bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of near Infrared Spectroscopy to Discriminate between and Predict the Nutrient Composition of Different Species and Parts of Bamboo: Application for Studying Giant Panda Foraging Ecology
Authors: Wiedower E. , Hansen R. , Bissell H. , Ouellette R. , Kouba A. , Stuth J. , Rude B. , Tolleson D.
Published: November 2009

Giant pandas ( Ailuropoda melanoleuca) are specialist feeders, dependent upon bamboo as their main dietary resource. Due to the difficulty of many captive facilities to meet the natural qualitative diet changes in bamboo species and plant parts consumed seasonally by giant pandas, it is important to understand the nutritional quality of this forage and the differences among plant parts for improved husbandry. Near infrared (NIR) reflectance spectroscopy has been used as a tool to measure forage quality for both domestic and free-ranging species. The objective of this study was to determine the capability of NIR spectroscopy to: (1) discriminate between bamboo parts, (2) discriminate between bamboo species and (3) to predict the nutrient composition of bamboo. All bamboo samples were received from the Memphis Zoo Bamboo Farm (Memphis, TN, USA), dried at 60°C and ground to pass through a 1 mm screen before analysis. Discrimination between a total of 722 branch, culm and leaf samples resulted in an R2 of 0.88 and SECV of 0.18. Spectra from a total of 756 samples of four different species were used to create a discriminant equation among bamboo species. This resulted in an R2 of 0.47 and SECV of 0.29. Validation sets were correctly predicted at the following rates: (part) branch 94%, culm 100% and leaf 100%; (species) Phyllostachys aurea 10%, P. aureosulcata 98%, P. glauca 80% and Pseudosasa japonica 73%. Calibration equations for crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and organic matter (OM) were created using all bamboo samples. For each nutritional constituent, the calibration R2 values exceeded 0.96. The average SEP across all constituents was 0.21% for CP, 2.35% for NDF, 3.62% for ADF, 0.84% for DM and 0.25% for OM. NIR spectroscopy was used to predict nutrient characteristics and discriminate between bamboo plant parts and species. The inability to discriminate among bamboo species is most likely due to a close physiological similarity between at least two of the species. Results suggest that NIR spectroscopy can be used to analyse bamboo forage quality which may have applications to captive giant panda husbandry.
Chemometric Monitoring of Designed Composting Processes Using Laboratory Measurements and near Infrared Spectroscopy
Authors: Lillhonga Tom , Grünwald Julia , Geladi Paul
Published: November 2009

Fox manure, food waste and yard waste were used as pure composts to construct a laboratory-scale designed (simplex mixture) experiment with repeated centre points that was monitored over 31 calendar days by near infrared (NIR) spectroscopy (900–1700 nm) and additionally by sampling for wet chemical and physical laboratory measurements: pH, energy, moisture content, NH3/NH4+ (simply called ammonium) concentration, and temperature. Three methods of data analysis were tested on the resulting data matrices: (1) modelling of the mixture design by Scheffé models, (2) principal component analysis (PCA) with interpretation of score and loading plots for the laboratory parameters and the NIR spectra separately and (3) partial least squares (PLS) regression modelling between NIR spectra and laboratory parameters. Significant Scheffé models were obtained and these could be used to make response surfaces of the parameters as a function of time. The PCA scores for the laboratory data reproduced the mixture triangles at the start of the experiment and showed that all the aerobic composts evolved to a common endpoint region. The PCA analysis of the NIR data indicated that score plots are a useful tool for monitoring the decomposition process of composts. Each of the composts could be followed over time by observing directions in the score space and changes in the step distances in score space. PLS models were built for each of the laboratory parameters and, additionally, composting time against NIR spectra, where spectra from the three centre points were used as an independent test set. The parameters pH, temperature, ammonium concentration and composting time all gave RER values above 10 and RPD values above 3 were obtained for temperature, pH and composting time.
Increased Complement Factor H with Decreased Factor B Determined by Proteomic Differential Displays as a Biomarker of Tai Chi Chuan Exercise
Authors: Yang Kuender D , Chang Wan-Ching , Chuang Hau , Wang Pei-Wen , Liu Rue-Tsuan , Yeh Shu-Hui
Published: November 2009

Background: Exhaustive exercise can be associated with short-term immune suppression, but moderate exercise such as tai chi chuan (TCC) has been shown to have beneficial effects on immunity. The mechanisms for the health benefits of exercise remain to be determined, and no potential biomarkers for these beneficial health effects have been identified. This study investigated serum proteomic markers in individuals participating in TCC exercise.

Methods: Two-dimensional fluorescence difference gel electrophoresis was used to compare proteomic markers in 3 individuals before and after 12 weeks of TCC exercise. The different protein spots were identified by mass spectrometry and validated in an additional 20 individuals by western blot analysis.

Results: We identified 39 protein spots for 18 proteins with a noticeable increase or decrease after TCC exercise. Validation of the differentially displayed proteins with 20 paired pre- and postexercise samples revealed a significant increase in complement factor H (P = 0.0034) associated with decreases in C1 esterase inhibitor (P = 0.0038) and complement factor B (P = 0.0029).

