bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas and Viscous Effects on the ESPs Performance
Authors: Monte Verde W.. , Biazussi J.. , Bannwart A.. , Sassim N. Arrifano , Estevam V.. 
Published: May 2013

Abstract
This paper aims at presenting the experimental ESP performance curves (head, brake horsepower and efficiency) when operating with gas-liquid mixtures and viscous fluids.
In order to investigate the ESP performance operating with gas-liquid, a three-stage ESP with some modifications in its casing was used so that we could visualize the flow inside the pump. This pump was tested with gas void fraction varying between 0% and 10%, different liquid flow rate and speed.
Pump tests operating with viscous fluid were conducted in a radial three-stage ESP with viscosity ranging from 1 to 820 cP and different speeds.
Data has shown that it is possible to verify the performance degradation of ESP operating under unfavorable conditions, contributing, therefore, to a better physical understanding of the phenomena involved.
Benefits of PCP Charge Pumps Applied to Sand-Producing Reservoirs
Authors: Montiveros Mariano , Echavarria Lucas , Briozzo María 
Published: May 2013

Abstract
Heavy sandy fluids production is one of the biggest challenges for an artificial lift system. Progressing cavity pumping (PCP) has always been the preferred method, but as sand cuts get higher a PCP by itself is not enough: this is when charge pumps come into the picture.
This system consists of a main pump, which has high lift and low volumetric capacity; a charge pump which has low lift and three times the capacity of the main pump and a perforated nipple between them. This arrangement provides higher suction velocities reducing the deposition of solids in the rathole and the recirculation between both pumps helps keeping the perforations clean.
This study is based on the first experience in Argentina using charge pumps. The field is "Cerro Huanul Sur" and is located in the Neuquen Basin. This system was installed in seven wells and this study covers the benefits and limitations of each case.
The design of the bottomhole assembly was tailored to the specific needs of each well. This included the analysis of fluid properties, well configuration and production history. The installations were carefully supervised and the performance tracked using data logging and surveillance.
The completion of this type of wells is costly and time consuming since the sand cut has to be reduced to acceptable values. Once in production, the typical problems are blocked suction, formation of sand bridges in the annular space between casing and tubing, bridges in the tubing itself and sanded pump. In the conclusion this study will show how these issues were all overcome; reducing completion time, the interventions of the well with a flush-by unit or a pulling rig and downtime, and increasing pump run life.
Eleven Year Results of Total Hip Arthroplasty in Patients with Secondary Osteoarthritis Due to Slipped Capital Femoral Epiphysis
Authors: Schoof Benjamin , Citak Mustafa , O’Loughlin Padhraig F , Kendoff Daniel , Haasper Carl , Gehrke Thorsten , Gebauer Matthias 
Published: May 2013

Background:Total hip arthroplasty (THA) in patients with a history of Slipped Capital Femoral Epiphysis (SCFE), is typically indicated to address the consequent deformity of the proximal femur and/or acetabulum. It can be a challenging procedure for the orthopaedic surgeon. Previous studies have focused on prevention of osteoarthritis post-SCFE. However, there is a paucity of data on the outcomes of total hip arthroplasty in patients with osteoarthritis secondary to SCFE. This study was performed to assess the mid-term results of total hip arthroplasty in this patient cohort.Materials and Methods:All patients with secondary osteoarthritis due to slipped capital femoral epiphysis, treated with total hip arthroplasty between 1987 and 2005, were included in this retrospective study (n=30). Thirty patients (17 male, 13 female) met the inclusion criteria with one patient lost to follow-up and one unrelated death one year before follow up examination, thereby leaving 28 patients (32 hips) eligible for the study with a mean follow-up time period of 11.2 years. The Harris Hip Score (HHS) and MOS 36 short form health survey (SF36) were determined preoperatively and at most recent follow-up for all patients. Complications were also noted for all cases.Results:The mean Harris Hip Score increased significantly from 47 (32-59; SD=8.3) to 92.3 (65-100; SD=8.2) (p<0.0001). The SF-36 health survey showed an improvement of quality-of-life in all sub-scales. Overall, revision surgery was required in six cases (19 %). Aseptic loosening, leading to implant removal, was noted in five cases. A single-stage revision to address infection was performed in one case. The cumulative survival rate at latest follow-up was 81 %. No other complications were encountered during the study.Conclusions:Despite a higher failure rate, compared to total hip arthroplasty in the treatment of primary osteoarthritis, total hip arthroplasty can be considered a feasible option for patients with secondary osteoarthritis of the hip due to slipped capital femoral epiphysis. The current study demonstrates good outcomes in patients treated with a cementless column-preserving prosthesis, which is of particular relevance for this young patient cohort. However, further clinical prospective randomized studies are warranted to provide more definitive evidence.
Renal Function Following Three Distinct Weight Loss Dietary Strategies During 2 Years of a Randomized Controlled Trial
Authors: Tirosh Amir , Golan Rachel , Harman-Boehm Ilana , Henkin Yaakov , Schwarzfuchs Dan , Rudich Assaf , Kovsan Julia , Fiedler Georg M. , Blüher Matthias , Stumvoll Michael , Thiery Joachim , Stampfer Meir J. , Shai Iris 
Published: May 2013

