bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Concept In Acidizing Utilizing Chemical Retardation
Authors: Knox John A. , Lasater R.M.
Published: December 2007

Publication Rights Reserved

This paper is to be presented at the 39th Annual Fall Meeting of the Society of Petroleum Engineers on Oct. 11–14, 1964, in Houston, Tex., and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper.

Establishing a technique to compare the reaction times of various types of acid solutions on limestone was the first phase in the development of a new method for retarding acid. With a critical comparison available, the well known approaches could be more properly evaluated.

The limitations of the available methods of retardation became obvious and pointed out the necessity of finding a better way to retard acid.

For several years, the approach of chemically retarding acid solutions has been under consideration by the industry, but no practical economical system was found. With the development of a fairly rapid testing technique, which simulates bottom hole conditions, the chemical retardation of acid received increased effort and a highly efficient method resulted.

Reaction times, using the new system, of up to 3 hours at 200 degrees F on pure limestone formations have been observed. The effect of chemical type, temperature, pressure and surface area to volume ratio was studied.

A possible theory describing the mechanism for this type of retardation is discussed.

Introduction

Many thousands of research hours have been devoted to the problem of stimulating oil and gas wells with various types of acid over the last thirty years. Oil companies and service companies have shared the responsibility of studying both the methods of application and materials used in these applications in an effort to improve stimulation results.

For many years acidizing was the primary stimulation method for most well problems.
Clean Fluids Improve Completion Results
Authors: Rike J. L. , Pledger T. M.
Published: December 2007

The preponderance of evidence shows that completion effectiveness, and especially well productivity, is directly related to the use of clean completion and workover fluids.

Even small amounts of solids (500 ppm) in completion and workover fluids can be enough to bridge in perforation tunnels, in channels behind pipe, and in gravel packs and in propped fractures. This plugging is responsible for many wells producing at 1085% of full potential; for multiple squeeze attempts so often necessary to successfully seal cement channels; and for sticking pipe during concentric tubing operations.

It is a widely held myth among industry operations personnel that plugg ng material is easily removed with reactive materials such as HF acid in the case of clay solids or HCl acid in the case of carbonate solids.

Tests and field experience indicate that significant increases in flow conductivity are obtained not only with clean fluids instead of muds and dirty fluids, but also when larger pressure differentials into the wellbore exist while perforating.
Semi-Automated Control of Low Volume Production Leases
Authors: Standish Thomas R.
Published: December 2007

While automated control systems have been developed for leases producing large volumes of crude, smaller volume leases have been left to traditional methods of well control. New developments in electronics now provide semi-automated well control and analysis which produces the same information as a fully automated system at a reduced per well cost.
Injection Well Workover Program In The Levelland Field: A Case History
Authors: Wilkes James H.
Published: December 2007

Sun Production Company performed a workover program in which 14 injection wells were selectively acidized to improve injection profiles. Sixty-four percent of the workovers were successful in improving vertical distribution of water injection. Increased oil production paid out the project in less than a year and raised the secondary reserves estimate by 657,000 bbls.
San Andres Reservoir Pressure Coring Project for Enhanced Oil Recovery Evaluation, Bennett Ranch Unit, Wasson Field, West Texas
Authors: Swift Terry E. , Goodrich John , Kumar Raj , McCoy R. L.
Published: December 2007

During late 1979, Gruy Federal Inc., under contract to DOE, participated with the operator in pressure coring operations in Texas Pacific BRU No. 310, Bennett Ranch Unit, Wasson field, west Texas. The well was planned as part of a program to continue development of the waterflood unit on 20-acre spacing. In all, 26 cores were cut over a 210-foot interval of the San Andres dolomite. The cored interval extended some 50 feet below the estimated original oil-water contact, allowing evaluation of CO2 floodable oil saturation in the transition zone. The analysis of the pressure coring data has provided valuable information that could not have been obtained from conventional cores and/or logs.
Waterflood Residual Oil Saturation Technology Test In A Semi-Consolidated Sandstone Reservoir
Authors: Myal F. Richard , Wesson T. C.
Published: December 2007

Gary Energy Corporation has conducted for the U.S. Department of Energy an evaluation of the technology available to measure residual oil saturation following waterflood secondary oil recovery processes in the Bell Creek Field, Powder River County, Montana.

