bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Child Care and Adiposity at Ages 1 and 3 Years
Authors: Benjamin Sara E. , Rifas-Shiman Sheryl L. , Taveras Elsie M. , Haines Jess , Finkelstein Jonathan , Kleinman Ken , Gillman Matthew W.
Published: July 2009

BACKGROUND: The majority of infants in the United States are in nonparental child care, yet little is known about the effect of child care on development of obesity.

OBJECTIVE: To examine the relationship between child care attendance from birth to 6 months and adiposity at 1 and 3 years of age.

METHODS: We studied 1138 children from a prospective cohort of pregnant women and their offspring. The main exposure was time in child care from birth to 6 months of age, overall and by type of care: (1) child care center; (2) someone else's home; and (3) child's own home by nonparent. The main outcomes were weight-for-length (WFL) z score at 1 year and BMI z score at 3 years of age.

RESULTS: A total of 649 (57%) infants attended child care; 17% were cared for in a center, 27% in someone else's home, and 21% in their own home by a nonparent. After adjustment for confounders, overall time in child care was associated with an increased WFL z score at 1 year and BMI z score at 3 years of age but not skinfold thicknesses. Center and own home care were not associated with the outcomes, but care in someone else's home was associated with an increase in both the 1- and 3-year outcomes.

CONCLUSION: Child care in the first 6 months of life, especially in someone else's home, was associated with an increased WFL z score at 1 year and BMI z score at 3 years of age.
Pediatric Patient Safety in Emergency Departments: Unit Characteristics and Staff Perceptions
Authors: Shaw Kathy N. , Ruddy Richard M. , Olsen Cody S. , Lillis Kathleen A. , Mahajan Prashant V. , Dean J. Michael , Chamberlain James M. ,   for the Pediatric Emergency Care Applied Research Network
Published: July 2009

OBJECTIVES: The goals were (1) to describe emergency department (ED) characteristics thought to be related to patient safety within the Pediatric Emergency Care Applied Research Network, (2) to measure staff perceptions of the climate of safety in EDs, and (3) to measure associations between ED characteristics and a climate of safety.

METHODS: Twenty-one EDs were surveyed to assess physical structure, staffing patterns, overcrowding, medication administration, teamwork, and methods for promoting patient safety. A validated survey on the climate of safety was administered to all emergency department staff members. Safety climate scores were compared to evaluate associations with ED characteristics.

RESULTS: A total of 1747 staff members (49%) responded to the survey on the climate of safety. A minority of EDs had organized safety activities such as safety committees (48%) or walk-rounds (38%), used computerized physician order entry (38%), had ED pharmacists (19%), or had formal physician/registered nurse teams (38%). The majority (67%) treated patients in hallways. Most (67%) varied staffing on the basis of seasonal patient volume. Of the 1747 ED staff members (49%) responding to the survey, there was a wide range (28%–82%) in the proportion reporting a positive safety climate. Physicians' ratings of the climate of safety were higher than nurses' ratings, and perceptions varied according to work experience. Characteristics associated with an improved climate of safety were a lack of ED overcrowding, a sick call back-up plan for physicians, and the presence of an ED safety committee.

CONCLUSIONS: Large variability existed among EDs in structures and processes thought to be associated with patient safety and in staff perception of the safety climate. Several ED characteristics were associated with a positive climate of safety.
Medication Use Among Children <12 Years of Age in the United States: Results From the Slone Survey
Authors: Vernacchio Louis , Kelly Judith P. , Kaufman David W. , Mitchell Allen A.
Published: July 2009

OBJECTIVES: Using data from the Slone Survey, we sought to define the prevalence of over-the-counter and prescription medication use among US children <12 years of age and to determine the prevalence and patterns of use of the most commonly used medications.

METHODS: The Slone Survey was a random-digit-dial telephone survey of medication use in the previous 7 days for a representative sample of the US population. Between February 1998 and April 2007, we enrolled 2857 children 0 to 11 years of age from the 48 contiguous US states.

RESULTS: The survey response rate was 61%. Overall, 56% of children had used ≥1 medication product in the 7 days preceding the interview, with 15%, 7.1%, 3.1%, and 1.9% taking 2, 3, 4, and ≥5 medications, respectively, during that time period. Twenty percent of children took ≥1 prescription-only medications, but <6% used ≥2 prescription-only drugs within a given week. Fewer than 0.5% of children were reported to have used any particular herbal product. The most commonly used over-the-counter medication products were acetaminophen alone, multivitamins, and ibuprofen alone. The most commonly used prescription-only medications across all age groups were amoxicillin, albuterol, and multivitamins with fluoride. The most commonly consumed active ingredients (excluding vitamins) were acetaminophen, iron, ibuprofen, and various cough/cold ingredients (pseudoephedrine, dextromethorphan, and various first-generation antihistamines).

CONCLUSIONS: The majority of US children <12 years of age use ≥1 medication product in a given week. The preponderance of pediatric medication exposure involves over-the-counter products.
Delayed Pediatric Office Follow-up of Newborns After Birth Hospitalization
Authors: Profit Jochen , Cambric-Hargrove Alva J. , Tittle Kay O. , Pietz Kenneth , Stark Ann R.
Published: July 2009

BACKGROUND: Key recommendations of the American Academy of Pediatrics guideline on management of severe hyperbilirubinemia in healthy infants of ≥35 weeks' gestation include predischarge screening for risk of subsequent hyperbilirubinemia, follow-up at 3 to 5 days of age, and lactation support. Little information is available on contemporary compliance with follow-up recommendations.