Conclusions: In this first study of proteomic biomarkers of TCC exercise, we found an increase in complement factor H associated with a decrease in complement factor B. Complement factor H is involved in protection from microangiopathy and macular degeneration and may represent a useful marker of the health effects of exercise.
Association of Very Highly Elevated C-Reactive Protein Concentration with Cardiovascular Events and All-Cause Mortality
Authors: Hamer Mark , Chida Yoichi , Stamatakis Emmanuel
Published: November 2009

Background: The clinical relevance of very highly increased high-sensitivity C-reactive protein (hsCRP) concentrations (>10 mg/L) is incompletely understood. We examined the association between very highly increased hsCRP and risk of incident cardiovascular disease (CVD) events and all-cause mortality.

Methods: We recruited 5248 participants free from overt CVD and acute infection [mean age 53.5 (SD 12.4) years, 55.5% women] from the Scottish Health Survey, a representative sample of community-dwelling adults. hsCRP and other conventional risk factors were measured at baseline.

Results: Over an average of 7 years’ follow-up, there were a total of 259 incident CVD events (including myocardial infarction, coronary artery bypass, percutaneous coronary angioplasty, stroke, heart failure) and 357 all-cause deaths. Very highly increased hsCRP was associated with CVD events after adjustment for Framingham risk score (FRS), body mass index (BMI), central obesity, and hormone replacement therapy (HRT) (hazard ratio 2.40, 95% CI 1.51–3.81) and also with all-cause death (hazard ratio 3.64, 95% CI 2.57–5.15). With the addition of CRP scores to the conventional Framingham model, 7.4% of participants were reclassified into a high-risk (>20% FRS) CVD category. Very highly increased hsCRP was also associated with several modifiable risk factors, including smoking, HDL cholesterol, and central obesity.

Conclusions: hsCRP >10 mg/L was a stronger predictor of clinical events than a conventional cut point of 3 mg/L. Very highly increased hsCRP may provide clinically meaningful prognostic information.
Cruising, hysteria, knowledge: The Man Who Knew Too Much (1956)
Authors: Greven David
Published: November 2009

The protagonists of Hitchcock's The Man Who Knew Too Much (1956) are a married couple who each chafes against normative gender roles. While the film has its reactionary side, in its insistence on exploring the various threats to gendered normativity from within and without, it's one
of the most ideologically unstable and unclassifiable films of the 1950s. This essay treats the film as an exploration of women's discontent with 50s American Mommyism and as an allegory of Cold War-era homosexuality, especially cruising. Critics such as Robert J. Corber have read the film's
construction of motherhood as misogynistic; in contrast, this essay argues that the representation of Jo McKenna's maternal ambivalence registers dissatisfactions with normative gender roles assigned to women. Analogously, her husband's growing attraction/repulsion to encroaching homoerotic
energies signals discontentment with post-war codes of American masculinity. These paired gendered revolts what I call gender protest are linked to Hitchcock's deployment of the cinematic star both to camouflage and intensify his parodistic skewering of iconic myths of American manhood and
womanhood.
Dead men tell no tales: outlaw John A. Murrell on the antebellum stage
Authors: Smith Thomas Ruys
Published: November 2009

Outlaw John A. Murrell, credited with the planning of a failed slave uprising in Mississippi in 1835, was a significant figure in antebellum popular culture. Previously unrecognized, however, is his use as a character on the antebellum stage. Proof of his employment in this role can
be found in the Harvard Theatre Collection, home to a hitherto unidentified manuscript copy of a melodrama entitled Murrell, the Pirate A Play in Three Acts. In this article, its creator is identified as Nathaniel Harrington Bannister, a significant pre-war actor-playwright. An exploration
of its performance history reveals its significance in a variety of ways. It highlights the degree to which John Murrell was an adaptable and ambiguous antebellum villain. It helps to illuminate the life and career of Bannister and his contribution to the American stage. It provides new insights
into the life and career of Charles Burke, another significant actor-playwright of the antebellum years who developed an important connection to Murrell, the Pirate. And because of Burke's association with the play, it also becomes plausible to place it as an important step on the road in
the development of Joseph Jefferson III's production of Rip Van Winkle, one of the most successful and influential nineteenth century American plays.
Reviews
Authors: Fernndez-Quijada David , Goss Brian
Published: November 2009

Television in the Multichannel Age: A Brief History of Cable Television, Megan Mullen (2008)Malden: Blackwell Publishing, x + 238 pp., ISBN 9781405149709 Paperback, 18.99, Hardback, 47.50

What the Heck Are You Up to, Mr. President?: Jimmy Carter, America's Malaise and the Speech That Should Have Changed the Country, Kevin Mattson (2009)New York: Bloomsbury, 272 pp., ISBN-10: 1596915218, Hardback, ISBN-13: 978-1596915213, Hardback, $(US) 25.00
Drivers of colonization and succession in polar benthic macro- and microalgal communities
Authors: Campana Gabriela Laura , Zacher Katharina , Fricke Anna , Molis Markus , Wulff Angela , Liliana Quartino María , Wiencke Christian
Published: November 2009