This paper presents the results of ten stand alone tests conducted to determine waterflood residual oil saturation. The engineering techniques used in an attempt to determine the magnitude and distribution of the remaining oil saturation included pressure cores, conventional openhole logs, Carbon-Oxygen logs, Dielectric logs, the Nuclear Magnetism log, Thermal Decay Time logs and a Partitioning Tracer test.
Enhancing Employee Longevity: Diet and Exercise Strategies for Dealing With Obesity
Authors: Kuo W. H.
Published: December 2007

Obesity is the number one threat to workers' health in the 21st century. It is a contributing factor in many types of cancer and its sequelae make it the top culprit of employee disability. This paper offers medical research findings on appropriate diet and exercise regimens to ameliorate obesity and maintain appropriate body weight on a long-term basis.
Strain Relaxation Method for Predicting Hydraulic Fracture Azimuth From Oriented Core
Authors: Teufel Lawrence W.
Published: December 2007

A reliable method of predicting the orientation of massive hydraulic fractures in low-permeability formations is of great importance to the gas industry. An accurate prediction of the fracture orientation would allow optimum well location and spacing for increased recoveries in a developing field. In order to predict the azimuth of a hydraulic fracture, it is necessary to know the direction of the minimum horizontal compressive stress, because a hydraulic fracture propagates perpendicular to this stress direction. In this study a strain relaxation technique is presented as a possible method of determining the directions and the ratio of the maximum and minimum horizontal strains (stresses) from oriented core, and thus predict the fracture orientation.
Use of Constant Pressure, Finite Capacity Type Curves for Performance Prediction of Fractured Wells in Low-Permeability Reservoirs
Authors: Thompson J. K.
Published: December 2007

This paper describes the general use of previously published1 constant-pressure finite capacity type curves in predicting performance of fractured wells in low-permeability (< 0.1 md) gas reservoirs. Several well case histories are presented illustrating the use of these "reciprocal dimensionless rate" type curves in matching and forecasting well performance in tight formations. The effect of certain physical factors on predictions are also briefly discussed.

The prediction method and case histories in this paper represent the use of a relatively simple but reliable technique for time-rating of tight formation reserves. The method illustrates hand calculations which are readily adaptable to basic computer programming for use by individuals or smaller companies who may not have access to more sophisticated MHF simulators or for straightforward, single-phase flow examples where the time and expense of a MHF simulator may not be warranted.
Advances in Evaluating Gas Well Deliverability Using Variable Rate Tests Under Non-Darcy Flow
Authors: Henri Pascal
Published: December 2007

Several new mathematical models which simultaneously incorporate the effects of non-Darcy flow in formation and variable flow rate have been developed and discussed with respect to the determination of fracture and reservoir properties using tests of pressure drawdown. From these models, an appropriate approach for determining the permeability, non-Darcy flow coefficient and skin factor using the prefracture tests of short duration was shown. Another proper approach for analysing the postfracture tests was also presented. The effects of non-Darcy flow and variable rate have been emphasized, and significant progress in the interpretation of single-point variable drawdown test was made. The efficiency of this new approach is illustrated by means of a real field example.
Tight Gas Sandstone Channel Continuity and Directivity, Upper Cretaceous and Paleocene, Greater Green River Basin, Wyoming
Authors: Hodges Lance T. , Knutson Carroll F.
Published: December 2007

In order to provide background characterization information that might help achieve increased gas production from tight gas sands in the Greater Green River Basin in Wyoming, we studied outcrops of rocks in three areas: Rock Springs Uplift, Hoback Basin, and Cretaceous Mountain. Formations studied were: Paleocene (Ft. Union equivalent), Hoback, Lance, Mesaverde (Hoback Basin), Ericson, and Rock Springs. Besides photographic and base and compass surveys of channel beds in these areas, detailed measurements were made on 25 channels. About 80 tabular or parallel inclined foreset, hummocky and trough cross beds in each channel were selected for geometric and orientation measurement. The most comprehensive data was obtained on the Rock Springs Formation.

Heights of cross beds varied from 0.1 feet to several feet. Median heights ranged from 0.2 feet to 1.2 feet. For parallel inclined beds, Lance and Paleocene rocks have similar height distributions, as do Rock Springs and Hoback Formations. Ericson units have the largest cross beds. Trough heights for Paleocene and Hoback rocks are usually less than Rock Springs rocks. The Lance Formation has the smallest troughs (height and width). Dip angle distributions of parallel inclined beds are very similar for the Rock Springs, Hoback, Ericson, and Lance Formations. Paleocene and Mesaverde parallel inclined beds have larger dip angles.

Channel thickness varies from Lance, with an 8 foot median, to Ericson, with a median of 19 feet. Channel continuity was difficult to determine, but Rock Springs and Ericson have the longest observed lengths, frequently more than 1 mile. Channel paleocurrent directions were calculated from cross bed data. Nearby channels showed some similar directions.