OBJECTIVE: To assess timing and content of the first newborn office visit after birth hospitalization in urban and suburban pediatric practices in Houston, Texas.

METHODS: We reviewed office records for the first visit within 4 weeks of birth during January through July 2006 for apparently healthy newborns with a gestational age of ≥35 weeks or birth weight of ≥2500 g seen within a pediatric provider network. For each pediatrician, we selected every fifth patient up to a total of 6.

RESULTS: Of 845 records abstracted, 698 (83%) were eligible for analysis. Infants were seen by 136 pediatricians in 39 practices. They had vaginal (64%) or cesarean (36%) deliveries at 20 local hospitals, of which 17 had routine predischarge bilirubin screening policies. Only 37% of all infants, 44% of vaginally delivered infants, and 41% of exclusively breastfed infants were seen before 6 days of age. Thirty-five percent of the infants were seen after 10 days of age. Among 636 infants seen at ≤15 days, jaundice was noted on examination in 33%; of these, 44% had bilirubin measured. Nine infants had phototherapy documented after birth hospitalization.

CONCLUSIONS: Among a large group of urban and suburban pediatricians, implementation of the American Academy of Pediatrics recommendation for follow-up was inconsistent, and delayed follow-up was common. Understanding reasons for delayed follow-up and providing guidance for jaundice management may promote a safer first week of life.
Impact of Ethics and Economics on End-of-Life Decisions in an Indian Neonatal Unit
Authors: Miljeteig Ingrid , Sayeed Sadath Ali , Jesani Amar , Johansson Kjell Arne , Norheim Ole Frithjof
Published: July 2009

OBJECTIVE: The aim of this article was to describe how providers in an Indian NICU reach life-or-death treatment decisions.

METHODS: Qualitative in-depth interviews, field observations, and document analysis were conducted at an Indian nonprofit private tertiary institution that provided advanced neonatal care under conditions of resource scarcity.

RESULTS: Compared with American and European units with similar technical capabilities, the unit studied maintained a much higher threshold for treatment initiation and continuation (range: 28–32 completed gestational weeks). We observed that complex, interrelated socioeconomic reasons influenced specific treatment decisions. Providers desired to protect families and avoid a broad range of perceived harms: they were reluctant to risk outcomes with chronic disability; they openly factored scarcity of institutional resources; they were sensitive to local, culturally entrenched intrafamilial dynamics; they placed higher regard for “precious” infants; and they felt relatively powerless to prevent gender discrimination. Formal or regulatory guidelines were either lacking or not controlling.

CONCLUSIONS: In a tertiary-level academic Indian NICU, multiple factors external to predicted clinical survival of a preterm newborn influence treatment decisions. Providers adjust their decisions about withdrawing or withholding treatment on the basis of pragmatic considerations. Numerous issues related to resource scarcity are relevant, and providers prioritize outcomes that affect stakeholders other than the newborn. These findings may have implications for initiatives that seek to improve global neonatal health.
Nutritional Practices and Growth Velocity in the First Month of Life in Extremely Premature Infants
Authors: Martin Camilia R. , Brown Yolanda F. , Ehrenkranz Richard A. , O'Shea T. Michael , Allred Elizabeth N. , Belfort Mandy B. , McCormick Marie C. , Leviton Alan ,   and the Extremely Low Gestational Age Newborns Study Investigators
Published: July 2009

OBJECTIVES: The goals of this study were to describe nutritional practices in the first month of life for a large cohort of extremely low gestational age newborns and to determine the impact of these nutritional practices on growth velocity (GV) over the same period.

METHODS: The sample included 1187 infants born at 23 to 27 weeks of gestation, at 14 institutions, between 2002 and 2004. Inclusion criteria included survival until day 28 and weight information for days 7 and 28. GV, expressed as grams per kilogram per day, was calculated for the interval between days 7 and 28. Nutritional practices during the first week and on days 14, 21, and 28 were compared with current nutritional guidelines in the literature. Multivariable logistic regression models estimated the contribution of limited nutrition to limited GV.

RESULTS: Protein and fat delivery approximated current nutritional recommendations, whereas carbohydrate and total energy intake delivery did not. Despite this, GV of our study infants exceeded the current guideline of 15 g/kg per day. Nevertheless, we found extrauterine growth restriction (ie, weight for gestational age below the 10th centile) in 75% of the infants at 28 days, compared with only 18% at birth. A GV of 20 to 30 g/kg per day was associated with infants' maintaining or exceeding their birth weight z score, with rates in the upper range for the gestationally youngest infants. Early (day 7) nutritional practices were positively associated with GV measured between days 7 and 28.

