bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lessons Learned from Perforated Liner Stuck in N. Azadegan Field
Authors: Rong Li , Huihong Luo , Kaicai Yu , Zhiping Li , Yansheng Lu , Qiang Wang 
Published: December 2013

Abstract
N.Azadegan oilfield is a laminar characteristic of bottom water limestone reservoir with about 50m thickness from hole toe to oil-water interface, so a water cone may exist. When water breaks through to the wellbore and reaches 10% in the field, the production well will be closed in accordance with Buy-back development contract. So all of 21 highly deviated wells and some horizontal wells are planned to use enough open-hole swell packers for preventing and managing water cut. But there is the few report about stuck perforated liner with swell packer in the high angle hole.
This paper discusses expandable experiments of swell packer in the lab and well completion string design such as packer’ setting placement, then give some risks analysis of running 4-1/2" perforated liner in 6" open hole such as severe dogleg in three dimension trajectory,144mm packer OD and rubber property, 1300m length open hole in higly deviated section and friction force etc. In the first 12 wells in N.Azadegan field, there are 4 wells’ cases of stuck 4-1/2" perforated liner with two or three packers. By reviewing the typical field cases of stuck perforated liner with packers in two wells, this paper analyzes several possible reasons include i.e. mud properties change, frequent trips to cause wellbore destruction, the severe dogleg, quick expansion after rubber absorb oil molecular and present the main reasons for stuck liner, then develop a solution that would allow the well of stuck perforated liner to be completed, finally focuses on modification of oil swelling packer from rubber element design to evaluation test based on in-suit mud. One of intentions in this paper is to give a case history and the lessons learned for further enhance the reliability of this kind of oil swelling packer, avoiding the risk of sticking perforated liner and promoting the use of swellable packer in the other field.
A Novel workflow for fracture characterization and well placement using BHI data in WBM and OBM in deep unconventional reservoirs of North Kuwait
Authors: Acharya Mihira N. , Chakravorty Sandeep , Rao Narhari S. , Darous Christophe , Al-Ajmi Saad A. , Joshi Girija K. , Al-Doheim Arif , Dashti Qasem , Al-Anzi Ealian H. 
Published: December 2013

Abstract
The tight deep carbonate reservoirs of Oxfordian age in North Kuwait consist of tight limestone interbedded with organic rich shale layers. The overall matrix porosity is generally very low and the production is mainly from fractures in the crestal part of main structures. Borehole images are routinely acquired in vertical to moderately deviated wells drilled with oil-base mud for fracture characterization.
For detailed fracture property evaluation, a highly deviated pilot hole was drilled with water-base potassium formate mud for the first time across the reservoir section and drill-pipe conveyed high-resolution electrical borehole image data was acquired. The upper half of the interpreted interval showed potential open fractures sets, NE-SW striking fracture set was most abundant. An advanced fracture segment extraction workflow was used to determine porosity and aperture of different fracture sets.
The first horizontal well was then drilled as a lateral in the target reservoir with oil-base mud restricting direct computation of fracture properties. The electrical and acoustic images in OBM indicated fracture concentrations at quite a few places along the horizontal well trajectory, the most conspicuous occurring at the zones where heavy mud losses were encountered while drilling. A 2D litho-structural model was constructed along the well trajectories using the dip data and open-hole logs to correlate finer carbonate and organic shale layers and fracture distribution across the layers. This workflow permitted extending fracture properties along horizontal well as well.
Finally, a high-resolution 3D structural model was constructed using outputs from previous workflows and data from two nearby vertical / less deviated wells. The final model showed a folded structure, which was absent in the existing model of the field. Thus the innovative workflow provides a means to generate an accurate structural and fracture model for the reservoir, integrating the fracture characteristics of the individual sub-layers with the main fracture corridors.
Estimation of Total Hydrocarbon in the Presence of Capillary Condensation for Unconventional Shale Reservoirs
Authors: Chen Jin-Hong , Mehmani Ayaz , Li Baoyan , Georgi Daniel , Jin Guodong 
Published: December 2013