Information on succession in marine benthic primary producers in polar regions is very scarce, particularly with regard to effects of abiotic and biotic drivers of community structure. Primary succession begins with rapid colonizers, such as diatoms and ephemeral macroalgae, whereas slow, highly seasonal recruitment and growth are characteristic of annual or perennial seaweed species. Colonization of intertidal and subtidal assemblages on polar rocky shores is severely affected by physical disturbance and by seasonal changes in abiotic conditions. Biotic factors, such as grazing, can strongly affect colonization patterns and also alter competitive interactions among benthic algae. Ambient UV radiation affects the diversity of macroalgal communities during early and later stages of succession. In contrast, microalgal assemblages have high tolerance to UV stress. Climate warming could alter algal latitudinal distribution and favor invasion of polar regions by cold-temperate species. Reduced sea ice cover and retreating glaciers could expand colonization areas but alter light, salinity, sedimentation and disturbance processes. Although the key role of macroalgae in coastal systems and, to a much reduced extent, the importance of microphytobenthos have been documented for polar regions, information on the successional process is incomplete and will benefit from further ecological studies.
How to choose a prosodic template. On verb innovation and variation in Hebrew
Authors: Laks Lior
Published: November 2009

This paper examines the factors that play a role in blocking and non-blocking in verb formation in Modern Hebrew. Hebrew verbs are formed in prosodic templates (so-called binyanim) that consist of a vocalic template and affixes in some of them. I address the criteria for the selection of such templates with regard to verb innovation, relation between existing forms and variation of forms. I will show that the selection of a particular binyan is the result of an interaction between markedness and faithfulness constraints on the one hand and thematic-syntactic considerations on the other hand. While certain constraints block the formation of verbs in some binyanim, there are cases of non-crucial ranking of constraints that gives rise to free variation of existing forms.
3D-Oberflächenvermessung mit einem Stereo-Rasterelektronenmikroskop3D Surface Measurement with a Scanning Electron Microscope
Authors: Vynnyk Taras , Fahlbusch Thomas , Reithmeier Eduard
Published: November 2009

Die Vermessung von mikro-strukturierten technischen Oberflächen ist eine aktuelle Kernfragestellung der Messtechnik. In diesem Beitrag werden 3D-Rekonstruktionsverfahren von rasterelektronenmikroskopischen Aufnahmen, insbesondere die photometrische Methode, vorgestellt. Zur Verifikation des entwickelten Modells wurde ein Rasterelektronenmikroskop mit zwei Detektoren versehen.
Untersuchung betontechnologischer Fragestellungen mit Hilfe eingebetteter flexibler faseroptischer Fabry—Pérot-InterferometerInvestigations of Durability Parameters of Concrete by Means of Embedded Flexible Fiber-Optic Fabry—Pérot Interferometers
Authors: Schuler Stephanie , Hillemeier Bernd , Fuhrland Matthias , Meinel Dietmar , Habel Wolfgang R.
Published: November 2009

Die Dauerhaftigkeit von Betonbauteilen zu einer messbaren Größe zu machen, ist ein vorrangiges Ziel der Baustoffforschung. Schrumpfen, Schwinden und Temperaturverformungen gefährden bei Hochleistungsbetonen deren Dauerhaftigkeit. Die begleitende messtechnische Deformationsmessung wird daher zu einer unverzichtbaren Methode, Betonrezepturen zielsicher und ökonomisch hinsichtlich der Dauerhaftigkeit zu entwickeln. Ein flexibler Fabry–Pérot-Interferometer-Sensor ermöglicht die messtechnische Erfassung der frühen Deformationsprozesse bereits ab dem Moment des Betoneinbaus. Der Artikel zeigt das Sensorprinzip, Untersuchungen zur In-situ-Referenzierung und zur Rückwirkung des Sensors sowie dessen Einsatzmöglichkeiten in der Baustoff- und Materialforschung.
Raloxifene and body composition and muscle strength in postmenopausal women: a randomized, double-blind, placebo-controlled trial
Authors: Jacobsen Didy E , Samson Monique M , Emmelot-Vonk Marielle H , Verhaar Harald J J
Published: November 2009

Objective

To compare the effects of raloxifene and placebo on body composition and muscle strength.

Design

Randomized, double-blind, placebo-controlled trial involving 198 healthy women aged 70 years or older conducted between July 2003 and January 2008 at the University Medical Centre, Utrecht, The Netherlands.

Methods

Participants were randomly assigned to receive raloxifene 60 mg or placebo daily for 12 months. Measurements were taken at baseline, 3, 6, and 12 months, and change from baseline was calculated. Main outcome measures were body composition (bioelectrical impedance analysis), muscle strength, and muscle power (maximum voluntary isometric knee extension strength, explosive leg extensor power, and handgrip strength).

Results

At 12 months, the body composition of women taking raloxifene was significantly different from that of women taking placebo: fat-free mass (FFM) had increased by a mean of 0.83 (2.4) kg in the raloxifene group versus 0.03 (1.5) kg in the placebo group (P=0.05), and total body water had increased by a mean of 0.6 (1.8) litres in the raloxifene group versus a decrease of 0.06 (1.1) litres in the placebo group (P=0.02). Muscle strength and power were not significantly different.

