviour of refined bleached and deodorized palm olein in different loads using a four-ball tribotester

AbstractVegetable oil is one of the bio-oils that have been promoted to replace petroleum-based products due to its eco- friendly characteristics. Palm oil has high productivity rate, and so it could fulfil the demand for a bio-lubricant. In this paper, the influence of the normal load on friction and wear performance were investigated for a RBD palm olein and compared with paraffinic mineral oil using four-ball tribotester. The normal load was varied from 30 kg to 60 kg. All experimental works were conforming to ASTM D 4172. The results exhibited that the RBD palm olein has lower coefficient of friction compared to paraffinic mineral oil. However, the wear scar of ball bearings lubricated with RBD palm olein showed larger diameter compared to paraffinic mineral oil. As a conclusion, RBD palm olein has better performance compared to paraffinic mineral oil in terms of capability to reduce friction

Advances and challenges in umbilical cord blood and tissue bioprocessing: procurement and storage

Umbilical cord tissue and blood is banked to complement the rapidly advancing field of tissue engineering and regenerative medicine for both autologous and allogeneic therapeutic applications. Whilst many problems concerning the use of the hematopoietic and multipotential mesenchymal stromal cells contained therein may be addressed through the future development of GMP-compliant manufacturing strategies, collection and bioprocessing of these tissues can be optimised in the present to maximise clinical outcomes. In this review, we describe current procurement, processing and storage approaches for umbilical cord blood and tissue; current challenges and how these may be met to augment translation and use of therapeutics harnessing their derivatives