bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening Considerations for Curable Resin-Coated Proppants
Authors: van Batenburg Diederik , Nieuwland Bas , Sandy Joe
Published: July 2008

Curable resin-coated proppants (RCP) have been used to minimize proppant flowback from propped hydraulic fractured oil and gas wells for years, yet proppant backproduction is still reported to be a major operational problem. The industry cannot currently explain why some hydraulic fractures propped with curable RCP produce proppant back while others containing only uncoated proppant do not produce any proppant back.

This paper presents results of a study done to help determine screening considerations for curable resin-coated proppants. The study involved curing and crushing proppant plugs under a variety of conditions ranging from frac-and-pack applications in shallow wells to fracturing applications in deep horizontal wells. These tests were conducted to identify suitable RCPs for given applications.

The unconfined compressive strength (UCS) of proppant plugs cured in the treatment fluid at reservoir temperature with closure stress applied, is currently used as the screening criterion for curable RCP. The UCS needs to be as high as possible while the same resin coating should not consolidate the proppant while left in the well after a treatment without closure stress applied. This study demonstrates that at least six data points are needed to obtain a representative value for the unconfined compressive strength (UCS) of proppant for any one set of conditions. Although several studies of factors affecting the performance of RCPs have been presented in the literature, the conclusions in these studies are generally based on limited data for one set of conditions and are, therefore, often questionable.

In addition, the effect of cooldown and subsequent heatup on RCPs after a treatment has not been considered previously as a factor in proppant backproduction. This paper demonstrates that this temperature effect is an important parameter to consider. Stress cycling has been identified as one of the failure mechanisms for RCP in experiments. These experiments were conducted at ambient temperature with proppant packs cured at temperatures between 160 and 200°F (71 and 93°C). We conducted similar experiments at simulated in-situ conditions to verify whether the mechanism was still effective for these conditions. We found that the addition of thermoplastic film material to RCP cured at 300°F (149°C) increased its resistance to stress cycling.
Effect of Formation Minerals On HEC Gel Return Permeability and Techniques to Overcome Potential Damage
Authors: Hossaini Mohammad , Gabrysch Allen
Published: July 2008

This paper describes the methodology and results of a series of tests conducted on HydroxyEthyl Cellulose (HEC) gel to determine its effects on return permeability. HEC gel is widely used in the oilfield as a carrier fluid in gravel packing operations and is generally considered to cause minimal formation damage. However, results of this study indicate that even when HEC gel is efficiently removed from the formation, interaction between the fluid and the formation can result in reduced return permeability. Therefore, particular care must be given to quality control and mixing procedures to minimize potential formation damage.

HEC gel break-back procedures used by oilfield laboratories for return permeability measurement are based on displacement studies related to reservoir engineering. In these tests, flow through a Berea core is maintained at constant pressure and later, after introduction of the test fluid, the change in permeability is calculated as a percent of the initial permeability. In these cases, any resulting loss of permeability was assumed to be caused by HEC gel trapped in the formation.

To insure complete HEC degradation over time and temperature with and without the presence of formation minerals, seven different breaker systems were evaluated to select the most efficient system.

This study concludes that damage caused by HEC residue is minimal compared to the damage caused by the interaction of the fluid and the rock minerals present in various formations. The results of our investigation also indicate that the performance of breakers is influenced by the presence of formation minerals.

This paper will present experimental data of HEC gel break-back in the presence of formation minerals as well as the testing of chemical additives designed to minimize damage and deliver improved return permeability.
Stabilization of Montmorillonite Clay in Porous Media by Polyacrylamides
Authors: Zaitoun A. , Berton N.
Published: July 2008

The critical salinity concentration (CSC) was used to compare the ability of nonionic polyacrylamides (PAM) and cationic polyacrylamides (CPAM) to stabilize montmoriilonite clay dispersed in sandpacks. The method consists of injecting brine at decreasing salinity levels until clay release is detected by a continuous increase in pressure drop.

As expected, because of the neutralization of negative clay surface charges by adsorbed macromolecules, CPAM have a higher stabilizing power than PAM, lowering the CSC of NaCl from 27 500 to only 500 ppm, and the CSC of KCI from 5000 to 1000 ppm. However, because of their ionicity and very high adsorption level, CPAM strongly reduce sandpack permeability. Likewise, a low-molecular-weight PAM may be preferred because of its good stabilizing power associated with a minimal loss of core permeability.
Multirate Well Testing to Evaluate the Effectiveness of Frac Packing
Authors: McLeod Harry O. , Jordan Scott W. , Shurtz David F.
Published: July 2008