CONCLUSION: The early provision of nutrients is an important determinant of postnatal growth. Extrauterine growth restriction remains high in extremely premature infants even when they achieve a GV rate within current guidelines.
Sleep Outcomes in Children With Hemifacial Microsomia and Controls: A Follow-up Study
Authors: Cloonan Yona K. , Kifle Yemiserach , Davis Scott , Speltz Matthew L. , Werler Martha M. , Starr Jacqueline R.
Published: July 2009

OBJECTIVE: Children with craniofacial anomalies are at high risk for sleep-disordered breathing (SDB), yet its prevalence among children with craniofacial conditions is not known. Children with hemifacial microsomia (HFM) are likely particularly vulnerable to SDB as a result of underdevelopment of the mandible and oropharynx. Nevertheless, most children with HFM are not referred for sleep studies. We hypothesized that sleep outcomes would be worse in children with HFM versus control subjects.

METHODS: We conducted a follow-up study among 124 case participants and 349 control subjects who previously participated in a study of HFM risk factors. Parents completed the Pediatric Sleep Questionnaire (PSQ) regarding symptoms of SDB and sleep habits. Regression models were adjusted for region, age, sex, race/ethnicity, and maternal education.

RESULTS: Snoring was more commonly reported for children with HFM (29%) than for control subjects (17%). Compared with control subjects, children with HFM more often had symptoms consistent with SDB. On average, case participants' parents reported 1.9 times as many symptoms on the PSQ breathing scale and 1.3 times more symptoms on the PSQ sleepiness scale than did control subjects' parents, with little difference on the PSQ behavior scale. Parents of children with HFM reported 1.4 times more night awakenings than did control subjects' parents.

CONCLUSIONS: Children with HFM experienced more snoring and other symptoms of SDB than did control subjects. Pediatricians should be aware of the increased vulnerability for SDB among children with mandibular or external ear underdevelopment or asymmetry and should refer to a sleep specialist as needed.
Neurodevelopmental Disability Through 11 Years of Age in Children Born Before 26 Weeks of Gestation
Authors: Johnson Samantha , Fawke Joe , Hennessy Enid , Rowell Vicky , Thomas Sue , Wolke Dieter , Marlow Neil
Published: July 2009

BACKGROUND: To assess functional disability in children born before 26 weeks of gestation at 11 years of age and the stability of findings in individuals between 6 and 11 years of age.

METHODS: Of 307 surviving children born in 1995, 219 (71%) were assessed at 11 years of age alongside 153 classmates. Children were evaluated by using standardized tests of cognitive ability and clinical condition at both ages.

RESULTS: Using classmate data to determine reference ranges, serious cognitive impairment (score of less than −2 SD) was present in 40% of extremely preterm children and 1.3% of classmates (odds ratio [OR]: 50 [95% confidence interval (CI): 12–206]) at 11 years of age. Overall, 38 (17%) extremely preterm children had cerebral palsy; moderate or severe impairment of neuromotor function, vision, and hearing was present in 10%, 9%, and 2% of these children, respectively. Combining impairment across domains, 98 (45%) extremely preterm children had serious functional disability compared with 1% of the classmates (OR: 61 [95% CI: 15–253]); this was more common in boys than girls (OR: 1.8 [95% CI: 1.0–3.1]) and in those born at 23 or 24 weeks' gestation compared with those born at 25 weeks' gestation (OR: 1.8 [95% CI: 1.0–3.1]). The prevalence of serious functional disability was 46% at 6 years of age and 45% at 11 years of age. Using multiple imputation to correct for selective dropout, it is estimated that 50% (95% CI: 44%–57%) of extremely preterm children are free of serious disability at 11 years of age.

CONCLUSIONS: Extremely preterm children remain at high risk for neurodevelopmental disability at 11 years of age compared with term peers. The prevalence of disability remained stable between 6 and 11 years of age, and large individual shifts in classification of disability were unusual.
Implicit Versus Explicit Curricula in General Pediatrics Education: Is There a Convergence?
Authors: Balmer Dorene F. , Master Christina L. , Richards Boyd , Giardino Angelo P.
Published: July 2009

OBJECTIVE: To describe and analyze the implicit curriculum of a general pediatrics inpatient setting and to understand how it maps onto competency-based goals and objectives in the explicit curriculum.

METHODS: We conducted a case study on a general pediatrics floor, which entailed 143 hours of direct observation during 8 months and 39 in-depth interviews with pediatric residents and General Pediatric attendings who were observed on multiple occasions as they worked on the floor. Data were derived from field notes and interview transcripts. We inductively coded the data, clustered it according to competency domains, and systematically inspected it to derive themes about the convergence of the implicit and explicit curricula.

RESULTS: The implicit curriculum, shaped by ordinary events, activities, and conversations, taught residents “how things work.” The implicit curriculum aligned well with the competency-based goals and objectives in the explicit curriculum; residents had frequent opportunities to meet >90% (29 of 32) of the written objectives. Nonetheless, no one referred to the explicit curriculum or to the competency domains throughout the study. In contrast to the neat list of goals and objectives in the explicit curriculum, the implicit curriculum was extraordinarily messy and dominated by 1 competency domain: patient care. Moreover, the implicit curriculum was not formally recognized as integral to a competency-based model of education.

