bluuebunny/crossref_metadata_2025 huggingface dataset:
The International Criminal Tribunal for the Former Yugoslavia: Planners and Instigators or Foot Soldiers?
Authors: Caine Philip
Published: July 2009

The International Military Tribunal at Nuremberg prosecuted the most infamous criminals of the Nazi regime whereas the International Criminal Tribunal for the Former Yugoslavia (ICTY) has brought to trial only two of the ‘big guns' of the Balkans conflicts. The aim of this study is to assess the effectiveness of the ICTY in fulfilling its mandate to prosecute those most responsible for serious violations of international humanitarian law committed during the conflicts of the Former Yugoslavia. The research combines a literature-based assessment of the ICTY together with focused interviews of the main decision-makers in the Office of the Prosecutor, and seeks to assess the factors involved in the initiation of investigations and the selection of individuals for indictment. The independence and autonomy of the Prosecutor is identified as one of the most significant factors in the selection of indictees, but whilst the highest ranking individuals were always the main targets for indictment by the Office of the Prosecutor, the findings suggest that a weak mandate, inadequate resources and indifference by the international community forced the hand of the Prosecutor into indicting lower level suspects. Further ad hoc tribunals are planned by the United Nations and the lessons learned from the experience of the ICTY are essential if they are to administer international justice effectively.
The Effect of Educational Differences on the Level of Job Satisfaction in Police Officers in Turkey
Authors: Özel Ali , Bayındır Nida , İnan Hatice Zeynep , Özel Emine
Published: July 2009

In order to maintain the well-being of a country, it is essential to understand the needs of that country's police officers and what affects their job satisfaction. Current literature shows that there are many factors that can impact on a police officer's job satisfaction. The current research examines the job satisfaction of police working in the city of Kutahya, both in central Kutahya and in the counties of Kutahya. The study focused on the relationship between the level of education and job satisfaction for police in central Kutahya and the counties of Kutahya, as well as if the pleasure and dissatisfaction they experience in the organisation is related to demographic factors. Accordingly, the study examined some factors which are assumed to affect job satisfaction, such as communication gaps, friendship, promotion opportunities, management style, fair wages and fair work assignment. The results showed that the level of education does not affect the job satisfaction of police officers who work in central Kutahya or the counties of Kutahya. Moreover, data analysis showed that the police enjoy their job even though they complain about their job and the negative conditions that they experience in their job.
The Relevance of Harm as the Criterion for the Punishment of Impossible Attempts
Authors: Christie Sarah A.
Published: July 2009

There has been much debate about the relevance of punishment in cases of impossible attempts. This article sets out the current position in Anglo-American jurisdictions and considers the rationale behind punishment in hypothetical impossible attempt cases in order to draw out the key issues at the heart of responsibility. The cases of the inadequately prepared attempt and the attempt which is doomed to failure are compared to illustrate the relevance of the potential to cause harm in the justification for punishing such actors. The article concludes with the suggestion that the relevant criterion is the presence of the potential to cause imminent harm, as opposed to future, speculative harm.
Male Sex Work and the Internet Effect: Time to Re-Evaluate the Criminal Law?
Authors: Ashford Chris
Published: July 2009

The criminal law relating to sex work was last modified in the Sexual Offences Act 2003. Three years later in January 2006 the UK government published a ‘prostitution strategy’ that set out four core aims: challenge the view that street prostitution is inevitable and here to stay; achieve an overall reduction in street prostitution; improve the safety and quality of life of communities affected by prostitution, including those directly involved in street sex markets, and finally, to reduce all forms of commercial sexual exploitation. This framework prima facie failed to take into account both the issue of male sex work and also the Internet effect upon sex work. This article seeks to examine the intersection of technology and male for male sex work and reviews both the criminal law and UK policy framework in that context.
Born to Fail? Policing, Reform and Neighbourhood Problem Solving
Authors: Bullock Karen , Tilley Nick
Published: July 2009

The issue of problem solving as a component of neighbourhood policing is an important and potentially highly problematic one. The UK government claims in its 2008 Green Paper, From the Neighbourhood to the National, to be ‘absolutely committed to neighbourhood policing as the bedrock for local policing in the 21st Century’. Yet experience tells us that implementation of problem solving is likely to be far from straightforward. This article draws attention to the many obstacles identified over 25 years of experimentation with the principles of problem solving. The article examines what is known about implementation of problem solving in the police service and the factors which influence its delivery. It draws attention to lessons learnt and the implications for the delivery of neighbourhood policing.
We Can Terrorise Them! Young Offender Perceptions of Police Community Support Officers
Authors: Pamment Nicholas
Published: July 2009