A gas well in the Gulf of Mexico was frac packed with 40/60 mesh gravel using a high temperature borate cross-linked HPG polymer fluid. The flow rate and wellhead pressure were monitored during cleanup. When no further cleanup of fracturing fluid was observed, a multirate test and pressure buildup were conducted on the well. These data were interpreted to give: reservoir permeability and pressure, skin factor, fracture half-length, and fracture conductivity. The multirate testing provided the non-Darcy flow coefficient. Based upon the flowing cross sectional area of the gravel filled perforations, the non-Darcy coefficient was assumed to dominate the completion pressure drop. This coefficient was analyzed to yield the permeability of the gravel in the packed perforations connected to the fracture. This initial test and analysis showed that the permeability was much less than laboratory measured values. This damage was attributed to residual polymer damage. The well was monitored for one year. During this time, the gravel permeability increased. A multirate test and pressure buildup test were performed one year after treatment, and analysis showed that all damage to the gravel permeability had disappeared. The calculations used in these analyses are presented.
Slopes Analysis of Frac & Pack Bottomhole Treating Pressures
Authors: Valko P. , Oligney R. E. , Schraufnagel R. A.
Published: July 2008

A simple means has been developed to analyze frac & pack bottomhole treating pressures which gives insight to the fracture evolution and end-of-job proppant distribution. The method requires minimal input, is relatively model independent (as far as fracture propagation is concerned) and can be used in real time. This is not history matching, but rather an analysis or screening tool.

The key element of frac & pack treatments is the tip screen-out, a period of injection during which the fracture is inflated and the fracture extent remains relatively constant. The fracture may often extend in subsequent periods of regular fixed-area width growth with possible "jumps" and/or other irregular areal extension periods between them. The slope of the increasing pressure curve during a "regular" period may be interpreted to obtain the "packing radius" of the fracture, characteristic for the given period. The progression of packing radiuses can be combined with information on the proppant injection history to give final proppant distribution.
Controlling Organic Deposits and Sludge in a Severe Hostile Environment
Authors: Ftgueroa-Ortiz V. , Cazares-Robles F. , Fragachan F. E.
Published: July 2008

Formation damage, tubing plugging and plugged production equipment caused by the deposition of organic deposits and sludge are inherent in many workover and stimulation operations around the world.

This paper describes the methodology followed to improve production through adequate stimulation treatments and control of the organic and sludge deposition existing in the south-east of Mexico. In fact, this is a recurring problem that has existed for xnanv years severely affecting oil production.

Evaluation of the results and conclusions derived at different stages of the analysis are discussed. The benefits of emulsifying the acid with an aromatic (external phase), are also presented including the key factor of the iron reducing agent in a ferric iron environment in addition to the required iron sequestering agent.

Results of stimulations performed in the area are discussed including well performance months after treatments.
A Novel Reducing Agent for Combatting Iron-Induced Crude Oil Sludging: Development and Case Histories
Authors: Vinson Edward F.
Published: July 2008

This paper presents the results of a study of sludge formation from the reaction of "real-world" hydrochloric acid with several crude oils. Dissolved ferric iron has previously been shown to be a major factor in the genesis of sludges in acidizing treatments. This work compares the sludge abatement capabilities of a novel iron reducing agent with those of several iron control agents in common use in the oilfield. Simple tests based on established API procedures are used. Results of field treatments using the new reducing agent are included.
Postfracture Formation Evaluation in the Valhalla Field, Alberta
Authors: Ning X. , Collins J. L. , Marcinew R. P. , Dumont G. L. , Hogg J. R.
Published: July 2008

A number of highly permeable oil wells in the Valhalla field require re-fracturing treatments to optimize production. However, occasionally re-fracturing treatments are unsuccessful because the wells appear damaged after the treatments.

Presented are the results of an extensive study of the probable damage mechanism, and remediation of a well in the Valhalla field. A carefully designed and conducted pressure buildup test yielded better estimates of near wellbore and formation properties than the conventional test. A numerical reservoir simulator is used in the case study to history match the measured pressure buildup data and predict production. The cause and extent of the damage were determined, thus allowing modifications to be made to future re-fracturing programs. The well was then stimulated successfully with a second re-fracturing treatment.

The methodology presented in this study is designed to aid petroleum engineers to understand the importance of applying well-designed and interpreted pressure transient tests, to assess critical formation behavior.
Effect of Cleanup Acids on Compressive Strength of Proppants Used In Gravel Packing
Authors: Welch J. C. , Hossaini Mohammad
Published: July 2008

While originally developed for fracturing, manmade ceramic proppants are sometimes used for gravel packing wells. This is primarily due to their improved performance. However, the high solubility of ceramic proppants present in cleanup acids is a cause for concern when these proppants are used in gravel packing. This paper presents the results of a study investigating the effect of cleanup acids on the solubility and compressive strength of commercial gravel and ceramic proppants used in gravel packing.

A laboratory setup was designed to simulate material in a perforation tunnel. It included a Hassler core holder and lead sleeve mounts. Pre-flush, acid stages, and post-flush were pumped through the confined gravel and exposure time simulated field pumping times. Following acid exposure, the samples were checked for weight loss, submitted for SEM analysis, and tested for crush resistance. Fines and oversize particle generation were compared to untreated samples using standards set forth in API-RP 581.

