Storage and Commodity Markets is primarily a work of economic theory, concerned with how the capability to store a surplus affects the prices and production of commodities. Its focus on the behaviour, over time, of aggregate stockpiles provides insights into such questions as how much a country should store out of its current supply of food considering the uncertainty in future harvests. Related topics covered include whether storage or international trade is a more effective buffer and whether stockpiles are more useful in raw or processed form. Several chapters are devoted to analysing such government programmes as price bands, buffer stocks, and strategic reserves. This material is in the domain of applied welfare analysis with public finance. Because the theory presented is sufficiently general, it should be of interest to macroeconomists studying aggregate inventories or savings and to those in operations research studying inventory and pricing policies of large firms.
[1] X-ray and electric field measurements were made during five nearby negative natural lightning strikes in north central Florida during the summer of 2004. The observed X-ray emission typically was detected $1 ms before the first return stroke, during the stepped-leader phase, and had energies extending up to a few hundred keV. The X rays were produced in discrete, intense bursts emitted in coincidence with the formation of the leader steps, demonstrating unambiguously that the source of lightning X rays is closely related to the stepping process. The X-ray emission from lightning stepped leaders is found to be remarkably similar to that from lightning dart leaders, suggesting that these different types of leaders share a common mechanism. The reported observations have important implications for understanding how runaway breakdown occurs and how lightning leaders propagate. Citation: Dwyer, J. R., et al. (2005), X-ray bursts associated with leader steps in cloud-to-ground lightning,
We report the observation of an intense gamma‐ray burst observed on the ground at sea level, produced in association with the initial‐stage of rocket‐triggered lightning at the International Center for Lightning Research and Testing at Camp Blanding, FL. The burst was observed simultaneously on three NaI(Tl)/photomultiplier tube detectors that were located 650 m from the triggered lightning channel with gamma‐ray energies extending up to more than 10 MeV. The burst consisted of 227 individual gamma‐rays that arrived over a 300 μs time period in coincidence with an 11 kA current pulse. The burst of gamma‐rays had very different characteristics from the x‐ray emission frequently seen in association with the dart leader/return stroke sequences of triggered lightning and may represent a new kind of event, likely originating from cloud processes thousands of meters overhead.
Using a NaI(Tl) scintillation detector designed to operate in electrically noisy environments, we observed intense bursts of energetic radiation (>> 10 kiloelectron volts) during the dart leader phase of rocket-triggered lightning, just before and possibly at the very start of 31 out of the 37 return strokes measured. The bursts had typical durations of less than 100 microseconds and deposited many tens of megaelectron volts into the detector. These results provide strong evidence that the production of runaway electrons is an important process during lightning.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.