Abstract
Accurate reserve estimates for unconventional shale gas reservoirs are critical to their economic assessment and field planning. Reserves are typically assessed with log and core measurements. Much of the log-derived information is validated with cuttings and core data. In particular, adsorption isotherms are measured in the laboratory and used to estimate ultimate recovery.
Accurate shale gas reserve estimations require a storage model that incorporates the physics of small scale, i.e., nanopores. This model is critical for the interpretation of log data and the prediction of long-term production and ultimate recovery. Current models partition gas into two parts: gas adsorbed on the pore surface with density comparable to liquid and free gas in the shale rock pores and natural fractures. Such a storage model, however, fails to consider the extremely favorable conditions for capillary condensation in the kerogen-rich rocks: pores in the kerogen range from a few nanometers to a few hundred nanometers and the pore surfaces are strongly oil wet. These two conditions are highly favorable for capillary condensation to occur; consequently, a significant amount of hydrocarbon probably exists in kerogen pores in the liquid state. Capillary condensation in shale gas core plugs has been verified in a laboratory study and significantly more hydrocarbons were observed than one would have expected in a traditional model that does not include capillary condensation.
We propose a new shale gas storage model for organic-rich shale rocks that accounts for capillary condensation. In this model part of the ‘gas’ exists in liquid phase inside kerogen pores. Capillary condensation is easy to model for single-component hydrocarbons. Under reservoir conditions, the hydrocarbons are usually a mixture of multiple components. This paper presents the method and theoretical result for estimating the total hydrocarbon volume for hydrocarbon mixtures in organic rich shales in the presence of capillary condensation.
Harnessing of Coal Energy Through Underground Coal Gasification (UCG) in India – Opportunities and Challenges in Processing and Utilisation of Syngas
Authors: Dani K. C. , Baskaran V. K. , Kumar K. , Varyani S. , Pokhriyal S. K. 
Published: December 2013

Abstract
India is blessed with large reserves of deep seated coal which cannot exploit economically with the available technology. The gap in demand and supply of energy is on rise for the nation. Underground coal gasification (UCG) is a way of accessing the un-mineable coal for its energy contents and as a chemical feed stock. The coal is converted into syngas insitu and the gas is produced on the surface. Coal mines in Gujarat in association with GIPCL the technology for UCG is being acquired from a Mining Institute of Russia. The site is selected through a process of detailed characterization of lignite seams. Detailed design for the surface layout, already been accomplished. Like surface gasification, the syngas in a UCG trial also needs to be cleaned up to make it usable. The extent of cleaning required depends on end use of the gas. The prevailing emissions and waste disposal regulations at location concerned also determine the equipment & process to be used for cleaning. The design of surface facilities for the Vastan pilot is aimed at maintaining the optimal parameters essential for stabilized gas composition and calorific value (CV). The ultimate goal is designing an environment friendly commercial plant. Major challenges in gas processing for the successful trial include identification of end usage of low CV syngas, separation of sticky condensate from gas, handling of CO2, ultimately turning it into an economical proposition. Opportunities during pilot run are securing technical and economic parameters of syngas processing and determination of economic utilization and most vital being the indigenization of the technology. The paper deals at length with likely difficulties to be handled and benefits to be accrued in the syngas processing in the trial. It covers pilot specific UCG process and facilities required at surface to refine the syngas.
Formation Kinetics of Gemfibrozil Chlorination Reaction Products: Analysis and Application
Authors: Krkošek Wendy H. , Peldszus Sigrid , Huck Peter M. , Gagnon Graham A. 
Published: December 2013

ABSTRACT: Aqueous chlorination kinetics of the lipid regulator gemfibrozil and the formation of reaction products were investigated in deionized water over the pH range 3 to 9, and in two wastewater matrices. Chlorine oxidation of gemfibrozil was found to be highly dependent on pH. No statistically significant degradation of gemfibrozil was observed at pH values greater than 7. Gemfibrozil oxidation between pH 4 and 7 was best represented by first order kinetics. At pH 3, formation of three reaction products was observed. 4′‐ClGem was the only reaction product formed from pH 4–7 and was modeled with zero order kinetics. Chlorine oxidation of gemfibrozil in two wastewater matrices followed second order kinetics. 4′‐ClGem was only formed in wastewater with pH below 7. Deionized water rate kinetic models were applied to two wastewater effluents with gemfibrozil concentrations reported in literature in order to calculate potential mass loading rates of 4′ClGem to the receiving water.
A low-cost automated flow analyzer based on low temperature co-fired ceramic and LED photometer for ascorbic acid determination
Authors: Pessoa-Neto Osmundo , Santos Vagner , Vicentini Fernando , Suarez Willian , Alonso-Chamarro Julián , Fatibello-Filho Orlando , Faria Ronaldo 
Published: December 2013

