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Search Results: 1 - 10 of 224952 matches for " Kevin C. Igwilo "
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A Review on Gas Well Optimization Using Production Performance Models—A Case Study of Horizontal Well  [PDF]
Kevin C. Igwilo, Emeka Emmanuel Okoro, Anthony Afam Nwude, Angela Onose Mamudu, Charles Y. Onuh
Open Journal of Yangtze Oil and Gas (OJOGas) , 2018, DOI: 10.4236/ojogas.2018.31005
Abstract: This study considered the solution methods to determine optimal production rates and the rates of lift gas to optimize regular operational objectives. The foremost tools used in this research are offered as software platforms. Most of the optimization hitches are solved using derivative-free optimization based on a controlled well Performance Analysis, PERFORM. In line with production optimization goal to maximize ultimate recovery at minimum operating expenditure, pressure losses faced in the flow process are reduced between the wellbore and the separator. Nodal analysis is the solution technique used to enhance the flow rate in order to produce wells, categorize constraints and design corrective solution. A hypothetical case is considered and sensitivity analysis using the IPR Models for horizontal gas wells provides the effect on pressure and liquid drop out. The gas lift method is economically valuable as it produced an optimal economic water cut of 80 percent with 2 - 4 MM scf/day rate of gas injection; thus, 1800 - 2000 STB/day gas was produced.
Repeat Whole Blood Donation Correlates Significantly with Reductions in BMI and Lipid Profiles and Increased Gamma Glutamic Transferase (GGT) Activity among Nigerian Blood Donors  [PDF]
Teddy C. Adias, Anastecia Chika Igwilo, Zaccheaus Awortu Jeremiah
Open Journal of Blood Diseases (OJBD) , 2012, DOI: 10.4236/ojbd.2012.24017
Abstract: Background: The effect of repeated blood donation on some biochemical values of healthy adult male blood donors in Calabar, Nigeria was studied. Methods: One hundred and fifty three (153) healthy repeat blood donors and 90 first time blood donors constituted the study population. Samples were analyzed using colorimetric procedures. Results: The BMI values of 24.4 ± 2.4 kg/ m2 in the first time donors was significantly higher than the 21.7 ± 1.7 kg/m2 obtained in repeat donors (P < 0.001). Among all the biochemical parameters, total cholesterol showed a significant change of 2.55 ± 0.74 mmol/l after repeated donations as compared to 3.45 ± 1.47 mmol/l in the first time donors (P < 0.005). Gamma glutamyl transferase (GGT) was significantly higher in repeat donors (70.5 ± 13.5 μl) than the first time donors (62.5 ± 13.3 μl) (P < 0.05). An LDL value of 1.02 ± 0.8 mmol/l in repeat donors was significantly lower than 1.69 ± 1.0 mmol/l in first time donors (P < 0.05). A VLDL value of 0.32 ± 0.2 mmol/l in repeat donors was equally lower than 0.44 ± 0.2 mmol/l obtained in the first time donors (P < 0.05). GGT showed positive correlation with lactate dehydrogenase (LDH) and low density lipoproteins (LDL) at P < 0.05 and P < 0.01 respectively among the repeat blood donors. Triglycerides showed a positive correlation with very low density lipoprotein (VLDL) among repeat donors at P < 0.05 significant level. Pearson correlation analysis also indicates that a significant positive relationship exists between GGT and low density lipoprotein (r = 0.891, P < 0.001). The regression analysis defined the relationship as linear (y = 0.0578x + 36.87; r2 = 0.7934, P < 0.05). Conclusion: A reduction in the values of some lipid profiles and high GGT activity is associated with repeated blood donations in this study population. Repeated blood donation may play a significant role in reducing the incidence of heart disease.
Economic Advantage of In-Country Utilization of Nigeria Crude Oil  [PDF]
Emeka Emmanuel Okoro, Adewale Dosunmu, Kevin Igwilo, Paul A. L. Anawe, Angela O. Mamudu
Open Journal of Yangtze Oil and Gas (OJOGas) , 2017, DOI: 10.4236/ojogas.2017.24018
Abstract: Crude oil refining is a unique and important link in the supply chain of petroleum products from the wellhead to the end user. Refining adds value through conversion of crude oil and other flows into dozens of co-refined products. Nigeria is probably the largest importer of refined petroleum products on the continent, creating a lucrative refinery market in Europe and the United States. Subsidies have also contributed to the low capacity utilization in our refineries. The current situation of the four National refineries and high dependency on crude oil proceeds has made Nigeria government a full time exporter of crude oil. Because of our population, the demand for refined products which are imported in foreign currency have induced pressure on our local currency; thus, presenting a large cost to the economy. Instead of looking for international crude oil traders or embarking on discounted sales of our sweet crude in this era of low crude oil price, it will be profitable to utilize this crude oil in Nigeria. We will not only export the raw crude but also enrich our petrochemical industries and agricultural sector with the byproducts or co-products from its refining. Investment in petrochemical industry will really bring about an astounding effect in our economy because of enlargement of private domain which will usher new phase of life by reducing inequalities in the nation’s income. There has never been a doubt about the large size of the Nigerian market for refined crude oil and petrochemical products. As more countries are discovering crude oil, Nigeria’s crude oil export will gradually drop leaving us with excess crude oil instead of excess crude account. There is a need for government to develop industrial sectors that support or leverage its energy resources. The actualization will make it possible for Nigeria to change from raw material supplier to value-added product supplier.
