bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determinación de la cinética, pruebas de crecimiento y efecto de inhibición <i>in vitro</i> de <i>Lactobacillus casei</i> en <i>Staphylococcus aureus</i>, <i>Staphylococcus epidermidis</i>, <i>Streptococcus agalactiae</i> y <i>Escherichia coli</i>
Authors: Jurado-Gámez Henry , Gúzman-Insuasty Manuel 
Published: August 2015

<p>Se determinó la cinética, pruebas de crecimiento y el efecto de inhibición <em>in vitro</em> de <em>Lactobacillus casei</em> sobre <em>Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae </em>y<em> Escherichia coli</em>. Se usaron cepas de casa comercial y cepas aisladas en la Vereda La Victoria, Corregimiento de Catambuco al suroccidente del municipio de Pasto, Nariño, Colombia. Se evaluó el efecto de los antibióticos Dicloxacilina, Cefepima, Cefalotina, Ciprofloxacina, Gentamicina, Penicilina, Trimetropim Sulfa y Ampicilina. Se evaluó la inhibición producida por <em>L. casei</em> y su sobrenadante sobre las bacterias patógenas. El crecimiento de la bacteria láctica se evaluó con tres niveles de pH (2,5, 4,5 y 7), tres concentraciones de sales biliares (0,5, 1 y 2%) y dos de bilis bovina (1 y 1,2%), y dos temperaturas (38 y 45°C). Igualmente se determinó la cinética de crecimiento y las variables pH, azúcar total, proteína y ácido láctico. Mediante HPLC se determinaron los péptidos y los ácidos orgánicos presentes en el sobrenadante. <em>L. casei </em>mostró susceptibilidad a la Ciprofloxacina y Ampicilina, mientras que <em>S. aureus </em>mostró susceptibilidad y resistencia a todos los antibióticos para la cepa comercial y aislada respectivamente, el mismo comportamiento se presentó con <em>S. epidermidis</em>. Las cepas de <em>S. agalactiae</em> y <em>E. coli</em> aisladas y comerciales mostraron susceptibilidad a los antibióticos. La cepa láctica mostró un efecto de inhibición de <em>S. aureus</em>, <em>S. epidermidis</em> y <em>S. agalactiae</em>, pero no fue efectiva con <em>E. coli</em>, igual comportamiento se observó con el uso del sobrenadante de la bacteria láctica. Se encontró crecimiento de 1 x 10<sup>10</sup> y 5,1 x 10<sup>7</sup> UFC/ml para 1 y 1,2 % de bilis bovina; 2,3 x 10<sup>7</sup>, 1 x 10<sup>9</sup> y 3 x 10<sup>8</sup> UFC/ml para 0,5, 1 y 2 % de sales biliares respectivamente; 1,1 x 10<sup>11</sup>, 2,0 x 10<sup>10</sup> y 1,0 x 10<sup>10</sup> UFC/ml para pH de 2,5, 4,5 y 7 respectivamente. La fase exponencial se encontró a 16:48 horas con un crecimiento de 3 x 10<sup>10</sup> UFC/ml. La variables pH, azúcar, acidez y proteína durante la fase exponencial fueron de 4,94, 0,88 mg/l, 2,89 mg/l y 1,9 mg/l, respectivamente. La prueba de HPLC para péptidos mostró la presencia de una cadena VAL-TIR-VAL y para ácidos orgánicos se encontró una producción de 83,46% de ácido láctico. <em>L. casei </em> mostró buenas características probiótica que permitirían su aplicación en ensayos in vivo para el control de microorganismos causantes de mastitis subclínica en vacas.</p>
The Deepithelialized Dorsal Tongue Flap for Reconstruction of Anterior Palatal Fistulae: Literature Review and Presentation of Our Experience in Egypt
Authors: Habib Ahmed S.E. , Brennan Peter A. 
Published: August 2015