Abstract
An automated flow analyzer based on low temperature co-fired ceramic (LTCC), a solid-phase reactor (SPR) and a low-cost photometer was designed for ascorbic acid (AA) determination in pharmaceutical formulations. It consists of a peristaltic pump, three-way solenoid valves, SPR to chemically convert Cu(II) into Cu(I), and a LTCC device for mixing the liberated copper with bathocuproine and detection. The flow cell in the LTCC employed an ultrabright LED — photodiode photometer. The analyzer successfully determined AA in pharmaceutical formulations. The analytical curve from 8.5×10−6 to 7.0×10−4 M gave a detection limit of 7.0×10−7 M and a RSD of 2.1% for a 2.0×10−4 M AA solution (n = 10). A high sampling frequency of 102 h−1 and low reagent and sample consumption (150 µL) resulted.
Solvent extraction with organophosphorus extractants in environmental samples: determination of cadmium(II) in natural water
Authors: Mánuel Victoria , Pinto Juan , Mendiguchía Carolina , Moreno Carlos 
Published: December 2013

Abstract
In this work, Cd(II) extraction in natural waters by organophosphorus extractants as organic phase, as well as its back-extraction in an acidic media, has been studied. Cadmium extraction behavior at natural waters’ pH conditions (values in the range 7–8) was studied with two different extractants and co-ions, obtaining the highest extraction efficiency when using 0.1M Cyanex 272 in kerosene as organic phase and 0.1 M NO3
− as co-ion. Once they were selected, the effect on the extraction efficiency of sample pH, buffer concentration, extraction time, Cyanex 272 concentration as well as back-extractant concentration, was studied. The presence of the main inorganic and organic ligands in the sample was also studied, observing that extraction efficiency was affected most significantly when chlorides were present, with a decrease of about 14%, proving negligible for the others. Under the selected conditions, spiked real samples were successfully analyzed.
The exploration of interaction studies of smaller size, mostly ignored yet intrinsically inestimable molecules towards BSA; An example of STD and DOSY NMR
Authors: Tanoli Sheraz , Tanoli Nazish , Usmani Saman , Zaheer-Ul-Haq  , Ferreira Antonio 
Published: December 2013

Abstract
Larger size or novel structure molecules are always appreciated by all fields of experimental and computational science. Conversely, molecules with smaller size and simple structures are usually ignored with no explanation as to why. However, the vast majority of more diminutive molecules behave as a cornerstone in the synthesis of a bigger structural framework. Subsequently, we planned to uncover the interactions of small molecules towards macromolecules, and successfully presented the binding results of 2-aminopyridine and Isovanillin towards BSA through NMR techniques. STD epitope mapping and also the DOSY results provided evidence that Isovanillin remained closer to the binding cavity of protein. Titration experiments afforded 584 µM (0.584mM) and 487 µM (0.487 mM) dissociation constants for isovanillin and 2-aminopyridine respectively. Furthermore, changes in diffusion coefficient (with and without protein addition in DOSY spectra) were found to be 0.081 log (m2 s−1) and 0.096 log (m2 s−1) points for isovanillin and 2-aminopyridine respectively. Docking studies exhibit that these molecules can tie to site 1 (sub-area IIA) through the pi-pi interaction and hydrogen bonding with Trp213. Our results demonstrated that both compounds could be utilized as part of a transporter in the circulatory system and their extension-inspired compounds may be utilized in new drug design.
Crystallographic and structural characterization of heterometallic platinum complexes Part V. Heteropentanuclear complexes
Authors: Melník Milan , Mikuš Peter , Holloway Clive 
Published: December 2013

