bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Omar Field (N. E. Syria) is Overcoming Its Mid-Life Crisis
Authors: Neidhardt J. , Farran H. , Gonzalez I. , Vledder P. , Doughry Y. 
Published: March 2008

Abstract
With an approximate STOIIP of 760 MMbbls, the Omar field is the largest field in Al Furat Petroleum Company's portfolio. The field – located in the Euphrates Graben 45km SE of DeirEzZor - was discovered in 1987 and holds a maximum undersaturated oil column of more than 500m with two original oil-water contacts of 3750 and 3778 meters subsea. The oil production almost exclusively originates from two sandstone formations: the Cretaceous sheet-like shallow marine Lower Rutbah (RUL) and the Triassic coastal fluvial plane Mulussa F (MUF) formation. The Omar Field is formed by an elongated, high relief tilted horst block, which is internally compartmentalised.
Originally, the field produced naturally at a peak net oil rate of some 80kbpd but production declined rapidly because of the lack of any pressure support. Following the implementation of water injection from 1991 onwards a plateau production of around 60-70kbopd was achieved for some five years (1994-1997) declining to the current net oil production of 20 kbopd.
Despite the structural complications, the injector-producer connectivity in the laterally extensive RUL sands could be established rather confidently and recoveries in excess of 55% should eventually be achievable. Predicting water-flood efficiency in the Mulussa F 3D sand channel labyrinth turned out more complicated. As a matter of fact, it was demonstrated that the resolution achievable by static reservoir modelling was not sufficient to predict the water-flood efficiency meaningfully. As a consequence a statistical infill campaign was launched with a focus to infill the existing major gaps between the MUF wells and secondly to establish a line drive waterflood pattern while investigating the merits of a dense five spot.
The results of this infill drilling campaign (executed in 2005-2006) and a new 600-fold high-resolution seismic survey gave a multi-disciplinary team the challenge to improve in identifying more attractive targets while reducing the downside drilling results observed during the infill campaign. A combination of the new structural data with a regional geological well correlation fully and iteratively integrated with dynamic well information and production data, indicates that the recovery in the MUF formation could well be optimized through a more deterministic instead of the previously adopted statistical infill drilling approach.
From Lean to Extreme-Lean Well Profile: Field Experience in the Mediterranean Sea
Authors: Donati F. , Ferrara P. , Maestrami Michele , Oppelt J. , Krüeger S. 
Published: March 2008

Abstract
The main subject of this paper will be to outline the field experience achieved with a new type of well profile and directional drilling system. Reducing the cost of well construction has been a driver for many new technologies. The lean casing profile introduced by Eni about a decade ago was a successful step towards lowering the drilling and completion cost in the vertical, top hole section. Automated vertical drilling tools have been the technical enabler of such concept. Recently Eni has moved further towards an even more radical "Extreme Lean Well Profile". This paper gives a brief insight into the well design concept and the enabling technology behind it. The drilling technology is based on the well-known automated vertical drilling system, which has been enhanced by the capability to drill an enlarged hole size below a casing, without compromising the verticality and hole quality. In the main part of the paper two field applications, in the Mediterannean Sea offshore Egypt, are described. The paper will also cover the lessons learned especially from the second of the first two field applications. The extreme lean well profile and automated vertical reaming technology can provide value to several drilling campaigns not only through the reduction of well construction cost. Another major benefit is the ability to run an intermediate casing string, if required because of difficult well conditions, and still arrive at the same diameter of casing in the reservoir. The completion concept as well the enabling tool technology is very unique and has not been available to the industry until recently.
Well-Testing Planning in Deepwater Wells in High-Pressure, High-Temperature Environments – The Brazil Experience
Authors: Salguero Alejandro , Almanza Edgar , Nivens Harold 
Published: March 2008