The channels studied in the Green River Basin generally have good continuity and fair directivity. A high resolution dipmeter log could be used to record cross bed dip directions, which could be used to roughly determine the sandstone unit trends. This information could be used to help design better fracture jobs, and thus help increase gas productivity.
Resource Identification by Principal Components Analysis as Applied to Low-Permeability Reservoirs
Authors: Bialobok Stephanie J.
Published: December 2007

A preliminary step to determine the amount of recoverable reserves in a hydrocarbon reservoir may be the reconstruction of the depositional environment of the basin. Many of the major basins of the U.S. have similar origins as extensive inland seas where organic debris accumulated and hydrocarbons were generated as the sediments were compacted. If hydrocarbon-producing basins are essentially similar, then a technique for identifying the resource potential of one basin may be applicable to others.

A statistical technique known as Principal Components Analysis was used to reduce the dimensionality of a mineralogical data set from five cores of Devonian shale, a low-permeability source bed reservoir in the Appalachian Basin. The data set was reduced to three-dimensional arrays by the calculations of three hypothetical variables, the principal components, from the original variables. The resultant principal components, which explained 93 percent of the variation within the data set, were plotted graphically against the stratigraphy of the cores in an attempt to determine the extent of the basin. It is conceivable that this technique would be useful in other low-permeability reservoirs with equally satisfying results.
A Model for the High Frequency Response of Reservoir Rocks and its Implications on Dielectric Log Interpretation
Authors: Lysne Peter
Published: December 2007

The electrical response of wet reservoir rocks is primarily due to the motion of ions within the pore structure. Electric fields pin some ions at matrix-fluid interfaces, and they contribute to the bulk dielectric properties of the rock. The geometry of the pore structure influences these properties and information concerning it, as well as the water content of the rock, can be inferred from multiple frequency dielectric measurements. Taken together, this information may allow a prediction of the flow properties of the rock.
Prop Transport in Hydraulic Fractures: A Critical Review of Particle Settling Velocity Equations
Authors: Clark Peter E. , Quadir Jamal A.
Published: December 2007

The settling rate of particles in a fracturing fluid is a major factor in determining the distribution of propping agent in a hydraulic fracture. It is important to know the shape of the prop pack as well as the distribution of prop slurry in a fracture in order to optimize fracturing treatment designs. Terminal settling velocities of prop particles in hydraulic fracturing treatments are governed by fluid viscosity, fluid velocity, frac width, particle size, and particle density. There are a number of equations, based on both theoretical ground and empirical results, that can be used to predict the settling rate and thus the prop distribution in a fracture. Not all of these equations yield the same values for the terminal settling velocity of a particle under the same conditions. In this paper a number of the accepted methods will be reviewed. Predicted terminal settling velocities for a number of different conditions prevalent during a fracturing treatment will be presented.

When a particle falls through a liquid containing other particles, the terminal settling velocity of the particle is different than a single particle falling through the same liquid. This effect, termed hindered settling, can be handled in a number of different ways. Several of the equations used to treat hindered settling will be covered along with a critique of their applicability in prop transport calculations.
The Relationship of Permeability to Confining Pressure in Low Permeability Rock
Authors: Jennings James B. , Carroll Herbert B. , Raible Clarence J.
Published: December 2007

Laboratory permeability measurements of low permeability (less than 1 md) reservoir rock is significantly affected by test confining pressure. Knowledge of the confining pressure is required to predict permeability at reservoir conditions. A model is proposed which relates electrical conductivity, permeability, and pore dimensions to confining pressure. The model assumes that rock pores are interconnected by thin cracks and microfractures which can be modeled by rectangular slits. For this model, core permeability is related to confining pressure by a third order polynomial, and electrical conductivity is related to confining pressure by a first order polynomial. Electrical conductivity and permeability versus confining pressure measurements were made on test cores having laboratory Klinkenberg permeabilities from 20 to 200 microdarcys. The experimental measurements were found to be consistent with the slit model theory.
NMR Determination of Porosity and Permeability of Western Tight Gas Sands
Authors: Cowgill Donald F. , Pitman Janet K. , Seevers D. O.
Published: December 2007

Samples of fine-grained sandstone from the Colorado Interstate Gas Exploration (CIGE), Natural Buttes No. 21 core, Uinta Basin, Utah were studied using pulsed nuclear magnetic resonance (NMR) and standard mineralogical techniques. Brine-saturated rock porosities varied from 1 to 13 percent and were found deducible from the magnitude of the proton NMR. The complex pore geometry and presence of authigenic carbonate and clay minerals in these samples precluded the use of standard flow models for predicting brine permeabilities from T decays. A network model of the pore system is proposed and shown capable of accurately reproducing measured rock permeabilities, which varied from 10−4 to 1 millidarcy.
Value-Based Proficiency Training and Training in Leadership and Culture Building
Authors: Stellberg S. , Søiland V.
Published: December 2007

This paper describes an ongoing programme aiming to develop culture and management in a large corporation. A complex demand for dynamic cultural processes resulted in the establishment of a "Value-based Proficiency Training"programme including the entire workforce (phase 1).