Abstract
This review classifies and analyzes over eighty heteropentanuclear Pt complexes. There are eight types of metal combinations: Pt4M, Pt3M2, Pt2M3, PtM4, Pt3MM′, Pt2M2M′, PtM2M′2 and PtM3M′. The five metal atoms are in a wide variety of arrangements: trigonal-bipyramidal (most common), square-pyramidal, spike-triangular, butterfly, cubane, linear and one unique. Platinum bonds to a variety of triad partner metal atoms, soft, through borderline to hard. The shortest Pt-M bond distances for non-transition and transition M are 2.406(4) Å (M = Ge) and 2.30(1) Å (M = Co). The shortest Pt-Pt bond distance is 2.580(1) Å. Several relationships between the structural parameters were found and are discussed. Several complexes exist in two isomeric forms and others contain two crystallographically independent molecules. Both the isomers as well as independent molecules are examples of distortion isomerism.
Spectroscopic route to monitoring individual surfactant ions and micelles in aqueous solution: A case study
Authors: Geng Junfeng , Johnson Brian , Wheatley Andrew , Luo Jack 
Published: December 2013

Abstract
Using a very popular and commonly used surfactant sodium dodecylbenzene sulfonate (SDBS, C18H29SO3Na) for a case study, we report a new method of monitoring different forms of surfactant molecules in aqueous solution and measuring their critical micelle concentration (CMC) by ultraviolet-visible (UV-Vis) spectroscopy. The forms of SDBS micelles are also investigated by synthesizing and characterizing NiB nanoparticles using the micelles as molecular templates. In addition, the observed shifts of UV-Vis bands are analysed from the viewpoint of the electrons locations and distributions within the molecules and the possible overlap of their electronic orbitals between neighbouring molecules in each micelle.
Solid contact Zn2+ -selective electrode with low detection limit and stable and reversible potential
Authors: Wardak Cecylia 
Published: December 2013

Abstract
A new solid contact Zn2+ polyvinylchloride membrane sensor with 2-(2-Hydroxy-1-naphthylazo)-1,3,4 -thiadiazole as an ionophore has been prepared. For the electrode construction, ionic liquids, alkylmethylimidazolium chlorides are used as transducer media and as a lipophilic ionic membrane component. The addition of ionic liquid to the membrane phase was found to reduce membrane resistance and determine the potential of an internal reference Ag/AgCl electrode. The electrode with the membrane composition: ionophore: PVC: o-NPOE: ionic liquid in the percentage ratio of (wt.) 1:30:66:3, respectively, exhibited the best performance, having a slope of 29.8 mV decade−1 in the concentration range 3×10−7–1×10−1 M. The detection limit is 6.9×10−8 M. It has a fast response time of 5–7 s and exhibits stable and reproducible potential. It has a fast response time of 5–7 s and exhibits stable and reproducible potential, which does not depend on pH in the range 3.8–8.0. The proposed sensor shows a good and satisfactory selectivity towards Zn2+ ion in comparison with other cations including alkali, alkaline earth, transition and heavy metal ions. It was successfully applied for direct determination of zinc ions in tap water and as an indicator electrode in potentiometric titration of Zn2+ ions with EDTA.
Inverse problems on star-type graphs: differential operators of different orders on different edges
Authors: Yurko Vyacheslav 
Published: December 2013

Abstract
We study inverse spectral problems for ordinary differential equations on compact star-type graphs when differential equations have different orders on different edges. As the main spectral characteristics we introduce and study the so-called Weyl-type matrices which are generalizations of the Weyl function (m-function) for the classical Sturm-Liouville operator. We provide a procedure for constructing the solution of the inverse problem and prove its uniqueness.
Relation modules of infinite groups, II
Authors: Evans Martin 
Published: December 2013