OBJECTIVE
This study addressed the long-term effect of various diets, particularly low-carbohydrate high-protein, on renal function on participants with or without type 2 diabetes.

RESEARCH DESIGN AND METHODS
In the 2-year Dietary Intervention Randomized Controlled Trial (DIRECT), 318 participants (age, 51 years; 86% men; BMI, 31 kg/m2; mean estimated glomerular filtration rate [eGFR], 70.5 mL/min/1.73 m2; mean urine microalbumin-to-creatinine ratio, 12:12) with serum creatinine &lt;176 μmol/L (eGFR ≥30 mL/min/1.73 m2) were randomized to low-fat, Mediterranean, or low-carbohydrate diets. The 2-year compliance was 85%, and the proportion of protein intake significantly increased to 22% of energy only in the low-carbohydrate diet (P &lt; 0.05 vs. low-fat and Mediterranean). We examined changes in urinary microalbumin and eGFR, estimated by Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration formulas.

RESULTS
Significant (P &lt; 0.05 within groups) improvements in eGFR were achieved in low-carbohydrate (+5.3% [95% CI 2.1–8.5]), Mediterranean (+5.2% [3.0–7.4]), and low-fat diets (+4.0% [0.9–7.1]) with similar magnitude (P &gt; 0.05) across diet groups. The increased eGFR was at least as prominent in participants with (+6.7%) or without (+4.5%) type 2 diabetes or those with lower baseline renal function of eGFR &lt;60 mL/min/1.73 m2 (+7.1%) versus eGFR ≥60 mL/min/1.73 m2 (+3.7%). In a multivariable model adjusted for age, sex, diet group, type 2 diabetes, use of ACE inhibitors, 2-year weight loss, and change in protein intake (confounders and univariate predictors), only a decrease in fasting insulin (β = −0.211; P = 0.004) and systolic blood pressure (β = −0.25; P &lt; 0.001) were independently associated with increased eGFR. The urine microalbumin-to-creatinine ratio improved similarly across the diets, particularly among participants with baseline sex-adjusted microalbuminuria, with a mean change of −24.8 (P &lt; 0.05).

CONCLUSIONS
A low-carbohydrate diet is as safe as Mediterranean or low-fat diets in preserving/improving renal function among moderately obese participants with or without type 2 diabetes, with baseline serum creatinine &lt;176 μmol/L. Potential improvement is likely to be mediated by weight loss–induced improvements in insulin sensitivity and blood pressure.
A parameter-free smoothness indicator for high-resolution finite element schemes
Authors: Kuzmin Dmitri , Schieweck Friedhelm 
Published: May 2013

AbstractThis paper presents a postprocessing technique for estimating the local regularity of numerical solutions in high-resolution finite element schemes. A derivative of degree p ≥ 0 is considered to be smooth if a discontinuous linear reconstruction does not create new maxima or minima. The intended use of this criterion is the identification of smooth cells in the context of p-adaptation or selective flux limiting. As a model problem, we consider a 2D convection equation discretized with bilinear finite elements. The discrete maximum principle is enforced using a linearized flux-corrected transport algorithm. The deactivation of the flux limiter in regions of high regularity makes it possible to avoid the peak clipping effect at smooth extrema without generating spurious undershoots or overshoots elsewhere.
The role of rock mining for maintaining Dauco carotae-Crepidetum rhoeadifoliae Hejný et Grüll in Hejný et al. 1979 — a new to Poland plant association
Authors: Nowak Sylwia , Nowak Arkadiusz 
Published: May 2013

