Gasoline-derived methyl tert-butyl ether as a potential obesogen linked to metabolic syndrome

正The power and efficiency of gasoline engines is often improved through the use of fuel with high octane ratings.The octane rating of fuel could be further increased with oxygenate additives such as alcohols and ethers, with methyl tert-butyl ether (MTBE) being one of the most common gasoline additives. The Agency for Toxic Substances and Disease     

The idea of sustainable development

In this lecture, I demonstrate how very different macroeconomic history begins to look if Nature is included as a capital asset in production activities. The tentative conclusions I draw from the evidence are: (1) high population growth in the world’s poorest regions (South Asia and sub-Saharan Africa) has been an obstacle to the achievement of sustainable economic development there; relatedly, (2) when population growth is taken into account, the accumulation of manufactured capital, knowledge, and human capital (health and education) has not compensated for the degradation of natural capital in South Asia and sub-Saharan Africa and, in all probability, even in the UK and the US; (3) China is possibly an exception to (1) and (2). This article is based on the Keynote Lecture delivered at the international symposium on “Sustainability in an Unequal World”, held in Tokyo on November 24, 2006. The exposition relies on my book, Economics: A Very Short Introduction, Oxford University Press, Oxford, 2007. The author is the Frank Ramsey Professor of Economics at the University of Cambridge and a Fellow of St. John’s College, Cambridge.     

Do energy prices affect employment? Decomposed international evidence

This paper analyzes the energy price-employment nexus and contributes to the literature by showing that it is important to decompose the regulatory effect into demand, cost, and factor-shift effects. This is done by means of a cross-country multi-sectoral dataset. The results show that both rising energy prices and shadow prices of energy have no significant effect on net employment when the manufacturing sectors only are analyzed. While finding significant variations across countries, the average employment effects become significantly positive once jobs in the economy as a whole are considered. This change is driven mainly by larger positive cost effects, which more than offset the negative demand effects and reductions in the positive factor-shift effects. Moreover, the paper reveals that the often implemented approach of using a simple regulation regressor, instead of decomposing the employment effect, can result in biased estimates.     

Cost pass-through to higher ethanol blends at the pump: Evidence from Minnesota gas station data

We examine the pass-through of wholesale prices to retail prices in the market for E85, which contains 51%–83% ethanol, and in the much larger market for E10, which contains 10% ethanol. We use a panel dataset consisting of monthly observations from 2007 to March 2015 on wholesale and retail prices for 274 Minnesota gas stations that sell both E10 and E85. Consistent with prior research, the cumulative pass-through coefficient for E10 is 1.00 after one month. In contrast, the E85 market is sparse, and although pass-through increased over time, we estimate it to be only 0.53 statewide from 2012 to 2015. Pass-through is higher at stations with more local E85 competitors. In the Twin Cities, which has a high density of E85 stations, pass-through is nearly complete, but outside the Twin Cities slightly less than half the wholesale discount of E85, relative to E10, is passed on to the consumer.     

Non-renewable resource prices: Deterministic or stochastic trends?

In this paper, we examine temporal properties of 11 natural resource real price series from 1870 to 1990. Recent studies by Ahrens and Sharma [Trends in natural resource commodity prices: deterministic or stochastic? J. Environ. Econom. Manage. 33(1997)59–74], Berck and Roberts [Natural resource prices: will they ever turn up? J. Environ. Econom. Manage. 31(1996)65–78], and Slade [Grade selection under uncertainty: least cost last and other anomalies, J. Environ. Econom. Manage. 15(1988)189–205], among others, find that many non-renewable resource prices have a stochastic trend. We revisit this issue by employing a Lagrangian multiplier unit root test that allows for two endogenously determined structural breaks with and without a quadratic trend. Contrary to previous research, we find evidence against the unit root hypothesis for all price series. Our findings support characterizing natural resource prices as stationary around deterministic trends with structural breaks. We additionally show that both pre-testing for unit roots with breaks and allowing for breaks in the forecast model can improve forecast accuracy. Overall, the results in this paper are important in both a positive and normative sense; without an appropriate understanding of the dynamics of a time series, empirical verification of theories, forecasting, and proper inference are potentially fruitless.     

