bluuebunny/crossref_metadata_2025 huggingface dataset:
Guidelines for Filler-Material Selection To Minimize Preferential Weld Corrosion in Pipeline Steels
Authors: Mahajanam Sudhakar P. , Joosten Mike W.
Published: March 2011

Preferential weld corrosion (PWC) has long been a problem in the oil and gas industry for pipelines used in process facilities, seawater injection, produced-water service, offshore platforms, and downhole-production systems. This paper reviews recent PWC field failures in light of mitigation guidelines from existing literature. Environmental effects take precedence over chemical composition and microstructure in determining PWC susceptibility. Therefore, the primary approach to minimize PWC is continuous corrosion inhibition. The ideal PWC-prevention method would be the use of autogenous welds or welds made with matching consumables. However, this is not a practical option in the field where most pipelines are typically made from carbon (C) manganese (Mn) steels with broad chemical compositions, thereby making them susceptible to PWC. The feasible alternative is to use filler materials with strict compositional control concerning the following elements: nickel (Ni), silicon (Si), and chromium (Cr). In addition, increased-preheat and high-heat input welding processes should be employed to minimize PWC susceptibility.
Well-Integrity Assessment and Assurance: The Operational Approach for Three CO2-Storage Fields in Italy
Authors: D’Alesio P.. , Poloni R.. , Valente P.. , Magarini P.A.. A.
Published: March 2011

In 2004 Eni Exploration and Production (E&P) launched the GreenHouse Gases (GHG) Project to develop technologies and select fields suitable for geological sequestration of carbon dioxide (CO2).

For the well area, the project includes Well-integrity assessment: Verify and (if necessary) reinstate the structural integrity of the existing wells.Well-integrity assurance: Establish the technical requirements to ensure the integrity of new CO2-injection wells.

Well-integrity assessment has been carried out by developing and implementing an operational methodology for three Italian fields: Cortemaggiore, Palino-Ascoli-Candela-Satriano (PACS), and Giaurone-Armatella-Gela. This methodology includes the comparison between the sustained casing pressures (SCPs) measured in the annuli and the relevant maximum allowable pressures (MAPs) to estimate how close each well is to losing its safety conditions. Then, the methodology foresees specific investigations for the critical wells to identify the magnitude and possible causes of the SCPs occurrence. Finally, it includes the preparation of suitable remedial and/or monitoring plans.

Stress-analysis studies supported these activities by calculating the mechanical resistance, under the planned operational conditions, of production casings and tubings of the CO2-injection wells.

As for well-integrity assurance, technical requirements for new CO2-injection wells have been established on the basis of the project for Well Cortemaggiore 157 Dir, constructed to carry out the pilot test for the injection of CO2 in a depleted level of the Cortemaggiore field.

Specific studies have been carried out for the PACS and Giaurone-Armatella-Gela fields. The former is a gas field with high CO2 content—CO2 will be separated and reinjected. The latter is an oil field—CO2 injection will be used as an effective means for enhancing oil recovery.

This paper describes the operational approach followed for these activities and describes the main requirements for the new CO2-injection well.
On SAGD in Oil Sands Reservoirs With No Caprock and Top Water Zone
Authors: Al-Turki Ali A. , Gates Ian D. , Maini Brij B.
Published: March 2011

The ever-increasing world demand for energy to satisfy current needs and future economic growth has forced the oil and gas industry to exploit challenging energy resources. Heavy oil and oil sands are challenging because of the complexity of reservoirs together with high-oil viscosities, which are often greater than hundreds of thousands to millions of centipoise. Most steam-based recovery processes, such as cyclic steam stimulation (CSS) and steam-assisted gravity drainage (SAGD), require a competent caprock to prevent excessive steam losses and maintain good thermal efficiency and production rates, as well as preventing steam flow to surface. However, there exist significant amounts of oil sands resources, which have little or no caprock; thus, at this point, these resources are considered inaccessible. This research examines the feasibility of using SAGD in oil sands reservoirs with no caprock with detailed thermal reservoir simulation. The results of this research provide guidelines that explain how to implement the SAGD process in shallow oil sands reservoirs with no caprock. This could unlock a resource that is currently considered inaccessible. The results show that vertical chamber growth can be controlled to some extent by using variable pressure operating strategies and coinjection of a noncondensable gas, such as methane. In oil sands reservoirs without caprocks, pressure control is critical, especially if there is to be minimal fluid invasion from the oil sands formation into the water zone above. However, the pressure must be sufficient to delay or prevent flow of water into the steam chamber. This study is important because in Alberta, Canada alone there are billions of barrels of shallow oil sands resources without sufficient caprock to operate conventional high-pressure steam recovery processes, such as CSS and SAGD. The results of the study provide a technical basis to design feasible low-pressure steam processes for such reservoirs.
Noncondensable Gas Distribution in SAGD Chambers
Authors: Yuan Jian-Yang , Chen Joyce , Pierce Gerry , Wiwchar Brian , Golbeck Hart , Wang Xinkui , Beaulieu Gilles , Cameron Shauna
Published: March 2011

This paper summarizes a set of SAGD experiments conducted live under an X-ray scanner. These experiments were specifically designed for mapping noncondensable gas distribution and their movement in an active steam chamber during SAGD.