The public have regularly called for the return of the ‘bobby on the beat’ and the ‘Dixon of Dock Green’ way of policing, and under the Police Reform Act (2002) we have seen a return to neighbourhood policing. However, uniform presence on our streets is likely to come in the form of Police Community Support Officers (PCSOs). According to the Home Office, the public value the role of the PCSO but the media representation of these officers is far from positive. PCSOs spend much of their time dealing with nuisance caused by youths. With this in mind, observations and short semi-structured interviews were undertaken with a number of young offenders who were under the supervision of a Youth Offending Team (YOT) to explore their perceptions of PCSOs. The results show that they have poor credibility and are not considered a deterrent by the young people.
Macroalgal (Boodlea composita) bloom at Kure and Midway Atolls, Northwestern Hawaiian Islands
Authors: Vroom Peter S. , Asher Jacob , Braun Cristi L. , Coccagna Edmund , Vetter Oliver J. , Cover Wendy A. , McCully Kristin M. , Potts Donald C. , Marie Amarisa , Vanderlip Cynthia
Published: July 2009

The first recorded macroalgal bloom to occur at Kure and Midway Atolls in the highly protected Northwestern Hawaiian Islands was observed during summer 2008 on shallow water reefs. The native green macroalga Boodlea composita formed dense mats centimeters in thickness in select areas and formed decomposing masses on beaches at Kure Atoll. Mild oceanographic conditions during winter 2008 likely weakened lagoonal flushing systems, and when coupled with weeks of low wind and warm sea surface temperatures during the proceeding summer months, physical conditions within the lagoons of each atoll fostered rapid growth of this normally non-blooming alga.
Invasive potential of Kappaphycus alvarezii off the south coast of Rio de Janeiro state, Brazil: a contribution to environmentally secure cultivation in the tropics
Authors: Castelar Beatriz , Reis Renata Perpetuo , Moura Ana Luísa , Kirk Rodrigo
Published: July 2009

The carragenophyte Kappaphycus alvarezii has been introduced into tropical regions, including Brazil, for aquaculture purposes. Our study estimated the biomass loss of farmed cuttings, the establishment of cuttings outside the rafts, the occurrence of spores, and evaluated the invasive potential of K. alvarezii at three sites in Rio de Janeiro state. Temperature, salinity, water transparency, wind velocity and direction (hydrodynamic indicator) and solar radiation (irradiance availability indicator) varied spatially. We found no spores in cultivated cuttings and no verified spore recruitment on artificial substrata. Biomass loss of cuttings varied temporally; however, it was restricted to the cultivation management area of one site and was low compared to native algal biomass. The establishment of cuttings was apparently limited by herbivory at Ilha Grande Bay and controlled by water transparency, hydrodynamics and temperature at Sepetiba Bay. The invasive potential of K. alvarezii was considered remote. However, the use of environmental protocols for cultivation activities is necessary to prevent environmental impacts, mainly in tropical regions.
Functions of TAM RTKs in regulating spermatogenesis and male fertility in mice
Authors: Chen Yongmei , Wang Huizhen , Qi Nan , Wu Hui , Xiong Weipeng , Ma Jing , Lu Qingxian , Han Daishu
Published: July 2009

Mice lacking TYRO3, AXL and MER (TAM) receptor tyrosine kinases (RTKs) are male sterile. The mechanism of TAM RTKs in regulating male fertility remains unknown. In this study, we analyzed in more detail the testicular phenotype of TAM triple mutant (TAM−/−) mice with an effort to understand the mechanism. We demonstrate that the three TAM RTKs cooperatively regulate male fertility, and MER appears to be more important than AXL and TYRO3. TAM−/− testes showed a progressive loss of germ cells from elongated spermatids to spermatogonia. Young adult TAM−/− mice exhibited oligo-astheno-teratozoospermia and various morphological malformations of sperm cells. As the mice aged, the germ cells were eventually depleted from the seminiferous tubules. Furthermore, we found that TAM−/− Sertoli cells have an impaired phagocytic activity and a large number of differentially expressed genes compared to wild-type controls. By contrast, the function of Leydig cells was not apparently affected by the mutation of TAM RTKs. Therefore, we conclude that the suboptimal function of Sertoli cells leads to the impaired spermatogenesis in TAM−/− mice. The results provide novel insight into the mechanism of TAM RTKs in regulating male fertility.
The global distribution of net primary production: resolving the paradox
Authors: Huston Michael A. , Wolverton Steve
Published: July 2009