Objective The purpose of this study was to present our experience with the closure of challenging palatal fistulae using the deepithelialized dorsal anterior tongue flap. We highlight the efficacy of suturing the tip of the tongue flap to the nasal septum for prevention of flap detachment. Design Prospective analysis of cleft patients with anterior palatal fistulae repaired by deepithelialized dorsal anterior tongue flap. Setting Institutional center. Patients/Participants A total of 30 patients with anterior palatal fistulae in the setting of previous cleft palate or fistula repair. Interventions Deepithelialized dorsal anterior tongue flap for treatment of anterior palatal fistulae. Outcome Measures Patients had repair using deepithelialized dorsal anterior tongue flap between 2011 and 2014. Patients’ photographs and clinical records were collected. The technique of flap harvesting and method of securing it in its position are described in this study. Results Patients were followed up over a mean period of 13.8 months to check flap viability, competent repair, and donor site function and aesthetics. All patients showed uneventful healing without complications. Conclusions This technique offered a secure method of palatal fistulae reconstruction. Further research is needed to show this technique's advantages and drawbacks.
Impact of Structural Discontinuities on Fluid Flow and Production Behaviour: Case Study of the Yowi Field, Offshore Niger Delta, Nigeria
Authors: Momta Prince S. , Odigi Minapuye I. 
Published: August 2015

Abstract
Structural discontinuity implies the presence of faults and fractures that have significant control on fluid communication within the subsurface. The Yowi field has experienced drastic decline in oil production just after two years of commencement of production. Possible factors responsible for this problem can be attributed to both geologic and engineering uncertainties. An integrated approach was adopted by first identifying geological factors and consequently validating its results with production behaviour. Results of the study revealed that the presence of network of fractures and the homogeneity of facies unit would have contributed to significant coning and early water breakthrough beside the poor reservoir management. Well log motif of the N5.2 sand displays a blocky shape, having a gradational upper contact and a sharp lower boundary. This indicates channel sand likely deposited within the beach environment. The sand-body shows high net-to-gross ratio, low volume of shale and excellent porosity and permeability values. Five CT-scanned core sample plugs also show the presence of massive regular and systematically formed vertical fractures. Fracture network presented a naturally fractured reservoir condition which accounted for significant coning due to high vertical permeability resulting in lowering the critical rate and more rapid breakthrough time. These fractures appear to be induced by both regional stress and the high drilling density on the subsurface structure in the field. This finding provides a more predictive insight into coning behaviour and a blueprint for post-breakthrough performance analysis.
Evaluation of the Cuttings Carrying Capacity of a Formulated Synthetic-Based Drilling Mud
Authors: Okon Anietie N. , Agwu Okorie E. , Udoh Francis D. 
Published: August 2015

Abstract
A synthetic-based drilling mud was formulated from derived ester using palm fruit pulp; with primarily focus to evaluate its cuttings carrying potential. The formulated mud was tested for its rheological properties and density. To evaluate its cuttings carrying capacity, the mud was flowed through cuttings bed in a simulated wellbore using 2m (about 6.56ft) long PVC pipe with internal diameter of four inch (4″) inclined at an angle of fifteen degrees (15°) to the horizontal. The results obtained from the flow loop experiment indicate that the formulated mud has a good cuttings carrying capacity with 97% of cuttings transported with hole cleaning potential at a flow rate of 140ft3/min; and the calculated cuttings carrying index (CCI) was 1.35. The results further depict that an increase in the mud's plastic viscosity, yield point and density from 6cp, 10lb/100ft2 and 8.63lb/gal to 17cp, 13lb/100ft2 and 9.50lb/gal resulted in poor cuttings carrying capacity and hole cleaning potential with less CCI value of 0.90. In addition, a sensitivity study of the rheological properties of the formulated mud indicates that with a plastic viscosity (PV) value of 17cp, an effective cuttings carrying capacity and hole cleaning potential was obtained at a flow rate of 180ft3/min. The sensitivity study further reveals that plastic viscosity is the predominant mud's rheological property in evaluating the cuttings carrying index (CCI) of drilling fluid. Therefore, at considerable plastic viscosity, yield point and mud density, the formulated synthetic-based mud exhibits a promising cuttings carrying capacity and hole cleaning potential as a good drilling fluid in drilling operations.
Optimizationof Wax Deposition in Sub-Cooled Pipeline Using Response Surface Methodology
Authors: Adeyanju Olusiji A. , Oyekunle Layioye O. 
Published: August 2015