CONCLUSIONS: Representing the competency domains in ways that better reflect how learning opportunities in the implicit curriculum align with the goals and objectives in the explicit curriculum may increase awareness of the full range of residents' learning experiences.
High-strength bulk Al-based bimodal ultrafine eutectic composite with enhanced plasticity
Authors: Park Jin Man , Mattern Norbert , Kühn Uta , Eckert Jürgen , Kim Ki Buem , Kim Won Tae , Chattopadhyay Kamanio , Kim Do Hyang
Published: July 2009

An in situ bulk ultrafine bimodal eutectic Al–Cu–Si composite was synthesized by solidification. This heterostructured composite with microstructural length scale hierarchy in the eutectic microstructure, which combines an ultrafine-scale binary cellular eutectic (α-Al + Al2Cu) and a nanometer-sized anomalous ternary eutectic (α-Al + Al2Cu + Si), exhibits high fracture strength (1.1 ± 0.1 GPa) and large compressive plastic strain (11 ± 2%) at room temperature. The improved compressive plasticity of the bimodal-nanoeutectic composite originates from homogeneous and uniform distribution of inhomogeneous plastic deformation (localized shear bands), together with strong interaction between shear bands in the spatially heterogeneous structure.
Directional recrystallization and microstructures of an Fe–6.5wt%Si alloy
Authors: Zhang Zhongwu , Chen Guang , Bei Hongbin , Li Feng , Ye Feng , Chen G.L. , Liu C.T.
Published: July 2009

Directional recrystallization of an Fe–6.5wt%Si alloy was investigated by changing hot zone temperatures and growth rates. Elongated (columnar) grains with an aspect ratio more than 10 can be produced when growth parameters are carefully adjusted. It was found that at a fixed growth rate, the grain length and aspect ratio increase with increased hot zone temperatures. At a fixed hot zone temperature, there is a critical growth rate at which columnar grains have the largest average aspect ratio. Below or above this growth rate, the aspect ratio decreases. Texture and grain orientation analysis showed that the preferentially selective growth to form columnar grains was favored by the formation of low-energy surfaces and grain boundaries.
A constitutive theory and modeling on deviation of shear band inclination angles in bulk metallic glasses
Authors: Zhao Ming , Li Mo
Published: July 2009

A constitutive theory for metallic glasses is established that is based mainly on the Drucker-Prager model and a free-volume theory. The primary emphasis of this theory is on volume dilatation and its consequences on mechanical responses in metallic glasses that have been known from studies in both experiments and atomistic simulations. We also implemented the constitutive theory in a finite element modeling scheme and conducted numerical modeling of deformation of a metallic glass under plane-strain tension and compression. In particular, we focused our attention on the deviation of the shear band inclination angle, a commonly observed phenomenon for metallic glasses. We found very good qualitative agreement with available experimental data on shear band inclination angle and stress-strain relation. We also give a detailed discussion on different constitutive models, in particular the Coulomb-Mohr model, in the context of predicting the shear band inclination angle.
Effects of the catalysts on the evolution of in-plane stress in alkoxide-derived silica gel coatings during heating
Authors: Kozuka Hiromitsu , Iwase Tetsuya
Published: July 2009

The effects of the catalysts on the evolution of in-plane stress during heating were studied for silica gel coatings prepared from alkoxide solutions. Tetramethylorthosilicate was hydrolyzed in the presence of nitric acid, acetic acid, and ammonia as catalysts. Gel films were deposited on Si(100) wafers by spin coating, and heated at a constant rate of 5 °C/min up to 500 °C. During heating, in situ measurement of the in-plane stress was conducted by measuring the radius of curvature of the substrate. In-plane, tensile stress increased up to 560 and 370 MPa in the films prepared with HNO3 and CH3COOH, respectively. However, the stress was much smaller at 30–40 MPa, which remained almost constant during heating, for the films prepared with NH3. The much smaller stress resulted from the much lower degrees of the progress of densification during heating, which was revealed in the changes in thickness and infrared absorption spectra during heating. The low degrees of the progress of densification were caused by the colloidal nature of the gel films.
On the effects of thermal treatment on the composition, structure, morphology, and optical properties of hydrogenated amorphous silicon-oxycarbide
Authors: Gallis Spyros , Nikas Vasileios , Eisenbraun Eric , Huang Mengbing , Kaloyeros Alain E.
Published: July 2009

The composition, structure, morphology, and optical characteristics of hydrogenated amorphous silicon-oxycarbide (a-SiCxOyHz) materials were investigated as a function of experimental processing conditions and post-deposition thermal treatment. Thermal chemical vapor deposition (TCVD) was applied to the growth of three different types of a-SiCxOyHz films, namely, SiC-like (SiC1.08O0.07H0.21), Si-C-O (SiC0.50O1.20H0.22), and SiO2-like (SiC0.20O1.70H0.24). The resulting films were subsequently annealed at temperatures ranging from 500 °C to 1100 °C for 1 h in an argon atmosphere. The composition, structure, and morphology of as-deposited and post-annealed films were characterized by Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS), nuclear-reaction analysis (NRA), and scanning electron microscopy. Corresponding optical properties were assessed by spectroscopic ultraviolet-visible ellipsometry (UV-VIS-SE). These studies led to the identification of an optimized process window for the growth of Er doped silicon oxycarbide (SiC0.5O1.0:Er) thin film with strong room-temperature photoluminescence emission measured around 1540 nm within a broad (460 nm to 600 nm) wavelength band. Associated modeling studies showed that the effective cross section for Er excitation in the SiC0.5O1.0:Er matrix was approximately four orders of magnitude larger than its analog for direct optical excitation of Er ions.
Synthesis and thermodynamic evaluation of intermetallic Mg-Ni/Mg-Cu nanoscale powders
Authors: Lei Jun-Peng , Dong Xing-Long , Zhao Fu-Guo , Huang Hao , Zhang Xue-Feng , Lu Bo , Lei M.K.
Published: July 2009

