bluuebunny/crossref_metadata_2025 huggingface dataset:
State Change in Preterm Infants in Response to Nursing Caregiving: Possible Gender Effects
Authors: Thomas Karen , Tsai Shao-Yu , Brown Sara
Published: November 2011

Purpose:To describe the effect of nursing caregiving on infant sleep-wake states by gender in preterm infants

Design:Descriptive measures at 34 weeks postmenstrual age and at discharge

Sample:Twenty-two hospitalized preterm infants

Main Outcome Variable:Infant state and caregiving episodes were coded in 15-second intervals from video recordings of approximately three hours duration. Time plots of state and caregiving were analyzed visually to summarize spontaneous state changes and state change associated with caregiving.

Results:Sleep and wake state distribution did not differ statistically by gender; however, the rate of state change in male infants was twice that of females (p=.012) at discharge. At discharge, male infants received approximately twice as many care episodes as females. At discharge, the rate of state change in response to caregiving in male infants was four times that of female infants (p=.026). Males exhibited a greater percentage of caregiving episodes related to state change than did females at discharge (p=.018). Findings suggest further exploration of possible gender differences in state regulation and state change in response to caregiving.
Supporting Siblings & Their Families During Intensive Baby Care
Authors: Rector Linda
Published: November 2011

Most health care professionals who work with neonates in the hospital setting acknowledge the benefits of family-centered care. Textbooks and journal articles that focus on neonatal problems usually include a section on the importance of supporting parents through this stressful time. Strategies for including siblings in the NICU are found in a sidebar or in a few short paragraphs, as afterthoughts in the big picture of family-centered care.
Transitioning Premature Infants from Gavage to Breast
Authors: Nye Carla
Published: November 2011

Breast milk provides physiologic and neurodevelopmental protection for premature infants. Most hospitals are breast-milk friendly, but the number of premature infants breastfeeding successfully at discharge is relatively small. There are evidence-based techniques to improve the odds of premature infants breastfeeding at discharge and into the first year of life. Measures that help the infant make the transition to the breast include kangaroo care, nonnutritive sucking, avoidance of bottles, and consistent and supportive staff. A guide to management of the transition process is provided in this article.
The Importance of Quiet in the Home: Teaching Noise Awareness to Parents Before the Infant is Discharged from the NICU
Authors: Goines Lisa
Published: November 2011

Research over several decades describes various adverse health effects of noise on the hospitalized neonate. Noise is a direct cause of long-lasting auditory problems and a significant cause of cardiovascular and respiratory problems and neurologic impairment. Many hospitals have turned the NICU into a quiet environment that promotes the neonate’s health and well-being. But auditory pathways continue to develop during the neonatal period, reaching maturation at 12 months and beyond. Some of this development thus occurs after the neonate is discharged from the hospital. It is a responsibility of NICU professionals to teach families about the health benefits of noise modulation and planned quiet in the home environment. This teaching may make a world of difference to the continued healthy growth, development, and well-being of the infant.
Extrauterine Growth Restriction: A Review of the Literature
Authors: Ruth Valerie
Published: November 2011

Extrauterine growth restriction (EUGR) is a common condition in very low birth weight (VLBW) preterm infants (≤1,500 g). Most affected infants have a birth weight that is average for gestational age, but by the time of hospital discharge have a weight that is less than the tenth percentile for corrected gestational age. EUGR is the most frequent morbidity among VLBW survivors at their time of discharge from the hospital. Studies to elucidate the causes of EUGR have been inconclusive. Recent research has found an association between EUGR, developmental outcomes, and long-term morbidity. Low birth weight has also been associated with chronic diseases later in life. These findings emphasize the critical nature of understanding the phenomenon of EUGR and ways it can be prevented.
Neonatal Peripherally Inserted Central Catheters: Recommendations for Prevention of Insertion and Postinsertion Complications
Authors: Paulson Pamela , Miller Kellee
Published: November 2011

Peripherally inserted central catheters (PICCs) continue to be necessary in neonatal care. They benefit many premature infants and those needing long-term intravenous access. An experienced inserter, early recognition of PICC candidates, early PICC placement, knowledge of anatomy, and correct choice of vein all increase placement success. As with any invasive procedure, there are risks. These include pain, difficulty advancing the catheter, damage to vessels, catheter malposition, and bleeding. Utilizing assessment skills, following the product manufacturer’s instructions, and carefully placing the catheter should minimize most of these risks. Additional risks include postinsertion complications such as occlusions, thrombosis, catheter failure, infection, and catheter malposition. Proper nursing care—which includes controlling infection, properly securing the catheter, and changing the dressing as needed—is key to preventing complications and maintaining the PICC until treatment has been completed.
A Case Presentation of Early Intervention with Dolichocephaly in the NICU: Collaboration Between the Primary Nursing Team and the Developmental Care Specialist
Authors: McManus Beth , Capistran Philip
Published: November 2011