Abstract
Key factors affecting wax deposition in sub-cooled pipelines (wall (coolant) temperature (A), inlet oil temperature (B), and the percentage of wax inhibitors in the crude (C), and oil flow rate (D)) were experimental studied using the fabricated flow loop rig designed to simulate the flow of relatively higher temperature crude oil in sub-cooled pipeline.
In an effort to investigate the possibility of minimizing the wax deposits volume in a flow of crude oil in sub-cooled pipeline, response surface methodology (RSM) was used to evaluate the individual and interactive effects of four variables affecting the wax deposits process using central composite design (CCD). It was observed that for the crude oil samples the experimental data highly fitted to the predicted data because of the predicted R-squares is in reasonable agreement with the adjusted R-square.
In the laminar-turbulent transition flow regimes (2000 &lt; Reynolds number (Re) &gt; 3000), A, B, C, D,AB, AC, BC, A2, B2, and C2 are significant, as their individual P-value were less than 0.05 by each of the term, while AD, BD, CD and D2, are insignificant as their P-values were more than 0.05. While in the laminar flow regime (Re &lt; 2000) the results were similar to that observed in the turbulent flow regime except the flow rate term, (D) which was insignificant (with P-values of more than 0.05) due to insignificant effect of shear dispersion and removal in the laminar flow regime.
In applying the response surface methodology central composite design (RSMCCD) in the Minitab-16 software to minimized wax deposit in crude oil flow in sub-cooled pipeline wax deposits were reduced to 64cm3 in the laminar flow regime and 43cm3 in the laminar-turbulent transition flow region. The small error percentage between the predicted and actual volume of wax deposit (4.68% in the laminar and 4.55% in the laminar-turbulent transition flow regime: indicated that the software models were valid and accurate in representing the actual experimental values and also in predicting the inhibition of wax deposit within the range studied.
The Study of CO2 Flooding and Sequestration in Tight Gas Reservoir: Different Completion Measures
Authors: Dou Xiangji , Liao Xinwei , Wang Huan , Zhao Tianyi , Cheng Zhiming , Ren Weiyan , Zhang Rui 
Published: August 2015

Abstract
Sequestrating CO2 in gas reservoirs can substantially enhance gas recovery and effectively mitigate globe warming problem. As a kind of unconventional reservoirs, tight gas reservoir has been one of main sources of natural gas supply. The objective of this paper is to discuss CO2 sequestration effect for wells with different completion measures in tight gas reservoir.
Based on Sulige gas field, a typical block is selected to investigate CO2 flooding in tight gas reservoir. A compositional numerical model of five-spot pattern is established with a horizontal well in the middle, while 4 vertical wells on the edge. With the model, several CO2 flooding scenarios of horizontal well with different completion measures are studied to investigate the influence of completion measures. Development strategies such as production rate and total gas injection volume are investigated. The improved gas recovery obtained by CO2 flooding for each scenario is quantified by comparing with natural depletion mode.
Different completion measures can be found in tight gas reservoir. The difference in completion can result in different well performance. The results of this study show that the recovery factor of horizontal well with SRV is larger than those of the other two. Some characteristics of tight gas reservoir, such as reservoir permeability stress-sensitivity, non-Darcy flow should be taken into consideration when determine development strategies. Besides the economy benefit obtained by enhanced gas recovery, CO2 flooding can also realize greenhouse gas geological sequestration and thus acquire environmental benefit.
Technical contributions in this paper including (a) investigating the CO2 flooding and sequestration effect for different completion measures in tight gas reservoir; (b) discussing the influence of permeability stress-sensitivity, non-Darcy flow on development strategies determination.
The Effect of Water-based Mud on Borehole Stability of Deeper Formations in Field X
Authors: Akinfolarin Ayodele 
Published: August 2015

