bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating the Utility of Multispectral Information in Delineating the Areal Extent of Precipitation
Authors: Behrangi Ali , Hsu Kuo-lin , Imam Bisher , Sorooshian Soroosh , Kuligowski Robert J. 
Published: January 2009

Abstract
Data from geosynchronous Earth-orbiting (GEO) satellites equipped with visible (VIS) and infrared (IR) scanners are commonly used in rain retrieval algorithms. These algorithms benefit from the high spatial and temporal resolution of GEO observations, either in stand-alone mode or in combination with higher-quality but less frequent microwave observations from low Earth-orbiting (LEO) satellites. In this paper, a neural network–based framework is presented to evaluate the utility of multispectral information in improving rain/no-rain (R/NR) detection. The algorithm uses the powerful classification features of the self-organizing feature map (SOFM), along with probability matching techniques to map single- or multispectral input space into R/NR maps. The framework was tested and validated using the 31 possible combinations of the five Geostationary Operational Environmental Satellite 12 (GOES-12) channels. An algorithm training and validation study was conducted over the conterminous United States during June–August 2006. The results indicate that during daytime, the visible channel (0.65 μm) can yield significant improvements in R/NR detection capabilities, especially when combined with any of the other four GOES-12 channels. Similarly, for nighttime detection the combination of two IR channels—particularly channels 3 (6.5 μm) and 4 (10.7 μm)—resulted in significant performance gain over any single IR channel. In both cases, however, using more than two channels resulted only in marginal improvements over two-channel combinations. Detailed examination of event-based images indicate that the proposed algorithm is capable of extracting information useful to screen no-rain pixels associated with cold, thin clouds and identifying rain areas under warm but rainy clouds. Both cases have been problematic areas for IR-only algorithms.
Subinertial Slope-Trapped Waves in the Northeastern Gulf of Mexico
Authors: Hallock Z. R. , Teague W. J. , Jarosz E. 
Published: January 2009

Abstract
Current velocity from moored arrays of acoustic Doppler current profilers (ADCPs) deployed on the outer shelf and slope, south of Mobile Bay in the northeastern Gulf of Mexico, shows evidence of alongslope, generally westward-propagating subinertial baroclinic Kelvin waves with periods of about 16 and 21 days, amplitudes of 5–10 cm s−1, and wavelengths of about 500 km. The observed waves were highly coherent over the slope between about 200 and 500 m and accounted for a significant amount of the current variability below 200 m. The source of the waves could be attributed to effects of the Loop Current on the west Florida slope but is more likely due to direct forcing by Loop Current–generated eddies impacting the experimental area.
Measurements of Ocean Surface Turbulence and Wave–Turbulence Interactions
Authors: Veron Fabrice , Melville W. Kendall , Lenain Luc 
Published: January 2009

Abstract
The uppermost layers of the ocean, along with the lower atmospheric boundary layer, play a crucial role in the air–sea fluxes of momentum, heat, and mass, thereby providing important boundary conditions for both the atmosphere and the ocean that control the evolution of weather and climate. In particular, the fluxes of heat and gas rely on exchange processes through the molecular layers, which are usually located within the viscous layer, which is in turn modulated by the waves and the turbulence at the free surface. The understanding of the multiple interactions between molecular layers, viscous layers, waves, and turbulence is, therefore, paramount for an adequate parameterization of these fluxes. In this paper, the authors present evidence of a clear coupling between the surface waves and the surface turbulence. When averaged over time scales longer than the wave period, this coupling yields a spatial relationship between surface temperature, divergence, and vorticity fields that is consistent with spatial patterns of Langmuir turbulence. The resulting surface velocity field is hyperbolic, suggesting that significant stretching takes place in the surface layers. On time scales for which the surface wave field is resolved, the authors show that the surface turbulence is modulated by the waves in a manner that is qualitatively consistent with the rapid distortion theory.
The Influences of TOVS Radiance Assimilation on Temperature and Moisture Tendencies in JRA-25 and ERA-40
Authors: Sakamoto Masami , Christy John R. 
Published: January 2009