The programme aims to create a common culture with respect to attitudes and organisational behaviour derived from the notion that value-based proficiency training holds the individual responsible and influence an enduring change in behaviour. The concept seems unique with regards to developing management in practice and influencing culture in large corporations. Through practice and training the participants identify and develop a common consensus with respect to best practice based on successful experience in addition to establishing cultural core values as a foundation for HSE decision processes.

The programme made visible a need for leadership training in order to secure and enhance the elements within daily practices. Experiences in phase 1 and interviews with a number of leaders built the foundation for an advanced "Management Leadership and Culture Building"-programme (phase 2). Its aim is to raise the awareness of the importance of leaders as culture builders in order to promote a safe culture of performance.

Results reveal a consistent effectiveness of training with respect to strengthening good leadership, culture building and raising personal awareness and responsibility of individual personnel. Based on the above, the company has instituted an in-house training centre as a permanent and integrated part of the business. The training centre is drifted by internal personnel allowing for continuous training and a constant focus on a cultural development within the organization. External consultants and research institutions have contributed with respect to the planning and implementation.
Stochastic Modeling of Fractured Gas Wells Completed in Low Permeability Noncontinuous Lenticular Reservoirs
Authors: Evans Ronald D. , Carroll Herbert B.
Published: December 2007

A mathematical model is presented which forms the basis for a reservoir simulator that can be used to assist in interpretation and prediction of the performance of hydraulically fractured gas wells completed in noncontinuous sand lense formations. Equations are derived to simulate both reservoir and well performance. They are general in that the following effects are considered: 1. noncontinuous sand lenses 2. three-dimensional flow in the reservoir and one-dimensional flow in the fracture. 3. non-Darcy flow in the reservoir and fracture 4. wellbore and fracture storage 5. formation damage on the fracture face 6. frictional pressure drop in the production string and 7. Klinkenberg effect. An opertional two dimensional gas reservoir simulator has been developed which includes these effects and has been verified for some selected test cases.
NOx Emissions from Steam Generators Used in Thermal Enhanced Oil Recovery
Authors: Nelson Lawrence P. , Folsom Blair A.
Published: December 2007

Recovery of the substantial crude oil reserves in central California has been restricted by stringent state regulations limiting the NOx emissions from steam generators used to enhance the recovery process. These regulations specify that emissions reductions below a baseline level are required when certain ambient NO2 triggering levels are exceeded. There have been no comprehensive test programs aimed at defining baseline emissions from steam generators or the effects of design parameters on those emissions. There have, however, been many individual tests of steam generators that have been performed primarily to comply with licensing requirements and these show that NOx emissions from standard 15 MW (50 × 106 Btu/hr) generators vary by a factor of five, from 160 to 825 cm3/m3 NOx, corrected to 3 percent O2. Clearly, this indicates a need to identify an established baseline to which emissions levels from alternative configurations may be compared.

The study described in this paper entailed compilation of all available test results and analysis of these to 1) define the NOx emissions baseline, 2) delineate the effects of several design variables on emissions, and 3) address the effectiveness of field tested NOx reduction techniques and equipment. From these results, the 15 MW (50 × 106 Btu/hr) steam generator with a conventional burner was observed to be the most common configuration. The type of burner and steam generator were found to be relatively unimportant, probably because of similarities in design between manufacturers. The generator capacity was of greater importance. Steam generators with 6 MW (20 × 106 Btu/hr) nominal capacity exhibited NOx emissions exceeding the 15 MW (50 × 106 Btu/hr) conventional burner levels, as did 15 MW (50 × 106 Btu/hr) generators equipped with low excess air burners (designed for high thermal efficiency). Field test results from two NOx reduction methods were also analyzed. Ammonia injection into the combustion products showed significant effect on NOx emissions; current technology low NOx burners were characterized by emissions near conventional burner levels.
An Analysis of Fracturing Pressures in the South Belridge and Lost Hills Fields
Authors: Swanson Glenn S. , Meeken Richard B.
Published: December 2007

This paper presents both theories and rules of thumb believed applicable to everyday fracturing situations in the Lost Hills and South Belridge fields. Pressure analysis is featured with emphasis on bottom hole fracturing pressure calculation and interpretation. Suggestions for the application of findings are offered in hopes of increasing the efficiency of current frac completion and treating methods.
Numerical Simulation of Thermal Recovery Processes
Authors: Soliman Mohamed Y. , Brigham W. E. , Raghavan Raj
Published: December 2007

This paper presents the development and application of an In-Situ combustion model designed to simulate a laboratory combustion tube. This model is a first step to a comprehensive field model. It considers both mass and heat balance equations. Combustion is assumed to occur from direct burning of oil. Except for this assumption, the simulator rigorously considers the flow of different fluid phases through a combustion tube. To expand the mass and heat balance equations, we use a fully implicit finite difference scheme. The resulting system of equations is solved simultaneously.

