The environment as a factor of production

The authors develop a model of environmental resource use in production with an empirical analysis of how electric power companies consume and bank sulfur dioxide pollution permits. The model considers emissions, fuels, and labor as variable inputs with quasi-fixed inputs of permits and capital. Incorporating information from permit markets allows the authors to distinguish between user costs and asset shadow values. Their findings indicate that firms are holding stocks of pollution permits for reasons other than short-term cost savings. The results also reveal substantial substitution possibilities between emissions, permits stocks, and other factors of production. The authors speculate that anticipated secondary markets for carbon-offset inventories related to the flexibility mechanisms of the Kyoto Protocol will have similar effects for greenhouse-gas emitting firms.Markets and Market Access,Economic Theory&Research,Payment Systems&Infrastructure,Environmental Economics&Policies,Montreal Protocol,Environmental Economics&Policies,Economic Theory&Research,Energy and Environment,Carbon Policy and Trading,Montreal Protocol

Uncertainty and the price for crude oil reserves

Innovations in futures, options, and derivative instruments permit active trading, speculating and hedging - linking markets for physical petroleum products with financial markets. These derivative markets continuously value petroleum delivered today and for future dates, providing a market price for inventories. Underground petroleum reserves are also an inventory defined by exploration surveys and development drilling. Thus, observable market information can be used to value these reserves. Option - valuation models can be used to price reserves using observable markets, but are dependent on unexplained convenience yields revealed by the term structure of futures prices. The authors apply a general inventory pricing model to petroleum inventories and generate an empirical model of the returns to storage for petroleum markets. They examine the determinants of the crude oil convenience yield using a stochastic control model. They specify optimal production and inventory conditions using a third-order cost function and estimate them using monthly observations. Their inventory arbitrage condition embodies the Hotelling principle and Kaldor's convenience yield, and includes a premium on the dispersion in crude oil prices. The empirical results suggest that returns to storage contain both a cost-reducing component and often sizable premiums associated with the dispersion of petroleum prices. Their findings suggest that crude oil markets differentiated by quality and location provide similar premiums. The premiums associated with the dispersion of petroleum prices may account for persistent backwardation in crude oil prices. This finding may also explain the wide discrepancies between Hotelling values and transaction prices found in previous studies.Economic Theory&Research,Environmental Economics&Policies,Markets and Market Access,Labor Policies,Payment Systems&Infrastructure,Oil Refining&Gas Industry,Environmental Economics&Policies,Access to Markets,Markets and Market Access,Economic Theory&Research

Substitution and technological change under carbon cap and trade : lessons from Europe

The use of carbon-intense fuels by the power sector contributes significantly to the greenhouse gas emissions of most countries. For this reason, the sector is often key to initial efforts to regulate emissions. But how long does it take before new regulatory incentives result in a switch to less carbon intense fuels? This study examines fuel switching in electricity production following the introduction of the European Union’s Emissions Trading System, a cap-and-trade regulatory framework for greenhouse gas emissions. The empirical analysis examines the demand for carbon permits, carbon based fuels, and carbon-free energy for 12 European countries using monthly data on fuel use, prices, and electricity generation. A short-run restricted cost function is estimated in which carbon permits, high-carbon fuels, and low-carbon fuels are variable inputs, conditional on quasi-fixed carbon-free energy production from nuclear, hydro, and renewable energy capacity. The results indicate that prices for permits and fuels affect the composition of inputs in a statistically significant way. Even so, the analysis suggests that the industry’s fuel-switching capabilities are limited in the short run as is the scope for introducing new technologies. This is because of the dominant role that past irreversible investments play in determining power-generating capacity. Moreover, the results suggest that, because the capacity for fuel substitution is limited, the impact of carbon emission limits on electricity prices can be significant if fuel prices increase together with carbon permit prices. The estimates suggest that for every 10 percent rise in carbon and fuel prices, the marginal cost of electric power generation increases by 8 percent in the short run. The European experience points to the importance of starting early down a low-carbon path and of policies that introduce flexibility in how emission reductions are achieved.Energy Production and Transportation,Energy and Environment,Environment and Energy Efficiency,Carbon Policy and Trading,Markets and Market Access

Wind-tunnel investigation of a flush airdata system at Mach numbers from 0.7 to 1.4

Flush pressure orifices installed on the nose section of a 1/7-scale model of the F-14 airplane were evaluated for use as a flush airdata system (FADS). Wing-tunnel tests were conducted in the 11- by 11-ft Unitary Wind Tunnel at NASA Ames Research Center. A full-scale FADS of the same configuration was previously tested using an F-14 aircraft at the Dryden Flight Research Facility of NASA Ames Research Center (Ames-Dryden). These tests, which were published, are part of a NASA program to assess accuracies of FADS for use on aircraft. The test program also provides data to validate algorithms for the shuttle entry airdata system developed at the NASA Langley Research Center. The wind-tunnel test Mach numbers were 0.73, 0.90, 1.05, 1.20, and 1.39. Angles of attack were varied in 2 deg increments from -4 deg to 20 deg. Sideslip angles were varied in 4 deg increments from -8 deg to 8 deg. Airdata parameters were evaluated for determination of free-stream values of stagnation pressure, static pressure, angle of attack, angle of sideslip, and Mach number. These parameters are, in most cases, the same as the parameters investigated in the flight test program. The basic FADS wind-tunnel data are presented in tabular form. A discussion of the more accurate parameters is included