Many researches over the past 3 decades have shown that noncondensable gases may have critical impacts on SAGD performance. Some may be positive and others may be negative, depending on reservoir and operating conditions. To better use the positives, avoid the negatives, and for better SAGD performance predictions, it is crucial to understand how these gases behave in a steam chamber. It is arguable that noncondensable gases tend to accumulate at the steam front where steam condenses. However, this assertion has only been supported by numerical simulations. Field observation data have been too sparse. Meaningful tracking of gas production is not a normal practice in the field.

The first experiment was conducted in an aluminum vessel packed with 4 darcy sands at 1.0 MPa. The second experiment was conducted in a scalable system consisting of a titanium pressure vessel and a PEEK cell, allowing the SAGD experiment to run at 2.1 MPa. Both experiments used bitumen fully saturated with methane at reservoir conditions and were run live under the X-ray scanner. X-ray images were taken at given time intervals. Temperature profiles were obtained directly from thermocouples. Density profiles were computed from the X-ray images. Methane in the free gas phase were calculated and mapped. After each experiment, samples from the opened cell were also tested for additional observation and confirmation.

These experiments confirmed the assertion that noncondensable gas tends to concentrate along the steam front. It was also demonstrated that the steam temperature zone does not coincide with the oil-depleted zone, indicating that in a SAGD reservoir with nontrivial presence of noncondensable gases, temperature measurements at observation wells alone would not reflect the boundary of the steam chamber. The more representative measure of a steam chamber should be the mapping of the oil-depleted zone. A more comprehensive monitoring of gas production plus 4D seismic would be needed to determine the oil-depleted zone in the field operation.
Well-Production Challenges and Solutions in a Mature, Very-Low-Pressure Coalbed-Methane Reservoir
Authors: Okotie Victoria U. , Moore Robert L.
Published: March 2011

Coalbed-methane (CBM) production in the San Juan basin of northwestern New Mexico and southwestern Colorado has spanned more than 30 years. Some parts of the field, such as the high-permeability Fairway, are now in a mature stage of reservoir-pressure depletion. Optimization of well-production operations in the Fairway presents many challenges because of its extremely low reservoir pressure (less than 100 psi in some areas), heavy coal-fines production, difficult artificial-lift challenges, increasing CO2%, and the presence of paraffin, inorganic scale, and corrosion.

We use history matching by reservoir simulation to help diagnose the causes of well-production inefficiencies and then plan how to mitigate them. Simulation of Fairway wells typically require the use of an increasing reservoir-permeability trend caused by coal-matrix shrinkage with the desorption of methane and CO2. However, we have observed in some Fairway wells that below a reservoir pressure of approximately 300 psi, there is a flattening or even a decrease in the permeability trend. This shift in the permeability trend is likely caused by coal failure (i.e., a change in mechanical properties of coal) that is evidenced in the wells by an increased amount of coal-fines production.

This paper is written in two parts. The first part presents the challenges we face in operating Fairway wells and the solutions we have developed to overcome them. Field observations and operating guidelines will be shared, along with well-intervention histories where we have seen success. The second part discusses our use of reservoir simulation to diagnose the causes of reduced well-production efficiency.
Front Self-Correction for In-Situ Combustion
Authors: Paitakhti Oskouei Seyed Javad , Moore Gordon , Maini Brij B. , Mehta Sudarshan A.
Published: March 2011

Since it was discovered in the early 1920s, several improvements have been suggested for in-situ combustion (ISC) technology. Top-down combustion displacement is a process proposed for application with horizontal well technologies. In this configuration, air is injected near the top of the reservoir, close to the overburden, through a horizontal well or a number of vertical wells. Fluids are produced from the reservoir through horizontal wells placed near the bottom of the reservoir. In this configuration, the combustion front moves downward with gravity and displaces fluids to the production well.

Combustion front formation and its stability are major concerns in this arrangement. While the short distance between injector and producer addresses the cold oil blocking problem in the reservoir, it has the potential to create air fingers, which could prevent stable advance of the combustion zone in a horizontal plane. Front self-correction must occur to prevent oxygen from fingering to the production wells.

To prove this idea, experiments at reservoir pressure were carried in a 2D SAGD model with Athabasca bitumen. Air was injected into the SAGD steam chamber from the top, and fluids were produced from the bottom. Front advancing directions were monitored by a series of thermocouples located inside the model. It was found that the combustion zone starts spreading horizontally in the model until it reaches a limiting point, then it starts moving downward as a horizontal front. Despite heterogeneity of the oil saturation and relative permeability in the steam chamber and unswept zones, the combustion front moved almost as a horizontal plane and no sharp fingers were recorded in the experiments. These experiments show that stable top-down combustion is feasible.
Offshore-Platform Startup Challenges: Materials Integrity and Remediation
Authors: Mahajanam Sudhakar P.V. , Joosten Mike W.
Published: March 2011

Offshore oil- and gas-production environments provide severe challenges in terms of materials selection and day-to-day operations. Several issues encountered during commissioning of a North Sea platform and the remedial actions are presented.