The model calculates data on pressure, temperature and saturation distribution inside a combustion tube. These data are compared to published laboratory combustion tube data as well as other existing numerical simulators.

In addition, the model also simulates hot water flooding and steam injection. Calculated temperature and saturation distribution for both of these processes are presented.
NMR Desaturation and Surface Relaxivity Measurements on Clastic Rocks
Authors: Dastidar R. , Sondergeld C. H. , Rai C. S.
Published: December 2007

Archie1 recognized the importance of information obtained over multiple observational scales. As confidence grows in properties measured by vastly improved logging capabilities, we tend to ignore Archie's original insight. Nuclear Magnetic Resonance2, NMR, yields rock independent estimates of porosity as well as estimates of bound and movable water and the distribution of pore bodies. These measures are combined with empirical core studies to infer permeabilities and to predict capillary pressure from NMR data. Our experimental study is designed to evaluate these empirical relationships and to understand the variability in T2 response due to the intrinsic properties of the porous network.

We have analyzed 90 cores with mixed orientation from five different clastic formations. The analysis included high pressure mercury injection, NMR desaturation, permeability, porosity and mineralogical measurements. NMR measurements were performed with a 2 MHz spectrometer. The porosity of the cores ranged from 4% to 23% while measured air permeabilities ranged from 0.01 to 900 md.

The T2 cutoff i.e., the boundary between free and bound water, for the complete set of samples ranges from 6 to 100 msec which represents significant departures from the typically assumed 33 ms cutoff for clastics. Mineralogical dependence is observed in the behavior of T2 cutoff. In general, the permeability estimation based on a weighted geometric mean of the T2 time performed better than the model based on the ratio of free fluid index to bound volume index. Mapping of pore bodies as measured with NMR to pore throat derived from Hg injection resulted in estimation of surface relaxivities which ranged from 6 to 50 μm/sec. These relaxivities were used to generate pseudo-capillary pressure curves from NMR which map well with the measured capillary pressures. Comparison between the cumulative NMR and mercury data yields insight into differences in the pore structure between samples. Mineralogical composition of the matrix influences the surface relaxivity especially if paramagnetic ions (e.g. Fe2+) are present3. On an average there is a general decrease in surface relaxivity with increase in quartz content.
Use of principal component analysis, factor analysis and discriminant analysis to evaluate spatial and temporal variations in water quality of the Mekong River
Authors: Shrestha Sangam , Kazama Futaba , Nakamura Takashi
Published: December 2007

Multivariate statistical techniques, such as principal component analysis (PCA), factor analysis (FA) and discriminant analysis (DA), were applied for the evaluation of temporal/spatial variations and the interpretation of a large complex water quality dataset of the Mekong River using data sets generated during 6 years (1995–2000) of monitoring of 18 parameters (16,848 observations) at 13 different sites. The results of PCA/FA revealed that most of the variations are explained by dissolved mineral salts along the whole Mekong River and in individual stations. Discriminant analysis showed the best results for data reduction and pattern recognition during both spatial and temporal analysis. Spatial DA revealed 8 parameters (total suspended solids, calcium, sodium, alkalinity, chloride, iron, nitrate nitrogen, total phosphorus) and 12 parameters (total suspended solids, calcium, sodium, potassium, alkalinity, chloride, sulfate, iron, nitrate nitrogen, total phosphorus, silicon, dissolved oxygen) are responsible for significant variations between monitoring regions and countries, respectively. Temporal DA revealed 3 parameters (conductivity, alkalinity, nitrate nitrogen) between monitoring regions; 3 parameters (total suspended solids, conductivity, silicon) in midstream region; and 2 parameters (conductivity, silicon) in upstream, lower stream and delta region which are the most significant parameters to discriminate between the four different seasons (spring, summer, autumn, winter). Thus, this study illustrates the usefulness of principal component analysis, factor analysis and discriminant analysis for the analysis and interpretation of complex datasets and in water quality assessment, identification of pollution sources/factors, and understanding of temporal and spatial variations of water quality for effective river water quality management.
Data-driven modelling: some past experiences and new approaches
Authors: Solomatine Dimitri P. , Ostfeld Avi
Published: December 2007