Conclusion

Raloxifene significantly changed body composition (increased FFM; increased water content) compared with placebo in postmenopausal women.
Knockdown of FOXO3 induces primordial oocyte activation in pigs
Authors: Moniruzzaman Mohammad , Lee Jibak , Zengyo Mai , Miyano Takashi
Published: November 2009

Mammalian ovaries are endowed with a large number of primordial follicles, each containing a nongrowing oocyte. Only a small population of primordial oocytes (oocytes in primordial follicles) is activated to enter the growth phase throughout a female's reproductive life. Little is known about the mechanism regulating the activation of primordial oocytes. Here, we found that the primordial oocytes from infant pigs (10- to 20-day-old) grew to full size at 2 months after xenografting to immunodeficient mice, whereas those from prepubertal pigs (6-month-old) survived without initiation of their growth even after 4 months; thereafter, they started to grow and reached full size after 6 months. These results suggest that the mechanism regulating the activation of primordial oocytes in prepubertal pigs is different from that in infant pigs. In this regard, the involvement of FOXO3, a forkhead transcription factor, was studied. In prepubertal pigs, FOXO3 was detected in almost all (94±2%) primordial oocyte nuclei, and in infant pigs, 42±7% primordial oocytes were FOXO3 positive. At 4 months after xenografting, the percentage of FOXO3-positive primordial oocytes from prepubertal pigs had decreased to the infant level. Further, siRNA was designed to knock down porcine FOXO3. FOXO3-knockdown primordial follicles from prepubertal pigs developed to the antral stage accompanied by oocyte growth at 2 months after xenografting. These results suggest that primordial oocytes are dormant in prepubertal pigs by a FOXO3-related mechanism to establish a nongrowing oocyte pool in the ovary, and that a transient knockdown of the FOXO3 activates the primordial oocytes to enter the growth phase.
High-Throughput Genetic Mapping of Mutants via Quantitative Single Nucleotide Polymorphism Typing
Authors: Liu Sanzhen , Chen Hsin D , Makarevitch Irina , Shirmer Rebecca , Emrich Scott J , Dietrich Charles R , Barbazuk W Brad , Springer Nathan M , Schnable Patrick S
Published: November 2009

Advances in next-generation sequencing technology have facilitated the discovery of single nucleotide polymorphisms (SNPs). Sequenom-based SNP-typing assays were developed for 1359 maize SNPs identified via comparative next-generation transcriptomic sequencing. Approximately 75% of these SNPs were successfully converted into genetic markers that can be scored reliably and used to generate a SNP-based genetic map by genotyping recombinant inbred lines from the intermated B73 × Mo17 population. The quantitative nature of Sequenom-based SNP assays led to the development of a time- and cost-efficient strategy to genetically map mutants via quantitative bulked segregant analysis. This strategy was used to rapidly map the loci associated with several dozen recessive mutants. Because a mutant can be mapped using as few as eight multiplexed sets of SNP assays on a bulk of as few as 20 mutant F2 individuals, this strategy is expected to be widely adopted for mapping in many species.
Genetic Evidence for an Essential Oscillation of Transmembrane-Spanning Segment 5 in the Escherichia coli Ammonium Channel AmtB
Authors: Inwood William B , Hall Jason A , Kim Kwang-Seo , Fong Rebecca , Kustu Sydney
Published: November 2009

Ammonium channels, called Amt or Mep, concentrate $\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{{+}}\) \end{document}$ against a gradient. Each monomer of the trimer has a pore through which substrate passes and a C-terminal cytoplasmic extension. The importance of the C-terminal extension to AmtB activity remains unclear. We have described lesions in conserved C-terminal residues that inactivate AmtB and here characterize 38 intragenic suppressors upstream of the C terminus (∼1/3 of total suppressors). Three that occurred repeatedly, including the previously characterized W148L at the pore entry, restored growth at low NH3 to nearly wild-type levels and hence restored high activity. V116L completely restored function to two of the mutant proteins and, when separated from other lesions, did not damage wild-type AmtB. A179E notably altered folding of AmtB, compensated for all inactivating C-terminal lesions, and damaged wild-type AmtB. V116L and A179E lie at the cytoplasmic end of transmembrane-spanning segments (TM) 3 and 5, respectively, and the proximal part of the C-terminal tail makes intimate contacts with the loops following them before crossing to the adjacent monomer. Collectively, the properties of intragenic suppressor strains lead us to postulate that the C-terminal tail facilitates an oscillation of TM 5 that is required for coordinated pore function and high AmtB activity. Movement of TM 5 appears to control the opening of both the periplasmic entry and the cytoplasmic exit to the pore.
The Retinal Determination Gene eyes absent Is Regulated by the EGF Receptor Pathway Throughout Development in Drosophila
Authors: Salzer Claire L , Elias Yair , Kumar Justin P
Published: November 2009