Dolichocephaly, narrow width and long anterior-posterior cranial distance, is more commonly seen in preterm than in term infants. It seems to persist after NICU discharge and may be a marker for adverse neurodevelopment. This article reports a case of cranial molding in one extremely low birth weight infant. He was placed on a viscoelastic mattress and a twice weekly developmental care program. Cranial molding was measured using the cranial index (CI), a ratio of width to length. Initially, the patient presented with dolichocephaly (CI = 72 percent). By week 2, CI measurements approached normal limits (CI = 75 percent). When placed on continuous positive airway pressure, the infant presented with substantial dolichocephaly (CI = 66.7 percent). Following position changes to midline, CI measurements continued to improve and remained within normal limits until discharge. This dual-element program was feasible, acceptable to parents and staff, and may be effective for identifying and managing dolichocephaly.
Birth to Breast—A Feeding Care Map for the NICU: Helping the Extremely Low Birth Weight Infant Navigate the Course
Authors: Dougherty Dorothy , Luther Maureen
Published: November 2011

Breast milk has been shown to contribute significantly to positive neurodevelopmental and medical outcomes in the extremely low birth weight (ELBW) infant population. It is crucial that ELBW infants receive their mother’s colostrum as a first feeding, followed by expressed breast milk for as long as possible. Evidence-based literature supports the difficult challenges both mothers and ELBW infants face if they are to succeed at breast pumping and breastfeeding. Influencing factors include the medical fragility of the infant, limited frequency and duration of kangaroo care between mother and infant, lack of an adequate volume of breast milk, as well as inconsistent or incorrect information surrounding the use of breast milk and breastfeeding.

A feeding care map as described in this article can help the bedside nurse assist the mother-ELBW infant dyad in optimizing breast milk volumes, laying the groundwork for breastfeeding. Displaying supportive practices and preterm infant developmental milestones, the map categorizes infant, maternal, and dyad feeding issues along a progressive time line from admission to discharge.
News of The Academy of Neonatal Nursing
Authors: Brott Shirley
Published: November 2011

Come join us this spring in Boston, Massachusetts, for the 6th National Advanced Practice Neonatal Nurses Conference at the Westin Boston Waterfront, April 3–5, 2009. The Westin is just three miles from Logan International Airport. The Westin is not only convenient for those coming from out of town, it is a beautiful hotel loaded with amenities and located close to Boston’s historical landmarks, shopping, and restaurants.
Welcome to the NICU: Helping Parents Adjust to NICU Life
Authors: Discenza Deb
Published: November 2011

TO THE NEONATAL PROFESSIONAL, the scene is common: the shell-shocked father, looking totally lost and stricken with worry, coming into the NICU behind a team rolling an incubator containing a tiny and fragile infant. At a later point, the mother visits her baby for the first time and is overwhelmed to see her child hooked up to medical equipment. The parents may know little about the equipment surrounding the cocoon of the incubator and even less about the seriousness of their child’s condition. But they do know that if their child is in the NICU, then he is in danger.
SCHIP Renewal
Authors: McCain Gail
Published: November 2011

IN FEBRUARY OF THIS YEAR, THE STATE CHILDREN’S HEALTH Insurance Program (SCHIP) Reauthorization Act of 2009 was officially extended through 2013. SCHIP is a joint insurance program between the federal government and the states, which provides health insurance for low-income children and pregnant women who are not eligible for Medicaid. That is, states provide SCHIP for children in families with incomes up to 200 percent of the federal poverty level ($21,000 to $42,000 for a family of four). SCHIP currently provides health care insurance to approximately 7 million children who otherwise would not receive health care benefits.1 There are an additional 6 million children who are eligible, but not enrolled in either SCHIP or Medicaid.2 As more families face job loss and the associated loss of health insurance, SCHIP is even more important for the health and development of infants and children in low income families.
Kangaroo Care with Twins: A Case Study in Which One Infant Did Not Respond as Expected
Authors: Jarrell Julia , Ludington-Hoe Susan , Abouelfettoh Amel
Published: November 2011

Purpose:The purposes were to relate responses (including unacceptable ones) of twins to shared kangaroo care (KC), to provide explanations for the unexpected responses, and to offer suggestions for safe nursing practice.

Design:A descriptive, evaluative case study was conducted. Both twins received KC while their vital signs and maternal breast temperatures were manually recorded every 30 seconds. Descriptive statistics were computed.

Sample:Identical twins, born to a 19-year-old African-American primigravada, were 34 3/7 weeks postconceptional age with weights of 1,760 and 1,480 g, respectively, when tested. Preterm labor resulted in spontaneous vaginal birth at 30 weeks gestation.

Main Outcome Variables:Infant heart and respiratory rates, oxygen saturations, abdominal temperatures, and maternal breast temperatures.