Physically based (process) models based on mathematical descriptions of water motion are widely used in river basin management. During the last decade the so-called data-driven models are becoming more and more common. These models rely upon the methods of computational intelligence and machine learning, and thus assume the presence of a considerable amount of data describing the modelled system's physics (i.e. hydraulic and/or hydrologic phenomena). This paper is a preface to the special issue on Data Driven Modelling and Evolutionary Optimization for River Basin Management, and presents a brief overview of the most popular techniques and some of the experiences of the authors in data-driven modelling relevant to river basin management. It also identifies the current trends and common pitfalls, provides some examples of successful applications and mentions the research challenges.
Water demand management – shifting urban water management towards sustainability
Authors: Kayaga S. , Smout I. , Al-Maskati H.
Published: December 2007

Whereas the world population is increasing at a high rate, especially in urban areas, water resources have not only remained constant, but are being polluted at a high rate, which inevitably results in fresh water scarcity. Current urban water management concepts and practices cannot adequately respond to these changes. There is need for water professionals to change the way they manage water resources in urban areas if we are to ensure economic and environmental sustainability. In addition to consideration of supply-side options, we need to apply water demand management (WDM) tools both on the utility and end-user sides. This paper describes the basic concepts of WDM, provides a case study of their application in Bahrain, and briefly introduces the five-year EU-funded SWTCH Project that aims at creating a paradigm shift in urban water management practices.
Water supply benchmarking – a cross-border comparison of outcomes and benefits in Austria and southern Germany
Authors: Neunteufel R. , Kiesl H. , Perfler R. , Haberl R. , Schielein J. , Theuretzbacher-Fritz H. , Kölbl J. , Kainz H.
Published: December 2007

Recently, many countries have started benchmarking studies with the aim of improving performance in their water sectors. To see regional differences in water supply, a cross-country comparison based on five benchmarking projects of Austria and different German federal states was done. It was verified that the influencing factors on costs are mainly related to regional and structural parameters, causing the crosscountry differences. Besides the age of the mains, urbanity is one of the major influencing factors on burst rates, leakage, and also on mains rehabilitation. The survey on the benefits of benchmarking suggests that it more than pays for itself. Most participants found opportunities to optimize operation and efficiency. No company stated higher costs than benefits. Benchmarking does not only optimize efficiency, but more importantly, quality, reliability and sustainability of supply services.
Modeling the impact of permeate flux and hydrodynamic conditions on fouling in submerged hollow fiber membranes
Authors: Lin H. , Bérubé P.R.
Published: December 2007

A series of studies was undertaken to investigate the impact of the system hydrodynamics (i.e., sparging intensity and membrane module configuration) the operating permeate flux and fouling reduction measures on the evolution of the trans-membrane pressure (TMP). The evolution in TMP could be modeled using a simple exponential relationship that incorporated the impact of the air sparging intensity, the membrane module configuration and the backwash cycles on the evolution in TMP. The extent of reversible fouling was a function of the operating permeate flux and the hydrodynamic conditions in the membrane system and could be characterized based on the difference between the operating permeate flux and the critical permeate flux. Reversible fouling could be eliminated during each backwash cycle. The extent of irreversible fouling was relatively low and was expected to be a function of the diffusion and adsorption tendency of foulants within the membrane pores.
Family Caregiving or Caregiving Alone: Who Helps the Helper?
Authors: Sims-Gould Joanie , Martin-Matthews Anne
Published: December 2007

This study advances the understanding of family caregiving by examining the relationship between adult children caregivers and their helpers. Specifically, it focuses on examining “who helps whom” and extends analyses beyond the dyadic focus of caregiving in later life. The focus on helping and caregiving addresses the variety of contributions and responsibilities involving not only the caregiver who was the target respondent in this research, but also others identified as helpers in the provision of care.

The data for this study are derived from the Work and Eldercare Research group of CARNET: The Canadian Aging Research Network. Secondary analysis of CARNET data focuses on data collected from 250 individuals with significant caregiving responsibilities for at least one older person. Findings extend Kahn & Antonucci's convoys of social support model (1981) and Cantor's model of social care (1991) by disentangling some of the dimensions of helping and caregiving, such as the distinction between direct and assistive help.
Social Network Data Validity: The Example of the Social Network of Caregivers of Older Persons with Alzheimer-Type Dementia
Authors: Carpentier Normand , Ducharme Francine
Published: December 2007

This article offers reflection on the validity of relational data such as used in social network analysis. Ongoing research on the transformation of the support network of caregivers of persons with an Alzheimer-type disease provides the data to fuel the debate on the validity of participant report. More specifically, we sought to understand the factors that might influence the description of the support network by persons involved in caregiving. The issue warrants special attention, given that social relations – in their form and their content – constitute the raw material of network analysis. We propose that how persons describe their social network corresponds to a subjective process that rests, in part, on their representation of their cultural and social universe.
Allophone Students in French Second-Official-Language Programs: A Literature Review
Authors: Mady Callie
Published: December 2007