Abstract
High-pressure/high-temperature (HP/HT) deepwater areas continue to challenge performance of well testing, especially when considering wells defined as "deepwater." This definition is applied to wells that are at least 15,000 feet deep. Also, these wells are considered HP/HT when they have bottomhole pressures of approximately 10,000 psi and bottomhole temperatures in excess of 300°F. Several wells under these extreme environmental conditions have recently been tested in Brazil, and these attempts have confirmed the importance of the proper preliminary analysis of test parameters according to the specifications of the prospect, the requirements at surface, and the possible impact of testing at bottomhole conditions. Typical variables such as high hydrostatic pressures and high temperatures are usually considered, but it is also important to assess the types of operations involved in performing the tests that could increase the value of the different physical variables in such a way that the tool string could be damaged. Often, combined variables can surpass the design characteristics of the test tools, and if this occurs, the test data or even the well could be lost. Thus, it is critical that design specifications of the necessary equipment and operational limitations be considered with a detailed analysis of operations and alternatives in a HAZID/HAZOP.
This paper will focus on the steps that must be followed to enable successful well-testing evaluations in HP/HT environmental conditions. With the planning suggested, it is possible to minimize the risks that can negatively impact testing operations. The planning, design criteria and tools required to perform successful well-testing evaluation in severe well conditions will be discussed in detail. The steps discussed here for designing deepwater well-tests can provide a safety envelope for equipment and help ensure that the operations will be successfully performed.
β-Cell Replication Is the Primary Mechanism Subserving the Postnatal Expansion of β-Cell Mass in Humans
Authors: Meier Juris J. , Butler Alexandra E. , Saisho Yoshifumi , Monchamp Travis , Galasso Ryan , Bhushan Anil , Rizza Robert A. , Butler Peter C. 
Published: March 2008

OBJECTIVE— Little is known about the capacity, mechanisms, or timing of growth in β-cell mass in humans. We sought to establish if the predominant expansion of β-cell mass in humans occurs in early childhood and if, as in rodents, this coincides with relatively abundant β-cell replication. We also sought to establish if there is a secondary growth in β-cell mass coincident with the accelerated somatic growth in adolescence.
RESEARCH DESIGN AND METHODS— To address these questions, pancreas volume was determined from abdominal computer tomographies in 135 children aged 4 weeks to 20 years, and morphometric analyses were performed in human pancreatic tissue obtained at autopsy from 46 children aged 2 weeks to 21 years.
RESULTS— We report that 1) β-cell mass expands by severalfold from birth to adulthood, 2) islets grow in size rather than in number during this transition, 3) the relative rate of β-cell growth is highest in infancy and gradually declines thereafter to adulthood with no secondary accelerated growth phase during adolescence, 4) β-cell mass (and presumably growth) is highly variable between individuals, and 5) a high rate of β-cell replication is coincident with the major postnatal expansion of β-cell mass.
CONCLUSIONS— These data imply that regulation of β-cell replication during infancy plays a major role in β-cell mass in adult humans.
The usability of (sodium alginate/acrylamide) semi‐interpenetrating polymer networks on removal of some textile dyes
Authors: Şolpan Dilek , Torun Murat , Güven Olgun 
Published: March 2008

AbstractIn this study, (sodium alginate/acrylamide) interpenetrating polymer networks ((NaAlg/AAm)IPN) have been prepared at definite composition. The aqueous solution of 3% (w/v) sodium alginate and 50% (w/v) acrylamide was irradiated with 60Co‐γ rays at a dose rate of 0.07 kGy/h up to 5 kGy. The percent conversion was determined gravimetrically and 100% gelation was achieved at 5 kGy dose. To understand whether the semi‐interpenetrating polymer network of sodium alginate is performed, Fourier Transform Infrared (FTIR) spectra of polyacrylamide (PAAm), sodium alginate, and the semi‐interpenetrating polymer network were recorded. It is found that the FTIR spectra of PAAm, NaAlg, and the semi‐interpenetrating polymer network are different. The thermograms of PAAm, sodium alginate, and the semi‐interpenetrating polymer network were recorded for investigating their thermal character. (NaAlg/AAm)IPN hydrogels were immersed to swell in a solution of pH 7, at a temperature of 25°C. The swelling results at pH 7.0 indicated that (NaAlg/AAm)IPN hydrogel, containing 3% NaAlg showed maximum % swelling in water but swelling increased in the order of water > Magenta > Methylene Blue > Safranine‐O > Methyl Violet. Diffusion of water and aqueous solution of dyes within (NaAlg/AAm)IPN hydrogels was found to be of Fickian character at the initial stage of swelling with regard to values calculated for diffusion coefficient of (NaAlg/AAm)IPN hydrogels in water and aqueous solution of dyes. Some diffusion parameters were calculated from swelling of (NaAlg/AAm)IPN in water and dyes and their adsorption isotherms were plotted. In the adsorption experiments, the efficiency of (NaAlg/AAm)IPN hydrogels to adsorb Magenta, Safranine‐O, Methylene Blue, and Methyl Violet dyes from water was studied. (NaAlg/AAm)IPN hydrogels showed different adsorption for different aqueous solution of dyes at pH 7.0. Adsorption isotherms were constructed for (NaAlg/AAm)IPN‐dye systems. S type adsorption in the Giles classification system was found. Thermal and spectroscopic characterization of semi‐interpenetrating polymer network of sodium alginate and acrylamide and dye adsorbed semi‐interpenetrating polymer network of sodium alginate and acrylamide was recorded. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Solid state structure and mechanical properties of melt mixed poly(trimethylene terephthalate)/polycarbonate blends
Authors: González I. , Eguiazábal J. I. , Nazábal J. 
Published: March 2008