Abstract
Let F
n denote the free group of rank n and d(G) the minimal number of generators of the finitely generated group G. Suppose that R ↪ F
m ↠ G and S ↪ F
m ↠ G are presentations of G and let $$\bar R$$ and $$\bar S$$ denote the associated relation modules of G. It is well known that $$\bar R \oplus (\mathbb{Z}G)^{d(G)} \cong \bar S \oplus (\mathbb{Z}G)^{d(G)}$$ even though it is quite possible that . However, to the best of the author’s knowledge no examples have appeared in the literature with the property that . Our purpose here is to exhibit, for each integer k ≥ 1, a group G that has presentations as above such that . Our approach depends on the existence of nonfree stably free modules over certain commutative rings and, in particular, on the existence of certain Hurwitz-Radon systems of matrices with integer entries discovered by Geramita and Pullman. This approach was motivated by results of Adams concerning the number of orthonormal (continuous) vector fields on spheres.
Minority carrier recombination lifetimes in n-type CdMgSe mixed crystals measured by means of the photothermal infrared radiometry
Authors: Pawlak M. , Maliński M. 
Published: December 2013

AbstractMinority recombination lifetimes of n-type CdMgSe mixed crystals were estimated by using infrared photothermal radiometry (PTR) amplitude and phase frequency spectra. The results obtained by the PTR method indicate that the lifetimes of optically generated carriers in CdSe and CdxMg1−xSe crystals are about 0.1 μs. The diffusion length of minority carrier in n-type CdSe single crystal was found to be 4.42 μm and it is in a good agreement with the literature value. It was found that with the increasing thermal-to-plasma component coefficient A the carrier concentration increases as expected from PTR theory.
Enhancement in UV emission and band gap by Fe doping in ZnO thin films
Authors: Srivastava Anchal , Kumar Nishant , Khare Sanjay 
Published: December 2013

AbstractEnhancement of the optical band gap of ZnO from 3.14 to 3.29 eV has been obtained using Fe dopant. Undoped and doped ZnO films are deposited by sol-gel spin coating. XRD patterns indicate polycrystalline nature and hexagonal wurtzite structure of Zn1−xFexO films. EDX analysis confirms the presence of iron dopant. The photoluminescence spectra show an ultraviolet emission peak at 398 nm (NBE emission) and defect emission peak at 485 nm. Intensity of the NBE emission is much higher for the doped samples with its ratio to defect emission intensity highest for 2 at. %doping. The NBE emission shifts to higher energy with increasing dopant concentration in a manner similar to that exhibited by the band gap. Surface morphology has been studied using FESEM.
Impact of PhD training on scholarship in a neurosurgical career
Authors: Choi Bryan D. , DeLong Michael R. , DeLong David M. , Friedman Allan H. , Sampson John H. 
Published: December 2013

Object
The purpose of this study was to report the prevalence of neurosurgeons with both medical degrees (MDs) and doctorates (PhDs) at top-ranked US academic institutions and to assess whether the additional doctorate education is associated with substantive career involvement in academia as well as greater success in procuring National Institutes of Health (NIH) research funding compared with an MD-only degree.

Methods
The authors reviewed the training of neurosurgeons across the top 10 neurosurgery departments chosen according to academic impact (h index) to examine whether MD-PhD training correlated significantly with career outcomes in academia.

Results
Six hundred thirteen neurosurgery graduates and residents between the years 1990 and 2012 were identified for inclusion in this analysis. Both MD and PhD degrees were held by 121 neurosurgeons (19.7%), and an MD alone was held by 492. Over the past 2 decades, MD-PhD trainees represented a gradually increasing percentage of neurosurgeons, from 10.2% to 25.7% (p < 0.01). Of the neurosurgeons with MD-PhD training, a greater proportion had appointments in academic medicine compared with their MD-only peers (73.7% vs 52.3%, p < 0.001). Academic neurosurgeons with both degrees were also more likely to have received NIH funding (51.9% vs 31.8%, p < 0.05) than their single-degree counterparts in academia. In a national analysis of all active NIH R01 grants awarded in neurosurgery, MD-PhD investigators held a disproportionate number, more than 4-fold greater than their representation in the field.

Conclusions
Dual MD-PhD training is a significant factor that may predict active participation in and funding for research careers among neurological surgeons at top-ranked academic institutions. These findings and their implications are of increasing relevance as the population of neurosurgeons with dual-degree training continues to rise.