Corrosion protection of carbon-steel bolting by encapsulation was employed to stop deterioration of an improperly applied anodic coating.

Iron contamination from debris generated during topside construction and chlorides from the marine atmosphere provided the conditions necessary for ferric chloride pitting corrosion of uncoated 316 stainless steel (SS), duplex and super duplex SS, and 6% Mo SS pipework and vessels. Several offshore cleaning/coating methods were evaluated, and a new procedure for cleaning was identified that achieved the desired goal without removal of metal or affecting the corrosion-resistant alloy's passive film integrity.

Insulated SS instrument tubing was susceptible to crevice corrosion and chloride stress corrosion cracking (Cl-SCC) under wet insulation at the temperatures generated by the heat tracing. Solutions were suggested to minimize such forms of corrosion.

Coatings exceeding the manufacturer's recommended thickness had been applied to several high-temperature vessels and to pipework to prevent SCC as well as ferric chloride pitting. The potential for coating disbondment at elevated temperatures because of high dry-film thickness (DFT) was evaluated through a testing program and on-site inspections.
Convection at the Edge of a Steam-Assisted-Gravity-Drainage Steam Chamber
Authors: Sharma Jyotsna , Gates Ian D.
Published: March 2011

Steam-assisted gravity drainage (SAGD) has become the preferred process to recover bitumen from Athabasca deposits in Alberta. The method consists of a lower horizontal production well, typically located approximately 2 m above the base of the oil zone, and an upper horizontal injection well located roughly 5 to 10 m above the production well. Steam flows from the injection well into a steam chamber that surrounds the wells and releases its latent heat to the cool oil sands at the edge of the chamber. This research re-examines heat transfer at the edge of the steam chamber. Specifically, a new theory is derived to account for convection of warm condensate into the oil sand at the edge of the chamber. The results show that, if the injection pressure is higher than the initial reservoir pressure, convective heat transfer can be larger than conductive heat transfer into the oil sand at the edge of the chamber. However, enhancement of the heat-transfer rate by convection may not necessarily imply higher oil rates; this can be explained by relative permeability effects at the chamber edge. As the condensate invades the oil sand, the oil saturation drops and, consequently, the oil relative permeability falls. This, in turn, results in the reduction of the oil mobility, despite the lowered oil viscosity because of higher temperature arising from convective heat transfer.
Prediction of Asphaltene Precipitation During Solvent/CO2 Injection Conditions: A Comparative Study on Thermodynamic Micellization Model With a Different Characterization Approach and Solid Model
Authors: Tavakkoli Mohammad , Masihi Mohsen , Ghazanfari Mohammad H. , Kharrat Riyaz
Published: March 2011

There are different thermodynamic models that have been applied for modelling of asphaltene precipitation caused by various reasons, such as solvent/CO2 injection and pressure depletion. In this work, two computer codes based on two different asphaltene precipitation thermodynamic models--the first being the thermodynamic micellization model with a different characterization approach and the second being the solid model--have been developed and used for predicting asphaltene precipitation data reported in the literature as well as in the obtained data for Sarvak reservoir crude, which is one of the most potentially problematic Iranian heavy oil reserves under gas injection conditions. For the thermodynamic micellization model, a new approach was obtained by applying the characterization method taken from the thermodynamic solid model for oil component characterization. This new approach introduced a new matching parameter to the model, representing the interaction coefficients between asphaltene components and light hydrocarbon components, which resulted in a significant improvement in the thermodynamic micellization model predictions of asphaltene precipitation data under gas injection conditions. The model parameters obtained from a sensitivity analysis were applied in both thermodynamic models, and the experimental data of asphaltene precipitation were predicted. The asphaltene precipitation predictions from the solid model showed good agreement with the data taken under gas/solvent injection conditions. Especially for the trend of the titration curve after the peak point, reasonable agreements were observed which could rarely be found in the available literature. It has been observed that although the thermodynamic micellization model with a different characterization approach is more complex than the solid model, it is able to predict the trends of asphaltene precipitation curves for gas titration conditions reasonably well. Also, its predictions matched well with more experimental data points in comparison to the solid model predictions.
Examining the Effects of an Electronic Classroom Response System on Student Engagement and Performance
Authors: Bartsch Robert A. , Murphy Wendy
Published: March 2011

This experiment examines the causal effect an electronic classroom response system (ECRS) has on students. Previous studies using an ECRS in the classroom indicate improved performance; however, many have confounds typical of classroom studies. To complement these studies, we conducted a laboratory study to minimize these confounds and concentrate on student engagement. We randomly assigned participants ( n = 52) to receive a 10–minute lecture either with or without an ECRS. The lecture contained questions to increase student engagement but not provide student and instructor feedback of concept mastery. Afterwards, the lecture participants were given a surprise quiz. Students using the ECRS scored significantly higher. We discuss the implications of this experiment for the ECRS literature.
Developing Pre-Service Teachers' Technology Integration Expertise Through the Tpack-Developing Instructional Model
Authors: Koh Joyce H. L. , Divaharan Hanti
Published: March 2011