AbstractThis work presents the Dauco carotae-Crepidetum rhoeadifoliae plant association, which is new to Poland. The association has been observed in industrial reclamation areas in the vicinity of carbonate mineral excavation sites in the central part of the Opole region. In the vast majority of cases, plots of this association developed in reclaimed areas. The majority of diagnostic species for the association was found within surveyed plots, including Verbascum thapsus, V. densiflorum and Bryum argenteum. Taxa characteristic of the alliance were also constantly present, i.e. Daucus carota, Melilotus alba, M. officinalis, Echium vulgare and Erysimum hieracifolium. This association belongs to the rarest syntaxa in Poland included in the Dauco-Melilotion alliance of ruderal communities with a predominance of hemicryptophytes, therophytes and perennials. The main diagnostic species — Crepis rhoeadifolia, belongs to very rare elements of Polish flora. It has been observed only in the southern part of the country in approx. 20 sites. Crepis rhoeadifolia had not been observed in Silesia for approx. 40 years, which is why it was considered to be an extinct taxon in this region. Rediscovering of the species allowed for diagnosing the Dauco-Crepidetum rhoeadifoliae association. This association is an example of a pioneer phytocenosis of, most likely, anthropogenic origin in Silesia.
Comparative study of particle size analysis of hydroxyapatite-based nanomaterials
Authors: Barabás Réka , Czikó Melinda , Dékány Imre , Bizo Liliana , Bogya Erzsébet 
Published: May 2013

AbstractThe purpose of this work was to compare hydroxyapatite (HAP) and composites of HAP, HAP with chitosan (CS), and HAP with poly(vinyl pyrrolidone) (PVP), in terms of their particle size and morphology, using different methods, such as Coulter counter analysis, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Although many researchers have studied HAP and CS/HAP and PVP/HAP composites extensively, there is no evidence of a comparative study of their particle sizes. For this reason, different complementary methods have been used so as to provide a more complete image of final product properties — particle size — from the perspective of possible applications. The syntheses of HAP and HAP with polymer nanoparticles were carried out employing a precipitation method. Variation in particle size with synthesis time and influence of the reactants’ concentration on the materials’ preparation were systematically explored. Crystallite size calculated from XRD data revealed nanosized particles of HAP, CS/HAP, and PVP/HAP materials in the range of 2.5–9.2 nm. Coulter counter analysis revealed mean particle sizes of one thousand orders of magnitude larger, confirming that this technique measures agglomerates, not individual particles. In addition, the particles’ morphology and an assessment of their binding mode were completed by TEM measurements.
A comparative study on direct production of ethyl levulinate from glucose in ethanol media catalysed by different acid catalysts
Authors: Xu Gui-Zhuan , Chang Chun , Zhu Wei-Na , Li Bo , Ma Xiao-Jian , Du Feng-Guang 
Published: May 2013

AbstractDirect production of ethyl levulinate (EL) from glucose catalysed by a liquid acid catalyst (sulfuric acid) and a solid acid zeolite catalyst USY NKF-7 (USY) in ethanol media was investigated in this study. Effects of the initial glucose concentration (C G0), reaction temperature (T), amount of acid catalyst, and water addition on the yields of EL were compared, respectively. The results show that higher yield of EL can be obtained at lower C G0. Higher temperature and acid concentration can accelerate the reaction rate, but the formation rate of the by-products increases more quickly than that of EL. Water addition also can result in the decrease of the yield of EL. Although sulfuric acid is efficient in the production of EL, the USY is more efficient in converting glucose to 5-ethoxymethyl-2-furaldehyde. Moreover, the use of USY can limit the diethyl ether production, and it can be reused for multiple times.
Theoretical investigation on the reaction of HS+ with CH3NH2
Authors: Zhang Li-Li , Liu Hui-Ling , Tang Hao , Huang Xu-Ri 
Published: May 2013

AbstractThe singlet and triplet potential energy surfaces for the reaction of HS+ with the simplest primary amine, CH3NH2, were determined at the CCSD(T)/6-311+G(d,p) level using the B3LYP/6-311G(d,p) and QCISD/6-311G(d,p) geometries. All possible reaction channels were explored. The results show that three paths on the singlet potential energy surface and one path on the triplet potential energy surface are competitive. These four feasible paths provide products which are presented in the paper and they are consistent with previous experimental results. On the other hand, the stationary points involved in the most favourable path all lie below those of the reactant and thus the title reaction is expected to be rapid, which is also consistent with the experiment.
Influence of superplasticizers on the course of Portland cement hydration
Authors: Šiler Pavel , Kolářová Iva , Krátký Josef , Havlica Jaromír , Brandštetr Jiří 
Published: May 2013