AbstractPoly(trimethylene terephthalate) (PTT)/poly (carbonate of bisphenol A) (PC) blends were obtained in the melt state by direct injection molding and also by extrusion followed by injection molding. The blends rich in PTT were monophasic, while the blends rich in PC were biphasic with the two components of the blends present in both phases. Both the monophasic and biphasic blends were partially miscibilized, and also partially reacted, as observed by FTIR. The extent of the reaction was greater in previously mixed blends. The observed synergism in the modulus of elasticity was attributed to the increased orientation of the blend components upon blending. Although decreases in elongation at break were observed and attributed to degradation of PTT, the blends were clearly ductile and compatible. This was a consequence of either their monophasic structure, or of the presence of the two components in the two phases of the blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Emulsion‐induced ordered microporous films using amphiphilic poly(ethylene oxide)‐block‐poly(n‐butyl isocyanate) block copolymers
Authors: Ishizu Koji , Makino Masataka , Hatoyama Naomasa , Uchida Satoshi 
Published: March 2008

AbstractWell‐defined poly(ethylene oxide)‐block‐poly(n‐butyl isocyanate) (PEO‐block‐PBIC; AB) diblock copolymers were prepared with trichloropentadienyl titanium (IV) (CpTiCl3) catalyst. Ordered microporous films (hexagonal pattern) were constructed by emulsion micelles of A110B230 diblock copolymer (the subscript indicates the degree of polymerization of each block component) formed from CHCl3/H2O/tetrahydrofuran (THF) = 100/5/10 (v/v) solution. The addition of THF promoted uniform micelles in immiscible CHCl3/H2O mixed solvent as well as the effect of phase transfer catalyst. Diblock copolymers formed spherical micelles, consisting of a PEO core and a PBIC corona. At some concentration, interaction between micelles forced a disorder–order transition, resulting in freezing of micelles in some superlattice. Subsequently, the leaving gaps among micelles were filled by PBIC block chains on a corona through the evaporation of organic solvents. At last, water within hydrophilic PEO core was vomited through the film matrix. We also constructed the microporous films using A110B230 diblock copolymer by the current water‐assisted method. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Real‐time measurement of cytosolic free calcium concentration in HL‐60 cells during static magnetic field exposure and activation by ATP
Authors: Belton Michelle , Commerford Kristy , Hall Justin , Prato Frank S. , Carson Jeffrey J.L. 
Published: March 2008

AbstractCalcium ions are involved in a number of important signal transduction pathways in cells. Cytosolic calcium concentration ([Ca2+]c) can be affected by the activation of Ca2+ channels through the action of ligands such as ATP. The response of [Ca2+]c to ligands may be affected by external factors like magnetic fields. The purpose of this study was to determine if exposure to a static magnetic field (SMF) for 800 s altered the [Ca2+]c response to ATP in undifferentiated HL‐60 cells. We sham exposed or field exposed fura‐2 loaded HL‐60 cells to a SMF of 1, 10, and 100 mT. Cells were activated with ATP 300 s into the exposure. The level of [Ca2+]c was followed before, during, and after field or sham exposure with a ratiometric fluorescence spectroscopy system. It was found that high concentrations of ATP resulted in greater [Ca2+]c responses, but faster recovery to near basal levels. The application of 1, 10, or 100 mT SMF did not affect the [Ca2+]c response to ATP. Future work could examine the effect of a longer SMF exposure on the [Ca2+]c response to ATP. Longer exposures might provide sufficient time for morphological changes in the plasma membrane to occur. Bioelectromagnetics 29:439–446, 2008. © 2008 Wiley‐Liss, Inc.
Quaternary protein mimetics of gp41 elicit neutralizing antibodies against HIV fusion‐active intermediate state
Authors: Sadler Kristen , Zhang Ying , Xu Jiaxi , Yu Qitao , Tam James P. 
Published: March 2008