This study describes the TPACK-Developing Instructional Model which prescribes an instructional process for developing pre-service teachers' Technological Pedagogical Content Knowledge (TPACK) during the instruction of Information and Communication Technology (ICT) tools. This model proposes three phases for developing teachers' TPACK through ICT instruction. The phases are: fostering teachers' acceptance and technical proficiency; pedagogical modeling; and pedagogical application. An ICT instructional intervention designed with this model as its framework and its effects on the TPACK development of 74 pre-service teachers were examined. Qualitative analyses of their course reflection comments found that they predominantly developed Technological Knowledge and Technological Pedagogical Knowledge. More emphasis on subject-focused pedagogical modeling, product critique, and peer sharing may better develop their Technological Content Knowledge and TPACK. Future developments of the TPACK-Developing Instructional model are discussed.
Welfare Reform in the U.S.: A Policy Overview Analysis
Authors: Martin Megan C. , Caminada Koen
Published: March 2011

Several previous papers have marked the United States as an outlier: high poverty rates, low public social spending but high private social expenditures; a rather strong belief that people are poor because of laziness or lack of will; and remarkable differences across the States due to state discretion. With that established context in mind, this paper analyzes U.S. welfare in more detail, focusing on the impact of TANF—part of the major welfare reform that took place in the United States in 1996. U.S. welfare reform emphasized an American preference for work, and it was a move further away from the strategies other “wealthy” nations use to address poverty. Initially U.S. welfare reform did serve to increase work participation rates, although the earnings of most individuals who left welfare were still below the poverty line, even many years after their exit. We found huge variation of welfare eligibility rights across states, depending on the state's ability to pay and preferences to meet a certain level of social standard or other (social) objectives such as child care, work support and employment programs.
Energy Burden and the Need for Integrated Low‐Income Housing and Energy Policy
Authors: Hernández Diana , Bird Stephen
Published: March 2011

Using detailed sociological and public health qualitative interview data, we demonstrate that energy poverty is more pervasive, and results in a greater energy burden for low‐income tenants, than many policymakers would assume. This is due in part to a lack of funding, policy non‐coordination, and a lack of understanding of the social and economic benefits of energy conservation, energy education, and flexible utility billing policies. Examining LIHEAP, weatherization, utility, and housing assistance policies, we suggest that a coordinated, regional approach to home energy and housing policy that integrates programs in each area will provide a more coherent policy solution.
The Next Generation of Poverty Reduction Strategy Papers in Africa: What is the Role for Capacity Buiding?
Authors: Ikhide Sylvanus I , Obadan Michael I
Published: March 2011

In the late 1990s and at the early path of this century, most African economies embraced poverty reduction strategy papers (PRSPs) as a policy prescription out of the poverty abyss into which their economies had sunk since the early 1970s. The results from the first generation of PRSP processes have been encouraging and have acted as a stimulus for the second generation PRSPs. However, capacity constraints have tended to create difficulties for many of these countries, slowdown the pace of implementation of the PRSP, as well as undermine the achievement of objectives. This study, focusing on a sample of countries in Africa, attempts to identify and characterise the nature of capacity building constraints in the formulation and implementation of PRSPs and suggests capacity building efforts for dealing with these constraints. Four major areas of capacity constraints were identified: capacity for poverty and social impact analysis, monitoring and evaluation, absorptive capacity, public expenditure management, and constraints on prioritisation. Given funding constraints, the paper concludes by prioritising areas of capacity building interventions by capacity building institutions and donors in a bid to strengthen capacity building in Africa.
Review of The Crisis Caravan: What's Wrong with Humanitarian Aid?
Authors: Beard Virginia Parish
Published: March 2011

Linda Polman, drawing from over fifteen years experience reporting from war zones for a range of European radio stations and newspapers, uses rich case study analysis to posit a picture of ineffective and ill‐targeted foreign assistance that departs alarmingly from the industry's claim of impartial assistance to victims of conflict. On the contrary, Ms. Polman paints a convincing portrait of captured aid, supporting the business of war and military strategy, pushing the ethical boundaries on such questions as whether doing something is always better than doing nothing, and whether good intentions are enough to warrant certain means and outcomes. She argues for greater transparency, honesty and accountability across the humanitarian assistance industry with rich, detailed accounts of areas for needed change. This is an essential read for students, practitioners and scholars of international conflict, development and aid.
The Good‐looking National Commission on Fiscal Responsibility and Reform
Authors: Dobelstein Andrew
Published: March 2011

Andrew Dobelstein, Professor Emeritus at The University of North Carolina ‐ Chapel Hill School of Social Work responds to Eric R. Kingson's article entitled “A Tale of Three Commissions: The Good, The Bad, and The Ugly.” The article was published as part of Poverty & Public Policy Volume 2, Issue 3.
Elimination of corporal punishment of children's a human right
Authors: Stevanovic Ivana , Srna Jelena
Published: March 2011