Results:Infant A’s vital signs exceeded acceptable clinical limits during shared KC; vital signs returned to normal range once Infant A was returned to the incubator. Infant B’s vital signs approximated clinically acceptable ranges throughout the session. Breast temperatures did not differ. Individuality mandates vigilant assessment of infant responses to shared KC.
NICU Noise and the Preterm Infant
Authors: Brown Gemma
Published: November 2011

Premature infants in the NICU are often exposed to continuous loud noise despite research documenting the presence and damaging effects of noise on the preterm infant’s development. Excessive auditory stimulation creates negative physiologic responses such as apnea and fluctuations in heart rate, blood pressure, and oxygen saturation. Preterm infants exposed to prolonged excessive noise are also at increased risk for hearing loss, abnormal brain and sensory development, and speech and language problems. Reducing noise levels in the NICU can improve the physiologic stability of sick neonates and therefore enlarge the potential for infant brain development. Recommendations include covering incubators with blankets, removing noisy equipment from the incubator environment, implementing a quiet hour, educating staff to raise awareness, and encouraging staff to limit conversation near infants.
NICU Parents’ Top Ten Worries at Discharge
Authors: Discenza Deb
Published: November 2011

AN INFANT’S DISCHARGE FROM the NICU creates a flurry of activity on the part of both the parents and the professionals. Though everyone has been planning for this day, its exact timing and requirements often remain elusive until the day comes. So much has happened, and so much more will happen going forward. The parents are often in a tailspin as to how to handle their growing anxiety. Although they rarely verbalize their fears, NICU parents universally experience them.
Understanding the Sequence of Pulmonary Injury in the Extremely Low Birth Weight, Surfactant-Deficient Infant
Authors: Peterson Steven
Published: November 2011

Human lung development begins around day 26 postconception and continues throughout early childhood. Many crucial events can affect this delicate tissue as it develops, leading to altered and abnormal growth and development of the lungs, thereby yielding a variety of morbidities and sometimes even mortality. Understanding the pathophysiology of lung injury in the extremely low birth weight neonate is essential when caring for these infants, especially during the first hours of life. This article provides bedside clinicians with foundational information related to acute lung injury and the sequence of events that can ultimately lead to neonatal chronic lung disease and bronchopulmonary dysplasia.
Supporting Mothers in Recovery: Parenting Classes
Authors: Blunt Brenda
Published: November 2011

Drug addiction is a serious issue in today’s society. Women are giving birth to infants who are born addicted to illicit drugs, and these mothers are not able to care for their infants safely and competently without training and support. This article examines the prevalence of the problem. It also discusses the possible impact of parenting skills classes, as part of recovery efforts, for women seeking recovery who have recently given birth. Several programs already in place in the U.S have shown positive results for these mothers and their infants. Infants exposed in utero to illicit drugs need to be given all of the resources society can provide in an effort to stop the intergenerational cycle of drug addiction.
Breastfeeding Changes for VLBW Infants in the NICU Following Staff Education
Authors: Pineda Roberta , Foss Joanne , Richards Lorie , Pane Camille
Published: November 2011

Purpose:To assess the effectiveness of an educational intervention aimed at staff and parents in changing breastfeeding practices in the NICU.

Design:The breastfeeding education initiative consisted of three parts: breastfeeding training for NICU staff, issuance of complementary breastfeeding materials to mothers of infants in the NICU, and addition of a breastfeeding pathway to the individualized care plan. Infants admitted before and after the initiative were compared to evaluate for changes in breastfeeding practices.

Sample:The study sample included very low birth weight (VLBW) infants hospitalized in the NICU for more than seven days and born weighing <1,500 g. Infants were grouped based on whether they were admitted before (pre-intervention) or after (post-intervention) implementation of the education initiative.

Main Outcome Variables:Health care professional (HCP) knowledge of breastfeeding interventions in the NICU was measured using a posttest following training. Breast milk feeding initiation rates, breastfeeding rates, and rates of breast milk feeding at discharge were measured via retrospective chart review among pre- and post-intervention infant groups.

Results:The post-intervention group demonstrated significant improvement in rates of breastfeeding (infants being put directly to the breast) in the NICU compared with the pre-intervention group. General positive trends in breast milk feeding initiation (up 11 percent) and breast milk feeding at discharge (up 5 percent) were observed, but these increases failed to reach significance.
The Complete Blood Count
Authors: Milcic Terri Lynne
Published: November 2011

THE COMPLETE BLOOD COUNT (CBC) is one of the more common laboratory tests ordered during the neonatal period. The CBC may be obtained to evaluate for anemia, infection, and thrombocytopenia.1The test offers a wealth of clinical information about the hematopoietic system, including erythrocyte, leukocyte, and thrombocyte values. Establishing normal neonatal ranges has been difficult because blood has not been drawn on healthy neonates of similar ages.2Reference ranges that consist of the 5th to 95th percentile compiled from various studies have been used to approximate normal neonatal values.3A variety of factors such as sample site, timing of the sample, gestational age, and the neonate’s degree of health can affect the CBC.1Therefore, the astute practitioner must be able to recognize the clues and nuances of the CBC to guide the diagnostic assessment.4
Importance of Nursing Leadership in Advancing Evidence-Based Nursing Practice
Authors: Bradshaw Wanda
Published: November 2011

