652 research outputs found

    Predicting Sanding Potential Using Empirical Method in “Ebendo” Field, Niger Delta, Nigeria

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    Sand formations represent a large fraction of oil and/or gas reservoirs in the world, hence it becomes imperative to determine the competency of the reservoirs to produce sand-free hydrocarbon. This informed the empirical technique adopted in this study to evaluate elastic parameters such as shear modulus (G), bulk compressibility (Cb), shear modulus to bulk compressibility (G/Cb) ratio and Unconfined Compressive Strength (UCS) to determine sand influx in the “Ebendo” Field, Niger Delta, Nigeria. To achieve this goal, seven (7) hydrocarbon-bearing sand units with thicknesses ranging from 12.51 to 48.63 m were identified at depth range of 1884.79 - 3350.15 m across the four (4) wells. These elastic parameters were estimated at the interval of interest. The range of values obtained for G/Cb ratio in EBD (01 and 02) is 1.49 × 1012 - 5.40 × 1012 psi2 while the range of values for G/Cb ratio in EBD (04 and 06) is 0.06 × 1012 - 0.41 × 1012 psi2. This result suggests that EBD (01 and 02) have no potential to sanding while EBD (04 and 06) have a high probability of sanding when compared to the threshold value of 0.8 × 1012 psi2. The production history of the “Ebendo” Field also correlates with the findings of this study. The low values of UCS in EBD (04 and 06) also agrees with the observation. Thus, this study has shown the efficacy of using empirical method as a quick approach to predicting sand production in the “Ebendo” Field and this technique could be used in other fields with similar geological setting

    Time-resolved energy transfer from single chloride terminated nanocrystals to graphene

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    We examine the time-resolved resonance energy transfer of excitons from single n-butyl amine-bound, chloride-terminated nanocrystals to two-dimensional graphene through time-correlated single photon counting. The radiative biexponential lifetime kinetics and blinking statistics of the individual surface-modified nanocrystal elucidate the non-radiative decay channels. Blinking modification as well as a 4 times reduction in spontaneous emission were observed with the short chloride and n-butylamine ligands, probing the energy transfer pathways for the development of graphene-nanocrystal nanophotonic devices

    Predicting Sanding Potential Using Empirical Method in “Ebendo” Field, Niger Delta, Nigeria

    Get PDF
    Sand formations represent a large fraction of oil and/or gas reservoirs in the world, hence it becomes imperative to determine the competency of the reservoirs to produce sand-free hydrocarbon. This informed the empirical technique adopted in this study to evaluate elastic parameters such as shear modulus (G), bulk compressibility (Cb), shear modulus to bulk compressibility (G/Cb) ratio and Unconfined Compressive Strength (UCS) to determine sand influx in the “Ebendo” Field, Niger Delta, Nigeria. To achieve this goal, seven (7) hydrocarbon-bearing sand units with thicknesses ranging from 12.51 to 48.63 m were identified at depth range of 1884.79 - 3350.15 m across the four (4) wells. These elastic parameters were estimated at the interval of interest. The range of values obtained for G/Cb ratio in EBD (01 and 02) is 1.49 × 1012 - 5.40 × 1012 psi2 while the range of values for G/Cb ratio in EBD (04 and 06) is 0.06 × 1012 - 0.41 × 1012 psi2. This result suggests that EBD (01 and 02) have no potential to sanding while EBD (04 and 06) have a high probability of sanding when compared to the threshold value of 0.8 × 1012 psi2. The production history of the “Ebendo” Field also correlates with the findings of this study. The low values of UCS in EBD (04 and 06) also agrees with the observation. Thus, this study has shown the efficacy of using empirical method as a quick approach to predicting sand production in the “Ebendo” Field and this technique could be used in other fields with similar geological setting

    Comparative Study of Microwave-assisted and Conventional Synthesis of 3-[1-(s-phenylimino) Ethyl]-2H-chromen-2-ones and Selected Hydrazone Derivatives

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    In this study, 3-acetylcoumarin 1, used as the essential precursor was synthesized by the reaction of salicyaldehyde with ethyl acetoacetate in the presence of a catalytic amount of piperidine in solvent-free medium. Schiff bases 2-9 were obtained by the condensation reaction of 3-acetylcoumarin, 1 with various aniline derivatives while reaction of 3-hydrazinoquinoxalin-2-one with four different 6-susbtituted 3-acetylcoumarins afforded the corresponding hydrazones 10-13. Both Schiff bases and hydrazone products were synthesized under microwave irradiation method and conventional synthetic strategy for comparative study. The microwave assisted reaction was remarkably successful and gave both Schiff bases and hydrazones in higher yields at shorter reaction time compared to conventional heating method. The characterization of the synthesized compounds were structurally confirmed by analytical data as well as spectroscopic means which involved 1H-and 13C-nmr, ir, UV-visible and mass spectra