The authors indicate the necessity of explicit legal prohibition of all
corporal punishment of children that represent a violation of the right of
the child to respect his/her physical integrity and human dignity. The paper
emphasizes why all corporal punishment of children should be prohibited and
points out the progress made at the legislative level to the elimination of
all corporal punishment of children in some member states of the Council of
Europe and the Republic of Serbia.
Pupils have rights too
Authors: Banjanin-Djuricic Nada
Published: March 2011

The text points out the delicate problem of inadequate treatment of pupils by
teachers. Such treatment may include insults, verbal aggression, sarcasm, but
also the double meaning of the message in which it is hard to prove violation
of pupils? personality. Although characteristics of desirable relationship of
teachers toward children are specified by the Convention on the Rights of the
Child, Law on Foundations of the Education and Upbringing System, as well as
by the Protocol for Protection of Children and Students from Violence, Abuse
and Neglect in Educational Institutions, verbal aggression is still present,
but often unrecognized as a form of violation of pupils? rights - right to
respect of personality and right to development. The text describes an
attempt, almost an experiment, in the form of workshop model that can
contribute to recognition of this problem and help in finding constructive
ways to overcome it.
Effect of garlic on bacterial biofilm formation on orthodontic wire
Authors: Lee Heon-Jin , Park Hyo-Sang , Kim Kyo-Han , Kwon Tae-Yub , Hong Su-Hyung
Published: March 2011

Objective:

To examine the effect of garlic extract on the biofilm formation by Streptococcus mutans on orthodontic wire and on glucosyltransferase gene expression.

Materials and Methods:

Growth inhibition of oral bacteria was tested after 50 µL of garlic extract was placed on an agar plate. The minimum inhibitory concentration (MIC) of garlic extract on S mutans growth was first determined. After cultivating streptococci in biofilm medium (BM)-sucrose with garlic extract and orthodontic wire, adenosine triphosphate (ATP) measurement and viable cell counting was performed from the bacteria attached on the wire. Scanning electron microscopy (SEM) analysis of morphology was observed on bacterial cells attached to orthodontic wire. The effect of garlic extract on gene expression was evaluated using quantitative real-time polymerase chain reaction (PCR) of glucosyltransferase.

Results:

Though garlic extract had a clear antibacterial effect on all microorganisms, it also enhanced S mutans attachment on orthodontic wire. Low concentration of garlic extract also increased glucosyltransferase gene expression of S mutans.

Conclusions:

Despite its antibacterial function, garlic extract increases biofilm formation by S mutans to orthodontic wire, likely through upregulation of glucosyltransferase expression. Garlic extract may thus play an important role in increased bacterial attachment to orthodontic wires.
Risk of Bladder Cancer Among Diabetic Patients Treated With Pioglitazone
Authors: Lewis James D. , Ferrara Assiamira , Peng Tiffany , Hedderson Monique , Bilker Warren B. , Quesenberry Charles P. , Vaughn David J. , Nessel Lisa , Selby Joseph , Strom Brian L.
Published: March 2011

OBJECTIVE

Some preclinical in vivo studies and limited human data suggest a possible increased risk of bladder cancer with pioglitazone therapy. This is an interim report of an ongoing cohort study examining the association between pioglitazone therapy and the risk of bladder cancer in patients with diabetes.

RESEARCH DESIGN AND METHODS

This study includes 193,099 patients in the Kaiser Permanente Northern California diabetes registry who were ≥40 years of age between 1997 and 2002. Those with prior bladder cancer were excluded. Ever use of each diabetes medication (defined as two or more prescriptions within 6 months) was treated as a time-dependent variable. Cox regression–generated hazard ratios (HRs) compared pioglitazone use with nonpioglitazone use adjusted for age, sex, race/ethnicity, diabetes medications, A1C, heart failure, household income, renal function, other bladder conditions, and smoking.

RESULTS

The group treated with pioglitazone comprised 30,173 patients. There were 90 cases of bladder cancer among pioglitazone users and 791 cases of bladder cancer among nonpioglitazone users. Overall, ever use of pioglitazone was not associated with risk of bladder cancer (HR 1.2 [95% CI 0.9–1.5]), with similar results in men and women (test for interaction P = 0.8). However, in the a priori category of >24 months of therapy, there was an increased risk (1.4 [1.03–2.0]). Ninety-five percent of cancers diagnosed among pioglitazone users were detected at early stage.

CONCLUSIONS

In this cohort of patients with diabetes, short-term use of pioglitazone was not associated with an increased incidence of bladder cancer, but use for more than 2 years was weakly associated with increased risk.
Progression and Regression: Distinct Developmental Patterns of Diabetic Retinopathy in Patients With Type 2 Diabetes Treated in the Diabetes Care System West-Friesland, the Netherlands
Authors: Zavrelova Hata , Hoekstra Trynke , Alssema Marjan , Welschen Laura M.C. , Nijpels Giel , Moll Annette C. , de Vet Henrica C.W. , Polak Bettine C.P. , Dekker Jacqueline M.
Published: March 2011

OBJECTIVE

To identify distinct developmental patterns of diabetic retinopathy (DR) and assess the risk factor levels of patients in these clusters.

