For portfolio choice problems with proportional transaction costs, we discuss whether or not there exists a shadow price, i.e., a least favorable frictionless market extension leading to the same optimal strategy and utility. By means of an explicit counter-example, we show that shadow prices may fail to exist even in seemingly perfectly benign situations, i.e., for a log-investor trading in an...

We investigated a new procedure in which silicic acid column chromatography and fluorometry are used to assay plasma vitamin A. Using tntium-labeled vitamin A acetate and vitamin A alcohol as radioactive stan. dards, we identified two fluorescent components in plasma extracts chromatographed on silicic acid columns. One unidentified fluorescent component was eluted first with hexane or petroleu...

We present a coherent and unified group of general explanations for the various phase transitions, which may occur in the seven naturally occurring petroleum fluids with emphasis on their heavy organics. The seven petroleum fluids include, in the order of their fluidity, natural gas, near-critical gas-condensate, light crude, intermediate crude, heavy oil, tar sand and oil shale. At first the n...

Biodiesel production is a very modern and technological area for researchers due to the relevance that it is winning everyday because of the increase in the petroleum price and the environmental advantages. In this work it is made a review of the alternative technological methods that could be used to produce this fuel. Different studies have been carried out using different oils as raw materia...

9' be favourable compared with that of natural fats, and would almost certainly approach that of fatty acids from petroleum which presumably do not offer an attractive commercial proposition, since no company has yet undertaken the process. I would suggest that synthetic detergents will command a share of the detergent market which will depend on their efficiency and price. To that extent they ...

Pakistan is an agrarian country, and the main agricultural products are cotton, wheat, rice, sugarcane, fruits, and vegetables. Fuels derived from agricultural sources offer an alternate to the rapidly increasing price of petroleum fuels and the increasing scarcity and the toxicity of such fuels. This paper seeks to examine the impact of biofuels industry on the Pakistan economy. The paper furt...

In the presented research we have tested the application of photo ionization detector of ECOPROBE 5 analyzer to monitoring of low concentrations of petroleum products in water. Petroleum products are organic pollutants that are present in wastewater most frequently, which is caused by their broad applications and frequent incidents. Emergency leakage of petroleum and its products is predominant...

I discuss the short-run dynamics of commodity prices, production, and inventories, as well as the sources and effects of market volatility. I explain how prices, rates of production, ana’ inventory levels are interrelated, and are determined via equilibrium in two interconnected markets: a cash market for spot purchases and sales of the commodity, and a market for storage. I show how equilibriu...

Many organizations interested in renewable, domestic energy have switched from petroleum diesel to biodiesel blends for use in transportation and heavy-duty equipment. Although considerable evidence exists on the negative health effects of petroleum diesel exhaust exposures in occupational settings, there has been little research examining biodiesel exposures. Working collaboratively with a loc...