Abstract
The migration from water-based drilling fluids in the 1990s to predominately synthetic based drilling fluids in the 2000s by a major operator in the Niger Delta was not predicted on any scientific research on the effects of water based drilling fluids on borehole stability. In spite of this migration, the operator continued to have borehole stability problems in field X. In addition the cost of drilling fluids continued to rise to about 10% of the well cost in field X. Also there has been increasing stringent requirements by the regulators on the use of synthetic based drilling fluids. This paper describes the results of the investigation on the possibility of using water based drilling fluids to drill the deeper sections of wells in field X. The overall intent of the investigation is to reduce the drilling fluid cost and improve the environmental and regulatory performance of the operator. The project methodology consists of two approaches. First is a study of borehole stability problems in the project area. The second method consists of experimental studies of the field X formation samples to determine the mineralogy of the formations. Based on the study, a water-based mud system that could be used to drill these formations was developed. The result of the borehole stability study showed that borehole problems occurred in wells drilled with water based mud and as well as those drilled with pseudo-oil based muds. The experimental studies showed that the highest percentage of the smectites/illite reactive clays in the samples examined was 12%. Use of 7% KCl solution caused a reduction in the shale reactivity by as much as 39.6%. Use of a 9% KCl with 8% base oil water-based fluid led to a very low clay dispersion of 6.5%
Impact Of Reversible Invert Emulsion Drilling Fluid Rheology On Productivity
Authors: Okoro E. E. , Dosunmu A. , Oriji B. , Iyuke S. 
Published: August 2015

Abstract
Drilling muds are multi-component fluid systems designed to perform several functions during drilling operation and as a drill-in fluid under varying conditions of temperature and pressure. The use of conventional oil-base mud for drilling can bring with it an associated trade-off in formation damage. For a drilling engineer, oil-base muds control reactive shales, improve penetration rates and enhance overall drilling efficiency. For a reservoir engineer, the oil-wet state of the wellbore and filtercake may present a skin challenge. Reservoir productivity impairment resulting from using oil-base mud takes many forms. It may relate to plugging of completion equipment and gravel packs by poorly displaced oil-wet filtercake. Due to this oil-wet state, oil mud filtercakes and other oil-wet materials deposited during the drilling process are not easily dispersed or removed by cleanup chemicals. Emulsions composed of non-dispersed oil mud and displacement fluids often remain within the wellbore. During production operation, the flow from thereservoir can mobilize these oil-wet materials, plugging completion equipment and pore space. This may significantly impair well performance regardless of its design purpose. The most obvious solution for avoiding oil mud related productivity impairment would be to drill the formation with water-base mud. However, drilling engineers often use oil-base muds to minimize risk and efficiently reach extended drilling targets. The problems associated with oil-mud filtercake cleanup and change over operation during completion operations has prompt this study. Operators and service companies develop and apply novel technologies to improve drilling efficiency and maximize hydrocarbon recovery. This paper presents a review on the principle behind formulation and development of reversible mud with nano additives that will eliminate the hard choice that the drilling engineers have to choose between improving drilling performance and decreasing the risk of completion impairment; they can have both requirements in a single mud system.
Application of Uncertainty Management in a Brown Field using Reservoir Simulation: A Case Study of SPDC's Field Re-Development
Authors: Etokakpan Eteobong , Keme Bomo , Nwonodi Chike , Amogu Daniel , Orekoya Adedoyin , Longe Victor , Olubamise Taiwo , Ukauku Ikwan , Nworie Ejiuwa 
Published: August 2015