Abstract:

In Canada, education in French as a second language (FSL) offers students the opportunity to learn a second official language. Is such an opportunity appropriate for allophone students who are still in the process of learning English? This literature review provides a fourfold consideration of the issue. Section 1 examines the political response by investigating whether Canadian federal policies provide for the inclusion of allophone students in FSL programs. Section 2 provides an overview of provincial policies, specifically examining allophone students’ access to FSL. A review of the literature regarding the motivation of allophone students is found in Section 3. Finally, Section 4 details the research on the achievement of allophone students studying French.
Are soil lichen communities structured by biotic interactions? A null model analysis
Authors: Maestre Fernando T. , Escolar Cristina , Martínez Isabel , Escudero Adrián
Published: December 2007

Question: Are soil lichen communities structured by biotic interactions?

Location: Gypsum outcrops located next to Belmonte del Tajo, central Spain.

Methods: We sampled a total of 68 (50 cm × 50 cm) plots in gypsum outcrops from central Spain. Each plot was divided into 100 (5 cm × 5 cm) sampling quadrats, and the presence of all lichen species in every quadrat was recorded (6800 quadrats in total). We used two realistic null models to generate random communities unstructured by biotic interactions, and used them to test the hypothesis that soil lichen species co‐occur less often than expected by chance.

Results: We found fewer species combinations and less co‐occurrence than expected by chance. However, the latter result was dependent on the null model selected. The number of checkerboard pairs did not differ significantly from the null expectation.

Conclusions: Overall, our results suggest that gypsiferous soil lichen communities are structured by competitive interactions. They are consistent with studies conducted with a wide variety of taxa, and fill a gap in our knowledge of the factors driving the small‐scale distribution of these important organisms.
Evolutions, Revolutions and Trends in Biomaterials Science – A Perspective
Authors: Jandt K. D.
Published: December 2007

Despite a number of shortcomings biomaterials for implants have not changed much during the last decades. Yet, there is a revolution ongoing in fundamental biomaterials science research, which introduces new concepts and may help to answer a number of open questions. Bioactive and biomimetic nanomaterials in zero, one or two dimensions may be at the brink of transfer to clinical testing and application. These materials will in the future intervene actively in biological processes, such as protein adsorption, cell binding and growth.
Pentacyclic Compounds by Samarium Diiodide‐Induced Cascade Cyclizations of Naphthyl‐Substituted 1,3‐Diones
Authors: Wefelscheid Ulrike K. , Reissig Hans‐Ulrich
Published: December 2007

Treatment of naphthyl‐substituted cyclopentane‐1,3‐diones with the samarium diiodide‐ hexamethylphosphoramide (HMPA) complex in the presence of tert‐butyl alcohol provided the expected tetracyclic diols with steroid‐like structures. Surprisingly, reactions without the proton source led to the efficient formation of a new pentacyclic diol. In this case the toxic additive HMPA could be substituted by a combination of lithium bromide (in situ generation of samarium dibromide) and N,N‐dimethylimidazolidone. The styrene‐like alkene moiety of this product was used to prepare an ensemble of highly substituted pentacyclic steroid‐like compounds.
Insulin and solid‐phase synthesis, 1964–1970
Authors: Marglin Arnold
Published: December 2007

A chemical synthesis of insulin was undertaken by solid phase principles during the period 1964–70. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 200–202, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Identification of metabolic fluxes in hepatic cells from transient 13C‐labeling experiments: Part II. Flux estimation
Authors: Maier Klaus , Hofmann Ute , Reuss Matthias , Mauch Klaus
Published: December 2007

This contribution addresses the identification of metabolic fluxes and metabolite concentrations in mammalian cells from transient 13C‐labeling experiments. Whilst part I describes experimental set‐up and acquisition of required metabolite and 13C‐labeling data, part II focuses on setting up network models and the estimation of intracellular fluxes. Metabolic fluxes were determined in glycolysis, pentose‐phosphate pathway (PPP), and citric acid cycle (TCA) in a hepatoma cell line grown in aerobic batch cultures. In glycolytic and PPP metabolite pools isotopic stationarity was observed within 30 min, whereas in the TCA cycle the labeling redistribution did not reach isotopic steady state even within 180 min. In silico labeling dynamics were in accordance with in vivo 13C‐labeling data. Split ratio between glycolysis and PPP was 57%:43%; intracellular glucose concentration was estimated at 101.6 nmol per 106 cells. In contrast to isotopic stationary 13C‐flux analysis, transient 13C‐flux analysis can also be applied to industrially relevant mammalian cell fed‐batch and batch cultures. Biotechnol. Bioeng. 2008;100: 355–370. © 2007 Wiley Periodicals, Inc.
The effect of NQO1 polymorphism on the inflammatory response in cardiopulmonary bypass
Authors: Isbir C. Selim , Ergen Arzu , Tekeli Atike , Zeybek Umit , Gormus Uzay , Arsan Sinan
Published: December 2007