Nanometer-sized intermetallic Mg-Ni and Mg-Cu compound powders were prepared by a physical vapor deposition method (arc discharge) and characterized by means of x-ray diffraction and transmission electron microscopy. Based on an empirical specific heat equation, the effective heat of formation and its temperature dependence were calculated to explain phase formation in nanoscale powders of the binary Mg-Ni and Mg-Cu systems. It is shown that theoretic calculations are in good agreement with the experimental observations.
Sol-gel synthesis and characterization of Ag nanoparticles in ZrO2 thin films
Authors: Yokoyama Eisuke , Sakata Hironobu , Wakaki Moriaki
Published: July 2009

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.
250 °C isothermal section of ternary Sn-In-Cu phase equilibria
Authors: Lin Shih-kang , Chung Ting-ying , Chen Sinn-wen , Chang Chih-horng
Published: July 2009

Ternary Sn-In-Cu alloys are prepared and equilibrated at 250 °C for 2 to 20 weeks. The phases formed in these alloys are experimentally determined. The 250 °C Sn-In-Cu isothermal section is established according to the phase equilibrium information obtained in this study and that of the three constituent binary systems. It has eight single-phase regions, namely liquid, δ1-Cu41Sn11, ε-Cu3Sn, δ2-Cu7In3, η-(Cu6Sn5, Cu2In), Cu11In9, Cu2In3Sn, and α-(Cu) phases, 14 two-phase regions, and seven three-phase regions. In the Sn-In-Cu system at 250 °C, the η-Cu6Sn5 and η-Cu2In phases form a continuous solid solution and the ternary Cu2In3Sn compound is observed. The δ1-Cu41Sn11 phase is stabilized at 250 °C with the introduction of indium although it transforms into α-(Cu) and ε-Cu3Sn phases via a eutectoid reaction around 350 °C in the binary Sn-Cu system. Except for the Cu11In9 phase and the Cu2In3Sn ternary compound, the other binary compounds all have significant indium and tin mutual solubilities.
Reinforcing effects of carbon nanotubes in structural aluminum matrix nanocomposites
Authors: Choi Hyunjoo , Shin Jaehyuck , Min Byungho , Park Junsik , Bae Donghyun
Published: July 2009

The reinforcing effects of carbon nanotubes (CNTs) are investigated for aluminum matrix composites. The composites present a strong bonding between CNTs and the aluminum matrix using a controlled mechanical milling process, producing a network structure of aluminum atoms around CNTs. At the same time, CNTs that are dispersed during the milling process can be located inside aluminum powders, thereby providing an easy consolidation route via thermomechanical processes. A composite containing 4.5 vol% multiwalled CNTs exhibits a yield strength of 620 MPa and fracture toughness of 61 MPa·mm1/2, the values of which are nearly 15 and seven times higher than those of the corresponding starting aluminum, respectively.
Atomic-scale structural and compositional analyses of Ruddlesden-Popper planar faults in AO-excess SrTiO3 (A = Sr2+, Ca2+, Ba2+) ceramics
Authors: Šturm Sašo , Shiojiri Makoto , Čeh Miran
Published: July 2009

The microstructure in AO-excess SrTiO3 (A = Sr2+, Ca2+, Ba2+) ceramics is strongly affected by the formation of Ruddlesden-Popper fault–rich (RP fault) lamellae, which are coherently intergrown with the matrix of the perovskite grains. We studied the structure and chemistry of RP faults by applying quantitative high-resolution transmission electron microscopy and high-angle annular dark-field scanning transmission electron microscopy analyses. We showed that the Sr2+ and Ca2+ dopant ions form RP faults during the initial stage of sintering. The final microstructure showed preferentially grown RP fault lamellae embedded in the central part of the anisotropic perovskite grains. In contrast, the dopant Ba2+ ions preferably substituted for Sr2+ in the SrTiO3 matrix by forming a BaxSr1−xTiO3 solid solution. The surplus of Sr2+ ions was compensated structurally in the later stages of sintering by the formation of SrO-rich RP faults. The resulting microstructure showed RP fault lamellae located at the surface of equiaxed BaxSr1-xTiO3 perovskite grains.
Analysis and characterization by electron backscatter diffraction of microstructural evolution in the adiabatic shear bands in Fe–Cr–Ni alloys
Authors: Yang Huajie , Xu Yongbo , Seki Yasuaki , Nesterenko Vitali F. , Meyers Marc André
Published: July 2009

The microstructural evolution inside adiabatic shear bands in Fe–Cr–Ni alloys dynamically deformed (strain rates > 104 s−1) by the collapse of an explosively driven, thick-walled cylinder under prescribed strain conditions was examined by electron backscatter diffraction. The observed structure within the bands consisted of both equiaxed and elongated grains with a size of ∼200 nm. These fine microstructures can be attributed to recrystallization; it is proposed that the elongated grains may be developed simultaneously with localized deformation (dynamic recrystallization), and the equiaxed grains may be formed subsequently to deformation (static recrystallization). These recrystallized structures can be explained by a rotational recrystallization mechanism.
Corrosion products on biomedical magnesium alloy soaked in simulated body fluids
Authors: Xin Yunchang , Huo Kaifu , Hu Tao , Tang Guoyi , Chu Paul K
Published: July 2009