Members of the Eyes absent (Eya) protein family play important roles in tissue specification and patterning by serving as both transcriptional activators and protein tyrosine phosphatases. These activities are often carried out in the context of complexes containing members of the Six and/or Dach families of DNA binding proteins. eyes absent, the founding member of the Eya family is expressed dynamically within several embryonic, larval, and adult tissues of the fruit fly, Drosophila melanogaster. Loss-of-function mutations are known to result in disruptions of the embryonic head and central nervous system as well as the adult brain and visual system, including the compound eyes. In an effort to understand how eya is regulated during development, we have carried out a genetic screen designed to identify genes that lie upstream of eya and govern its expression. We have identified a large number of putative regulators, including members of several signaling pathways. Of particular interest is the identification of both yan/anterior open and pointed, two members of the EGF Receptor (EGFR) signaling cascade. The EGFR pathway is known to regulate the activity of Eya through phosphorylation via MAPK. Our findings suggest that this pathway is also used to influence eya transcriptional levels. Together these mechanisms provide a route for greater precision in regulating a factor that is critical for the formation of a wide range of diverse tissues.
Retinopathy of Prematurity
Authors: Heidary Gena , Löfqvist Chatarina , Mantagos Iason S. , Vanderveen Deborah K. , Hellström Ann , Smith Lois E.
Published: November 2009

Retinopathy of prematurity (ROP) is a clinically multifactorial process characterized by the aberrant vascularization of the retina that has potentially devastating effects on vision in preterm infants. Despite an appreciation for the postnatal risk factors that contribute to the development of ROP, this condition continues to be a major cause of childhood blindness. Studies using the mouse model of oxygen-induced retinopathy (OIR) have identified new therapeutic targets that may be used to guide treatment and determine which babies are at highest risk for ROP development. Such factors include the hypoxia-driven proteins vascular endothelial growth factor (VEGF) and erythropoietin (EPO) as well as the maternally derived factors insulin-like growth factor-1 (IGF-1) and omega-3 polyunsaturated fatty acids (PUFAs). Each has been demonstrated to have phase-specific effects on the pathogenesis of ROP. Through an understanding of the contribution of the IGF-1 pathway to the development of ROP in particular, a new algorithm has been developed (WINROP™) that uses postnatal weight gain to identify infants at highest risk for ROP in an attempt to target therapy and resources more effectively.
Pediatric Hospital Adherence to the Standard of Care for Acute Gastroenteritis
Authors: Tieder Joel S. , Robertson Andrea , Garrison Michelle M.
Published: November 2009

BACKGROUND: Adherence to published care guidelines for the management of acute gastroenteritis (AGE) is unknown.

OBJECTIVES: To evaluate the association of AGE guideline adherence with outcomes and resource use at pediatric hospitals.

DESIGN/METHODS: We studied children aged 6 months to 6 years with an International Classification of Diseases, Ninth Edition (ICD-9) discharge code indicative of AGE and without comorbid conditions in the emergency department, observation setting, or hospital. Laboratory studies, antiemetic use, and antibiotic use were evaluated, and the length of stay, mean adjusted total charges, and readmission proportion were documented. Multiple analysis of variance determined if the variance of adjusted charges, length of stay, and diagnostic studies were hospital-related. A regression analysis determined the association between guideline adherence and outcomes.

RESULTS: There were a total of 188873 patients; 174594 (92.4%) were not admitted, and 14279 (7.6%) were admitted. There was substantial variation in resource use among hospitals. The mean adjusted total charge for all patients was $863 (SD: 1336). The mean adjusted total charge for nonadmitted patients was $591 (SD: 636). Individual hospitals contributed to the variance of mean length of stay, total adjusted charges, and use of diagnostic studies after controlling for covariates (P < .001). Guideline adherence was associated with a mean decrease in the average adjusted cost ($591) for nonadmitted patients of $296 (95% confidence interval: −399 to −193).

CONCLUSIONS: Guideline-adherent hospitals demonstrated 50% lower charges for emergency department or observation patients with uncomplicated AGE without adversely affecting outcomes. Use of resources not routinely recommended by published AGE guidelines remains common in pediatric hospitals.
Fabrication of Photonic Crystal based Back Reflectors for Light Management and Enhanced Absorption in Amorphous Silicon Solar Cells
Authors: Curtin Benjamin , Biswas Rana , Dalal Vikram
Published: November 2009

Photonic crystal based back-reflectors are an attractive solution for light management and enhancing optical absorption in thin film solar cells, without undesirable losses. We have fabricated prototype photonic crystal back-reflectors using photolithographic methods and reactive-ion etching. The photonic crystal back-reflector has a triangular lattice symmetry, a thickness of 250 nm, and a pitch of 765 nm. Scanning electron microscopy images demonstrate high quality long range periodicity. An a-Si:H solar cell device was grown on this back-reflector using standard PECVD techniques. Measurements demonstrate strong diffraction of light and high diffuse reflectance by the photonic crystal back-reflector. The photonic crystal back-reflector increases the average photon collection by ˜9% in terms of normalized external quantum efficiency, relative to a reference device on a stainless steel substrate with an Ag coated back surface.
Viscoelastic Modeling and Reliability Assessment of Microelectronics Packages
Authors: Karmarkar Aditya , Zhai Charlie , Xu Xiaopeng , Lin Xiao , Rollins Greg , Moroz Victor
Published: November 2009