Our patients depend on us to do the best on their behalf. If we do not take accountability for our practice, continually examining what is the best way to deliver care, we are limiting our role to technical skills and not fully actualizing our professional role. [Evidence-based practice] is essential to practicing safely as nurses (p. 53).1
The Retinopathy of Prematurity Screening Examination: Ensuring a Safe and Efficient Examination While Minimizing Infant Discomfort
Authors: Hered Robert , Gyland Elizabeth
Published: November 2011

Retinopathy of prematurity (ROP) examinations in the NICU are necessary to protect vision in premature infants, but the examinations are associated with risk and discomfort. ROP examination risks include adverse effects from mydriatic agents, systemic responses to the stress of examination, and nosocomial infection. Infant discomfort may be lessened by limiting examination length and possibly by measures such as topical anesthetic, oral sucrose, and certain nonpharmacologic techniques. A well-organized ROP service facilitates appropriate scheduling of examinations and education of the infant’s parents. This article addresses causes of risk and infant discomfort, providing a framework for developing a safe and efficient ROP service while minimizing infant discomfort.
21-Hydroxylase Deficiency Congenital Adrenal Hyperplasia
Authors: Shaw Amy
Published: November 2011

CONONGENITAL ADRENAL hyperplasia (CAH) is an inborn error of metabolism that can produce life-threatening disease in the first one to three weeks of life, unless properly diagnosed and managed. This autosomal recessive disease results in insufficient biosynthesis of cortisol due to an enzyme defect in the adrenal gland. CAH due to 21-hydroxylase (21-OH) deficiency is found in 1/11,000–1/15,000 people in the general population, with a prevalence as high as 1/750 people in some populations such as the Yupik Eskimos in Alaska and the people of La Réunion in France.1 Males and females are equally affected by this disease due to the autosomal recessive pattern of inheritance.
Computerized Physician Order Entry: Lessons Learned from the Trenches
Authors: Ramirez Anne , Carlson Debra , Estes Carey
Published: November 2011

Implementation of computer physician order entry (CPOE) demands planning, teamwork, and a steep learning curve. The nurse-driven team at the hospital unit level is pivotal to a successful launch. This article describes the experience of one NICU in planning, building, training, and implementing CPOE. Pitfalls and lessons learned are described. Communication between the nurse team at the unit and the clinical informatics team needs to be ongoing. Self-paced training with realistic practice scenarios and one-on-one “view then practice” modules help ease the transition. Many issues are not apparent until after CPOE has been implemented, and it is vital to have a mechanism to fix problems quickly. We describe the experience of “going live” and the reality of day-to-day order entry.
Fluconazole to Prevent Systemic Fungal Infections in Infants: Reviewing the Evidence
Authors: Wilkerson Jamie , McPherson Christopher , Donze Ann
Published: November 2011

IN NEONATOLOGY, EVIDENCE-BASED practice (EBP) relies on well-designed, adequately powered trials to guide practitioners. Several large randomized controlled trials (RCTs) have been conducted to explore the use of fluconazole for fungal prophylaxis in premature infants. Despite the findings of these studies, practice varies among units. In a recent survey of members of the American Academy of Pediatrics (AAP), 34 percent of clinicians indicated that they have used antifungal prophylaxis and only 11 percent of clinicians indicated that a written protocol was in place in their NICU. Intravenous (IV) fluconazole (66 percent), oral nystatin (59 percent), and IV amphotericin (21 percent) were the three most commonly used agents among the respondents.1
Infant Massage in the NICU
Authors: Discenza Deb
Published: November 2011

MOTHERS OF BABIES IN THE NICU face a serious challenge: bonding with their infants despite doctors’ rounds, medical equipment, and requirements for minimal stimulation. When her infant becomes stable enough for touch, what can a mother do to provide comfort to her child? One approach is infant massage. There is much neonatal nurses can do to promote the connection between mother and child through infant massage. Infant Massage USA’s executive director, Linda Storm, discusses this approach and its benefits for baby and parent in the interview that follows.
Neonatal Resuscitation Program (NRP) 2011: New Science, New Strategies
Authors: Zaichkin Jeanette , Weiner Gary M.
Published: November 2011

In spring 2011, the American Academy of Pediatrics (AAP) will release sixth edition materials for the Neonatal Resuscitation Program (NRP). This edition brings changes in resuscitation practice and a new education methodology that shifts the instructor from “teacher” to “learning facilitator” and requires the NRP course participant to assume more responsibility for learning. The change from a lecture format to simulation-based learning requires instructors to learn new skills and meet new requirements to maintain instructor status.