It is possible that a perforation will plug during the acid stage. Since a plugged perforation would prevent a sweep by the postflush, gravel in the perforation would be exposed to live acid indefinitely. To gain insight into the effect of prolonged acid exposure, a sample of ceramic proppant and 12:3 mud acid + corrosion inhibitor was placed into a mud aging cell and heated for five days. Afterwards, the sample was checked for weight loss, submitted for SEM analysis, and tested for crush resistance.

Results of this study found that the effect of weight loss does not impact crush resistance when tested in accordance with the API-RP 58 gravel packing quality control procedure.
Effects of Completion Scenarios and Formation Damage on Two-Phase Inflow Performance of A Horizontal Well
Authors: Permadi Pudji
Published: July 2008

Completion scenarios and knowledge of formation damage distribution are key factors that determine the success of horizontal well applications. In a bottom water drive reservoir the completion scenario should be selective because a significant portion of the horizontal well section would not be productive at late production period. A simple correlation to estimate pseudoskin factors due to partial completion for a horizontal well is provided. When water or gas coning is not expected, distributed perforation intervals in a damaged formation yield the highest productivity.
Experience with Horizontal Wells in the Statfjord Field
Authors: Kostøl Petter , Berg Dag P.
Published: July 2008

The paper will review the most recent experience with completion techniques and production performance in horizontal wells in the Statfjord field. A total of 25 horizontal/extended reach wells have been drilled and completed to date. Wells with horizontal section up to 2230 m have been drilled and the longest horizontal displacement is 7290 m. Several well interventions have been performed in these wells, primarily for re-completion purposes. The paper will describe development of completion and intervention techniques with focus on perforating, well killing, well productivity and sand free production rates. Operational consequences in well interventions due to well design will be shown.

The first horizontal wells were perforated in overbalance on drillpipe, while today most intervals are perforated in underbalance with coiled tubing. Production and reservoir management for these wells will be discussed with focus on requirements for data acquisition and well intervention.

Future possibilities for horizontal wells on Statfjord and technology requirements will finally be discussed in the paper.
Three Methods of Achieving a True Hydraulic Seal/Control Across a Junction in a Multi Lateral Well
Authors: Ross Bob
Published: July 2008

For many multi lateral well applications, achieving a mechanically stable junction between the main well bore and a branch is critical, not only to meeting pressure integrity requirements during the initial completion, but also to maintaining control of individual lateral sections during future interventions. During 1996, three different completions systems designed to allow for a true hydraulic seal and/or control at the junction in a multilateral well will have been field tested in the North Sea/World. This paper describes the three systems, including the advantages and disadvantages of each, and will summarise their deployment and field performance.
Habitat Degradation and Conservation Status Assessment of Gallinaceous Birds in the Trans‐Himalayas, China
Authors: WANG WEI , REN GUOPENG , HE YUANHUI , ZHU JIANGUO
Published: July 2008

Abstract: The greatest concentration of Chinese Galliformes occurs in the Trans‐Himalayas. We selected 4 northwestern Yunnan counties (Lijiang, Shangri‐la, Deqin, and Weixi) in the Trans‐Himalayas to assess the conservation status of 9 gallinaceous forest birds. We developed maps depicting recent forest cover and modeled habitat availability of each gallinaceous forest bird based on 3 factors that restrict its distribution: geographic location, elevation range, and forest coverage. The conservation status of 4 species was inadequate, because <10% of their respective potential habitats were within existing nature reserves. To predict the historic habitats of the species we studied, we also delineated a forest map from the late 1950s. We calculated the loss and fragmentation of potential habitats within the past 40 years as degree of habitat degradation. Our results showed that all 9 species became reduced and fragmented of their potential habitats from the late 1950s to 2002. Assessing habitat degradation and conservation status of wild species could help identify the threatened species with poor protection and degraded habitats, thereby warranting more attention in future conservation strategies. To protect those threatened species, it is urgent that the government should design new nature reserves to fill the conservation gaps, and enlarge and strengthen the management of existing natural reserves to reduce effects of human activities on their habitats.
Eradication of Feral Pigs From Pinnacles National Monument
Authors: MCCANN BLAKE E. , GARCELON DAVID K.
Published: July 2008

Abstract: Feral pigs (Sus scrofa) have caused considerable damage where they have been introduced around the world. At Pinnacles National Monument, California, USA, managers were concerned that feral pigs were damaging wetland habitats, reducing oak regeneration, competing with native wildlife, and dispersing nonnative plant species through soil disturbance. To address these threats the National Park Service constructed an exclosure around 57 km2 of monument land and through cooperation with the Institute for Wildlife Studies eradicated all feral pigs within the area. Trapping, ground‐hunting, hunting dogs, and Judas techniques were used to remove feral pigs. Trapping techniques removed most pigs, but a combination of techniques was required to cause eradication. A series of bait sites and transects across the monument helped focus removal efforts and facilitated detection of the last remaining feral pigs in the exclosure. Consistent funding and cooperation from the National Park Service allowed for a seamless and comprehensive program that provided intensive removal of feral pigs. The successful eradication of feral pigs at Pinnacles National Monument should encourage managers in other areas to implement future control or eradication programs.
Breeding Propensity of Female Harlequin Ducks
Authors: BOND JEANINE C. , ESLER DANIEL , WILLIAMS TONY D.
Published: July 2008