Viscoelastic stress relaxation occurs at operating temperature in underfill materials of flip-chip packages with high power devices. Multi-level finite element analysis is performed to study the impact of the viscoelastic relaxation on package reliability. The stress simulations reveal that the relaxation in underfill material leads to higher stress concentration in solder bumps. The failure analysis shows that the induced high stress develops higher crack driving forces. The results demonstrate that the underfill material property such as viscosity can shift failure mode from die corner delamination to near bump delamination. Therefore, the numerical study can be used as a guideline to select underfill material for package reliability improvements.
High Performance Pyrolytic Graphite Heat Spreaders – Near Isotropic Structures and Metallization
Authors: Lemak Richard , Moskaitis Robert , Pickrell David , Kupp Don , Yocum Adam
Published: November 2009

Manufacturers of modern high performance military and commercial electronics are steadily increasing the power density of the components of their devices. The increase of small component size and/or higher power densities results in large component heat flux levels. In applications from laser diodes, radar transmit/receive (T/R) modules and LED lighting, solutions to thermal issues through advancements in heat spreaders and heat sink design are needed to continue the performance improvement of these devices and structures.

Advanced materials for heat spreaders should have high thermal conductivity, a coefficient of thermal expansion (CTE) that matches the electronics die, and a reasonable cost. Diamond, for example, has the highest thermal conductivity of any known solid material at room temperature, combined with a high modulus of elasticity, but has a CTE mismatch with silicon (die material) and a high relative cost.

As an alternative material, PYROID® HT pyrolytic graphite has a thermal conductivity of 1700 W/m °K in the x-y plane of the material (7 W/m °K in the z plane), costs more than 250 times less than diamond produced by chemical vapor deposition (CVD), and has a modulus of elasticity much lower than diamond. The lower modulus of elasticity of this material results in an order of magnitude lower thermal stress level between the spreader and the die than diamond.

In one case study involving a laser diode cooling application, the spreader/die is nearly two-dimensional. Thus, pyrolytic graphite can be oriented with high conductivity in the direction into the spreader and away from the die (x-y plane), and the low conductivity direction (z direction) along the die where minimal conduction is needed. For the cases where a three-dimensional spreader is required, laminated composite structures of pyrolytic graphite have been developed where the equivalent isotropic conductivity is over two times greater than the conductivity of copper. The graphite layers are metallized so that they can be bonded together by soldering and/or dies can also be attached by soldering. The adhesion of the metal layers to the graphite has been tested with several standard techniques. Graphite metallization techniques, thermal performance modeling and analysis of stress levels due to CTE mismatching will be discussed in this paper.
ZnO Microcrystals for Light Emitting Diode and Photovoltaic Applications with Integration on Flexible Substrates
Authors: Cole Jesse J , Jacobs Heiko
Published: November 2009

We report a new integration approach to produce arrays of ZnO microcrystals for optoelectronic and photovoltaic applications. Demonstrated applications are n-ZnO/p-GaN heterojunction LEDs and photovoltaic cells. The integration process uses an oxygen plasma treatment in combination with a photoresist pattern on Magnesium doped GaN substrates to define a narrow sub-100nm width nucleation region. ZnO is synthesized in the defined areas by a hydrothermal technique using zinc acetate and hexamethylenetetramine precursors. Nucleation is followed by lateral epitaxial overgrowth producing single crystal disks of ZnO. The process provides control over the dimension and location of the ZnO crystals. The quality of the patterned ZnO is high; the commonly observed defect related emission in the electroluminescence spectra is suppressed and a single near-band-edge UV peak is observed. Transfer printing of the ZnO microcrystals onto a flexible substrate is also demonstrated in the context of transparent flexible electronics.
Modulation of paraoxonase 1 and protein N-homocysteinylation by leptin and the synthetic liver X receptor agonist T0901317 in the rat
Authors: Bełtowski Jerzy , Wójcicka Grażyna , Jakubowski Hieronim
Published: November 2009

The adipose tissue hormone leptin and homocysteine (Hcy)-thiolactone are linked to the pathogenesis of atherosclerosis through their interactions with the anti-atherogenic enzyme paraoxonase 1 that has the ability to hydrolyze Hcy-thiolactone and minimizes protein N-homocysteinylation. Here we examined the relationships between hyperleptinemia, Hcy-thiolactonase, and protein N-homocysteinylation in rats. Hyperleptinemia was induced in adult rats by administration of leptin for 7 days (0.25 mg/kg twice daily s.c). We found that serum Hcy-thiolactonase was lower in hyperleptinemic than in control animals (−41.0%, P<0.001). Leptin administration increased the level of N-linked Hcy in plasma proteins (+92.9%, P<0.01), but had no effect on plasma total Hcy. These effects were not reproduced by pair-feeding. We also found that the synthetic liver X receptor (LXR) agonist, T0901317 (1 mg/kg per day) normalized Hcy-thiolactonase and protein N-homocysteinylation levels in leptin-treated rats. However, leptin-induced increase in plasma isoprostane levels (a marker of oxidative stress) was not normalized by T0901317. The NADPH oxidase inhibitor apocynin prevented leptin-induced increase in isoprostane levels but did not normalize Hcy-thiolactonase and protein N-homocysteinylation levels. These results suggest that the decreased capacity to metabolize Hcy-thiolactone and concomitant increase in protein N-homocysteinylation contribute to pro-atherogenic effect of chronic hyperleptinemia, independently of oxidative stress. LXR agonists normalize Hcy-thiolactonase levels and decrease protein N-homocysteinylation, especially under conditions associated with excess leptin such as metabolic syndrome.
Effective Zonal Isolation for CO2 Sequestration Wells
Authors: Sweatman R. E. , Santra A. , Kulakofsky D. S. , Calvert D. G. J.
Published: November 2009