The sixth edition of theTextbook of Neonatal Resuscitationand the fifth edition of theInstructor’s Manual for Neonatal Resuscitationare currently in press. The AAP granted permission to use material from these forthcoming publications in this article.
Support Like a Walking Stick: Parent-Buddy Matching for Language and Culture in the NICU
Authors: Ardal Frida , Sulman Joanne , Fuller-Thomson Esme
Published: November 2011

Purpose: (1) To explore the experience of non-English-speaking mothers with preterm, very low birth weight (VLBW) infants (<1,500 g); and (2) to examine mothers’ assessment of a peer support program matching them with linguistically and culturally similar parent-buddies.

Design: An exploratory, qualitative analysis based on grounded theory.

Sample: A convenience sample of eight mothers from four of the most prevalent non-English-speaking cultures (Spanish, Portuguese, Chinese, and Tamil) in an urban Canadian-teaching hospital.

Main Outcome Variable: Non-Anglophone mothers’ experience and support in the NICU.

Results: Study mothers experienced intense role disequilibrium during the unanticipated crisis of preterm birth of a VLBW infant; situational crises owing to the high-tech NICU environment and their infant’s condition; and developmental crises with feelings of loss, guilt, helplessness, and anxiety. Language barriers compounded the difficulties. Parent-buddies helped non-English-speaking mothers mobilize their strengths. Culture and language are important determinants of service satisfaction for non-English-speaking mothers. Linguistically congruent parent-to-parent matching increases access to service.
Wound Care in the Neonatal Intensive Care Unit
Authors: Fox Miriam D.
Published: November 2011

The skin is a vital organ with key protective functions. Infants in the NICU are at risk for skin injury because of developmental immaturity and intensive care treatments. When skin injury occurs, the neonatal nurse is challenged to provide wound care to optimize functional and cosmetic healing. Optimal wound care requires basic knowledge of the mechanisms of injury, physiology of wound healing, host factors affecting wound healing, and wound assessment. This knowledge provides the basis for determining appropriate wound treatment, including dressing selection. Attention to pain issues associated with wound care is difficult because of the infant’s developmental stage, but is essential because of the potentially negative life-long impact of pain. The premature infant’s propensity for skin stripping limits the selection of appropriate dressing, as does the paucity of research examining wound care products in this population.
The Use of Rate Transient Analysis Modeling to Quantify Uncertainties in Commingled Tight Gas Production Forecasting and Decline Analysis Parameters in the Alberta Deep Basin
Authors: Luo H. , Mahiya G. F. , Pannett S.
Published: November 2011

The evaluation of Expected Ultimate Recovery (EUR) for tight gas wells has generally relied upon the Arps equation for Decline Curve Analysis (DCA) as a popular approach. However, it is typical in tight gas reservoirs to have limited production history that has yet to reach boundary-dominated flow due to the low permeability of such systems. Commingled production makes the situation even more complicated with multi-boundary behavior. When suitable analogues are not available, Rate Transient Analysis (RTA) can play an important role to justify DCA assumptions for production forecasting.

The Deep Basin East field has been developed with hydraulically fractured vertical wells through commingled production from multiple formations since 2002. To evaluate potential of this field, DCA type curves for various areas were established according to well performance and geological trending. Multiple segment DCA methodology demonstrated reasonable forecasts, in which one Arps equation is used to describe the rapidly decreasing transient period in early time, and another for boundary-dominated flow. However, a limitation of this approach is the uncertainty of the forecast in the absence of extended production data as the EUR can be sensitive to adjustments in some assumed DCA parameters of the second segment. In this paper, we used RTA to assess reservoir and fracture properties in multiple layers and built RTA type well models around which uncertainty analyses were performed. The distributions of the model properties were then used in Monte Carlo analysis to forecast production and define uncertainty ranges for EUR and DCA parameters. The resulting forecasts and EUR distribution from RTA modeling generally support the DCA assumptions used for the type curves for corresponding areas of the field. The study also showed how the contribution from the various commingled layers changes with time. The proposed workflow provides a fit-for-purpose way to quantify uncertainties in tight gas production forecasting especially in cases when production history is limited and field-level numerical simulation is not practicable.
Field Testing and Numerical Simulation of Combined CO2 Enhanced Oil Recovery and Storage in the SACROC Unit
Authors: Xiao Chongwei , Harris Milton Lee , Wang Fred , Grigg Reid
Published: November 2011

The SACROC Unit in the Permian Basin has been under carbon dioxide (CO2) injection for enhanced oil recovery (EOR) for almost forty years since CO2 injection commenced in 1972. The mature CO2 operations in the SACROC Unit make it an optimal site for studying CO2 sequestration in conjunction with EOR. A pilot demonstration project was performed in a five-spot pattern, beginning at the end of 2008. The objective of this study is to understand the capacity and flow patterns of the CO2 plume to determine sequestration potential in conventional oil reservoirs.

The pilot site locates in the Northern SACROC platform and was set up as a five-spot pattern consisting of 4 injectors and 1 center producer. Water and CO2 injection had occurred earlier in the SACROC Unit during reservoir development. The pilot testing started in 2008 and has been under CO2 injection since then. After thirteen months of CO2 injection, the production data from the pilot showed that the oil production rate of the producer (well 56-17) increased over tenfold during the first year of CO2 injection which demonstrated significant enhanced oil recovery by CO2 injection.