RESEARCH DESIGN AND METHODS

A cohort of 3,343 patients with type 2 diabetes mellitus (T2DM) monitored and treated in the Diabetes Care System West-Friesland, the Netherlands, was followed from 2 to 6 years. Risk factors were measured, and two-field fundus photographs were taken annually and graded according to the EURODIAB study group. Latent class growth modeling was used to identify distinct developmental patterns of DR over time.

RESULTS

Five clusters of patients with distinct developmental patterns of DR were identified: A, patients without any signs of DR (88.9%); B, patients with a slow regression from minimal background to no DR (4.9%); C, patients with a slow progression from minimal background to moderate nonproliferative DR (4.0%); D, patients with a fast progression from minimal or moderate nonproliferative to (pre)proliferative or treated DR (1.4%); and E, patients with persistent proliferative DR (0.8%). Patients in clusters A and B were characterized by lower risk factor levels, such as diabetes duration, HbA1c, and systolic blood pressure compared with patients in progressive clusters (C–E).

CONCLUSIONS

Clusters of patients with T2DM with markedly different patterns of DR development were identified, including a cluster with regression of DR. These clusters enable a more detailed examination of the influence of various risk factors on DR.
Dairy Consumption and the Incidence of Hyperglycemia and the Metabolic Syndrome
Authors: Fumeron Frédéric , Lamri Amel , Abi Khalil Charbel , Jaziri Riphed , Porchay-Baldérelli Isabelle , Lantieri Olivier , Vol Sylviane , Balkau Beverley , Marre Michel ,   the Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) Study Group
Published: March 2011

OBJECTIVE

In the French Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort, cross-sectional analyses have shown that a higher consumption of dairy products and calcium are associated with a lower prevalence of the metabolic syndrome (MetS). We assess the influence of dairy products on 9-year incident MetS and on impaired fasting glycemia and/or type 2 diabetes (IFG/T2D).

RESEARCH DESIGN AND METHODS

Men and women who completed a food frequency questionnaire at baseline and after 3 years were studied (n = 3,435). Logistic regression models were used to study associations between the average year 0 and year 3 consumption of milk and dairy products, cheese, dietary calcium density, and incident MetS and IFG/T2D after adjusting for 1) sex, age, alcohol, smoking, physical activity, fat intake and 2) additionally for BMI. Associations between dairy products and continuous variables were studied by repeated-measures ANCOVA, using the same covariates.

RESULTS

Dairy products other than cheese, and dietary calcium density, were inversely associated with incident MetS and IFG/T2D; cheese was negatively associated with incident MetS. All three parameters were associated with lower diastolic blood pressure, and with a lower BMI gain. Higher cheese intake and calcium density were associated with a lower increase in waist circumference and lower triglyceride levels. Calcium density was also associated with a lower systolic blood pressure and a lower 9-year increase in plasma triglyceride levels.

CONCLUSIONS

A higher consumption of dairy products and calcium was associated with a lower 9-year incidence of MetS and IFG/T2D in a large cohort drawn from the general population.
Combined action of X-rays and nonylphenol on mouse sperm
Authors: Dobrzyńska Małgorzata
Published: March 2011

The aim of this study was to assess the effects of 2-weeks’ X-ray and/or nonylphenol (NP) exposure on male mice’s sperm count and quality. Pzh:SFIS mice were exposed to X-rays (0.05 Gy, 0.10 Gy, 0.20 Gy) or to nonylphenol (25 mg/kg bw, 50 mg/kg bw, 100 mg/kg bw) or to both agents (0.05 Gy + 25 mg/kg bw NP, 0.10 Gy + 50 mg/kg bw NP). At 24 h and 5 weeks after the end of exposure the sperm count, morphology and frequency of DNA damage in the male germ cells were estimated. Each agent alone diminished sperm count and morphology. The dose of 0.05 Gy of X-rays decreased the frequency of DNA damage. Combined exposure to lower doses of both agents significantly improved sperm morphology and decreased the level of DNA damage compared to one agent alone. Combined exposure to higher doses reduced the frequency of DNA damage compared to the effect of the appropriate dose of NP. Results of combined exposure to low doses of both agents suggest that 0.05 Gy of X-rays stimulate the DNA damagecontrol system and in consequence repair of DNA caused by X-rays and NP. It may be correlated with increased antioxidant capacity.
Alcohol consumption among adolescents in Kraljevo, Serbia
Authors: Djordjevic Natasa , Bogojevic Jelena , Kostic Marina
Published: March 2011