Experimental Evaluation of Temperature Effects on Detarium microcarpum, Brachystegia eurycoma and Pleurotus Biomaterial Mud  [PDF]
K. C. Igwilo, G. O. Osueke, S. T. A. Okolie, P. A. L. Anawe, Okoli Nnanna
Open Journal of Yangtze Oil and Gas (OJOGas) , 2017, DOI: 10.4236/ojogas.2017.22007
Abstract: Three sets of drilling fluids were formulated from biomaterials such as Detarium microcarpum, Brachystegia eurycoma and Pleurotus. The laboratory measurements were carried out on plastic viscosity, yield point and fluid loss exposed at required temperatures and then evaluated. The field Polyanionic cellulose additive that is currently in use was also formulated and used as a control sample to biomaterial products. Xanthan gumpolymer on equal concentration was added to both muds. The three sets of muds comprises the one without weighting material and the ones weighted up with calcium carbonate and barite respectively for both biomaterial mud and Polyanionic mud were examined as per American Petroleum Institute Standard. The graphs of the rheological properties and fluid loss against temperature were plotted. It was shown from the plots that the yield point and plastic viscosity decreased with increase in temperature while fluid loss increased with increase in temperature for both biomaterial mud and Polyanionic mud. It was also shown from the tables that the plastic viscosity and yield point are slightly better than the Polyanionic mud but less active in fluid loss than the Polyanionic mud.
Evaluation of the Fluid Loss Property of Annona muricata and Carica papaya  [PDF]
K. C. Igwilo, P. A. L. Anawe, S. T. A. Okolie, Ikeagwu Uzorchukwu, Onuh Charles
Open Journal of Yangtze Oil and Gas (OJOGas) , 2017, DOI: 10.4236/ojogas.2017.23010
Abstract: This technical paper evaluates the fluid loss property of Annona muricata and Carica papaya, prepared and measured as per API standard. This is a laboratory measurements carried out using low temperature and low pressure filter press. The prepared fluids were supplemented with 2 ppb XCD polymer product to enhance their carrying capacity. Their characteristics and commercial availabilities were also investigated. The 30 minutes filtrate volumes at 5 ppb, 10 ppb, 15 ppb and 20 ppb were obtained. The graph of concentrations versus the volume of the filtrate obtained was plotted. It was discovered that the concentration increases with decrease in volume of fluid loss and impermeable filtered mud cake was also obtained. Though, both gave good results, but the results of Annona muricata under the same conditions and concentrations were better than that of Carica papaya.
Evaluation of the Effects of Alcohol on De-Emulsification of Niger Delta Crude Oil Using Commercial De-Emulsifiers  [PDF]
K. C. Igwilo, S. T. A. Okolie, P. A. L. Anawe, Ogbudu Roland, Jude Odo
Open Journal of Yangtze Oil and Gas (OJOGas) , 2017, DOI: 10.4236/ojogas.2017.23013
Abstract: This research work evaluates the effects of alcohol on de-emulsification of Niger Delta crude oil using RP6000 and Chimec 2439 as de-emulsifiers. The laboratory measurements were carried out as per API standard. Stable emulsion was prepared using brine. The samples were de-emulsified. Methanol and ethanol were added respectively, with water and without water as modifiers. The measurements of the effect of adding alcohols on water separation efficiency were carried out using methanol to water ratio, M = 4:1 and ethanol water ratio, E = 4:1. The results show that solubility with alcohol is greater in emulsion than the solubility of alcohol without water. Some comparisons were also made based on the plots on percent water separation versus time for the two modifiers and de-emulsifiers. The maximum separation efficiency of 61% was obtained at concentration of 25% methanol, 75% RP6000, 20 ppm and Chimec 2439 gave maximum separation efficiency of 56.6% at concentration of 75%, 20 ppm at 120 minutes. Based on the results, methanol therefore gave larger effect on water separation efficiency than ethanol.