Abstract:Breeding propensity, the proportion of sexually mature females that initiate egg production, can be an important demographic trait when considering reproductive performance and, subsequently, population dynamics in birds. We measured egg production using yolk precursor (vitellogenin and very‐low‐density lipoprotein) analyses and we measured nesting using radiotelemetry to quantify breeding propensity of adult female harlequin ducks (Histrionicus histrionicus) in British Columbia, Canada, in 2003 and 2004. Using both methods combined, and accounting for error rates of each, we estimated that breeding propensity of adult females that migrated to breeding streams was 92%. These data suggest that, despite speculation that harlequin ducks have low breeding propensity, almost all adult females on our study site were not constrained in their ability to produce eggs and that influences on reproductive performance at later stages likely have much stronger effects on population dynamics.
Diazacon Inhibits Reproduction in Invasive Monk Parakeet Populations
Authors: AVERY MICHAEL L. , YODER CHRISTI A. , TILLMAN ERIC A.
Published: July 2008

Abstract: Throughout the United States, managers lack safe, effective methods to control expanding populations of the invasive monk parakeet (Myiopsitta monachus). Because the reproductive inhibitor diazacon (20,25 diazacholesterol) has been used effectively in captive monk parakeets, we provided diazacon‐treated sunflower seeds to birds at electric utility substations inhabited by parakeets in south Florida, USA. Nest productivity (nestlings plus eggs with embryos) averaged 1.31 (SE = 0.45, n = 100 nests) at 6 treated sites compared to 4.15 (SE = 0.68, n = 50 nests) at 4 untreated sites, a 68.4% reduction. Exposure of native bird species to treated bait was infrequent. Diazacon is an effective means to reduce reproductive success of monk parakeets, and development of methods to limit exposure of nontarget birds will enable more widespread use of this useful population management technique.
A Comparison of Methods for Estimating Northern Bobwhite Covey Detection Probabilities
Authors: RIDDLE JASON D. , MOORMAN CHRISTOPHER E. , POLLOCK KENNETH H.
Published: July 2008

Abstract: We compared the time‐of‐detection and logistic regression methods of estimating probability of detection for northern bobwhite (Colinus virginianus) coveys. Both methods are unusual in that they allow estimation of the total probability of detection (i.e., the product of the probability that a covey is available for detection [i.e., that a covey vocalizes] and detection given availability). The logistic regression method produced an average detection probability of 0.596 (SE = 0.020) and the time‐of‐detection method produced a detection probability estimate of 0.540 (SE = 0.086), and the 2 estimates were not significantly different. This is the first evaluation of the time‐of‐detection method with empirical field data. Although the time‐of‐detection and logistic regression method each have advantages, both can be used under appropriate conditions to improve estimates of bobwhite abundance by allowing for the estimation of detection probabilities. Improved estimates of bobwhite abundance will allow land managers to make more informed management decisions.
Modeling Distribution of Dispersal Distances in Male White‐Tailed Deer
Authors: DIEFENBACH DUANE R. , LONG ERIC S. , ROSENBERRY CHRISTOPHER S. , WALLINGFORD BRET D. , SMITH DAVID R.
Published: July 2008

Abstract: Dispersal distances and their distribution pattern are important to understanding such phenomena as disease spread and gene flow, but oftentimes dispersal characteristics are modeled as a fixed trait for a given species. We found that dispersal distributions differ for spring and autumn dispersals of yearling male white‐tailed deer (Odocoileus virginianus) but that combined data can be adequately modeled based on a log‐normal distribution. We modeled distribution of dispersal distances from 3 distinct populations in Pennsylvania and Maryland, USA, based on the relationship between percent forest cover and mean dispersal distance and the relationship between mean and variance of dispersal distances. Our results suggest distributions of distances for dispersing yearling male white‐tailed deer can be modeled by simply measuring a readily obtained landscape metric, percent forest cover, which could be used to create generalized spatially explicit disease or gene flow models.
Evaluation of an Aerial Survey to Estimate Abundance of Wintering Ducks in Mississippi
Authors: PEARSE AARON T. , DINSMORE STEPHEN J. , KAMINSKI RICHARD M. , REINECKE KENNETH J.
Published: July 2008