The distribution of the diversity and abundance of life on Earth is thought to be shaped by the patterns of plant growth (net primary production, NPP) in the oceans and on land. The well‐known latitudinal gradient of species diversity reaches its maximum in tropical rain forests, which are considered to be the most productive ecosystems on the planet. However, this high tropical productivity on land is the opposite of the well‐documented distribution of marine productivity, which is greatest in the high‐latitude oceans around the poles. This paradox can be resolved by a reevaluation of the terrestrial productivity gradient. Compilations of direct measurements of forest NPP show that annual NPP in tropical forests is no different than annual NPP in temperate forests, contrary to recent syntheses and to the output of global vegetation models. Other properties of forest ecosystems, such as basal area of trees, wood density, and the ratio of wood to leaf production, as well as animal properties such as body size, population density, and reproductive rates, support the conclusion that ecologically relevant terrestrial productivity is actually highest in the temperate latitudes, reaching a maximum between 30° and 50° before declining toward the poles. This “reversal” of the latitudinal productivity gradient, if substantiated by a systematic global sampling effort, will necessitate a major reevaluation of ecological and evolutionary theory, as well as conservation strategies and international development policies.
Comparative landscape dynamics of two anuran species: climate‐driven interaction of local and regional processes
Authors: Werner Earl E. , Relyea Rick A. , Yurewicz Kerry L. , Skelly David K. , Davis Christopher J.
Published: July 2009

The dynamics of ecological communities emerge from the interplay of local and regional processes, but there are few long‐term data on multiple interacting species across multiple sites to evaluate these processes. We report the population dynamics of two species of treefrogs, the spring peeper (Pseudacris crucifer) and the chorus frog (P. triseriata), in 37 ponds over 11 years. We examined the relation between larval traits of these species and responses to environmental change (a severe drought) at the local (pond) level, and the consequences to regional dynamics of the species. Consistent with experimental evidence, predators limited abundances of both species, competitive effects were undetectable, and pond hydroperiod and forest canopy cover affected species' presences and population sizes. The drought caused strong reductions in pond hydroperiods and predator densities, which led to increases in colonization probability and decreases in extinction probability for the chorus frog. These habitat dynamics resulted in the colonization of 15 new ponds and exponential growth in regional population size of the chorus frog. Colonization probability was positively related to pond connectivity. Pond occupancy rates for the spring peeper were relatively constant, but important source ponds on the landscape changed with the drought. Ponds with extensive forest canopy cover were sink habitats for both species, and high pond connectivity appeared to be necessary to maintain species' presences in these habitats. Landscape dynamics were responsible for changes in the fundamental spatial structure of species' populations, e.g., the chorus frog transitioned between approximations of a classic metapopulation and a patchy population over the course of the study. Many of these results were driven by the interplay of climate variation and spatial food web structure, indicating the importance of incorporating this interaction into metacommunity theory. Our results further indicate the crucial role of habitat (pond) heterogeneity to species persistence, i.e., moderating the potential Moran effects of spatially correlated weather conditions. Overall this study illustrates: (1) how natural systems constantly transition between metapopulation/metacommunity states typically treated as static in the literature, (2) the extensive interconnection of phenomena at different scales in ecology, and (3) the importance of habitat heterogeneity and landscape context for amphibian conservation strategies.
Empirical tests of metacommunity theory using an isolation gradient
Authors: Driscoll Don A. , Lindenmayer David B.
Published: July 2009

All metacommunity theories incorporate dispersal as a key process influencing community composition. If communities are examined across a habitat‐patch isolation gradient, different metacommunity theories predict contrasting patterns of community divergence and responses of rare species. We used bird and reptile data collected in three years from 168 habitat patches in a fragmented agricultural landscape, and bird data gathered from 63 remnants embedded in a pine plantation over two years to examine predictions arising from six metacommunity theories: A, neutral; B, species sorting; C, species sorting at low isolation but neutral at high isolation; D, neutral at low isolation but species sorting at high isolation; E, mass effects; and F, patch dynamics. We identified three classes of predictions arising from these theories that we could test using community survey data: (1) trajectories of rare species across an isolation gradient; (2) the influence of geographic distance, environmental parameters, and patch isolation on pair‐wise comparisons of community divergence; and (3) the influence of isolation and environmental parameters on the divergence of communities from a regional species pool. Some analyses indicated moderately common support for neutral and species‐sorting concepts, often acting simultaneously. Opposite responses by different groups of rare species to the isolation gradient showed that neutral and patch‐dynamic processes may act on different components of the same community. Different analyses provided support for different theories, and so helped us to avoid being misled by a single analysis. However, generally we found very little consistent support for any of the metacommunity theories. Our analyses suggested that different metacommunity mechanisms act ephemerally, sometimes simultaneously and on different subsets of the fauna in different regions. The complexity of responses means that metacommunity ideas cannot yet be used predictively in a management context. We encourage further testing of the multiple predictions that arise from current metacommunity concepts, using additional data sets. However, if metacommunity processes act simultaneously and ephemerally, the predictions of any one metacommunity theory may be hard to detect at the community level. In that case, examining the ecology of multiple species in the same landscape may be needed to characterize metacommunity processes in nature.
Mercury-selenium compounds and their toxicological significance: Toward a molecular understanding of the mercury-selenium antagonism
Authors: Khan Mohammad A.K. , Wang Feiyue
Published: July 2009