This paper describes how the injection process in the SACROC pilot was simulated using a compositional simulator, Computer Modeling Group’s GEM. A simulation model with 47,104 grids was developed with geophysical data characterized from 3D seismic surveys and well logs. The simulation area is 6640 ft * 6640 ft * 840 ft, consisting of five wells in the pilot site. History matching gas, oil, and water production for each well since first drilled was performed to verify the model. The EOR under three injection schemes was predicted. The CO2 storage capacity under residual and solubility trapping mechanisms during CO2 miscible displacement was simulated and analyzed. This study demonstrated CO2 sequestration in oil reservoirs to be a low-risk, promising method for mitigating CO2 discharge into the atmosphere.
A New Analytical Approach To Investigate Heated Area in Thermal Recovery Techniques
Authors: Hosseini Behrooz Koohmareh , Ardali Mojtaba , Chalaturnyk Rick , Mamora Daulat
Published: November 2011

Analytical models to predict the performance of thermal recovery processes are useful tools for preliminary forecasting purposes and sensitivity studies and provide a better insight than simulation models into the physics of thermal processes. Classical models such as Marx and Lagerheim (1959), Willman (1961) and Farouq Ali (1971) are used extensively for steam-flood performance prediction. Several studies have been conducted to develop the theory for the estimation of the radius of the heated zone. This radius is important for computing the volume of recoverable oil, as well as to determine well spacing in steamflooding and cyclic steam stimulation. This work presents an analytical model to estimate the radius of heated zone in either conductive or conductive-convective heat transfer mechanisms, which mainly occur in Steam-Assisted Gravity Drainage (SAGD) and Cyclic Steam Stimulation (CSS) respectively. The heat flow equation was combined with mass and momentum convective transport equations in a porous medium, in an effort to correlate the temperature front velocity to the steam advancing front velocity. As the saturation front velocity is known from classical Buckley-Leverett transport equation, at each instant we investigated the transport distance of the heat front in a radial homogenous reservoir. The theoretical model takes gravity into account, but neglects the capillarity, and there is no longer the assumption of piston-like steam drive. CMG-STARS thermal simulation and COMSOL Multiphysics are used to compare and verify analytical model results. The improved model is superior to previous models used to calculate the radius of heated zone and the analytical results are in good agreement with the simulation results.
Electromagnetic Heating for In-Situ Production of Heavy Oil and Bitumen Reservoirs
Authors: Wacker Bernd , Karmeileopardus Denny , Trautmann Bernd , Helget Andreas , Torlak Muris
Published: November 2011

The Electro-Magnetic (EM) method is a newly developed technology aiming at heavy oil and in-situ bitumen production in an environmentally friendly way with smallest possible surface footprint.

This paper outlines the process of the development of the new EM technology for heavy oil and in-situ bitumen production. It documents the step-by-step approach following the roadmap from the white-paper technology analysis to the commissioning and performing of field tests. A reservoir simulation example is provided for in-situ production with EM-heating. The current status of the technology is R&D; pilot operation is expected from 2012/13 on.
Discrete Element Hydraulic Fracture Modeling - Evaluating Changes in Natural Fracture Aperture and Transmissivity
Authors: Nagel Neal , Damjanac Branko , Garcia Xavier , Sanchez-Nagel Marisela
Published: November 2011

Previous works have presented the results of successful simulations of fluid injection into naturally fractured shale using a Discrete Element Model (DEM). The simulations included coupled fluid flow-deformation analysis, failure type and extent calculations, as well as a series of parametric analyses. The parameters investigated included: 1) injection rate and its effect on the overall fracturing results, and 2) fluid viscosity, which had a significant influence on the ratio of tensile (mode 1) failure versus shear failure.

With the huge growth in the stimulation of naturally fractured formations such as fractured shales, it is clear that the industry needs new hydraulic fracturing simulation tools beyond the limits imposed by pseudo3D fracturing models. DEMs, in which both matrix block behavior and fracture behavior are explicitly modeled, offer one option for the specific modeling of hydraulic fracture creation and growth in a naturally fractured formation without, for example, the assumption of bi-planar fracture growth.

In this paper, we extend the previous works to quantify, for fractured shale gas plays, the effect of stress orientation, fluid viscosity, and rock mechanical properties in terms of changes in fracture aperture and transmissivity. Changes in fracture transmissivity directly correlate with improvements in well productivity – the primary goal of the stimulation.

The results of the study provide a means to improve shale completions by understanding the effects of the DFN orientation relative to the stress field, fluid viscosity, and rock mechanical properties on changes in fracture aperture, fracture transmissivity, and formation effective permeability, which directly relate to well productivity.
Determination of Equivalent Elastic Moduli for Coupled Geomechanical-Flow Simulation of SAGD
Authors: Khajeh Mohammad Mehdi , Chalaturnyk Rick , Boisvert Jeff
Published: November 2011

When characterizing stress sensitive reservoirs for reservoir performance prediction, considering flow simulation alone is insufficient; geomechanical and flow responses should be assessed concurrently.