Abstract: Researchers have successfully designed aerial surveys that provided precise estimates of wintering populations of ducks over large physiographic regions, yet few conservation agencies have adopted these probability‐based sampling designs for their surveys. We designed and evaluated an aerial survey to estimate abundance of wintering mallards (Anas platyrhynchos), dabbling ducks (tribe Anatini) other than mallards, diving ducks (tribes Aythini, Mergini, and Oxyurini), and total ducks in western Mississippi, USA. We used design‐based sampling of fixed width transects to estimate population indices (Ǐ), and we used model‐based methods to correct population indices for visibility bias and estimate population abundance (Ň) for 14 surveys during winters 2002–2004. Correcting for bias increased estimates of mallards, other dabbling ducks, and diving ducks by an average of 40–48% among all surveys and contributed 48–61% of the estimated variance of Ň. However, mean‐squared errors were consistently less for Ň than Ǐ. Estimates of Ň met our goals for precision (CV ≤ 15%) in 7 of 14 surveys for mallards, 5 surveys for other dabbling ducks, no surveys for diving ducks, and 10 surveys for total ducks. Generally, we estimated more mallards and other dabbling ducks in mid‐ and late winter (Jan‐Feb) than early winter (Nov‐Dec) and determined that population indices from the late 1980s were nearly 3 times greater than those from our study. We developed a method to display relative densities of ducks spatially as an additional application of survey data. Our study advanced methods of estimating abundance of wintering waterfowl, and we recommend this design for continued monitoring of wintering ducks in western Mississippi and similar physiographic regions.
Differential Effects of an Intense Wildfire on Survival of Sympatric Snakes
Authors: WEBB JONATHAN K. , SHINE RICHARD
Published: July 2008

Abstract: We analyzed 16 years of mark‐recapture data to investigate whether a wildfire influenced survival of an arboreal ambush‐forager (broad‐headed snake [Hoplocephalus bungaroides]) and a terrestrial active forager (small‐eyed snake Cryptophis nigrescens). We predicted that wildfire would cause direct mortality and reduce subsequent survival of both snake species. Contrary to this prediction, wildfire did not affect abundance of broad‐headed snakes, but abundance of small‐eyed snakes decreased by 48% after the wildfire. Estimated annual survival of small‐eyed snakes was 37% lower after fire (s=0.47, SE=0.07) than before fire (s=0.74, SE=0.05). Prescribed burning may be a suitable tool for creating open habitat mosaics for the endangered broad‐headed snake.
Dinosaur Evolution: Student Response to Dinosaur Ramblings
Authors: PARKER ISRAEL D. , LYONS EDDIE K. , LICONA MIGUEL M. , SCOGGIN ANNALIESE K. , SUMRALL SAMUEL A. , SUTTON ALEXANDRA E.
Published: July 2008

Abstract: In the 2007 Journal of Wildlife Management article “Dinosaur Ramblings,” Scalet described a shift in university and agency programs away from applied management research toward basic ecological research. We interpret Scalet's commentary as primarily synonymizing applied management research to game management and basic ecological research to nongame management and theoretical research. Although we agree with Scalet that a change in management practices has occurred, we believe that change is more an integration of applied and basic research as opposed to a shift away from management. We provide a hierarchical framework to alternatively explain Scalet's perceived shift in which we place applied management and basic theoretical research under the science of ecology. We believe integration of basic and applied research has been driven by the evolving structure of society and the public's changing view of natural resources. The integration of basic and applied research is necessary for informed and, thence, better management practices.
Transaction Cost Economics: An Assessment of Empirical Research in the Social Sciences
Authors: Macher Jeffrey T. , Richman Barak D.
Published: July 2008

This paper provides a comprehensive review of the empirical literature in transaction cost economics (TCE) across multiple social science disciplines and business fields. We show how TCE has branched out from its economic roots to examine empirical phenomena in several other areas. We find TCE is increasingly being applied not only to business-related fields such as accounting, finance, marketing, and organizational theory, but also to areas outside of business including political science, law, public policy, and agriculture and health. With few exceptions, however, the use of TCE reasoning to inform empirical research in these areas is piecemeal. We find that there is considerable support of many of the central tenets of TCE, but we also observe a number of lingering theoretical and empirical issues that need to be addressed. We conclude by discussing the implications of these issues and outlining directions for future theoretical and empirical work.
Rejuvenating SAARC: The Strategic Payoffs for India
Authors: Sawhney Aparna , Kumar Rajiv
Published: July 2008

The South Asian Association for Regional Cooperation, SAARC, founded in 1985, has floundered since its inception due to the lack of a strong political will. This article evaluates the political-economic and strategic benefits of deeper integration in South Asia from the Indian perspective. The abysmally low level of integration witnessed so far in the region has been driven by a myriad of constraints that restrict economic interaction among the South Asian countries. Gains from regional integration can emerge only after these constraints are effectively addressed. The central argument of the article is that recent global developments and increasing openness of SAARC economies are moving the principal drivers of this process towards a more supportive stance for SAARC and this creates a new window of opportunity. This opportunity must be seized by India as it has taken on the chairmanship of the organization, because a successful SAARC directly contributes to India's strategic objectives both in the region and also globally. In this context the article discusses ten reasons for India to rejuvenate integration efforts and revive regional cooperation in South Asia.
Host Country Educational Attainment and Vertical Specialization
Authors: Clark Don P.
Published: July 2008