AbstractDuring viral entry, the fusogenic state of human immunodeficiency virus Type 1 (HIV‐1) envelope protein gp41 is a quaternary structure consisting of three gp41 glycoproteins, each with two conserved helical domains (N‐HR and C‐HR). Thus far, the examination of monomeric gp41 peptides as an immunologically focused approach to vaccine design has not been successful. Here we report an approach using quaternary protein mimetics (called 3α mimetics) that are based on the gp41 N‐HR and C‐HR domains to closely mimic the fusogenic state and overcome the deficiencies of the monomeric peptide approach for synthetic vaccine design. The 3α mimetics are conveniently prepared by chemoselective ligation of unprotected monomeric peptides to an interstrand linker, and display enhanced conformational stability compared to the corresponding monomers. The 3α mimetics with or without a covalently attached T‐helper epitope were immunogenic and elicited antisera that bound both recombinant gp160, which contains gp41, and HIV‐1 virions and immunoprecipitated recombinant gp41. Anti‐3α mimetic antisera neutralized viral infectivity against R5‐ and X4‐tropic strains of HIV‐1 at 31.5°C. The results suggest that a quaternary protein approach to mimic conserved and functional domains of viral envelope proteins is desirable for HIV vaccine development as such antigens are more likely to produce immunologically‐focused and broadly neutralizing antibody responses. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 320–329, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Role of methoxypolyethylene glycol on the hydration, activity, conformation and dynamic properties of a lipase in a dry film
Authors: Secundo Francesco , Barletta Gabriel , Mazzola Giorgio 
Published: March 2008

AbstractA combined approach based on the use of ATR‐FT/IR and steady‐state fluorescence spectroscopy allowed to shed light on the effects of the additive methoxypolyethylene glycol (MePEG) on the hydration, conformation and dynamic properties of lipase from Burkholderia cepacia dehydrated to form a film. Spectroscopic data show that the additive has little effect on the structure of the protein; however, H/D exchange kinetic and fluorescence anisotropy suggest a more flexible enzyme molecule when in the presence of MePEG. By infrared spectroscopy, we estimated that, after conditioning the films at water activity of 1, the water content in the lipase dehydrated with MePEG is 5.4‐ and 4.7‐fold higher than in the absence of the additive and the additive alone, respectively. Additionally, our infrared data suggest that MePEG acts by hindering intermolecular protein–protein interactions and contributing to increase the accessibility and flexibility of the lipase in the dehydrated solid film. These factors also explain the enhancement of the enzyme catalytic activity (i.e., up to 3.7‐fold in neat organic solvent) when in the presence of MePEG. The method and results presented might better address the use of additives for the preparation of enzymes employed in non‐aqueous media or of proteins used in a dry form in different fields of biotechnology. Biotechnol. Bioeng. 2008;101: 255–262. © 2008 Wiley Periodicals, Inc.
3‐Substituted BINOL Schiff bases and their reductive products for catalytic asymmetric addition of diethylzinc to aldehydes
Authors: Liu Bing , Dong Zhi‐Bing , Fang Cao , Song Hai‐Bin , Li Jin‐Shan 
Published: March 2008

AbstractThree new chiral 3‐substituted BINOL Schiff bases and their reductive 3‐arylaminomethyl BINOL products have been synthesized and used for the asymmetric addition reaction of diethylzinc to aldehydes in the presence of titanium tetraisopropoxide. The reaction provided optically active secondary alcohols in high yield (86–100%) and good enantioselectivity (up to 92% ee). Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Tributary valley impoundment by trunk river floodplain development: a case study from the KwaZulu‐Natal Drakensberg foothills, eastern South Africa
Authors: Grenfell Michael Cyril , Ellery William , Grenfell Suzanne Elaine 
Published: March 2008