The interaction between mercury (Hg) and selenium (Se) is one of the best known examples of biological antagonism, yet the underlying mechanism remains unclear. This review focuses on the possible pathways leading to the Hg-Se antagonism, with an emphasis on the potential Hg-Se compounds that are responsible for the antagonism at the molecular level (i.e., bis[methylmercuric]selenide, methylmercury selenocysteinate, selenoprotein P-bound HgSe clusters, and the biominerals HgSexS1−x). The presence of these compounds in biological systems has been suggested by direct or indirect evidence, and their chemical properties support their potentially key roles in alleviating the toxicity of Hg and Se (at high Hg and Se exposures, respectively) and deficiency of Se (at low Se exposures). Direct analytical evidences are needed, however, to confirm their in vivo presence and metabolic pathways, as well as to identify the roles of other potential Hg-Se compounds. Further studies are also warranted for the determination of thermodynamic properties of these compounds under physiological conditions toward a better understanding of the Hg-Se antagonism in biota, particularly under real world exposure scenarios.
Organochlorine Contaminants in Fishes from Coastal Waters West of Amukta Pass, Aleutian Islands, Alaska, USA
Authors: Miles A. Keith , Ricca Mark A. , Anthony Robert G. , Estes James A.
Published: July 2009

Organochlorines were examined in liver and stable isotopes in muscle of fishes from the western Aleutian Islands, Alaska, in relation to islands or locations affected by military occupation. Pacific cod (Gadus macrocephalus), Pacific halibut (Hippoglossus stenolepis), and rock greenling (Hexagrammos lagocephalus) were collected from nearshore waters at contemporary (decommissioned) and historical (World War II) military locations, as well as at reference locations. Total (Σ) polychlorinated biphenyls (PCBs) dominated the suite of organochlorine groups (ΣDDTs, Σchlordane cyclodienes, Σother cyclodienes, and Σchlorinated benzenes and cyclohexanes) detected in fishes at all locations, followed by ΣDDTs and Σchlordanes; dichlorodiphenyldi-chloroethylene (p,p′DDE) composed 52 to 66% of ΣDDTs by species. Organochlorine concentrations were higher or similar in cod compared to halibut and lowest in greenling; they were among the highest for fishes in Arctic or near Arctic waters. Organochlorine group concentrations varied among species and locations, but ΣPCB concentrations in all species were consistently higher at military locations than at reference locations. Moreover, all organochlorine group concentrations were higher in halibut from military locations than those from reference locations. A wide range of molecular weight organochlorines was detected at all locations, which implied regional or long-range transport and deposition, as well as local point-source contamination. Furthermore, a preponderance of higher-chlorinated PCB congeners in fishes from contemporary military islands implied recent exposure. Concentrations in all organochlorine groups increased with δ15N enrichment in fishes, and analyses of residual variation provided further evidence of different sources of ΣPCBs and p,p′DDE among species and locations.
Multiphase Non-Darcy Flow in Proppant Packs
Authors: Barree R. D. , Conway M. W.
Published: July 2009

This paper builds on a model for single-phase, non-Darcy flow in porous media presented in by Barree and Conway (2004). In this work, the generalized equation for single-phase non-Darcy flow is extended to multiphase-flow conditions. Laboratory measurements of gas/water flow were conducted in several flow cells to determine relative permeability curves and the nonlinear relationship between individual-phase flow rate and induced potential gradient over a wide range of input fractional-flow conditions and over a range of Reynolds numbers (Re). A model is presented to predict multiphase non-Darcy flow in porous media that is applicable to high-deliverability reservoirs and hydraulically fractured wells.
A Robust Steady-State Model for Flowing-Fluid Temperature in Complex Wells
Authors: Hasan A. R. , Kabir C. S. , Wang X.
Published: July 2009

This paper presents an analytic model for computing the wellbore-fluid-temperature profile for steady fluid flow. Although wells with a constant-deviation angle can be handled with existing analytic models, complex well architectures demand rigorous treat-ment. For example, changing geothermal-temperature-gradient and deepwater wells present significant challenges. Additionally, available analytic models rarely provide calculation methods for various required thermal parameters, such as the Joule-Thompson (J-T) coefficient and fluid expansivity.

The approach taken in this study entails dividing the wellbore into many sections of uniform thermal properties and deviation angle. The governing differential equation is solved for each section, with fluid temperature from the prior section as the boundary condition. This piecewise approach makes the model versatile, allowing step-by-step calculation of fluid temperature for the entire wellbore. We present simple, thermodynamically sound approaches for estimating thermal parameters.