CO2 geologic-sequestration (GS) via injection wells into suitable subsurface strata is a safe, cost-effective way to mitigate climate change. However, using well cements to zonally isolate CO2 for up to 1,000 years, as required for permanent reservoir storage, may be challenging. Some researchers claim that cement fails when exposed to CO2, leading to potential leakage to the atmosphere or into underground structures that may contain drinking water. Other investigators show cement samples from 30 to 50 year-old wells that have maintained sealing integrity and prevented CO2 leakage, even though some degree of carbonation was found. This paper presents likely reasons for this disparity between research lab test results and actual well performance data, along with best practices to provide efficient cement-based zonal isolation of CO2 storage zones. Also discussed are recent laboratory results from testing cement samples surrounded by formation material treated at two different downhole conditions. In one case, the cement specimens were treated with a 40% humid CO2 at 140°F and 2,000 psi whereas in the second case they were treated with saturated CO2 in water at 200°F and 2,000 psi for various time intervals. Results show that samples of carefully designed cement systems had a mild carbonation without any sign of loss of mechanical or sealing integrity which could lead to zonal isolation failure. A newly-applied laboratory testing method used for decades for other purposes is proposed to determine CO2 sealing performance by cement in a relatively short time period compared to previous methods. In summary, this paper discusses a comprehensive approach that may be taken to help ensure long-term, effective CO2 zonal isolation in new wells, in existing wells (via remedial solutions), and in wells to be plugged and abandoned.
Simulating CO2 EOR Process: Numerical Investigation Based on the Experimental Results
Authors: Berenblyum R. , Calderon G. , Surguchev L.
Published: November 2009

Many experimental and analytical investigations of the CO2 performance at reservoir conditions have been performed world-wide in the recent years. However integrating many of those findings into reservoir simulation models still remains an open issue.

In this manuscript we address only the reservoir aspects of the CO2 injection to Enhance Oil Recovery (EOR) leaving behind transport, metal corrosion and economic issues related to CO2 injection. CO2 is an efficient agent to increase oil recovery, especially, if conditions of oil displacement are miscible. However, CO2"gas like" low viscosity at reservoir conditions may cause severe viscous fingering and displacement front instability resulting in low sweep efficiency. CO2 may boost precipitation of waxes and asphaltenes, thus reducing productivity or completely plugging the wells. CO2, being a chemically active component at reservoir conditions, may provoke chemical reactions and mineralogical changes in situ resulting in increased permeability, loose of sealing properties of the cap rock.

Based on the laboratory investigations we aim at building a consistent model to evaluate CO2 injection performance at reservoir conditions. The laboratory studies were conducted in such a way that a single or several natural phenomena were isolated and individually studied. The experimental results allowed us to gain a better knowledge of the process mechanisms. Doing history matching simulations of the experiments we evaluate critical parameters, validate and calibrate numerical models. The complexity of the simulation model is gradually built up from simple experiments to full scale simulation. The mechanisms addressed investigated are:

Viscous fingering; Multiphase compositional effects; Flow in naturally fractured porous media (diffusive fluxes and gravity segregation); CO2 dissolution in aqueous phase; Chemical interaction between rock and CO2; CO2 mobility control agents.

Special attention in this paper is paid to the viscous effects during CO2 injection at above critical reservoir conditions. The laboratory experiments were performed with different oils. Pure CO2 and CO2 -rich oleic phases were injected to investigate gravitational and viscous effects in the porous medium. It was shown that using relative permeabilities dependant on rate and interfacial tension can improve the accuracy of CO2 injection simulation. Water Alternating Gas (WAG) injection was shown to be an effective way for remediation of viscous fingering.

