Stock Market Volatility and Jumps in Times of Uncertainty

In this paper we examine the predictive power of latent macroeconomic uncertainty on US stock market volatility and jump tail risk. We find that increasing macroeconomic uncertainty predicts a subsequent rise in volatility and price jumps in the US equity market. Our analysis shows that the latent macroeconomic uncertainty measure of Jurado et al. (2015) has the most significant and long-lasting impact on US stock market volatility and jumps in the equity market when compared to the respective impact of the VIX and other popular observable uncertainty proxies. Our study is the first to show that the latent macroeconomic uncertainty factor outperforms the VIX when forecasting volatility and jumps after the 2007 US Great Recession. We additionally find that latent macroeconomic uncertainty is a common forecasting factor of volatility and jumps of the intraday returns of S&P 500 constituents and has higher predictive power on the volatility and jumps of the equities which belong to the financial sector. Overall, our empirical analysis shows that stock market volatility is significantly affected by the rising degree of unpredictability in the macroeconomy, while it is relatively immune to shocks in observable uncertainty proxies

Experimental investigation of the effects of simultaneous hydrogen and nitrogen addition on the emissions and combustion of a diesel engine

This article is made available through the Brunel Open Access Publishing Fund. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivative Works License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited. Copyright @ 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.Overcoming diesel engine emissions trade-off effects, especially NO and Bosch smoke number (BSN), requires investigation of novel systems which can potentially serve the automobile industry towards further emissions reduction. Enrichment of the intake charge with H + N containing gas mixture, obtained from diesel fuel reforming system, can lead to new generation low polluting diesel engines. This paper investigates the effect of simultaneous H + N intake charge enrichment on the emissions and combustion of a compression ignition engine. Bottled H + N was simultaneously admitted into the intake pipe of the engine in 4% steps starting from 4% (2% H + 2% N) up to 16% (v/v). The results showed that under specific operating conditions H + N enrichment can offer simultaneous NO, BSN and CO emissions reduction. Apart from regulated emissions, nitrogen exhaust components were measured. Marginal NO and zero NH emissions were obtained. NO/NO ratio increases when speed or load increases. Under low speed low load operation the oxidation of NO is enhanced by the addition of H + N mixture. Finally, admission of H + N has a detrimental effect on fuel consumption.UK Engineering and Physical Science Research Counci