Success is indicated when performance of the proposed model is compared with data from three wells, producing two-phase gas/oil mixture, single-phase oil, and single-phase gas. Sensitivity of the estimated fluid temperatures to various thermal properties is also examined with our model. Overall, the effects of the J-T coefficient and liquid expansivity are found to be significant.
Development of World-Class Oil Production and Water Injection Rate and High Ultimate-Recovery Wells in Deepwater Turbidites—Bonga Example
Authors: Inikori Solomon O. , Coxe Bert , Ageh Ebenezer , Van Der Bok Jaap
Published: July 2009

Bonga field in deepwater Nigeria produces hydrocarbons from classic deepwater turbidite reservoirs deposited in channel settings. The reservoirs consist of a series of amalgamated channel complexes with varying degrees of compartmentalization. The depostional configuration presented significant uncertainties in connected volumes, well placements, and sweep efficiency between water injector/producer well pairs. However, because of the high costs of deepwater developments, well count needs to be as low as practical, and production rates must be sustainably high to ensure economic robustness of the project. High rates and high ultimate recoveries are the foundations of successful deepwater projects. At Bonga, constant pressure maintenance is a key component to achieving high-rate, high-ultimate-recovery wells. Several research studies concluded that the required water-injection wells be designed for fracture injection (i.e., above sandface-fracture pressure) to sustain the required high rates, as opposed to reservoir matrix injection. This paper presents the results of these research efforts leading to this conclusion and the implications on reservoir management. Also presented is an overview of the challenges of developing these complex channel deposits and the new approach to modeling high-rate wells in deepwater turbidites.

Key to successful understanding of reservoir behavior (connectivity) and early indications of future reservoir performance is a systematic undertaking of interference tests at production startup.

After approximately 2 years of production, the results from the Bonga wells demonstrate that sustained high oil rates could be achieved with adequate pressure maintenance. Average oil production rates of vertical/deviated wells range from 15,000 to 22,000 BOPD and that of horizontal wells range from 25,000 to 35,000 BOPD. Estimated ultimate recovery (EUR) per well ranges from 20 to 100 million STB for Phase 1 wells and from 10 to 30 million STB for Phase 2 development wells, with several additional opportunities for infill drilling of lower-EUR wells. Nameplate capacity of 225,000 BOPD was achieved and sustained with just nine producers and six injectors. To maintain these high production well rates, world-class water-injection well rates (of between 40,000 and 70,000 B/D per well) have been sustained since first oil.

The fracture-injection approach is applicable both for onshore and offshore reservoir development but, more significantly, for deepwater reservoir development in which sustained high rates and economic considerations are paramount.
On the Influence of Viscosity on ESP Performance
Authors: Amaral Gilmar , Estevam Valdir , Franca Fernando A.
Published: July 2009

This paper presents experimental data and a preliminary analysis of the influence of fluid viscosity on centrifugal-pump performance. Two centrifugal pumps, a conventional radial (specific speed Nq=8 rev/min) and a semi axial electrical submersible pump (ESP) (Nq=28 rev/min) were tested with 1-cp water and clear glycerin. Adjusting and controlling the fluid temperature in a closed test loop, it was possible to vary the glycerin viscosity from 67 to 1,020 cp within the range of light and heavy crude oils.

The main purpose of these tests, in addition to appraising the influence of viscosity on the pump's overall performance through the measurement of the derating factors for head, flow, and power, was to supply detailed information on the energy-transfer processes taking place in the pump's internal components. To accomplish this, the pressure distribution along the flow path from the pump inlet eye to the discharge section, including detailed pressure difference across impellers and diffusers, was measured. Thus, in addition to measuring the flow rate, the overall pressure difference, the speed, the power and the mean operation temperature for fluids with various viscosities within a full range of operational conditions, detailed data on the energy-transfer processes performed by impellers and diffusers were also taken.

Later analyses indicated that, in addition to the physical dimensions, operational conditions, and fluid properties, the pump performance is set by the strong flow interactions that exist between impellers and diffusers. In other words, these succeeding internal blade rows influence each other in terms of the head gain and the viscous dissipation effects. Thus, any generalizing approach dealing with the influence of viscosity on the pump performance must account for those interactions to give a proper measure of the derating factors over an extended range of operational conditions. Unfortunately, this is not true for the procedures available in the open literature. They lack representation and do not deliver proper correction factors for pumps that are not similar to those that generate the correlation database or for pumps working under operational conditions other than at the best-efficiency point (BEP). The data presented herein can be a launching point for a deeper analysis aimed to tackle these limitations.
Evidence of a Horizontal Hydraulic Fracture From Stress Rotations Across a Thrust Fault
Authors: Maxwell S. C. , Zimmer U. , Gusek R. , Quirk D.
Published: July 2009

Microseismic imaging of a hydraulic-fracture stimulation showed significant fracture reorientation across a thrust fault. Fracture orientations were identified through a combination of alignment of event locations, polarization of the seismic waves, and injection details. Stimulation below the fault indicated a near-horizontal fracture geometry. Above the fault, a near-vertical fracture geometry was observed. A change in fault orientation was supported by differences in the microseismic-signal characteristics and the treatment-injection data. This difference in fracture geometry was attributed to rotations in the direction of minimum principal stress, which is consistent with observed differences in the injection pressures.
Optimizing Downhole Fluid Production of Sucker-Rod Pumps With Variable Motor Speed
Authors: Palka Krzysztof , Czyz Jaroslaw A.
Published: July 2009

Reciprocating oil pumps are operated traditionally by prime movers rotating at a constant speed. This paper demonstrates that by changing motor speed rapidly within a single stroke, pump production can be increased while stresses in the sucker rod and motor energy consumption are reduced. The optimal motor-speed profile is determined by representing the motor speed with Fourier series and searching for Fourier coefficients that maximize the production while satisfying the imposed constraints on stresses in the rod and on energy consumption. The pump-performance parameters required in the optimization process, such as fluid production, stresses in the rod, and motor torque resulting from a given variable motor speed, are calculated by predictive analysis. The analysis is based on a comprehensive dynamic model of the entire pumping system, comprising surface and downhole equipment.