Geostatistical techniques are well developed and can be used to build heterogeneous models of reservoir properties as input to subsequent transfer functions such as flow and geomechanical simulators. In the case of conventional flow simulation, each geological realization consists of a structural model, facies model and petrophysical property models (porosity, permeability, saturation, etc.), which are used to solve the appropriate fluid flow equations.

Rock mechanical properties play a similar role in geomechanical simulation as petrophysical properties play in fluid flow. Impact of heterogeneity consideration for geomechanical properties on coupled geomechanical flow simulation of SAGD process has been discussed by Khajeh et al. (2011) and they showed that to assess more accurate uncertainty analysis on flow and geomechanical responses of the SAGD process, considering realizations of the rock mechanical properties are required. The well documented Mechanical Earth Model (MEM) is a comprehensive geological model which can be used for coupled geomechanical-flow simulation of the SAGD process; however, homogenous rock mechanical properties are typically considered instead of stochastic models for computational reasons. The geomechanical response of a reservoir is sensitive to the values selected for geomechanical properties and it is practical to consider an equivalent homogeneous continuum such that geomechanical responses obtained from the homogenized model matches the geomechanical response of the truth (heterogeneous) model.

Different analytical homogenization techniques are developed to determine equivalent elastic moduli (EEM), but the majority of these techniques consider specific configurations of facies and do not work well for complex spatial configurations such as the sand/shale sequences typical of the McMurray formation of Alberta-Canada. Considering sand geomechanical properties to be representative of the reservoir is a common approach. Moreover, a mixing rule averaging approach could also be used for determination of EEM.

In this work, the accuracy of these various EEM methodologies are compared to EEM values obtained numerically by optimizing the geomechanical response of the reservoir. By knowing the vertical displacement profile (VDP) at the top of the reservoir for the fine scale (truth) model and the VDP’s obtained from the listed techniques, the accuracy of considered EEM values is assessed.

Sensitivity of change in VDP with respect to different operating conditions, type of elastic deformation and also spatial distribution of facies is examined.
Realistic Geomechanical Modeling of Hydraulic Fracturing in fractured Reservoir Rock
Authors: Alassi Haitham Tayseer , Holt Rune , Nes Olav-Magnar , Pradhan Srutarshi
Published: November 2011

A numerical technique based on discrete element method is presented in this paper to model failure in reservoir rock. The technique is considered as a geomechanical method which is coupled with a fluid flow simulator based on finite volume method. The two coupled methods are viewed as a tool that can model hydraulic fracturing in intact and naturally fractured rocks. Plasticity model is also included to represent rock brittleness, where a simple numerical test is performed to show a direct effect of plasticity. Discrete Fracture Network (DFN) model is coupled with the tool to represent the natural fractures in reservoir rocks, where modeling of some injection scenarios with different DFN densities are given.
Medicaid and Wealth: A Re-Examination
Authors: Gittleman Maury
Published: November 2011

Do public insurance programs crowd out private savings? I examine the relationship between Medicaid and wealth and make a contribution to the literature on this issue in two primary ways. First, I apply the instrumental-variables approach developed by Gruber and Yelowitz (1999) to a different dataset, the National Longitudinal Survey of Youth, 1979 (NLSY79), while at the same time examining an alternative instrument. The results turn out to differ depending on the instrument and, for one of the instruments, to be sensitive to assumptions needed to identify Medicaid’s effects. Second, I make use of the SIPP data employed by Gruber and Yelowitz themselves, and examine the sensitivity of their conclusions to omitted factors that may be related to both Medicaid eligibility and to wealth accumulation. While more robust than the results using the NLSY79, the SIPP estimates are found to depend both on the sample used and on certain specification restrictions. Taken together, the results suggest caution in making inferences about the impact of Medicaid on wealth.
Strategic Analysis and Auditor Risk Judgments
Authors: Kochetova-Kozloski Natalia , Messier William F.
Published: November 2011

The study investigates whether and how senior auditors' strategic analysis of a client affects their identification of significant business and financial statement risks, and their risk assessments. Sixty-seven senior auditors participated in an experiment that examined the effect of analyzing two aspects of strategic analysis (strategic positioning and the strategy implementation process) against performing no strategic analysis. An expert panel of senior managers was used to develop a benchmark for comparison purposes. Our results show that (1) auditors who performed guided strategic analysis did not identify more significant business and financial statement risks than auditors who did not perform strategic analysis, (2) senior auditors who performed strategic analysis of strategic positioning or the strategy implementation process assessed risk of material misstatement at the entity level more consistently with an expert panel than auditors who did not perform such an analysis, and (3) senior auditors' analysis of the client's strategy implementation process was associated with assessments of the strength of the control environment that were more consistent with the expert panel than assessments done by auditors who did not perform any strategic analysis or who performed only an analysis of strategic positioning.