AbstractThis paper investigates the origin and geomorphic evolution of Stillerust Vlei, a 189 ha wetland located approximately 150 km northwest of Durban in the temperate submontane foothills of the KwaZulu‐Natal Drakensberg Mountains. The investigation confirms the findings of previous research on the arid to semi‐arid South African interior, which established that many floodplain wetlands in eastern South Africa are located upstream of resistant rock barriers (dolerite intrusions) that cross river courses and form stable local base levels. Upstream of these barriers, rivers laterally plane less resistant Karoo sedimentary rocks (sandstones, mudstones), creating broad, low gradient valleys conducive to the formation of floodplain wetlands. In addition, the study examines how local levee and alluvial ridge accretion on the floodplain of Stillerust Vlei has impounded a small tributary valley, and drawing on observations of similar wetlands in the region, the paper explains the origin and geomorphic evolution of wetlands in floodplain‐abutting valleys, and associated streams that commonly become discontinuous toward their confluence with the trunk (floodplain) river. Controls on the origin and geomorphic evolution of Stillerust Vlei are placed within the context of slope‐channel decoupling and (dis)connectivity in sediment delivery, illustrating that wetlands are environments of deposition. As a result of dynamic trunk‐tributary relations, Stillerust Vlei holds a diversity of geomorphic features, and thus provides potential habitat for a diversity of biota. Copyright © 2008 John Wiley & Sons, Ltd.
Infant crying and maternal holding in the first 2 months of age: an Italian diary study
Authors: Bonichini Sabrina , Axia Giovanna , St. James‐Roberts Ian , DeCian Samantha 
Published: March 2008

AbstractThis study aims to confirm previous North American and North European findings about the normal developmental pattern of infant crying by studying the crying of Italian babies. A cohort of 70 healthy, full‐term Italian infants was assessed longitudinally at 2, 5 and 8 weeks of age. Mothers were asked to fill in 24‐h behaviour diaries for 3 consecutive days at each age. Results show significant differences in the amount of daily crying between 2 and 8 weeks and between 5 and 8 weeks. Different from other similar studies, no significant cry peak at 5 weeks was found in the Italian babies, but the amount of time Italian mothers spent holding their babies showed a peak at 5 weeks. Infants cried more during the evenings and mothers carried them most during this part of the day. Significant correlations between maternal holding and infant crying were found both concurrently and predictively. The amount of infant crying at 2 weeks predicted the amount of holding at 5 weeks. Results confirmed previous findings about the individual stability of daily crying in the first 8 weeks of age, but future research should take account of cultural variations in maternal holding in studying infant crying in different societies. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of surface acid groups associated with amorphous and structured carbon on the catalytic hydrodechlorination of chlorobenzenes
Authors: Amorim Claudia , Keane Mark A 
Published: March 2008

AbstractBACKGROUND: Catalytic hydrodechlorination (HDC) is a progressive approach to treating chlorinated waste streams. While carbon is widely used as a catalyst support, the influence of carbon surface functionality on HDC performance has not been established. This work sets out to assess the impact of surface acid groups associated with activated carbon (AC), graphite and graphitic nanofibers (GNF) on Pd promoted gas phase HDC of chlorobenzene (CB) and 1,3‐dichlorobenzene (DCB).RESULTS: The acid groups were introduced by HNO3 washing and the HDC reaction performed over bulk Pd and Pd physically mixed with each carbon. The carbon was subjected to a thermal treatment to remove the surface acidity. Characterization was by temperature programmed decomposition (TPD), temperature programmed hydrogen treatment (TPH), BET area, acid‐base titration, scanning and transmission electron microscopy. TPD, TPH and titration analyses served to establish the presence of surface oxygen groups after acid washing and facilitated an evaluation of the effectiveness of the thermal treatment to remove these groups.CONCLUSIONS: The surface acid groups inhibited HDC activity, a response most pronounced for Pd + AC, less so for Pd + graphite, while the effect was slight for Pd + GNF. HDC inhibition is attributed to chloroarene interaction with the surface functional (notably carboxylic) groups that impedes HDC. Fractional dechlorination of DCB was equivalent to or lower than CB HDC; there is some evidence of DCB interactions with heat treated graphite and GNF that served to raise HDC activity. Effective HDC over carbon based catalysts requires removal of surface acid groups. Copyright © 2008 Society of Chemical Industry