Low Temperature Photoluminescence Characterization of Orbitally Grown CdZnTe

The II-VI ternary alloy CdZnTe is a technologically important material because of its use as a lattice matched substrate for HgCdTe based devices. The increasingly stringent requirements on performance that must be met by such large area infrared detectors also necessitates a higher quality substrate. Such substrate material is typically grown using the Bridgman technique. Due to the nature of bulk semiconductor growth, gravitationally dependent phenomena can adversely affect crystalline quality. The most direct way to alleviate this problem is by crystal growth in a reduced gravity environment. Since it requires hours, even days, to grow a high quality crystal, an orbiting space shuttle or space station provides a superb platform on which to conduct such research. For well over ten years NASA has been studying the effects of microgravity semiconductor crystal growth. This paper reports the results of photoluminescence characterization performed on an arbitrary grown CdZnTe bulk crystal

Preliminary results from a subsonic high angle-of-attack flush airdata sensing (HI-FADS) system: Design, calibration, and flight test evaluation

A nonintrusive high angle-of-attack flush airdata sensing (HI-FADS) system was installed and flight-tested on the F-18 high alpha research flight vehicle. The system is a matrix of 25 pressure orifices in concentric circles on the nose of the vehicle. The orifices determine angles of attack and sideslip, Mach number, and pressure altitude. Pressure was transmitted from the orifices to an electronically scanned pressure module by lines of pneumatic tubing. The HI-FADS system was calibrated and demonstrated using dutch roll flight maneuvers covering large Mach, angle-of-attack, and sideslip ranges. Reference airdata for system calibration were generated by a minimum variance estimation technique blending measurements from two wingtip airdata booms with inertial velocities, aircraft angular rates and attitudes, precision radar tracking, and meteorological analyses. The pressure orifice calibration was based on identifying empirical adjustments to modified Newtonian flow on a hemisphere. Calibration results are presented. Flight test results used all 25 orifices or used a subset of 9 orifices. Under moderate maneuvering conditions, the HI-FADS system gave excellent results over the entire subsonic Mach number range up to 55 deg angle of attack. The internal pneumatic frequency response of the system is accurate to beyond 10 Hz. Aerodynamic lags in the aircraft flow field caused some performance degradation during heavy maneuvering

Biochemical and Genetic Characterization of PspE and GlpE, Two Single-domain Sulfurtransferases of Escherichia coli

The pspE and glpE genes of Escherichia coli encode periplasmic and cytoplasmic single-domain rhodaneses, respectively, that catalyzes sulfur transfer from thiosulfate to thiophilic acceptors. Strains deficient in either or both genes were constructed. Comparison of rhodanese activity in these strains revealed that PspE provides 85% of total rhodanese activity, with GlpE contributing most of the remainder. PspE activity was four times higher during growth on glycerol versus glucose, and was not induced by conditions that induce expression of the psp regulon. The glpE/pspE mutants displayed no apparent growth phenotypes, indicating that neither gene is required for biosynthesis of essential sulfur-containing molecules. PspE was purified by using cation exchange chromatography. Two distinct active peaks were eluted and differed in the degree of stable covalent modification, as assessed by mass spectrometry. The peak eluting earliest contained the equivalent mass of two additional sulfur atoms, whereas the second peak contained mainly one additional sulfur. Kinetic properties of purified PspE were consistent with catalysis occurring via a double-displacement mechanism via an enzyme-sulfur intermediate involving the active site cysteine. Kms for SSO32- and CN- were 2.7 mM and 32 mM, respectively, and kcat was 64s-1. The enzyme also catalyzed transfer of sulfur from thiosulfate to dithiothreitol, ultimately releasing sulfide

Effects of Grade Control Structures on Fish Passage, Biological Assemblages and Hydraulic Environments in Western Iowa Streams: A Multidisciplinary Review

Land use changes and channelization of streams in the deep loess region of western Iowa have led to stream channel incision, altered flow regimes, increased sediment inputs, decreased habitat diversity and reduced lateral connectivity of streams and floodplains. Grade control structures (GCSs) are built in streams to prevent further erosion, protect infrastructure and reduce sediment loads. However, GCS can have a detrimental impact on fisheries and biological communities. We review three complementary biological and hydraulic studies on the effects of GCS in these streams. GCS with steep (≥1:4 rise : run) downstream slopes severely limited fish passage, but GCS with gentle slopes (≤1:15) allowed greater passage. Fish assemblages were dominated by species tolerant of degradation, and Index of Biotic Integrity (IBI) scores were indicative of fair or poor biotic integrity. More than 50% of fish species had truncated distributions. After modification of GCS to reduce slopes and permit increased passage, IBI scores increased and several species were detected further upstream than before modification. Total macroinvertebrate density, biomass and taxonomic diversity and abundance of ecologically sensitive taxa were greater at GCS than in reaches immediately upstream, downstream or ≥1 km from GCS. A hydraulic study confirmed results from fish passage studies; minimum depths and maximum current velocities at GCS with gentle slopes (≤1:15) were more likely to meet minimum criteria for catfish passage than GCS with steeper slopes. Multidisciplinary approaches such as ours will increase understanding of GCS-associated factors influencing fish passage, biological assemblage structure and other ecological relationships in streams