Integration of the global economy through trade has enabled firms to adopt new production strategies. Rather than producing in a single country, stages of production are performed in multiple countries to exploit inherent locational advantages. This practice gives rise to vertical specialization across national boundaries. Here, the U.S. exports components to a foreign (host) country that uses them to produce a product that is returned to the U.S. or is exported to other countries. This paper investigates the relationship between host country educational attainment and the extent of vertical specialization. Despite the general finding that educational attainment exerts a decreasingly negative effect on such activity in host countries, a detailed analysis suggests there may be a positive relationship between educational attainment and vertical specialization over some parts of the educational attainment scale. A country can become more attractive as a production location when its workforce is educated.
Searching for Voters along the Liberal-Conservative Continuum: The Infrequent Ideologue and the Missing Middle
Authors: RePass David E
Published: July 2008

This article presents a new method of measuring the ideological orientation of the American electorate, using four variables found in the American National Elections Studies. The measure is tested for validity by examining its relation to a list of fundamental beliefs that we would expect a liberal and a conservative to hold. The proportions of liberals, conservatives and middle-of-the-roaders among the electorate over the past several decades are delineated. Both ideological orientation and party identification are then examined to determine the extent to which both of these predispositions coexist among the electorate. As of 2004, only 7.4 percent of potential voters were found to be both strong conservatives and strong Republicans, while 3.2 percent were strong liberals and strong Democrats. The majority of the electorate had neither strong predisposition. This majority should not be considered middle-of-the-roaders since they have little or no cognizance of the liberal-conservative continuum. The implications of these findings for party and candidate strategies, as well as for the assumption that voters need an ideological orientation in order to make sophisticated decisions, are discussed.
Review of Law and Order: Street Crime, Civil Unrest, and the Crisis of Liberalism in the 1960s
Authors: Weaver Vesla
Published: July 2008

Review of Michael Flamm's Law and Order: Street Crime, Civil Unrest, and the Crisis of Liberalism in the 1960s. Flamm provides a fresh take on the conservative ascendancy but is misleading about the role of race.
George W. Bush and Washington Governance: Effective Use of a Self-Limiting Style
Authors: Schier Steven E
Published: July 2008

How effective was the George W. Bush administration in using the levers of Washington governance to attain its goals? By late in Bush's presidency, his administration had received a reputation as less than competent due to their mismanagement of the response to Hurricane Katrina and the occupation of Iraq. Despite these "headline" reversals, a closer look at the evidence reveals an administration that often was quite effective in pursuing its goals with the federal bureaucracy, Congress and federal courts. The administration consistently pushed for expanded executive power consistent with its embrace of a unitary executive interpretation of their Constitutional power. Yet the hierarchical, managerial and partisan style of the administration proved self-limiting, as it increased partisan rancor in Washington and provided only a narrow margin for error that vanished after the 2006 elections.
Response to Weaver
Authors: Flamm Michael
Published: July 2008

The author of Law and Order replies to the reviewer's comments about his book.
The Demise of New Labour? The British 'Mid-Term' Elections of 2008
Authors: Rallings Colin , Thrasher Michael
Published: July 2008

The annual local elections in Britain are closely scrutinised for the clues they offer about the current state of public opinion. The 2008 contests attracted particular attention. The governing Labour party recorded its worst local election performance for 40 years; the Conservative opposition its best since John Major's electoral honeymoon in 1992. These elections, and other evidence, appear to have shifted the political narrative so that a Conservative victory at the next general election (due before mid-2010) is now seen as increasingly possible.
Rejoinder to Professor Maranto
Authors: Simmons Solon
Published: July 2008

Solon Simmons replies to Robert Maranto's comments about his article on political correctness in the academy.
Understanding Consumer Interest in Organics: Production Values vs. Purchasing Behavior
Authors: Bellows Anne C. , Onyango Benjamin , Diamond Adam , Hallman William K
Published: July 2008

Extensive research exists on who does or might purchase organic food products, however little research has addressed either who values organic production methods when deciding what to eat, and correspondingly, who does not purchase organics regularly. This paper reports that values about organic farming often do not translate into corresponding stated preferences about organic food consumption behavior. The paradox is examined within the context of the consumers socio-demographic characteristics as well as through opinions and preferences related to food in their lives.Results show that consumer claims of buying organics and placing importance on organic production systems when deciding what to eat are highly correlated (.472 at 1% significance level; p<. 001). Organic consumers, however, comprise only slightly more than one quarter (27%) of the highly enthusiastic proponents of organic production methods. Our results corroborate existing research that well-educated persons and those who are primary household shoppers purchase organics most frequently. Additionally, women and those who are older, have higher incomes, and are more liberal, as well as respondents who claim food production knowledge also tend to buy organic food regularly.Regression and factor analysis show that those who value organic production systems when deciding what to eat may be ranked in the following order: the religiously observant, older and female respondents, persons of color, and those who claim food production knowledge. Results show that many of these organic system proponents are under-represented as buyers, in particular: the religiously observant, those for whom food plays an integral role in their lives, the less educated, and lower income and older respondents.More attention should be directed to people who value organic production systems yet do not purchase organics. This will enhance understanding of the transaction barriers that impede consumer participation in the organic market. How this population values organic production systems also has implications for the development of public policy related to sustainable and organic agriculture.
Estimating the Welfare Loss to Consumers When Food Labels Do Not Adequately Inform: An Application to Fair Trade Certification
Authors: Rousu Matthew C. , Corrigan Jay R.
Published: July 2008