The aim of this study was to investigate the prevalence and predictors of alcohol consumption among adolescents in one town in Central Serbia. A questionnaire was used to obtain data from 191 Serbian students aged 18 years regarding personal experience with alcohol consumption and cigarette smoking, along with sociodemographics data. Alcohol consumption was reported by 97.4% subjects, with 34.9% having the first experience with alcohol at the age of 14 years or less. Binge drinking (the intake of five or more drinks at one sitting) was reported by 37.8% subjects. Significantly higher consumption of beer (p<0.0001) and spirits (p=0.03) was observed in boys. The most common reason for both initiation and continuation of drinking, regardless of gender, were celebrations (p≥0.12). Smokers were more likely than nonsmokers to consume all alcoholic beverages more frequently (p≤0.04) and in larger quantities (p≤0.004). More frequent or more extensive alcohol consumption, or both, was associated in boys with frequent going out and socializing (p≤0.01), close peer relationship (p=0.04), alcohol abuse within the immediate environment (p≤0.04), better financial status of family (p=0.04), and parental criticism (p≤0.02); in girls, it was associated with parental disapproval (p≤0.02), alcohol abuse within the immediate environment (p≤0.04), and general discontentedness (p=0.049). Regardless of gender, positive alcohol outcome expectancies increased alcohol consumption (p≤0.048), and negative expectancies decreased intake (p≤0.047).
Multtvariate diversity of Polish winter triticale cultivars for spike and other traits
Authors: Kociuba Wanda , Mądry Wieslaw , Kramek Aneta , Ukalski Krzysztof , Studnicki Marcin
Published: March 2011

Multtvariate diversity of Polish winter triticale cultivars for spike and other traits

The objective of the present study was to determine the extent and pattern of genotypic diversity for six spike quantitative characters and two other traits in 36 winter triticale cultivars released in Poland, to classify the cultivars into similarity groups (clusters) and to identify those traits, among the studied ones, which mostly discriminated distinguished groups of cultivars. The 36 cultivars, released in the period from 1982 to 1999, were evaluated across three years 2002-2004 at the Experimental Field Station in Czesławice near Nałęczów, Poland. The experiments were carried out on the brown soil with loess subsoil. In each year the one-replicated experimental design was used with 2 m2plots, rows 20 cm apart, and dense sowing using about 2 cm spacing of seeds. Analyses of variance for each trait data according to the random model (both cultivars and years were assumed to be random factors) were done. To classify and characterize genotypic diversity of the cultivars for the eight traits, the pattern analysis was used. It involved both cluster analysis using Ward's procedure with a measure of the multivariate similarity among cultivars being Squared Euclidean Distance and canonical variate analysis (CVA) on the basis of cultivarBLUPs for the original traits. Quite different groups of cultivars for the studied traits were found, specially one group was substantially distanced to the others. As it was shown by CVA, spike length and number of spikelets per spike as negatively correlated with number of grains per spikelet in the studied set of the cultivars relatively largest contributed to overall differentiation of the distinguished eight groups and then, these traits best discriminated among the eight cultivar groups in the term of Mahalanobis distance for the considered traits. The 1000 grain weight and grain protein content much less contributed to overall discrimination of the cultivar groups than the previous four traits. The most important agronomic traits characterizing productivity of the spike grain weight and its two components, e.g. number of grains per spikelet and number of grains per spike had least discriminating power for the groups of cultivars. Grain yield per unit area of cereals is a result of spike grain yield and the number of spikes per unit area. In these studies of winter triticale cultivar diversity only grain spike yield and its components were included. Thus, the presented study are a primary evaluating of phenotypic diversity in the cultivars. The further study on the cultivar diversity evaluation for grain yield per unit area and its components is necessary.
Spatially Diverse ISAR Imaging for Classification Performance Enhancement
Authors: Brisken Stefan , Matthes Dietmar , Mathy Torsten , Worms Josef
Published: March 2011

Spatially Diverse ISAR Imaging for Classification Performance Enhancement

One popular approach to the problem of Non-Cooperative Target Identification is the use of 2D Inverse SAR images. Methods to successfully identify a target include the comparison of a set of scattering centers in the ISAR image to a database or the estimation of target dimensions. While working well in theory, these techniques face major difficulties in practice. In the conventional case of a monostatic radar, visibility of scattering centers varies with the target aspect angle due to fading. In this paper we examine that the visibility of scattering centers can be improved by incoherent addition of images from spatially distributed radars. The main focus lies in the description and results of a multistatic ISAR experiment carried out at Fraunhofer FHR. We display theoretically derived bistatic synchronization errors in a practical system and formulate additional multistatic synchronization requirements, necessary to add up the images.
Gait Variations in Human Micro-Doppler
Authors: Tahmoush Dave , Silvious Jerry
Published: March 2011

Gait Variations in Human Micro-Doppler

Measurement of human gait variation is important for security applications such as the indication of unexpected loading due to concealed weapons. To observe humans safely, unobtrusively, and without privacy issues, radar provides one method to detect abnormal activity without using images. In this paper we focus on modeling the characteristics of human walking parameters in order to determine signature differences that are distinguishable and to determine the variability of normal walking to be compared to armed or loaded walking. We extract micro-Doppler from motion-captured human gait models and verify the models with radar measurements. We then vary the model to determine the extent of normal micro-Doppler variation in multiple dimensions of human gait. We also characterize the ability of radar to determine gender and suggest that alternative views to the frontal view may be more discriminative.
Reconstruction of the Reference Signal in DVB-T-based Passive Radar
Authors: Baczyk Marcin , Malanowski Mateusz
Published: March 2011