AbstractA multicell isoperibolic — semiadiabatic calorimeter was used for the measurement of temperature and the determination of the hydration heat evolution at earlier period of cement pastes setting and hardening. The measurements were aimed at the determination of the effect of superplasticizers (SPs) on the course of the Portland cement hydration. Commercial polycarboxylate SP was added to the mixtures and the heat effect was measured. With the increasing content of SP, the hydration temperature increased up to a certain value and then decreased. In case of a sufficient amount of water in the mixture to achieve complete hydration of cement, samples with the highest values of the maximum hydration temperature reached the highest values of the released total heat. If there is not a sufficient amount of water to achieve complete hydration, the samples with the highest values of the maximum hydration temperature reach the lowest values of the released total heat.
Meteorological controls on glacier mass balance in High Asia
Authors: Rasmussen L.A. 
Published: May 2013

AbstractThe aim of this study is to investigate spatial and temporal variations of meteorological variables known to control glacier mass-balance processes, and to demonstrate their relevance in High Asia. The study uses the NCEP/NCAR reanalysis database (US National Centers for Environmental Prediction and US National Center for Atmospheric Research), which is global and continuous since 1 January 1948. A positive degree-day (PDD) model of annual glacier-wide summer surface balance, Bs, uses upper-air temperatures at NCEP/NCAR gridpoints near each of six glaciers between 40 and 45° N and between 71 and 87°E and two others near 50° N, 87° E. Model error ranged between 0.19 and 0.41 mw.e., comparable with the observational accuracy of Bs. Sensitivity to temperature change, dBs=dT, ranges between –0.5 and –0.2 m w.e. a–1 °C–1 for these glaciers.
Safety, Tolerability and Pharmacokinetics of Orally Inhaled Zanamivir: A Randomized Study Comparing Rotacap/Rotahaler and Rotadisk/Diskhaler in Healthy Adults
Authors: Weller Stephen , Jones Lori S , Lou Yu , Piscitelli Stephen , Peppercorn Amanda , Ng-Cashin Judith 
Published: May 2013

Background During a pandemic, the need for available anti-influenza medications increases. There has been extensive use of the approved zanamivir Rotadisk/Diskhaler but no clinical data are available for administration by an alternative Rotacap/Rotahaler presentation. Methods In this randomized three-way crossover study, each healthy adult received zanamivir 10 mg every 12 h for 5 days via Rotadisk/Diskhaler, via Rotacap/Rotahaler and placebo via Rotacap/Rotahaler, with a washout period between treatments. Safety assessments were conducted throughout the study and at follow-up. Serial blood samples for pharmacokinetic analysis were collected over a 12-h dose interval on day 5 of each treatment period. Pharmacokinetic parameters were compared using a mixed-effects model. Results A total of 18 healthy adults were recruited and 17 subjects completed the study. A total of 20 adverse events (AEs) were reported (all grade 1) by nine subjects, with no AE reported ≥1x in any treatment group. Nasal congestion, reported by one subject in the zanamivir Rotadisk/Diskhaler group, was the only drug-related AE. No serious AEs or withdrawals due to AEs occurred during the study. There were no significant changes in clinical laboratory values, vital signs or spirometry. Serum zanamivir exposures were similar after administration via Rotacap/Rotahaler and Rotadisk/Diskhaler. Both oral inhalation presentations are likely to deliver similar zanamivir concentrations to sites of influenza infection in the respiratory tract. Conclusions The safety and pharmacokinetic results from this study support the use of the Rotacap/Rotahaler presentation, potentially allowing an increased number of zanamivir treatment courses to be supplied in the event of an influenza pandemic.
La Chine dans les négociations climatiques
Authors: Maréchal Jean-Paul 
Published: May 2013

L’objet de cet article est double. Il est tout d’abord de faire le point sur le rôle que joue la Chine dans le réchauffement climatique actuel ainsi que celui qu’elle pourrait y jouer dans l’avenir. Il est ensuite d’analyser la position de Pékin dans les négociations climatiques et donc de mieux comprendre la difficulté à élaborer un régime climatique « post-Kyoto ».
La Libye nouvelle, les enjeux des prochaines échéances électorales
Authors: Gambotti Christian 
Published: May 2013