Cardiopulmonary bypass (CPB) has been associated with systemic inflammatory response syndrome (SIRS). Endothelial dysfunction related to non‐laminar flow during CPB is known to play a key role in this complex pathology. Antioxidant response element (ARE) dependent NAD(P)H:quinone oxidoreductase 1 (NQO1) promoter is a regulatory element involved in the anti‐inflammatory mechanism in vasculature exposed to non‐laminar flow. Mutation of the NQO1 could represent a novel anti‐inflammatory effect in CPB. The goal of this study was to demonstrate whether genetic variants of NQO1 affect cytokine release after CPB. Eighteen patients who underwent standard coronary artery bypass grafting (CABG) operation were included in the study. Genotyping for NQO1 was performed. Serum Interleukin‐6 (IL‐6) levels were measured before induction, during CPB after declamping the aorta, and 24 h after operation. Clinical data were collected respectively. Seven patients were NQO1 T carriers and 11 patients were NQO1 T non‐carriers. During CPB, IL‐6 concentrations were increased in NQO1 T carriers compared to T non‐carriers (p = 0.038). Although ventilation times and blood loss were higher in T carriers these were not statistically significant. Patients with NQO1 T carriers showed significantly higher IL‐6 levels during CPB. Non‐laminar flow during CPB may diminish the transcriptional activation of the NQO1 in T carriers. Preoperative determination of this novel anti‐inflammatory mechanism could be useful to improve operative outcome in CPB. Copyright © 2007 John Wiley & Sons, Ltd.
Use of multislice CT for the evaluation of emergency room patients with chest pain: The so‐called “Triple rule‐out”
Authors: Gallagher Michael J. , Raff, Gilbert L.
Published: December 2007

Recent advances in computed tomography (CT) technology have made high resolution noninvasive coronary angiograms possible. Multiple studies involving over 2,000 patients have established that coronary CT angiography (CCTA) is highly accurate for delineation of the presence and severity of coronary atherosclerosis. The high negative predictive value (>95%) found in these studies suggests that CCTA is an attractive option for exclusion of coronary artery disease in properly selected emergency department patients with acute chest pain. CT is also a well established and accurate tool for the diagnosis of acute aortic dissection and pulmonary embolism. Recent technical developments now permit acquisition of well‐opacified images of the coronary arteries, thoracic aorta and pulmonary arteries from a single CT scan. While this so called “triple‐rule out” scan protocol can potentially exclude fatal causes of chest pain in all three vascular beds, the attendant higher radiation dose of this method precludes its routine use except when there is sufficient support for the diagnosis of either aortic dissection or pulmonary embolism. This article provides an overview of CCTA, and reviews the clinical evidence supporting the use of this technique for triage of patients with acute chest pain. © 2008 Wiley‐Liss, Inc.
ChemInform Abstract: Kolbeckite, ScPO4×2H2O, Isomorphous with Metavariscite.
Authors: Yang Hexiong , Li Chen , Jenkins Robert A. , Downs Robert T. , Costin Gelu
Published: December 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Pr4B10O21: A New Composition of Rare‐Earth Borates by High‐Pressure/High‐Temperature Synthesis.
Authors: Haberer Almut , Heymann Gunter , Huppertz Hubert
Published: December 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Cyclization of Vinyl Ethers Derived from Amino Alcohols.
Authors: Kukharev B. F. , Stankevich V. K. , Klimenko G. R. , Kukhareva V. A.
Published: December 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Selective Aerobic Oxidation of Activated Alcohols into Acids or Aldehydes in Ionic Liquids.
Authors: Jiang Nan , Ragauskas Arthur J.
Published: December 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Pd—C‐Induced Catalytic Transfer Hydrogenation with Triethylsilane.
Authors: Mandal Pijus K. , McMurray John S.
Published: December 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Organocatalytic Activation of TMSCN by Basic Ammonium Salts for Efficient Cyanation of Aldehydes and Imines.
Authors: Raj I. Victor Paul , Suryavanshi Gurunath , Sudalai A.
Published: December 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Reactivity of Olefin Metathesis Catalysts Bearing Cyclic (Alkyl)(Amino)Carbenes.
Authors: Anderson Donde R. , Lavallo Vincent , O'Leary Daniel J. , Bertrand Guy , Grubbs Robert H.
Published: December 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of 3,3,4,4,4‐Pentafluoro‐2‐oxobutane‐1‐sulfonyl Fluoride.
Authors: Stepashkov D. M. , Cherstkov V. F.
Published: December 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.