During, and beyond, a minimum 6-month field-validation period, the calculated optimal speed profile has been applied to control the movement of more than 20 pumps currently operating in Alberta, Canada. The resulting increased production and lower operating cost confirmed clearly the benefits of implementing a variable speed of the prime mover to improve pump performance. Presented examples demonstrate an increase of up to 133% in production without increasing energy consumption or loads in the system. Results similar to those with beam pumps can be achieved for hydraulically actuated pumps by applying variable flow rate or pressure to induce the calculated optimal polished rod velocity.
Unbiased Estimation of Intrinsic Permeability With Cumulants Beyond the Lognormal Assumption
Authors: Vargas-Guzmán J. A.
Published: July 2009

The usual practice is to transform intrinsic-permeability data with logarithms to get a linear relation with porosity. Such transformations are known to produce undesired effects in 3D geocellular-models (i.e., smoothing data, elimination of extreme values, and biased estimates). Ideally, logarithms of data may lead to Gaussian distributions, which are easily handled by classical spatial statistics and linear collocated-cokriging. The exponential model from back-transformed linear regression "underestimates" permeability. If the lognormal assumption is not met, a second order correction may "overestimate" permeability. Transformations of permeability data may uncover the fact that a truly non-Gaussian statistical distribution cannot be avoided, and this brings complications to the modeling of permeability. Shortcomings of transforms for non-Gaussian cases may affect the quality of reservoir models for history match forcing to the use of arbitrary multipliers. Systematically biased flow predictions might be avoided by proper modeling of flow parameters including intrinsic permeability. Truly non-Gaussian modeling of permeability is developed in this paper to find a solution to these problems. The analysis starts by linking the exponential model to power transformations from Taylor series. Residual-terms (RTs) are introduced for correct back-transformation of estimates. An advanced result, for the truly non-Gaussian case, is that the RTs take the form of numerical higher order cumulants and not moments. RTs represent the contribution of spatial heterogeneous components that occur when spatial permeability varies beyond a pair-wise covariance or variogram. Results in this paper show that "higher-order cumulants" improve permeability estimates significantly in rocks with large dispersion of values dominated by higher permeabilities (e.g., shaley sands and laminated grainstone carbonates). This study has proposed new ways for spatial modeling of permeability, avoiding under or overestimations, and the proposed approach provides the basis for the use of cumulants for spatial higher-order estimation.
Verification of Asphaltene-Instability-Trend (ASIST) Predictions for Low-Molecular-Weight Alkanes
Authors: Creek Jefferson L. , Wang Jianxin , Buckley Jill S.
Published: July 2009

Anticipating when and where asphaltenes may flocculate during oil production is a key step in successfully preventing or mitigating asphaltene problems in the field. Because there will be no deposition without precipitation, mapping of asphaltene stability over a wide range of temperature, pressure, and composition is required. The ASIST allows the determination of the onset of asphaltene instability to be established with a series of liquid n-alkanes. These data are used to predict asphaltene stability of live fluids by extrapolating the onset condition from the base data to reservoir conditions by use of a linear extrapolation of the onset solubility parameter vs. square root of the partial molar volume of the precipitant. This extrapolation has been demonstrated previously to be accurate for methane and a model oil. The present work verifies that such an extrapolation is valid for predicting the asphaltene instability for mixtures of methane, ethane, and propane with a representative stock-tank oil (STO). The STO was combined with known amounts of methane, ethane, or propane. The asphaltene onset pressure was determined by a combination of near-infrared (NIR) light scattering and microscopic observation. The onset conditions at ambient pressures were examined for flocculation periods ranging from 20 minutes to 24 hours. Onset pressures calculated with the 5-hour ASIST trends compared well with measured onset pressures.
Prediction of Gas Productivity From Eastern Nankai Trough Methane-Hydrate Reservoirs
Authors: Kurihara Masanori , Sato Akihiko , Ouchi Hisanao , Narita Hideo , Masuda Yoshihiro , Saeki Tatsuo , Fujii Tetsuya
Published: July 2009

The Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) has been evaluating methane-hydrate (MH) reservoirs located in the eastern Nankai trough from the viewpoints of geology, geophysics, petrophysics, and reservoir/ production engineering. As one of these studies, we have been predicting gas/water production performances from these MH reservoirs showing diverse characteristics. This paper presents the results of our examinations on the applicability of a variety of MH dissociation/production methods to these MH reservoirs and on the feasibility of future development in terms of gas production and economics.

