Bio-electricity and land use in the Future Agricultural Resources Model (FARM)     

Ronald D. Sands  Hannah Förster  Carol A. Jones  Katja Schumacher 《Climatic change》2014,123(3-4):719-730

Bio-electricity is an important technology for Energy Modeling Forum (EMF-27) mitigation scenarios, especially with the possibility of negative carbon dioxide emissions when combined with carbon dioxide capture and storage (CCS). With a strong economic foundation, and broad coverage of economic activity, computable general equilibrium models have proven useful for analysis of alternative climate change policies. However, embedding energy technologies in a general equilibrium model is a challenge, especially for a negative emissions technology with joint products of electricity and carbon dioxide storage. We provide a careful implementation of bio-electricity with CCS in a general equilibrium context, and apply it to selected EMF-27 mitigation scenarios through 2100. Representing bio-electricity and its land requirements requires consideration of competing land uses, including crops, pasture, and forests. Land requirements for bio-electricity start at 200 kilohectares per terawatt-hour declining to approximately 70 kilohectares per terwatt-hour by year 2100 in scenarios with high bioenergy potential.  相似文献   

Winter storm structure and melting‐induced circulations     

Ronald E. Stewart  Stephen R. Macpherson 《大气与海洋》2013,51(1):5-23

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SCALES FOR DETERMINING SLOPE FROM TOPOGRAPHIC MAPS     

Norman J. W. Thrower  Ronald U. Cooke 《The Professional geographer》1968,20(3):181-186

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Numerical Modeling of Thermal Conductive Heating in Fractured Bedrock     

Daniel P. Baston  Ronald W. Falta  Bernard H. Kueper 《Ground water》2010,48(6):836-843

Numerical modeling was employed to study the performance of thermal conductive heating (TCH) in fractured shale under a variety of hydrogeological conditions. Model results show that groundwater flow in fractures does not significantly affect the minimum treatment zone temperature, except near the beginning of heating or when groundwater influx is high. However, fracture and rock matrix properties can significantly influence the time necessary to remove all liquid water (i.e., reach superheated steam conditions) in the treatment area. Low matrix permeability, high matrix porosity, and wide fracture spacing can contribute to boiling point elevation in the rock matrix. Consequently, knowledge of these properties is important for the estimation of treatment times. Because of the variability in boiling point throughout a fractured rock treatment zone and the absence of a well-defined constant temperature boiling plateau in the rock matrix, it may be difficult to monitor the progress of thermal treatment using temperature measurements alone.  相似文献   

Sulfate reduction and methanogenesis in marine sediments     

Ronald S. Oremland  Barrie F. Taylor 《Geochimica et cosmochimica acta》1978,42(2):209-214

Methanogenesis and sulfate-reduction were followed in laboratory incubations of sediments taken from tropical seagrass beds. Methanogenesis and sulfate-reduction occurred simultaneously in sediments incubated under N₂, thereby indicating that the two processes are not mutually exclusive. Sediments incubated under an atmosphere of H₂ developed negative pressures due to the oxidation of H₂ by sulfate-respiring bacteria. H₂ also stimulated methanogenesis, but methanogenic bacteria could not compete for H₂ with the sulfate-respiring bacteria.  相似文献   

A Close Look at Satloc's Real-Time WADGPS System     

Michael L. Whitehead  Gary Penno  Walter J. Feller  Ivan C. Messinger  Willy I. Bertiger  Ronald J. Muellerschoen  Byron A. Iljima  Greg Piesinger 《GPS Solutions》1998,2(2):46-63

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Input data resolution‐induced uncertainty in watershed modelling     

Abhijit Patil  Zhi‐Qiang Deng  Ronald F. Malone 《水文研究》2011,25(14):2302-2312

The temporal‐spatial resolution of input data‐induced uncertainty in a watershed‐based water quality model, Hydrologic Simulation Program‐FORTRAN (HSPF), is investigated in this study. The temporal resolution‐induced uncertainty is described using the coefficient of variation (CV). The CV is found to decrease with decreasing temporal resolution and follow a log‐normal relation with time interval for temperature data while it exhibits a power‐law relation for rainfall data. The temporal‐scale uncertainties in the temperature and rainfall data follow a general extreme value distribution and a Weibull distribution, respectively. The Nash‐Sutcliffe coefficient (NSC) is employed to represent the spatial resolution induced uncertainty. The spatial resolution uncertainty in the dissolved oxygen and nitrate‐nitrogen concentrations simulated using HSPF is observed to follow a general extreme value distribution and a log‐normal distribution, respectively. The probability density functions (PDF) provide new insights into the effect of temporal‐scale and spatial resolution of input data on uncertainties involved in watershed modelling and total maximum daily load calculations. This study exhibits non‐symmetric distributions of uncertainty in water quality modelling, which simplify weather and water quality monitoring and reducing the cost involved in flow and water quality monitoring. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Qualitative risk assessment of multiple-use marine park effectiveness – A case study from NSW,Australia     