Abstract
A Japanese long-term reanalysis (JRA-25) was completed in 2006 utilizing the comprehensive set of observations from the 40-yr ECMWF Re-Analysis (ERA-40). JRA-25 and ERA-40 adopted the same type of assimilation systems: 3DVAR with direct use of satellite sounding radiances. Long-term upper-air thermal tendencies in both reanalyses are examined and compared with the observational deep-layer temperatures of the University of Alabama in Huntsville (UAH) and Remote Sensing Systems (RSS). The upper-air temperature tendencies in the reanalyses are significantly different from those of UAH and RSS, and they appear to be influenced by the way the observations of the Television and Infrared Observation Satellite (TIROS) Operational Vertical Sounder (TOVS) are used.
This study focuses on documenting problems in TOVS assimilation, especially problems in bias corrections used in the reanalyses. Referring to quantitative results in an examination of biases between the reanalyses and raw TOVS observations, this study identifies (i) spurious thermal tendencies derived from transitions in TOVS and in the reanalysis calculation streams, (ii) an excessive enhancement of the tropical water cycle in ERA-40, and (iii) an excessive cooling trend and unstable behavior in the stratospheric temperature in JRA-25.
The results of this study suggest that any inconsistencies in TOVS usage can lead to serious inconsistencies in the reanalyses. Therefore, time-consuming efforts to obtain reliable observational information from TOVS are necessary for further progress in reanalyses.
Statistical Extension of the National Hurricane Center 5-Day Forecasts
Authors: Wilks Daniel S. , Neumann Charles J. , Lawrence Miles B. 
Published: January 2009

Abstract
U.S. National Hurricane Center (NHC) forecasts for tropical cyclone tracks and wind speeds are extended in time to produce spatially disaggregated probability forecasts for landfall location and intensity, using a weighted bootstrap procedure. Historical analogs, with respect to the forecast characteristics (location, heading, and wind speed) of a current storm, are selected. These are resampled by translating their locations to random positions consistent with the current forecast, and recent NHC forecast accuracy statistics. The result is a large number of plausible Monte Carlo realizations that jointly approximate a probability distribution for the future track and intensity of the storm. Performance of the resulting forecasts is assessed for U.S. tropical cyclone landfall probabilities during 1998–2006, and the forecasts are shown to be skillful and exhibit excellent reliability, even beyond the 120-h forecast horizon of the NHC advisory forecasts upon which they are based.
A Comparison of Precipitation Forecast Skill between Small Convection-Allowing and Large Convection-Parameterizing Ensembles
Authors: Clark Adam J. , Gallus William A. , Xue Ming , Kong Fanyou 
Published: January 2009

Abstract
An experiment has been designed to evaluate and compare precipitation forecasts from a 5-member, 4-km grid-spacing (ENS4) and a 15-member, 20-km grid-spacing (ENS20) Weather Research and Forecasting (WRF) model ensemble, which cover a similar domain over the central United States. The ensemble forecasts are initialized at 2100 UTC on 23 different dates and cover forecast lead times up to 33 h. Previous work has demonstrated that simulations using convection-allowing resolution (CAR; dx ∼ 4 km) have a better representation of the spatial and temporal statistical properties of convective precipitation than coarser models using convective parameterizations. In addition, higher resolution should lead to greater ensemble spread as smaller scales of motion are resolved. Thus, CAR ensembles should provide more accurate and reliable probabilistic forecasts than parameterized-convection resolution (PCR) ensembles.
Computation of various precipitation skill metrics for probabilistic and deterministic forecasts reveals that ENS4 generally provides more accurate precipitation forecasts than ENS20, with the differences tending to be statistically significant for precipitation thresholds above 0.25 in. at forecast lead times of 9–21 h (0600–1800 UTC) for all accumulation intervals analyzed (1, 3, and 6 h). In addition, an analysis of rank histograms and statistical consistency reveals that faster error growth in ENS4 eventually leads to more reliable precipitation forecasts in ENS4 than in ENS20. For the cases examined, these results imply that the skill gained by increasing to CAR outweighs the skill lost by decreasing the ensemble size. Thus, when computational capabilities become available, it will be highly desirable to increase the ensemble resolution from PCR to CAR, even if the size of the ensemble has to be reduced.
Optimal and continuous anaemia control in a cohort of dialysis patients in Switzerland
Authors: Mathieu Claudine M , Teta Daniel , Lötscher Nathalie , Golshayan Dela , Gabutti Luca , Kiss Denes , Martin Pierre-Yves , Burnier Michel 
Published: January 2009

Abstract

Background
Guidelines for the management of anaemia in patients with chronic kidney disease (CKD) recommend a minimal haemoglobin (Hb) target of 11 g/dL. Recent surveys indicate that this requirement is not met in many patients in Europe. In most studies, Hb is only assessed over a short-term period. The aim of this study was to examine the control of anaemia over a continuous long-term period in Switzerland.

Methods
A prospective multi-centre observational study was conducted in dialysed patients treated with recombinant human epoetin (EPO) beta, over a one-year follow-up period, with monthly assessments of anaemia parameters.