Eastern Nankai trough MH reservoirs, which are composed of alternating beds of sand, silt, and clay in turbidite sediments, have various conditions of clay distribution and of initial pressure, temperature, permeability, and MH saturation. Some of these reservoirs contain MH of high saturation at a certain interval (MH concentrated reservoir), while in the others, MH is deposited sparsely (MH-nonconcentrated reservoir). Detailed numerical reservoir models were constructed for both MH-concentrated and -nonconcentrated reservoirs, consulting the well-log and seismic-interpretation results.

MH-dissociation/-production performances were then predicted through numerical simulation, assuming the application of various MH-dissociation methods (such as depressurization, well-bore heating, hot-water huff'n'puff, and hot waterflooding. The simulation studies clarified the difference in the gas production between MH-concentrated and -nonconcentrated reservoirs. These studies also revealed that the permeability not only of sand layers but also of clay layers has a significant effect on the gas productivity from MH-concentrated reservoirs. Furthermore, it was suggested that the hot-water injection was effective when it was applied as a secondary-recovery method after depressurization. Simple economic analyses on the basis of these simulation results exhibited the promise that some MH reservoirs in the Eastern Nankai trough could be developed economically if the well spacing and MH-dissociation/-production methods were designed appropriately.
Displacement Mechanisms of Micellar Solutions
Authors: Davis J.A. , Jones S.C.
Published: July 2009

This paper describes displacement mechanisms of micellar solution slugs, displaced by a thickened water "mobility buffer", in a glass micromodeland in consolidated Berea sandstone cores. Colored motion pictures, takenthrough a microscope, recorded interactions on a pore-to-pore basis in themicromodel. Production and differential pressure data from consolidated corespreviously waterflooded to residual oil saturation revealed displacementmechanisms macroscopically.

Oil is displaced miscibly, while interstitial water is displaced immisciblyby the injected micellar solution slug. Part of this water is dispersed andcarried near the leading edge of the slug, and some may remain as a residualsaturation. Thickened water displaces any residual water. It also emulsifieswith the slug material, thereby displacing it. The displacement sequence formsbanks of oil and water with relatively constant fractional flows, saturations, and mobilities. The mobility of oil and water flowing ahead of the slug definesslug viscosity required for stable displacement.

Equations are presented that describe several aspects of the displacementflow behavior: oil breakthrough, oil cut during production of the stabilizedbank, breakthrough of banked water and the resulting decreased fractional flowof oil, fluid mobilities, etc. Breakthroughs, calculated from the equations, are compared with experimental data.

Slugs of micellar solution, ranging from 1 to 5 percent PV, producedunusually high oil recoveries (up to 100 percent) in previously waterfloodedconsolidated cores. Investigation of the effect of mobility buffer size on oilrecovery indicated that recovery is reduced in 3-in. X 4-ft cores for mobilitybuffer sizes smaller than 50 percent of the pore volume.
Valuation of Natural Gas Property
Authors: Davis Ralph E. , Stephenson Eugene A.
Published: July 2009

The appraisal of natural gas properties is a complex problem affected bymany non-engineering factors. Attention will be brought here to the moreimportant matters that influence value of such properties, such as thenecessity of competent estimates of reserves, availability of the products andof market outlets, the expected rate of recovery, the anticipated prices ofproducts and future costs, the effect of the graduated income tax on profitswhich lead to greater value of a property to one owner than to another, andother items. To a degree, in each appraisal the problems are unique in that theapproach must be suited to the particular case.

During the past 30 years and more, many engineers and geologists haveaccumulated considerable experience in the problems of evaluating propertiescapable of producing oil and natural gas. An extensive literature has developedoutlining the principles and methods that govern appraisals. Emphasis is placedherein on the importance of careful analysis of the various factors whichshould lead to a determination of value, and to point out the inadequacy ofrather common engineering appraisals that frequently have little relation towhat has been termed "fair market value." In a Delaware court someyears ago an engineer admitted freely on cross-examination that his appraisalwas "an engineering valuation - not a determination of the fair marketvalue. Such so-called "engineering appraisals" are perhaps interesting, and occasionally may be of some use, but must not be considered of fairvalue.