Magnesium alloys are potential materials in biodegradable hard tissue implants. Their degradation products in the physiological environment not only affect the degradation process but also influence the biological response of bone tissues. In the work reported here, the composition and structure of the corrosion product layer on AZ91 magnesium alloy soaked in a simulated physiological environment, namely simulated body fluids (SBFs), are systematically investigated using secondary electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), and in situ monitoring of the corrosion morphology. Our results show that the corrosion product layer comprises mainly amorphous magnesium (calcium) phosphates, magnesium (calcium) carbonates, magnesium oxide/hydroxide, and aluminum oxide/hydroxide. The magnesium phosphates preferentially precipitate at obvious corrosion sites and are present uniformly in the corrosion product layer, whereas calcium phosphates nucleate at passive sites first and tend to accumulate at isolated and localized sites. According to the cross sectional views, the corrosion product layer possesses a uniform structure with thick regions several tens of micrometers as well as thin areas of several micrometers in some areas. Localized corrosion is the main reason for the nonuniform structure as indicated by the pan and cross-sectional views. The results provide valuable information on the cytotoxicity of magnesium alloys and a better understanding on the degradation mechanism of magnesium alloys in a physiological environment.
Magnetic force microscopy of combined reaction-processed polycrystalline equiatomic bulk L10 FePd
Authors: Ohodnicki Paul R. , Desphande Anirudha , Wiezorek Jorg M.K. , Klemmer Timothy J.
Published: July 2009

In this work, the correlation between magnetic-domain structure and microstructure in combined reaction-processed equiatomic L10 FePd has been investigated using magnetic force microscopy. The microstructure consisted of approximately equiaxed grains with an average grain size of ∼1 μm and a grain size distribution ranging from below the theoretical critical domain size (Dcrit∼0.2–0.3 μm) up to approximately 5 μm in diameter. The domain structure was characterized as “mixed” in nature, consisting of smaller single-domain grains, larger multidomain grains, and a larger scale interaction domain structure encompassing many grains. The domain boundaries separating interaction domains tended to lie along grain boundaries, and it is proposed that the observed interaction domains should be considered in descriptions of the magnetization and magnetization reversal behavior of this material. In particular, pinning of interaction domain walls by intragranular features of the microstructure such as grain boundaries and single-domain grains could play a role in the measured coercivities.
The temperature-dependent luminescence properties of BaAl2−xSixO4−xNx:Eu2+ and its application in yellowish-green light emitting diode
Authors: Zhang Mei , Li Baohong , Wang Jing , Zhang Zhiyang , Zhang Qiuhong , Su Qiang
Published: July 2009

The influences of (SiN)+ and Eu2+ concentration on the optical properties of BaAl2−xSixO4−xNx:Eu2+ were investigated. The lifetime results show that there are two different cation sites occupied by Eu2+ ions and the energy transfer occurs between them. The Huang–Rhys factor and the Stokes energy shift were determined, and thermal quenching with increasing temperature was observed. Finally, intense yellowish-green light emitting diodes (LED) with the color coordinate of (0.2936, 0.4483) under a forward-bias current of 20 mA was successfully fabricated on the basis of a structure consisting of BaAl2−xSixO4−xNx:Eu2+ phosphor and near-ultraviolet (∼395 nm) GaN chip.
Grain refinement effect of a pulsed magnetic field on as-cast superalloy K417
Authors: Ma Xiaoping , Li Yingju , Yang Yuansheng
Published: July 2009

The grain refinement effect of a pulsed magnetic field on superalloy K417 was studied. The experimental results show that fine equiaxed grains are acquired with proper thermal control under the pulsed magnetic field. The refinement effect of the pulsed magnetic field is affected by the melt cooling rate and the melt superheating. The refinement effect of the pulsed magnetic field is attributed to the dissociation of nuclei from the mold wall by melt vibration and the subsequent dispersion of nuclei by melt convection. The Joule heat and the melt convection caused by the pulsed magnetic field may defer the formation of solidified shell, which prolongs the continuous refinement process. The decrease of melt cooling rate reduces the number of nuclei produced on the mold wall but prolongs the duration for the nuclei to depart from the mold wall and disperse in the melt, which enhances the refinement effect of the pulsed magnetic field. The increase of melt superheating lessens the survival probability of the nuclei in the melt, which weakens the refinement effect of the pulsed magnetic field.
Banco de sementes do solo de margem viária dominada por capim-annoni-2 e sujeito ao controle com distúrbios no solo e introdução de gramíneas
Authors: Ferreira Nadilson Roberto , Medeiros Renato Borges de , Favreto Rodrigo
Published: July 2009