Results
Three hundred and fifty patients from 27 centres, representing 14% of the dialysis population in Switzerland, were included. Mean Hb was 11.9 ± 1.0 g/dL, and remained stable over time. Eighty-five % of the patients achieved mean Hb ≥ 11 g/dL. Mean EPO dose was 155 ± 118 IU/kg/week, being delivered mostly by subcutaneous route (64–71%). Mean serum ferritin and transferrin saturation were 435 ± 253 μg/L and 30 ± 11%, respectively. At month 12, adequate iron stores were found in 72.5% of patients, whereas absolute and functional iron deficiencies were observed in only 5.1% and 17.8%, respectively. Multivariate analysis showed that diabetes unexpectedly influenced Hb towards higher levels (12.1 ± 0.9 g/dL; p = 0.02). One year survival was significantly higher in patients with Hb ≥ 11 g/dL than in those with Hb <11 g/dL (19.7% vs 7.3%, p = 0.006).

Conclusion
In comparison to European studies of reference, this survey shows a remarkable and continuous control of anaemia in Swiss dialysis centres. These results were reached through moderately high EPO doses, mostly given subcutaneously, and careful iron therapy management.
Asymptomatic wide complex tachycardia: a case report
Authors: Mukerji Siddharth , Aloka Feras , Khasnis Atul 
Published: January 2009

Abstract
Wide complex tachycardias are a commonly encountered entity in coronary care units, intensive care units and emergency departments. Though, these arrhythmias are potentially fatal, they need to recognized first and treated appropriately. Associated physical signs are helpful in this. We present a case of a 54-year-old-female who recently underwent placement of an implantable cardioverter-defibrillator for cardiomyopathy and developed tachycardia.
Survey of Liquid Coumarin Dyes and Their Fluorescence Properties
Authors: Park So-Yeon , Kubota Yasuhiro , Funabiki Kazumasa , Matsui Masaki 
Published: January 2009

Abstract
Novel liquid 7-dioctylamino-, 7-(didecylamino)-, 7-(1-butylpentyloxy)-, and 7-(1-octylnonyloxy)-4-methylcoumarins were found. They showed melting points in the range of −55.1 to −42.8 °C as a metastable liquid phase followed by rearrangement in the range of 1.7 to 20.0 °C to form stable liquid phase. The 7-dialkylamino and 7-alkoxy derivatives showed fluorescence maxima at around 440 and 400 nm with fluorescence quantum yields ca. 0.16 and 0.06 in neat form, respectively.
Experimental Investigation of Carbon Oxidization
Authors: Yao Shuiliang , Mine Chieko , Kodama Satoshi , Yamamoto Shin , Fujioka Yuichi 
Published: January 2009

Abstract
The oxidation of carbon samples: C60, C60(OH)n, C60(O)n, C60(H)n, C70, diesel particulate matter (PM), activated carbon, and graphite was carried out using a thermogravimetry equipped with a mass spectrometer. It was found that incorporation of O, OH, and H onto C60 surfaces promotes oxidation at a temperature lower than that without incorporation. This finding is helpful to understand the mechanism of PM removal in plasma discharges. A simple oxidation mechanism of C60 and its derivatives is given.
Point-Source Fracturing: Extension of the LMN Analytical Model to Turbulent Flow
Authors: Liétard Olivier 
Published: January 2009

Abstract
A new analytical model of hydraulic fracturing under point-source conditions (LMN) has recently been proposed1 and later on corrected from a series of non critical mistakes.2 Its results for viscous fluids do agree with field evidences of an almost constant, however slightly increasing net pressure all along pad stages.
One severe limitation of the LMN model is its assumption of laminar flow, which had initially been made to ease up the mathematical treatment of the basic differential equation of the model, hence to rapidly come up with results directly applicable to the most common hydraulic fracturing jobs in highly deviated wells, i.e. those making use of crosslinked gels as proppant carriers.
The cases of Step Rate Tests pumped with water (or thin linear gels) and of the so-called riverfracs were deliberately disregarded during this first phase of the development of the LMN model. The present paper now addresses these cases by extending the latter to turbulent flow.
It is found that the resulting equation of the net pressure indicates an even weaker, however still positive, slope of the diagnostic (Nolte-Smith) plot than under laminar flow. In other words, the fracture width at the wellbore is about constant all along a fracturing treatment pumping a thin fluid at constant rate.
Improved Friction Reducer for Hydraulic Fracturing
Authors: Aften C. W. , Watson W. P. 
Published: January 2009