Conclusions on various CO2 injection phenomena and ability of reservoir modelling tools to handle those phenomena are drawn.
Geologic Heterogeneity in Basin-Scale Geologic Carbon Storage: Examples from the Powder River Basin, NE Wyoming and SE Montana
Authors: Melick Jesse J. , Gardner M. H. , Uland M. J.
Published: November 2009

Geologic carbon storage (GCS) requires consideration of storage capacity, injectivity and migration of gigatons of supercritical fluids in sedimentary basins. However, the size of basin-scale GCS models requires simplification that limits retention of geologic heterogeneity. Homogeneous GCS models (uniform and average properties in large cells) facilitate initial basin storage evaluation useful in screening, but cannot account for the actual reservoir architecture affecting both reaction and flow rates in heterogeneous media. The generation and integration of geological and petrophysical models (multi-field, regional aquifers) presented here highlight the uncertainty and risk created by using simplified GCS models to direct research and make policy decisions. This paper emphasizes a workflow that utilizes the natural hierarchy within sedimentary architecture to geologically upscale a family of static geomodels that retain multiple scales and types of heterogeneity. More importantly, geologic controls on heterogeneity can be explicitly manipulated to manage heterogeneity distributions known to change through the life of petroleum reservoirs. There is no reason GCS will not follow a similar path.
Cost-Effective Remediation Strategies for Storing CO2 in Geologic Formations
Authors: Kuuskraa V. A.
Published: November 2009

Because storage of CO2 for climate change mitigation is still an emerging industry, very little has been written on the topic of cost-effective remediation strategies for geological storage of CO2. The purpose of this presentation and paper is to begin to fill this gap in publically available technical information.

Much of the background that serves as the technical and experiential source for remediation of CO2 storage wells and sites has been drawn from our experience with the gas storage and the CO2 enhanced oil recovery industries. This paper compiles these past experiences and adds an overlay of the unique facets of geological storage for establishing a remediation strategy and a workable plan for CO2 storage, particularly in saline formations.

In addition, the paper highlights the importance of thorough site selection, rigorous well design and completion practices and the need for a monitoring system that provides an "early warning" of impending problems. The paper also reviews advanced well remediation strategies used by the gas storage industry to restore well productivity of potential value to establishing cost-effective CO2 storage in lower permeability formations.
Construction of a Mechanical Earth Model and Wellbore Stability Analysis for a CO2 Injection Well
Authors: Lee D. , Singh V. , Berard T.
Published: November 2009

A mechanical earth model (MEM) and wellbore stability analysis were completed for a CO2 injection well in the Eau Claire shale where in offset wells, severe borehole enlargements were experienced. This shale serves as a caprock for the Mt. Simon injection zone in the planned CO2 injection well and therefore, borehole enlargement had to be minimized to provide zonal isolation and containment for injection. After drilling the CO2 injection well, a comparison was made between the predrill prediction and actual results. Borehole enlargement was experienced at depths predicted by the predrill model, but borehole enlargement severity was minimized with improved drilling practices. To determine the formation stability, an MEM was built using offset well data and was calibrated with both borehole and regional data. Multiple stress models were examined, and calibration for unconfined compressive strength (UCS) values was provided from core tests in other wells. After calibration, the data was correlated to the planned well trajectory using formation tops, and the stresses were recalculated. The largest areas of uncertainty in the predrill prediction existed in the Eau Claire shale UCS and the maximum horizontal stress magnitude. Available shale core testing for UCS was likely biased toward stronger intact samples. The principle stress ordering and magnitudes from offset well testing showed a shallow thrust fault environment with deeper strike-slip environment.

Increasing mud weight to reasonable levels would not prevent shear failure in the Eau Claire shale as predicted by the models. Therefore, it was important to monitor the wellbore while drilling through the shale and mitigate borehole enlargement. For monitoring borehole enlargement, material across the shakers from the drilling process was examined for cavings. Digital pictures of the rock cuttings/cavings samples were taken before reaching the Eau Claire shale and through the interval. Mechanical vibration and backreaming were kept to a minimum across the Eau Claire shale while this section was open to minimize borehole enlargement.
Computational Studies of Two-Phase Cement-CO2-Brine Interaction in Wellbore Environments
Authors: Carey J. W. , Lichtner P. C.
Published: November 2009

Wellbore integrity is essential to ensuring long-term isolation of buoyant supercritical CO2 during geologic sequestration of CO2. In this report, we summarize recent progress in numerical simulations of cement-brine-CO2 interactions with respect to migration of CO2 outside of casing. Using typical values for the hydrologic properties of cement, caprock (shale) and reservoir materials, we show that the capillary properties of good quality cement will prevent flow of CO2 into and through cement. Rather, CO2, if present, is likely to be confined to the casing-cement or cement-formation interfaces. CO2 does react with the cement by diffusion from the interface into the cement, in which case it produces distinct carbonation fronts within the cement. This is consistent with observations of cement performance at the CO2-enhanced oil recovery SACROC Unit in West Texas (Carey et al. 2007). For poor quality cement, flow through cement may occur and would produce a pattern of uniform carbonation without reaction fronts. We also consider an alternative explanation for cement carbonation reactions as due to CO2 derived from caprock. We show that carbonation reactions in cement are limited to surficial reactions when CO2 pressure is low (< 10 bars) as might be expected in many caprock environments. For the case of caprock overlying natural CO2 reservoirs for millions of years, we consider Scherer and Huet's (2009) hypothesis of diffusive steady-state between CO2 in the reservoir and in the caprock. We find that in this case, the aqueous CO2 concentration would differ little from the reservoir and would be expected to produce carbonation reaction fronts in cements that are relatively uniform as a function of depth.