Os impactos das ações antrópicas nas rodovias favorecem um ecossistema diferenciado do seu entorno, facilitando o estabelecimento de espécies oportunistas, como o capim-annoni-2 (Eragrostis plana Nees). No Rio Grande do Sul os acostamentos de rodovias encontram-se invadido por esta espécie, constituindo-se como centro dispersor. Com este estudo objetivou-se descrever o tamanho e a composição do banco de sementes do solo (BSS) deste ambiente, e demonstrar o seu potencial para recompor a florística campestre de acostamentos degradados e invadidos através do estimulo do BSS. O experimento foi estabelecido à margem de uma estrada municipal, anexa à sede da Fazenda São Lucas, no município de Rio Pardo RS, no período de janeiro de 2005 a maio de 2006. O delineamento foi em blocos casualizados com parcelas subdivididas e com três repetições. Os tratamentos das parcelas foram: uso de subsolador e de subsolador mais grade com aplicação de calcário e fósforo. Nas subparcelas, foram semeadas Megathyrsus maximus, Setaria sphacelata, mistura de três espécies nativas de Paspalum ssp e exclusão (testemunha). A ocorrência de sementes de espécies exóticas representou 20% do BSS, destacando-se o capim-annoni-2. As espécies inibidoras do BSS do capim-annoni-2 foram Megathyrsus maximus e Setaria sphacelata, associadas à operação de subsolagem, gradagem e adubação. O tamanho e a riqueza do BSS indicam alto potencial de regeneração da vegetação herbácea nativa em acostamentos de rodovias invadidos por capim-annoni-2.
Emergência de plântulas de Copernicia Hospita Martius em função do tamanho da semente, do substrato e ambiente
Authors: Oliveira Alexandre Bosco de , Medeiros Filho Sebastião , Bezerra Antônio Marcos Esmeraldo , Bruno Riselane de Lucena Alcântara
Published: July 2009

A germinação lenta e desuniforme das sementes de palmeiras acarreta problemas na propagação das espécies pertencentes a esta família, dificultando, principalmente, a produção de mudas em escala comercial. Esse trabalho objetivou determinar o efeito do tamanho da semente, de substratos e do ambiente na emergência de plântulas de Copernicia hospita Martius. As sementes foram submetidas aos tratamentos: substratos [areia vermelha + bagana de carnaúba + húmus (2,5:2,5:1 em volume) e solo + arisco + composto orgânico Polefértil® (2:2:1 em volume)]; ambientes (pleno sol e casa de vegetação); e tamanho de sementes (pequena, média, grande e mistura). Os tratamentos foram comparados quanto à percentagem de emergência, avaliada aos 60 dias após a semeadura, índice de velocidade e tempo médio de emergência. Os fatores analisados não influenciam no percentual de emergência de plântulas. Sementes de C. hospita oriundas da mistura e de tamanho pequeno, semeadas em ambos os substratos analisados, sob casa de vegetação, proporcionam emergência mais rápida das plântulas.
Conservation of giant panda habitat in South Minshan, China, after the May 2008 earthquake
Authors: Xu Weihua , Wang Xuezhi , Ouyang Zhiyun , Zhang Jindong , Li Zhiqi , Xiao Yi , Zheng Hua
Published: July 2009

In May 2008, a major earthquake struck Sichuan Province, in southwestern China. In addition to catastrophic loss of human life and destruction of towns and villages, the earthquake severely damaged ecosystems that support some of the last remaining giant panda (Ailuropoda melanoleuca) populations in the wild. To measure the extent of this destruction, we analyzed panda habitat loss and fragmentation across the South Minshan Mountains, using Thematic Mapper (TM) images and field data collected before and after the earthquake. Results show that 354 km2 (23%) of panda habitat in this region was destroyed, 249 km2 of which was inside nature reserves. The remaining habitat was fragmented by landslides and mudflows, thereby threatening the giant panda's long‐term survival. Furthermore, the mean patch size of the remaining habitat inside reserves was only 23% of that outside, indicating markedly higher habitat fragmentation inside reserves compared to outside. To assist in regional conservation efforts for the giant panda and its habitat, we propose the creation of a conservation management unit that would include key areas, corridors, and current reserves, to encourage the dispersal/movement of pandas between isolated habitat patches. Other measures include human disturbance alleviation and “ecological compensation”, which would increase the efficacy of the conservation management unit.
Value of Information in the Oil and Gas Industry: Past, Present, and Future
Authors: Bratvold Reidar B. , Bickel J. Eric , Lohne Hans Petter
Published: July 2009

An important task that petroleum engineers and geoscientists undertake is to produce decision-relevant information. Some of the most important decisions we make concern what type and what quality of information to produce. When decisions are fraught with geologic and market uncertainties, this information gathering may such forms as seismic surveys, core and well test analyses, reservoir simulations, market analyses, and price forecasts—which the industry spends billions of US dollars each year. Yet, considerably less time and resources are expended on assessing the profitability or value of this information. Why is that?

This paper addresses how to make value-of-information (VOI) analysis more accessible and useful by discussing its past, present, and future. On the basis of a survey of SPE publications, we provide an overview of the use of VOI in the oil and gas industry, focusing on how the analysis was carried out and for which types of decisions VOI analysis has been performed. We highlight areas in which VOI methods have been used successfully and identify important challenges.