Abstract
An improved polyacrylamide friction reducer delivered in an inverse emulsion form has been developed for use in fresh water up to 2% KCl. The main benefits realized were an increased level of friction reduction along with an enhanced rate of inversion. These benefits were obtained without compromising the emulsion storage stability. These improvements were gained primarily by optimizing the breaker surfactant package used to release the polymer from its delivered form into the aqueous based treatment fluid.
Friction reducers are often a significant portion of the aqueous based chemical stimulation package used in either the stimulation and/or completion of oil/gas wells. Common friction reducers used for fresh water operations typically have a decline in performance when exposed to aqueous based fluids of increased salt content. The performance decline is not solely due to the nature of the polymer, but rather the mechanism of polymer release from its inverse emulsion state. The presence of salt not only affects the polymer configuration but also the ability of the inverse emulsion to release the polymer from its water internal phase into the water continuous stimulation fluid.
The new friction reducer was developed by examination of various surfactants by way of simple additions to ternary mixture designed experiments. A variety of bench top performance tests were used to narrow the selection yielding a final surfactant package. The final candidates were then screened using an in-house friction loop. The improved friction reducer dosed at 0.5gpt had a 29% increase in ultimate friction reduction in fresh water and a 119% increased performance in 2% KCl when compared to a standard friction reducer of similar charge and molecular weight. Ultimate performance enhancement was gained within reasonable raw material costs and stability limits.
With the increased ultimate friction reduction and superior inversion rate, this new product will reduce the energy required to deliver a specific volume at a set rate or increase the rate of the delivered volume at the same power for water based systems containing up to 2% KCl for stimulations and/or completions.
Irrational Fracturing — How Heuristics and Biases Affect Judgments in Fracpacking
Authors: Ammachathram V. M. 
Published: January 2009

Abstract
Fracpacking has evolved as the single, most preferred sand control completion technique in the world today. This dramatic increase in the number of fracpacks is reflected in increasing number of technology vessels, skid pumping equipment, remote data transmission capabilities and increasing numbers of personnel. The technical jargon of fracturing has become more and more common place as operating and service companies constantly try to break new barriers in the scope of fracturing and fracpacking.
Most operators and service companies have dedicated fracturing personnel, who have tremendous levels of expertise and experience in fracpacking. Unfortunately, when an application is embraced globally at such a fast paced level, personnel tend to rely subconsciously on what is called &quot;heuristics?? or &quot;rules of thumb?? that enable them to make key decisions on how to execute a fracturing treatment. The use of heuristics leads to systematic errors called &quot;biases?? that can affect the decision process as a whole; thereby affecting the entire treatment.
This paper examines the key heuristics that fracturing engineers employ. The goal of this paper is to minimize the probability of errors in judgment that are commonly made by exposing the underlying biases. For example, Anchoring and Adjustment is a common bias encountered in re-designing fracpack treatments everyday. If a group of engineers are involved in the re-design process, the first engineer that comes up with a pad volume has anchored his base volume in all the other participant's minds. The adjustments are then made based on the initial anchor and a desire to conform to the group's opinion (consensus bias). The net effect is that other possible values or solutions are either neglected or ignored. The Availability heuristic bases judgment on what is available in most recent or vivid memory. Engineers remember recently executed and problem jobs, and base their judgments on what they can instantly recall from these experiences. This paper combines the psychological impact in fracturing treatments and ways to harness these biases in a positive manner for a successful treatment.
Modified API/ISO Crush Tests With a Liquid-Saturated Proppant Under Pressure Incorporating Temperature, Time, and Cyclic Loading: What Does It Tell Us?
Authors: Freeman E. R. , Anschutz D. A. , Rickards A. R. , Callanan M. J. 
Published: January 2009

Abstract
The American Petroleum Institute (API) crush tests for proppants found in recommended practices (e.g. RP 56, 58, & 60) are typically used to compare the crush resistance of recognized API proppant sizes at a predetermined stress under dry and ambient conditions (API, 1995). This procedure has remained the same through several API committees since the early 1980s without change. More recently, the International Organization for Standardization, ISO 13503-2, reviewed the procedure and made only slight changes, most notably in the time for which the stress is to be applied (ISO, 2006). The "new" procedure from ISO gives no indication of how the stress changes the overall mesh distribution. It also sheds no light on how key factors such as moisture, temperature, time, or cyclic loading change performance characteristics. This work addresses these issues.
The down-hole environment where the proppants are placed is wet, hot, and pressurized. Incorporating these variables into a modified API test procedure for crush resistance better represents actual down-hole conditions to which a proppant is subjected. This information is critical in establishing required propped fracture conductivity, and thus, proppant selection.
In this study a standard API crush cell was modified for pressurized fluid flow at temperature and used to quantify the effects of the parameters described as compared to standard API crush tests. Tests were performed on the following proppants: light weight ceramic (LWC), intermediate density ceramic (IDC), and high strength bauxite (HSB).
Modified testing exposes critical proppant failures under conditions that more closely simulate those experienced downhole; these failures are not be revealed by current standard API/ISO test procedures. The modified procedure results in an improved method for better understanding downhole proppant pack performance.