车用汽油铅损害及其对策研究

针对车用汽油的抗爆性能要求,探讨四乙基铅（Ｐｂ（Ｃ２Ｈ５）４）抗爆添加剂的作用机理,并着重分析研究了由此而引起的发动机铅排放对人类造成的损害及给大气环境等带来的污染。还探讨了车用汽油铅损害的对策及其最新进展     

Modeling the partitioning of BTEX in water-reformulated gasoline systems containing ethanol

The objectives of this research were to quantify the extent of cosolvency for water–gasoline mixtures containing ethanol and to identify appropriate modeling tools for predicting the equilibrium partitioning of BTEX compounds and ethanol between an ethanol-bearing gasoline and water. Batch-equilibrium experiments were performed to measure ethanol and BTEX partitioning between a gasoline and aqueous phase. The experiments incorporated simple binary and multicomponent organic mixtures comprised of as many as eight compounds as well as highly complex commercial gasolines where the composition of the organic phase was not completely defined. At high ethanol volume fractions, the measured partition coefficients displayed an approximate linear relationship when plotted on semi-log scale as a function of ethanol volume fraction. At lower concentrations, however, there was a distinctly different trend which is attributed to a change in solubilization mechanisms at these concentrations. Three mathematical models were compared with or fit to the experimental results. Log-linear and UNIFAC-based models were used in a predictive capacity and were capable of representing the overall increase in partition coefficients as a function of increasing ethanol content in the aqueous phase. However, neither of these predicted the observed two-part curve. A piecewise model comprised of a linear relationship for low ethanol volume fractions and a log-linear model for higher concentrations was fit to data for a surrogate gasoline comprised of eight compounds and was then used to predict BTEX concentrations in the aqueous phase equilibrated with three different commercial gasolines. This model was superior to the UNIFAC predictions, especially at the low aqueous ethanol concentrations.     

Build it,but will they come? Evidence from consumer choice between gasoline and sugarcane ethanol

How consumers might switch from gasoline and diesel to alternative energy sources is not known, since the availability of alternatives is currently very limited. To bridge this gap, we exploit exogenous variation in ethanol prices at Brazil's pumps and uncover substantial consumer heterogeneity in the choice between long-established gasoline and an alternative that is similarly available and usable: sugarcane ethanol. We observe roughly 20% of flexible-fuel motorists choosing gasoline when gasoline is priced 20% above ethanol in energy-adjusted terms ($/mile) and, similarly, 20% of motorists choosing ethanol when ethanol is priced 20% above gasoline. We use transaction-level data to explore “non-price” characteristics which differentiate the two goods in the minds of different groups of consumers. Our findings suggest—and a counterfactual illustrates—that switching away from gasoline en masse, should this be desired, would require considerable price discounts to boost voluntary adoption, in the US and elsewhere.     

Costs and prices for renewable energy development in industrialized countries and applications to China

Developing renewable energy is now becoming a hot topic as it is important in dealing with climate change issue and energy supply issue. With the growing demand of energy, it has become urgent to develop the effective policies and measures that would enable people to maintain the living standards. Among all the measures, price is an essential one. In order to evaluate the costs and prices of the electricity from renewable energy sources (RES-E) and their effects to the market, this paper firstly focus on the extra costs of the RES-E by breaking it into four parts, including investment, construction, connection and operation. Then, the policy choices made in some typical industrialized countries are examined to find answers to the problems RES-E can raise. Finally, the choices made in China are examined in comparison to industrialized countries so as to determine how the current situation could be improved.     

Emergy analysis using US economic input-output models with applications to life cycles of gasoline and corn ethanol

A commonly encountered challenge in emergy analysis is the lack of transformity data for many economic products and services. To overcome this challenge, emergy analysts approximate the emergy input from the economy via a single emergy/money ratio for the country and the monetary price of economic inputs. This amounts to assuming homogeneity in the entire economy, and can introduce serious uncertainties in the results. This paper proposes and demonstrates the use of a thermodynamically augmented economic input-output model of the US economy for obtaining sector-specific emergy to money ratios that can be used instead of a single ratio. These ratios at the economy scale are more accurate than a single economy-wide emergy/money ratio, and can be obtained quickly for hundreds of economic products and services. Comparing sector-specific emergy/money ratios with those from conventional emergy studies indicates that the input-output model can provide reasonable estimates of transformities at least as a stop-gap measure until more detailed analysis is completed. A hybrid approach to emergy analysis is introduced and compared with conventional emergy analysis using life cycles of corn ethanol and gasoline as examples. Emergy and transformity data from the hybrid approach are similar to those from conventional emergy analysis, indicating the usefulness of the proposed approach. In addition, this work proposes the metric of return on emergy investment for assessing product alternatives with the same utility such as transportation fuels. The proposed approach and data may be used easily via web-based software.