Abstract
Managing uncertainties during subsurface modelling in brown field re-development requires robust identification and quantification of impact of the underlying uncertainties. Within a given cycle of integrated reservoir modelling, a modelling strategy can only be defined based on associated uncertainties and development options. This paper focuses on using the Design of Experiment to screen and quantify the impact of uncertainties and evaluate development outcomes in a brown field.
The paper details steps taken to identify and quantify subsurface uncertainties in a multi stacked reservoirs that could impact development options. The overall development strategy was to: (a) Introduce artificial lift and offtake management to keep existing wells flowing, (b) Install gas lift supply lines from new gas-lift skid at the flowstation to existing wells requiring gas-lift, (c) drill and complete additional wells using existing locations, (d) hook up the new wells to existing remote manifold and route to flowstations via existing bulklines. To access the impact of uncertain parameters and its ranges of uncertainty were identified and quantified based on current understanding of the reservoirs. The Plackett-Burman Design of Experiment was used to screen each parameter using the Tornado and/or Pareto Plots. The key uncertainties (heavy hitters) identified from the screening stage were carried forward to develop a Response Surface Model (RSM) using Box-Behnken experimental design in order to sample the full uncertainty space associated with each reservoir. The probability distributions of In-Place and cumulative production were generated using Monte-Carlo analysis and estimate of the Proved, Probable and Possible volumes and ultimate recovery were obtained (part of methodology)
From the study results, the feasibility for further oil and gas development based on 3D reservoir simulation with several development scenarios and options were evaluated. Results of the deterministic possible outcomes were used to identify specific cases that closely matched the Proved, Probable and Possible volumes from the Monte-Carlo distribution. Model provides tool for better well and reservoir management.
CO2 Capture & Utilization: Harnessing the CO2 Content in Natural Gas for Environmental and Economic Gains
Authors: Agiaye Emmanuel O. , Othman Mohammed 
Published: August 2015

Abstract
CO2 capture and utilization (CCU) is currently a global topical issue, and is viewed as one possible route to reduction of CO2 concentrations in the atmosphere. The core issues of development, economy and the environment which the world faces in current times are identified to be dependent on the provision of clean, efficient, affordable and reliable energy services. Presently the world is highly dependent on fossil fuels for provision of energy services, and the amount renewable energies can sufficiently replace is minimal. The deployment of appropriate CO2 separation technologies for the processing of natural gas is viewed as an abatement measure towards global CO2 emissions reduction. Selection of the optimum technology among the several separation technologies for a particular separation need requires special attention in order to harness the economic and environmental benefits. The captured CO2 would also require appropriate disposal or utilisation so as to prevent or ‘delay’ its re-entry into the atmosphere. These challenges of CCU involving natural gas particularly during processing which has become an area of intense research shall be discussed in the paper with respect to the selected technique for CO2 capture. A typical natural gas production scenario in Nigeria shall be analysed for potential CO2 capture. Further discussion shall be on the identification of the recovered CO2 gas utilisation framework such as CO2 flooding (in Enhanced Oil Recovery) for additional revenue generation, assessment of the CO2 savings and the contribution to the clean development mechanism (CDM).
Evaluation of Oil Spill Dispersants with a focus on their toxicity and Biodegradability
Authors: Nwaizuzu C. , Joel O. F. , Sikoki F. D. 
Published: August 2015

Abstract
Oil spill dispersants (OSD) are known to be efficient tools needed to clean and disperse many oil spills. Dispersants are used to disperse oil and prevent them from reaching the shorelines. There are two major concerns in the use of dispersants on our environment. Their toxicity, because the synergistic toxicity effects of these chemicals is of great concern as different chemicals that combine together in the same effluent can have toxic effects even when each of the individual chemicals is known to be non-toxic. Also their biodegradability, as every product whose final fate is in our environment should biodegrade quickly in order to avoid irreparable damage and disruption of the natural ecosystem. This work reviewed literature on oil spill dispersants from 1994–2014 focusing on their toxicity and biodegradability. From the review, many researchers however reported that dispersed oil is more toxic than the crude oil while very few were able to show that the dispersed oil was less toxic or equal in toxicity to the crude oil. They also showed that the dispersant increased the concentration of PAHs in the water column, this some accredited to be the cause of the increased toxicity. The effect of the toxicity on the various organs of the organism was noted as some recorded lesions on the gills of fish, drop in heart rate and so on. Many studies proved that dispersants do actually increase the biodegradability although to some it was restricted to some components of the crude oil. Some researchers however showed that the dispersant reduced the biodegradability of the crude oil. Also noted was the fact that various crude oils reacted differently when mixed with a dispersant and aquatic organisms reacted differently to different combinations of the dispersed oil. Temperature was shown to play a role in rate of biodegradability. More work needs to be done here in Nigeria to determine the cumulative impact oil spill dispersants have on the different organisms in the ecosystem when mixed with our various crude oils. Since the window of opportunity for use of a dispersant after an oil spill is recorded to be between hours to 2 days, this will aid timely decision making on the use of dispersants in our waters.