Government officials and other policymakers often face difficult decisions determining what information must be provided to consumers in the limited space available on food labels. An ideal label will cause consumers to make the same purchase that they would make if they had all relevant information, while an inferior label will induce a consumer to purchase a product he would not purchase if more information were available or to forgo purchasing a product that would have yielded positive consumer surplus. We present the design and results of an experimental auction that allows researchers to compare several alternative labels in order to determine the welfare loss from labels that do not adequately inform consumers. Further, we compare a set of candidate labels to assess whether one of the labels is better or worse at informing consumers.
Private Labeling and Competition between Retailers
Authors: Colangelo Giuseppe
Published: July 2008

This paper studies the effect of private labeling on retailer competition -an issue neglected in literature until now. Once implemented, private labeling may well be less favorable to society than previously thought because it can encourage consolidation of the retail industry. Either with linear pricing (when goods are not loose substitutes) or with wholesale price discrimination (when goods are not loose substitutes), the vertical channel is inclined to promote a retail monopoly while consumers prefer some retail competition. This conflict of interest would not arise in the absence of private labeling.
Conversion of ?-Zein to an Angiotensin I-Converting Enzyme Inhibitor under the Supercritical Water Condition
Authors: Hatakeda Kiyotaka , Maruyama Susumu , Suzuki Akira , Arai Kunio
Published: July 2008

Inhibitors of an angiotensin I-converting enzyme were produced from ?-zein in a batch reactor under subcritical and supercritical water conditions. Inhibitors produced under supercritical conditions in a flow reactor assembly were more sensitive. In a flow reactor system 5 mg of inhibitors were produced from 1 micromole of ?-zein. The hydrolysis products of ?-zein obtained in the flow reactor had a higher ACE inhibitory activity of 78% compared to 69% obtained using the batch reactor. An angiotensin I-converting enzyme [EC 3.4. 1 5. l] (ACE) is used to catalyze the production of vasoconstrictor angiotensin II and for the inactivation of the vasodilator bradykinin.
Effect of Various Parameters on the Solids Holdup in a Liquid-Solid Circulating Fluidized Bed
Authors: Palani Natarajan , Ramalingam Velraj , R.V. Seeniraj
Published: July 2008

A liquid-solid circulating fluidized bed (LSCFB) is operated at high liquid velocity, where particle entrainment is highly significant and between the conventional liquid fluidized bed and the dilute phase liquid transport regimes. In the present work, systematic experiments were carried out in a 0.094 m ID and 2.4 m height laboratory-scale liquid-solid circulating fluidized bed apparatus by using various solid particles and tap water as a fluidizing medium to study the hydrodynamics (axial solids holdup and solids circulation rate). The effects of operating parameters, i.e., primary liquid flow rate in the riser (jf), auxiliary liquid flow rate (ja), total liquid flow rate (jl), particle density (?s), particle diameter (dp) and solids feed pipe diameter (do) on the axial solids holdup distribution were analyzed from the experimental data. Finally, a correlation was developed from the experimental data to estimate average solid holdup in the riser, and it was compared with present experimental and available data in the literature. They agree well with a maximum root-mean-square deviation of 9.12 %.
Nanoreactors for Nanostructured Materials
Authors: Khomane Ramdas B , Kulkarni Bhaskar D
Published: July 2008

Organized systems such as micelles, reverse micelles, vesicles, polyelectrolyte capsules, liquid crystals, etc., formed through a self-assembling process represent nanoreactors that can be used for preparing nanostructured materials. Besides a fascinating academic subject, these nanoreactors provide a unique way to develop a special type of advanced material for a wide variety of applications in electronics, photonics, biomedical and other areas. The article examines the formation, functioning, properties and special attributes of these nanoreactors with a view towards their engineering analysis, design and possible integration in manufacturing technology.
Estimation of a Reduced Model of the BSM1 Activated Sludge Wastewater Treatment Plant
Authors: Barrou Ouadiaa , Karama Asma , Lakhal E. K. , Bernard Olivier , Pons Marie-Noelle , Corriou Jean-Pierre
Published: July 2008