Andrew D. Read  Ronald J. West 《Ocean & Coastal Management》2010,53(10):636-644

Effectiveness of the managed-use zones in six multiple-use marine parks located within New South Wales (NSW), Australia, was assessed using qualitative Ecological Risk Assessment (ERA) techniques. Permitted activities in these managed-use zones displayed considerable variation between individual marine parks within this one jurisdiction (NSW); many activities appeared to be inconsistent with the stated objectives; and, some were considered high risk. For example, in “habitat protection” zones, 24 out of 76 permitted activities were inconsistently applied across the parks and 10 activities were determined to be high risk. ERA indicated that many commercial fishing activities warranted restriction or prohibition in these zones, including trawling, set lining, drift lining, mesh netting and purse seining operations. The best fit between objectives of the managed-use zones and permitted activities was for the most recent park (Batemans Marine Park). Inconsistencies in application of zoning restrictions between these marine parks could lead to stakeholder confusion, unintentional non-compliance and failure to adequately protect the assets. As a result, it is suggested that these managed-use zones may not be achieving their stated objectives and that greater consistency in application of regulations was required. To implement the ERA recommendations, changes would be required across all of the NSW marine parks and this would be best accommodated during a staged review of all zoning plans. It is concluded that ERA is an effective tool to aid in systematically identifying permissible activities in order to meet marine park objectives.  相似文献   

The influence of 70 and 120 kHz tonal signals on the behavior of harbor porpoises (Phocoena phocoena) in a floating pen     

Kastelein RA  Verboom WC  Jennings N  de Haan D  van der Heul S 《Marine environmental research》2008,66(3):319-326

Two harbor porpoises in a floating pen were subjected to five pure tone underwater signals of 70 or 120kHz with different signal durations, amplitudes and duty cycles (% of time sound is produced). Some signals were continuous, others were intermittent (duty cycles varied between 8% and 100%). The effect of each signal was judged by comparing the animals' surfacing locations and number of surfacings (i.e. number of respirations) during test periods with those during baseline periods. In all cases, both porpoises moved away from the sound source, but the effect of the signals on respiration rates was negligible. Pulsed 70kHz signals with a source level (SL) of 137dB had a similar effect as a continuous 70kHz signal with an SL of 148dB (re 1muPa, rms). Also, a pulsed 70kHz signal with an SL of 147dB had a much stronger deterring effect than a continuous 70kHz signal with a similar SL. For pulsed 70kHz signals (2s pulse duration, 4s pulse interval, SL 147dB re 1muPa, rms), the avoidance threshold sound pressure level (SPL), in the context of the present study, was estimated to be around 130dB (re 1muPa, rms) for porpoise 064 and around 124dB (re 1muPa, rms) for porpoise 047. This study shows that ultrasonic pingers (70kHz) can deter harbor porpoises. Such ultrasonic pingers have the advantage that they do not have a "dinner bell" effect on pinnipeds, and probably have no, or less, effect on other marine fauna, which are often sensitive to low frequency sounds.  相似文献   

Sporadic meteor sources as observed by the Jicamarca high-power large-aperture VHF radar     

Jorge L. Chau  Ronald F. Woodman  Freddy Galindo 《Icarus》2007,188(1):162-174

We present, for the first time, the main sources of sporadic meteors as inferred from meteor-head echoes obtained by a high-power large-aperture radar (HPLAR). Such results have been obtained at the Jicamarca HPLAR (11.95° S, 76.87° W, 1° dip angle). Observations are based on close to 170,000 meteors detected in less than 90 h spread over 14 days, between November 2001 and February 2006. Meteors with solar orbits are observed to come from basically six previously known sources, i.e., North and South Apex, Helion, Anti-Helion, and North and South Toroidal, representing ∼91% of the observations. The other ∼9% represents meteors with observed velocities greater than the Sun's escape velocity at 1 AU, most of them of extra-solar origin. Results are given before and after removing the Earth's velocity and the sources are modeled with two-dimensional Gaussian distributions. In general, our results are in very good agreement with previously known sources reported by Jones and Brown [Jones, J., Brown, P.G., 1993. Mon. Not. R. Astron. Soc. 265, 524-532] using mainly specular meteor radar (SMR) data gathered over many years and different sites. However, we find slightly different locations and widths, that could be explained on the basis of different sensitivities of the two techniques and/or corrections needed to our results. For example, we find that the North and South Apex sources are well defined and composed each of them of two collocated Gaussian distributions, one almost isotropic with ∼10° width and the other very narrow in ecliptic longitude and wide in ecliptic latitude. This is the first time these narrow-width sources are reported. A careful quantitative analysis is needed to be able to compare the strengths of meteor sources as observed with different techniques. We also present speed and initial altitude distributions for selected sources. Using a simple angular sensitivity function of the combined Earth-atmosphere-radar instrument, and an altitude selection criteria, the resulting meteor sources are in better qualitative agreement with the results obtained with SMRs.  相似文献