We then identify and discuss the possible causes for the limited use of VOI methods and suggest ways to increase the use of this powerful analysis tool.
Drilling Difficult Formations Efficiently With the Use of an Antistall Tool
Authors: Selnes Knut Sigve , Clemmensen Carl , Reimers Nils
Published: July 2009

Antistall technology (AST) is a mechanical downhole solution that aims to adjust the drilling torque automatically in real time. Originally, the tool was developed by Tomax AS for coiled-tubing applications where it has proven its ability to successfully reduce vibrations, motor stalls, equipment failures, and general wear, in addition to increasing the penetration rate and run length (Dagestad et al. 2006). The tool was then developed further based on the need for a similar solution for rotary drilling. The goal was to eliminate cutter-induced torque variations and string stalls in difficult formations and resultant harmful effects. Prototype AST tools were made in sizes ranging from 6¾ to 8¼ in. The tools were then run in test wells and later in field operations with a variety of tool configurations until the database, in addition to two controlled trials, counted 25 regular jobs—mainly on the Norwegian Continental Shelf. The paper describes in detail, both based on theory and on field experience, how the bit-induced torque fluctuations are significantly decreased to improve penetration, and how bottomhole-assembly (BHA) damage is prevented to increase run lengths.
Enhanced Scale-Inhibitor Treatments With the Addition of Zinc
Authors: Kan Amy T. , Fu Gongmin , Al-Saiari Hamad A. , Tomson Mason B. , Shen Dong
Published: July 2009

This paper discusses research on scale inhibition and squeeze performance in the presence of Zn2+. Some scale inhibitors, such as bis-hexamethylenetriamine penta(phosphonic acid), BHPMP, and polymeric inhibitors, such as phosphinopolycarboxylate (PPCA), have poor retention characteristics in conventional squeeze treatment, where less than 50% of the inhibitor is retained in the formation. In this study, it was demonstrated that more than 90% of the same scale inhibitor was retained when Zn2+ was included in the squeeze formulation. Furthermore, Zn2+ showed significant synergistic effect on barite scale inhibition with certain amino-pentaphosphonate scale inhibitors [BHPMP and diethylenetrimine pentaphophonic acid (DTPMP)]. Stronger solution complexes are observed for aminophosphonates type scale inhibitors with Zn2+ than that with alkaline earth metal ions, such as Ca2+, Mg2+, and Ba2+. This stronger solution complex formation with Zn2+ may be attributed to the observed enhanced inhibition efficiency. Because of the lower solubility of Zn2+-scale inhibitor salts, Zn2+ added to the inhibitor pill significantly improves the retention of some scale inhibitors during squeeze treatment. In this paper, the projected squeeze life (PSL) is defined. When Zn2+ is used in the inhibitor pill, the PSL for BHPMP is increased by a factor of 60 without significantly affecting the cost. Simulation indicates that the squeeze life may be improved significantly at the Guerra well if this new squeeze procedure is used.
Integrated water resources management and modeling at multiple spatial scales in Jordan
Authors: Rosenberg David E.
Published: July 2009

Water shortages from intermittent public supplies are a major and expanding problem in the Hashemite Kingdom of Jordan. Yet individual users, utility managers, and government officials can improve access or cope with shortages in many ways. New supplies, more efficient use of existing resources, long-term investments to expand infrastructure and reduce leakage, and short-term measures to flexibly transfer, ration, or curtail some uses represent several different approaches for management. This paper reviews three separate systems analysis that use stochastic optimization with recourse. Analysis for individual residential users, the water utility serving 2.2 million residents in the capital Amman, and the entire kingdom comprising Amman and 11 other governorates identify complementary actions to be undertaken by individual users, utility managers, and government officials.
Water development in the Palestinian Territories since the Oslo Interim Agreement in 1995
Authors: Gray Alice
Published: July 2009

When the Palestinian Authority took control of the water sector in the occupied territories in 1995, they inherited an enormous challenge in terms of providing adequate water supplies and sanitation to the Palestinian population. Since the signing of the Oslo Interim Agreement in 1995, despite the prioritization of water development and large amounts of international funding, progress has been slow and many communities in the West Bank continue to suffer from acute water shortage, while in Gaza water quality continues to deteriorate at an alarming rate. Sewage treatment infrastructure throughout the Palestinian Territories is still grossly inadequate. This lack of progress is in part due to deteriorating security conditions which have made implementation of development projects problematic, but it also owes a great deal to the constraints of the ongoing military occupation and the inadequacy of existing agreements with Israel which impede Palestinians from assuming full sovereignty over their water sector, preventing effective development. Since the election of Hamas in 2006, complications over the supply of international aid to the Palestinian Authority both in Gaza and the West Bank has threatened to undermine such progress as has been made in developing the capacity of Palestinian institutions to manage water in the occupied territories, and is contributing to the precipitation of a humanitarian and environmental catastrophe.
Managing groundwater as a common-pool resource: an Australian case study
Authors: Sarker Ashutosh , Baldwin Claudia , Ross Helen
Published: July 2009

Over-appropriation and degradation of groundwater can result from lack of recognition of, and inappropriate arrangements for, managing groundwater as a common-pool resource. An irrigators group in the Lockyer Valley, South-East Queensland, Australia and the Queensland government are currently working together to address over-exploitation of groundwater through a co-management model designed to be nested within the state and national water reform framework. This paper applies Ostrom's design principles for common-pool resource governance to this proposed co-management framework to strengthen the approach.