Use of Reclaimed Asphalt Pavement in Conjunction with Ground Improvement: A Case History
Kevin C. Foye
Advances in Civil Engineering , 2011, DOI: 10.1155/2011/808561
Abstract: The use of Reclaimed Asphalt Pavement (RAP) in lieu of virgin crushed stone aggregate is becoming a widely accepted practice for a number of construction applications, particularly pavement base courses. A number of laboratory RAP studies have considered the mechanical properties of RAP bases in order to support pavement designs incorporating RAP. These studies have revealed a number of interesting relationships between RAP moisture content, compaction, and stiffness. This paper discusses the experiences of a design-build contractor integrating a geosynthetic ground improvement program with a RAP base during the reconstruction of a 1.95?ha asphalt parking lot. Field observations of base course construction with RAP explore some of the implications of laboratory findings. A number of interesting observations on the technical, construction, and economic issues resulting from the project challenges and the use of RAP are presented. 1. Introduction The use of Reclaimed Asphalt Pavement (RAP) in lieu of virgin crushed stone aggregate is becoming a widely accepted practice for a number of construction applications, particularly pavement base courses, as evidenced by its inclusion in department of transportation specifications, including Minnesota Department of Transportation (Mn/DOT) [1]. The use of RAP in this application is attractive for a number of reasons: first, it reduces the cost of material production by eliminating quarrying, crushing, and screening operations. Second, for repaving projects, it reduces handling and transportation costs since the RAP is retained onsite for reuse. Third, it reduces the consumption of natural resources and energy, as reflected in the reduced costs in the first two points. Engineers designing pavements require reliable design guidance to incorporate any material into their design pavement sections. Common flexible pavement design methodologies are largely calibrated to empirical studies while their formulation is informed by commonly measured mechanical properties, especially resilient modulus and various measurements that correlate with resilient modulus (Puppala [2], AASHTO [3]). Hence, studies to support the incorporation of RAP into pavement designs have focused on characterizing its mechanical properties. The mechanical properties of RAP are expected to largely mimic those of crushed stone aggregate due to its similar composition—with the notable exception of residual asphalt binder—and particle-size gradation. Several authors, including Attia and Abdelrahman [4], Mokwa and Peebles [5], and Locander [6] have
Structure of the Human Discs Large 1 PDZ2– Adenomatous Polyposis Coli Cytoskeletal Polarity Complex: Insight into Peptide Engagement and PDZ Clustering
Kevin C. Slep
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0050097
Abstract: The membrane associated guanylate kinase (MAGUK) family member, human Discs Large 1 (hDlg1) uses a PDZ domain array to interact with the polarity determinant, the Adenomatous Polyposis Coli (APC) microtubule plus end binding protein. The hDLG1-APC complex mediates a dynamic attachment between microtubule plus ends and polarized cortical determinants in epithelial cells, stem cells, and neuronal synapses. Using its multi-domain architecture, hDlg1 both scaffolds and regulates the polarity factors it engages. Molecular details underlying the hDlg1-APC interaction and insight into how the hDlg1 PDZ array may cluster and regulate its binding factors remain to be determined. Here, I present the crystal structure of the hDlg1 PDZ2-APC complex and the molecular determinants that mediate APC binding. The hDlg1 PDZ2-APC complex also provides insight into potential modes of ligand-dependent PDZ domain clustering that may parallel Dlg scaffold regulatory mechanisms. The hDlg1 PDZ2-APC complex presented here represents a core biological complex that bridges polarized cortical determinants with the dynamic microtubule cytoskeleton.
Screen-printed Electrochemical Sensors and Biosensors for Monitoring Metal Pollutants
Kevin C. Honeychurch
Insciences Journal , 2012,
Abstract: The present review (with 231 references) focuses on developments made in the area of screen-printed biosensors and sensors for the determination of metal ions in industrial, environmental and biomedical applications. The year 2012 represents the twentieth anniversary of the first reported application of screen-printed electrodes for the determination of metal ions. Focus is placed on fabrication techniques, operating details and performance characteristics for the selected applications. The greater proportion of articles have utilised the technique of stripping voltammetry, gaining detection limits in the low ng/mL (ppb) region. An increasing percentage of these have explored bismuth as an alternative to mercury for the modification of the carbon electrode surface. However, a steady number of applications have shown the possibility of utilising the unmodified screen-printed carbon, gold or silver electrode surface. More recently the alternative approach of electrochemical biosensors has become a growing area. The majority of these have exploited the inhabitation metal ions exhibit on the enzyme activity of urease, acetylcholinesterase and glucose oxidase gaining detection limits in the sub μg/mL region, however recent applications utilising thiol-functionalised oligonucleotides have been shown the possibility of gaining detection limits as low as 120 ng/L for Hg2+.
More forgotten tells of Mali: an archaeologist's journey from here to Timbuktu
Kevin C. Macdonald
Archaeology International , 1997, DOI: 10.5334/ai.0112
Abstract: The use of the word "tell" to describe a settlement mound is so intimately associated with western Asia that its transfer to West Africa may seem inappropriate. But the mounds of Mali are true tells, and their excavation is beginning to reveal a hitherto unsuspected history of pre-Islamic urban development in the Middle Niger Valley.
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