The complete BSM1 model is recognized as representative of activated sludge plants. However, its large number of states may render it inadequate for development of state observers and for control. Thus, a reduced model has been developed for the two main sections of the plant, the anoxic and aerobic reactors. Concepts of model reduction of biological models based on the analysis developed by Bernard (Bernard2005a, Bernard2005b) have been used. The output data have been obtained by simulating the inlet by data representative of dry weather. After transformation and treatment of the data, it has been shown that a kinetic model reduced to two reactions is able to represent 80% of the total variance. The pseudo-stoichiometric coefficients have been estimated and the pseudo reaction scheme has been validated with respect to the actual concentrations at the outlet of a considered section. The dynamics are generally well represented by the reduced model.
Effect of the Shape of the Baffles on the Hydrodynamics of a Fluidized Bed
Authors: Kaza Srinivasa Rao Venkata Naga
Published: July 2008

Gas flow in a gassolid fluidized bed is characterized by the predominance of bubbles. When gas flow is more than the minimum fluidization velocity, the top of the fluidized bed may fluctuate vigorously leading to unstable operation. Bed fluctuation and fluidization quality are interrelated. The quality of fluidization can largely be improved by introducing baffles in bubbling and turbulent fluidized beds. In the present work three baffle geometries, i.e., circular, triangular and square are used to determine different hydrodynamic parameters such as minimum fluidization velocity, bed expansion, pressure drop across the bed, fluctuation ratio, expansion ratio, etc. in a bubbling fluidized bed. A new parameter blockage ratio is introduced to analyze the behaviour of baffled fluidized beds. It is found from the current experimental studies that the blockage ratio mainly influences the hydrodynamics of the bed rather than the shape of the baffle.
Removal of Inclusions from Molten Aluminium by Flotation in a Stirred Reactor: A Mathematical Model and a Computer Simulation
Authors: Mirgaux Olivier , Ablitzer Denis , Waz Emmanuel , Bellot Jean-Pierre
Published: July 2008

Inclusions removal by flotation in mechanically agitated vessels is widely used in liquid aluminium treatments. Originating from different sources (oxide skins, refractory or recycling wastes), inclusions may have disastrous repercussions, such as physical properties alterations of the final products or difficulties during forging processes.With the aim of both a better understanding of the physical processes acting during flotation and the optimization of the refining process, a mathematical modelling of the behaviour of the inclusions population has been set up. Agglomeration, flotation and settling of inclusions are considered here. The model is divided in two steps: a 3D calculation of the biphasic liquid aluminium/bubbles fluid flow based on an Euler/Lagrange approach and a population balance. The population balance is performed with the assumption of a perfectly stirred reactor, and the calculation of agglomeration and flotation rates relies on mean values of fluid flow properties provided by the CFD simulation. Kruis & Kusters' model is employed for the calculation of the agglomeration rate and Kostoglou's model is used for the flotation rate. The fixed pivot method of Kumar & Ramkrishna is employed for the resolution of the population balance equation.A laboratory scaled flotation vessel is modeled and results of a simulation are presented.
Experimental and Numerical Investigation of Natural Convection Heat Transfer in Horizontal Elliptic Annuli
Authors: Sakr Ramadan Y. , Berbish Nabil S. , Abd-Aziz Ali A. , Hanafi Abdalla Said
Published: July 2008

Experimental and numerical studies for natural convection in two dimensional regions formed by a constant flux heat horizontal elliptic tube concentrically located in a larger, isothermally cooled horizontal cylinder were investigated. Both ends of the annulus are closed. Experiments were carried out for the Rayleigh number based on the equivalent annulus gap length ranges from 1.12x107 up to 4.92x107; the elliptic tube orientation angle varies from 0o to 90o and the hydraulic radius ratio, HRR, was 6.4. These experiments were carried out for the axis ratio of an elliptic tube (minor/major=b/c) of 1:3. The numerical simulation for the problem is carried out by using commercial CFD code. The effects of the orientation angle as well as other parameters such as elliptic cylinder axis ratio and hydraulic radius ratio on the flow and heat transfer characteristics are investigated numerically. The numerical simulations covered a range of elliptic tube axis ratios from 0.1 to 0.98 and for the hydraulic radius ratios from 1.5 to 6.4. The results showed that the average Nusselt number increases as the orientation angle of the elliptic cylinder increases from 0o (the major axis is horizontal) to 90o (the major axis is vertical) and with the Rayleigh number as well. Also, the average Nusselt number decreases with the increase of the hydraulic radius ratio. An increase up to 1.75 and further increases in the hydraulic radius ratio leads to an increase in the average Nusselt number. The axis ratio of the elliptic cylinder has an insignificant effect on the average Nusselt number. Both the average and local Nusselt number from the experimental results are compared with those obtained from the CFD code.Both the fluid flow and heat transfer characteristics for different operating and geometric conditions are illustrated velocity vectors and isotherm contours that were obtained from the CFD code. Also, two correlation equations that relate the average Nusslet number with the Rayleigh number, orientation angle, and hydraulic radius ratio and axis ratio are obtained.