Reconstruction of the Reference Signal in DVB-T-based Passive Radar

In the paper the problem of decoding of digital television signal and its reconstruction for the purpose of using it in passive radar is presented. The main focus is the reconstruction of the signal using a general purpose receiver, not dedicated to digital television signal reception. The performance of the proposed method is verified on simulated and real-life signals.
A New Algorithm for Phased Array Radar Search Function Improvement in Overload Situations
Authors: Mofrad Reza , Sadeghzadeh Ramazan
Published: March 2011

A New Algorithm for Phased Array Radar Search Function Improvement in Overload Situations

A new algorithm is proposed for phased array radar search function resource allocation. The proposed algorithm adaptively priorities radar search regions and in overload situations, based on available resources, radar characteristics, maximum range and search regions, optimally allocates radar resources in order to maximize probability of detection. The performance of new algorithm is evaluated by the multifunction phased array radar simulation test bed. This simulation test bed provides capability to design and evaluate the performance of different radar resource management, target tracking and beam forming algorithms. Some results are presented that show capabilities of this simulation software for multifunction radar algorithms design and performance evaluation.
Matrix Analysis and Pulse Transmission of Antenna Array for MIMO UWB Systems
Authors: Czawka Giennadij , Garbaruk Marek
Published: March 2011

Matrix Analysis and Pulse Transmission of Antenna Array for MIMO UWB Systems

This paper presents a theoretical matrix analysis of antenna structure consisting of two double-element planar antennas for ultra-wideband (UWB) application in 2*2 MIMO indoor communication systems. The structure and characteristics of pla-nar two-element UWB antenna are presented. Two matrix models of MIMO antenna system are represented in the paper. A stan-dard MIMO signal transmission matrix without taking into con-sideration the coupling between antennas is described. A new ap-proach to a full electromagnetic analysis based on the scattering matrix of the MIMO spatial antenna array is proposed. Func-tional power parameters for the whole MIMO UWB transmit-receive antenna structure are introduced. Results of computer si-mulations of different matrices describing a MIMO antenna sys-tem and the transmission propagation pulses are presented.
Design of an Ultrawideband CPW-Fed Monopole Antenna with a Band-Notch Function
Authors: Hosseini-Varkiani Mohsen , Hojat-Kashani Farokh , Hesari Manochehr
Published: March 2011

Design of an Ultrawideband CPW-Fed Monopole Antenna with a Band-Notch Function

In this paper, a CPW-fed monopole antenna for ultra wideband (UWB) applications using band-notch characteristics with size of (24×24×1.6 mm3) is presented. The antenna is designed for operation across the entire UWB from 3.1 to 10.6 GHz with band-notch in 5-6 GHz, by inserting an H-shaped slot on the CPW staircase feed line. The proposed antenna has a reflection coefficient below -10 dB through the frequency band. Also, reasonable gain values and good radiation pattern over the same frequency band have been observed. Details of the proposed antenna and experimental results are discussed and parametric study is presented.
A 100 W SiC MESFET Amplifier for L-band T/R Module of APAR
Authors: Wojtasiak Wojciech , Gryglewski Daniel
Published: March 2011

A 100 W SiC MESFET Amplifier for L-band T/R Module of APAR

In the paper, a 100W SiC MESFET amplifier design dedicated for a L-band T/R module of APAR is presented. The output power higher than 100 W has been achieved by combining in a balanced configuration two single stages with Cree's 60 W CRF24060 SiC MESFETs. The amplifier design methodology is based on the small-signal model and DC characteristics of SiC MESFET. The model is extracted using the transistor S-parameters at three operating points for On-state, Off-state and normally biased. The measurements and simulations prove usefulness of the proposed design method. The amplifier was excited with pulsed and cw signals for the case temperature ranging from 60°C to 140°C. As a result of the case temperature changes the output power drop was lower than 0.5 dB at the level of 150 W.
Staying Current by Searching the Veterinary Literature
Authors: Buchanan Robert A. , Wooldridge Anne A.
Published: March 2011

The body of knowledge in veterinary medicine and the biomedical sciences continues to grow logarithmically, and learning about new developments in veterinary medicine requires successful navigation of recently published literature worldwide. This article examines how veterinarians can use different types of automated services from databases and publishers to search the current and past literature, access articles, and manage references that are found.
Open Access of Publications by Veterinary Faculty in the United States and Canada
Authors: Nault André J.
Published: March 2011

The free availability of full-text veterinary publications in MEDLINE-indexed journals by US and Canadian veterinary faculty from 2006–7 was determined. Additionally, publishing databases were searched to obtain general statistics on veterinary publishing. A survey of institutional initiatives to promote open-access journals and institutional repositories was also performed. Veterinary faculty published a total of 4,872 articles indexed by MEDLINE in 679 different journals. Of these articles, 1,334 (27%) were available as free full text and were published in 245 different journals. Although 51 veterinary-specific journals offering immediate and free full-text access were identified, few articles in this study appeared in these titles. Rather, most free scholarly articles by veterinary faculty appeared in journals with an embargo period. Academic veterinary institutions may want to recommend acceptance of alternate forms of information dissemination (such as open-access journals and journals published only digitally) to encourage greater global dissemination of their research findings. The promotion and use of digital institutional repositories is also an area for future investment and warrants additional research.