During the past few years the effect of the graduated income tax has becomeespecially important in the appraisal of properties yielding income, andpromises to continue to be so far a long time. This tax places somecorporations in the 52 per cent bracket and subjects individuals to rates thatmay be as high as 85 to 90 per cent. To those institutions whose income is nottaxed, a property can be worth two or three times as much as it may be to theindividual in a high tax bracket.
Local Therapies to Heal the Penis: Fact or Fiction?
Authors: Kim Edward D.
Published: July 2009

ABSTRACT:Penile rehabilitation has been an area of intense study and debate over the last decade. Interest in this topic was stimulated by the observation that erectile dysfunction remained a significant problem after radical prostatectomy despite meticulous nerve‐sparing technique. Smooth muscle alterations and fibrotic changes in the penis were identified as the underlying causes of penile atrophy, veno‐occlusive dysfunction, and Peyronie's‐like changes that were observed after surgery. Initial observations that intracavernous injection therapies used on a regular basis postoperatively resulted in improvements in the return of spontaneous erectile function led to the development of penile rehabilitation protocols. Chronic dosing of oral type V phosphodiesterase inhibitors is now commonly used by urologists after radical prostatectomy despite a lack of convincing evidence from randomized, placebo‐controlled clinical trials. Use of local therapies to heal the penis may have applications beyond the postprostatectomy patient. This article reviews the current evidence behind penile rehabilitation therapy.
Length of Androgen Receptor—CAG Repeats in Fertile and Infertile Egyptian Men
Authors: Badran Wael A. , Fahmy Ibrahim , Abdel‐Megid Wael M. , Elder Kay , Mansour Ragaa , Kent‐First Marijo
Published: July 2009

ABSTRACT:Androgens play key roles in spermatogenesis, and they exert their effect via the androgen receptor (AR). The AR gene has a repetitive DNA sequence in exon 1 that encodes a polyglutamine tract. Instability in the glutamine (CAG) repeat unit length is polymorphic across ethnic groups. Previous studies of the relationship between the repeat unit length and male infertility have been contradictory. To establish the range of wild‐type alleles in Egyptian men, we determined the range of repeat lengths in a population of normally fertile, ethnically selected Egyptian men. We also investigated the association between trinucleotide repeat length within theARgene and male factor infertility in a population of ethnically selected Egyptian infertile men, who were compared with fertile, ethnic group—matched and age‐matched controls. The study included 129 clinically selected infertile Egyptian men who were scheduled for intracytoplasmic sperm injection and 52 ethnically matched fertile controls. The experimental population was grouped according to sperm counts ranging from nonobstructive azoospermia to normozoospermia. The CAG repeat N‐terminal domain region of theARgene was amplified in peripheral blood DNA, and allele size was determined by fragment analysis. Allele size and single‐nucleotide polymorphism and mutation rates were determined by sequencing individual amplified alleles. The mean CAG repeat length in the azoospermia group was 18.55 ± 2.0; in the severe oligozoospermia group it was 18.21 ± 3.42; in the oligozoospermia group it was 18.27 ± 2.93; and in the infertile with normal sperm count group it was 17.72 ± 2.0. In the control group, the mean CAG repeat length was 18.18 ± 3.63. No significant correlation was found between CAG repeat length and the risk of male factor infertility in an ethnically defined population of Egyptian men. However, a significant and positive correlation between CAG repeat length and serum testosterone concentration was demonstrated. This suggests the involvement of epigenetic regulation linked to this region.
The Emerging Link Between Hypogonadism and Metabolic Syndrome
Authors: Guay André T.
Published: July 2009

ABSTRACT:The metabolic syndrome (MS) is comprised of various medical conditions that confer increased risk of diabetes and cardiovascular disease. The pathophysiologic components of MS include glucose abnormality, obesity or increased waist circumference, increased blood pressure, and hyperlipidemia. There is an increased risk of hypogonadism in men with MS and its individual components, including insulin resistance, considered by some to be at the core of MS. Hypogonadism may even predict MS. These factors are interwoven and impact overall health, including sexual dysfunction. One interesting and important question is whether treating hypogonadism with testosterone replacement will ameliorate the pathological components of MS.
Erectile Dysfunction Management for the Future
Authors: Burnett Arthur L.
Published: July 2009

ABSTRACT:The field of erectile dysfunction (ED) management over time has witnessed assorted interventions to enable men to perform sexual intercourse. In recent times, major progress in ED research has led to increasingly effective treatments based on a refined knowledge of the scientific basis for penile erection. Current concepts suggest that therapeutic prospects on the horizon include novel pharmacotherapies, growth factor therapy, gene therapy, and regenerative medicine. The purpose of this review is to present the foundations for future therapies in ED management.
Postmortem Sperm Retrieval: The Canadian Perspective
Authors: Weber Bryce , Kodama Ron , Jarvi Keith
Published: July 2009

ABSTRACT: Postmortem sperm retrieval has been used worldwide. Following retrieval, sperm can then be used (usually by the surviving partner) to produce a child related to the now‐deceased male. This paper describes a request for postmortem sperm retrieval made by the family of a man who had suffered trauma leading to his death. The man had not given written consent for the retrieval and use of his sperm before his accidental death. The case illustrates some of the complex ethical and legal issues occurring in Canada and describes the new Canadian regulations, which prohibit postmortem sperm retrieval unless explicit written consent has been provided by the deceased.