Après la « révolution » de 2011, la Libye essaie de se reconstruire d’un point de vue politique, surtout, mais aussi économique. La révolution libyenne dans sa traduction électorale ne ressemble en rien à une révolution islamiste. S’agit-il, pour les partis islamistes, de prendre acte de la naissance d’une Libye nouvelle dont le symbole sera l’élection de Mohamed el-Megaryef à la présidence du Congrès national ? Le nouveau gouvernement libyen parviendra-t-il à reconstruire l’économie du pays ?
Temps, terreur, crime
Authors: Raufer Xavier 
Published: May 2013

Depuis 2012, de nombreux articles sont parus dans les médias pour saluer une variété de « Data in the Sky » ou de « Crime predictors ». Ces techniques de politiques « prédictives » sont censées permettre une diminution de la criminalité dans le monde entier dans la prochaine décennie. Est-ce crédible ? ces techniques sont-elles efficaces ? Non, car elles utilisent les mêmes algorithmes que ceux utilisés par Wall Street pour les “Quants” (analyses quantitatives) dans les années 1990 pour protéger la Bourse de New York d’un krach - et qui ne permirent pas pour autant d’anticiper la crise des subprimes commencée la fin de 2007. Pour la première fois, cet essai démontre l’importance de la temporalité sur les questions de géopolitiques et de sécurité globale, tout en donnant les bases philosophiques appropriées pour de telles recherches.
France, l'horizon Pacifique
Authors: Berg Eugène 
Published: May 2013

Au moment où la presse mondiale parle, avec son goût habituel de la dramatisation, de « la nouvelle guerre du Pacifique » lorsqu’elle évoque le contentieux territorial sino-japonais concernant les îles Senkaku/Diaoyu, il apparaît intéressant d’examiner le rôle et la place de la France dans cette vaste portion du territoire mondial. La France est le seul État de l’Union européenne à être activement présent dans le Pacifique avec une communauté française forte de 600 000 personnes et d’un réseau diplomatique fort de six ambassades dans la région. La France est reconnue comme un partenaire contribuant à l’équilibre politique et au développement économique de la région du fait des relations politiques bilatérales et multilatérales qu’elle conduit. Néanmoins, la France a-t-elle encore les moyens de maintenir une présence et une influence significatives dépassant son poids régional réel ?
La fonderie Favi, un leader mondial qui croit en l'homme
Authors: Zobrist Jean-François 
Published: May 2013

Jean-François Zobrist a une idée fixe : faire confiance à ses salariés qui créent la richesse de l’entreprise. Une aventure hors norme fait de sa PME, depuis trente-cinq ans, un leader mondial, un innovateur permanent et un modèle de rentabilité.
Délinquance et action publique : les illusions d'un diagnostic
Authors: Robert Philippe , Zauberman Renée , Jouwahri Fadoua 
Published: May 2013

Le débat sur la délinquance s’attarde sur les moyens, pas sur un diagnostic de ses évolutions. Sur ce dernier point, la doxa peut se résumer ainsi : « la violence croît tandis que les atteintes aux biens diminuent ». Une analyse détaillée des données disponibles sur le moyen terme permet de montrer qu’en rester là est trompeur et ne permet pas de sortir les politiques de sécurité de leurs impasses.
Centralized R&amp;D Subsidy Policy in an NEGG Model: A Welfare Analysis
Authors: Montmartin Benjamin 
Published: May 2013

Depuis l’agenda de Lisbonne (2000), les politiques européennes sont de plus en plus orientées vers le soutien à la R&D et à l’innovation. Dans ce contexte, cet article propose une analyse approfondie d’une politique centralisée de soutien à la R&D mise en place dans une zone économique composée de deux pays hétérogènes. Pour ce faire, nous développons un modèle de croissance spatialisée et explorons l’impact de la politique sur l’état d’équilibre et le bien-être. Si nos résultats montrent que cette politique permet d’augmenter le taux de croissance de la zone et d’y réduire les inégalités, l’analyse de bien-être apporte une vision plus contrastée des effets de la politique. En effet, même si cette dernière est en mesure d’éliminer certaines distorsions et d’améliorer le bien-être de la zone, elle conduit à un jeu à somme nulle au niveau national (la politique augmente le bien-être dans le petit pays mais réduit celui du grand pays) lorsque la diffusion des externalités de connaissances entre pays n’est pas très élevée. En conséquence, la mise en place d’une politique centralisée de soutien à la R&D dans une zone économique composée de deux pays hétérogènes ne sera bénéfique à l’ensemble de ses membres qu’à la faveur d’une diffusion spatiale très large des connaissances entre pays. Classification JEL : F43, H50, R12.