Data Availability: Contact the first author.
Assessing Risk with Analytical Procedures: Do Systems-Thinking Tools Help Auditors Focus on Diagnostic Patterns?
Authors: O'Donnell Ed , Perkins Jon D.
Published: November 2011

This study investigated whether auditors who used a diagram designed around systems-thinking principles to acquire information for analytical procedures would focus more on patterns of changes in accounts and assess misstatement risk differently than auditors who used an informationally equivalent diagram organized by business-process categories. During a laboratory experiment, experienced auditors performed analytical procedures using one of two alternative diagrams. Participants documented their concerns about misstatement risk and rated the diagnostic relevance of information about patterns of changes in accounts. Auditors who used the systems-thinking tool focused more on diagnostic patterns of fluctuations in accounts and came to different conclusions about risk.

Data Availability: Data will be made available by the authors upon request.
Does Time Constraint Lead to Poorer Audit Performance? Effects of Forewarning of Impending Time Constraints and Instructions
Authors: Low Kin-Yew , Tan Hun-Tong
Published: November 2011

We conduct an experiment to investigate the effects of early versus late warning of impending time constraints, as well as the presence of instructions to think out of the box on auditors' time-constrained performance. We find that forewarning auditors during audit planning of impending time constraints (i.e., early warning) leads to better time-constrained performance on an inventory task. The incremental benefit of warning is greater when auditors are explicitly instructed to think out of the box. We find that the mechanism by which the joint effects of forewarning and instructions improve auditors' performance is via their allocation of time to effective audit tests that enable them to meet the audit objectives.
Sensor Network Architectures for Monitoring Underwater Pipelines
Authors: Mohamed Nader , Jawhar Imad , Al-Jaroodi Jameela , Zhang Liren
Published: November 2011

This paper develops and compares different sensor network architecture designs that can be used for monitoring underwater pipeline infrastructures. These architectures are underwater wired sensor networks, underwater acoustic wireless sensor networks, RF (Radio Frequency) wireless sensor networks, integrated wired/acoustic wireless sensor networks, and integrated wired/RF wireless sensor networks. The paper also discusses the reliability challenges and enhancement approaches for these network architectures. The reliability evaluation, characteristics, advantages, and disadvantages among these architectures are discussed and compared. Three reliability factors are used for the discussion and comparison: the network connectivity, the continuity of power supply for the network, and the physical network security. In addition, the paper also develops and evaluates a hierarchical sensor network framework for underwater pipeline monitoring.
Complete Sequence, Analysis and Organization of the Orgyia leucostigma Nucleopolyhedrovirus Genome
Authors: Thumbi David K. , Eveleigh Robert J. M. , Lucarotti Christopher J. , Lapointe Renée , Graham Robert I. , Pavlik Lillian , Lauzon Hilary A. M. , Arif Basil M.
Published: November 2011

The complete genome of the Orgyia leucostigma nucleopolyhedrovirus (OrleNPV) isolated from the whitemarked tussock moth (Orgyia leucostigma, Lymantridae: Lepidoptera) was sequenced, analyzed, and compared to other baculovirus genomes. The size of the OrleNPV genome was 156,179 base pairs (bp) and had a G+C content of 39%. The genome encoded 135 putative open reading frames (ORFs), which occupied 79% of the entire genome sequence. Three inhibitor of apoptosis (ORFs 16, 43 and 63), and five baculovirus repeated ORFs (bro-a through bro-e) were interspersed in the OrleNPV genome. In addition to six direct repeat (drs), a common feature shared among most baculoviruses, OrleNPV genome contained three homologous regions (hrs) that are located in the latter half of the genome. The presence of an F-protein homologue and the results from phylogenetic analyses placed OrleNPV in the genus Alphabaculovirus, group II. Overall, OrleNPV appears to be most closely related to group II alphabaculoviruses Ectropis obliqua (EcobNPV), Apocheima cinerarium (ApciNPV), Euproctis pseudoconspersa (EupsNPV), and Clanis bilineata (ClbiNPV).
Effect of the environment on the electrical conductance of the single benzene-1,4-diamine molecule junction
Authors: Nakashima Shigeto , Takahashi Yuuta , Kiguchi Manabu
Published: November 2011

We investigated the effect of the environment on the electrical conductance of a single benzene-1,4-diamine (BDA) molecule bridging Au electrodes, using the scanning tunneling microscope (STM). The conductance of the single BDA molecule junction decreased upon a change in the environment from tetraglyme, to mesitylene, to water, and finally to N2 gas, while the spread in the conductance value increased. The order of the conductance values of the single BDA molecule junction was explained by the strength of the interaction between the solvent molecules and the Au electrodes. The order of the spread in the conductance values was explained by the diversity in the coverage of the BDA molecule at metal electrodes and atomic and molecular motion of the single-molecule junction.