    Antispermatogenic Activity Of Morinda Morindoides Root Bark Extract In Male Wistar Rats

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    To investigate the effect of the aqueous extract of the root bark of Morinda morindoides (Rubiaceae) on the reproductive activity of male Wistar rats, three groups (A, B and C) of six rats each were treated with 400,800 and 1600 mg/kg/day of Morinda morindoides root bark extract respectively for 28 days while 5mls/kg of distilled water was given to the control group D. At the end of the experimental period, animals were sacrificed and sperm characteristics, histology of the testes and epididymis were assessed. Morinda morindoides root bark extract caused a significant reduction (p<0.05) in sperm motility, a significant dose dependent reduction in the sperm count and a significant (p<0.05) dose dependent increase in morphological abnormalities of the spermatozoa of the treated rats. Histopathological evaluation of the testis and epididymis revealed varying degrees of degeneration and necrosis of the germinal epithelia cell of the seminiferous tubules and spermiostasis. Morinda morindoides root bark extract has significant anti-spermatogenic effects on adult male Wistar rats which could impair reproductive activities in these male Wistar rats. &nbsp

    Utilization of Ceramic Ware Waste as Complementary Aggregate in Hollow Masonry Unit Production

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    Continuous increase in ceramic ware waste from construction and demolition waste without good management practice has resulted in elevated volume of this waste category. However, utilization of this waste in masonry unit production could be a plausible option to solve this menace, particularly, in its ability to enhance masonry unit compressive strength. In this study, ceramic ware waste was utilized for hollow masonry unit production and three different natural fine aggregate to ceramic aggregate mix ratios of 100:0, 90:10, 80:20 and 70:30 were examined. Furthermore, the cement to total aggregate mix ratio considered was 1:7. Sequel to the process of aggregates mixing, casting, and subsequently demoulding, the masonry units were cured for 28 days prior to inspection for compressive test parameters. Results indicated that masonry unit with natural sand to ceramic waste mix ratio of 80:20 has the highest crushing strength at peak, yield and break point which were 60.903kN, 60.493kN and 53.863kN respectively. The compressive stress at peak and break were 6.57MPa and 6.50MPa in that order and Young’s modulus was 0.262GPa. Statistically, there were no significant differences at 95% confidence interval between the aggregate mix masonry units when the compressive strength indices were evaluated. Ceramics ware waste from demolition and construction waste is a suitable co-aggregate in hollow masonry unit production

    Antimicrobial and Thermal Properties of Coating Systems Modified with ZnO Nanoparticle and its Hybrid Forms: (A Review)

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    This review examines the unparalleled chemical and physical properties of ZnO nanoparticles and its hybrid forms. The influence of these multifunctional materials within the polymeric matrix of organic coatings was discussed. The scanning electron microscope is seen to provide relevant information about the dispersion of the hybrid and composite coating systems. This review provides concise information about the antimicrobial and thermal stability of composites

    THERMAL AND ANTIMICROBIAL EVALUATIONS OF NEWLY SYNTHESIZED HYBRID URETHANES FROM THEVETIA PERUVIANA SEED OIL

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    The thermal and antimicrobial properties of air drying polyesteramide-urethanes (hybrid) synthesized from Thevetia peruviana (a tropical and underutilized ornamental shrub) seed oil (TPSO) were evaluated. Physico-chemical characterizations (such as hydroxyl value, iodine value, saponification value, refractive index, inherent viscosity) of the resins were carried out using standard procedures. The polyesteramide was synthesized by reacting N, N'- bis(2- hydroxyethyl) Thevetia peruviana (I-IETA) [a product of aminolysis of TPSO] with Isophoronediisocyanate (IPDI). FTIR, 1H-NMR and 13C-NMR spectroscopic methods were used in structural .elucidation of the air dried hybrid urethanes. Antimicrobial activities as well as thermal stability (using TGA and DSC) of the coating films were evaluated. The SEM micrograph of the hybrid film and corrosion inhibitive test was also exa.rilined

    Meal delivery programs reduce the use of costly health care in dually eligible medicare and medicaid beneficiaries

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    Delivering food to nutritionally vulnerable patients is important for addressing these patients' social determinants of health. However, it is not known whether food delivery programs can reduce the use of costly health services and decrease medical spending among these patients. We sought to determine whether home delivery of either medically tailored meals or nontailored food reduces the use of selected health care services and medical spending in a sample of adults dually eligible for Medicare and Medicaid. Compared with matched nonparticipants, participants had fewer emergency department visits in both the medically tailored meal program and the nontailored food program. Participants in the medically tailored meal program also had fewer inpatient admissions and lower medical spending. Participation in the nontailored food program was not associated with fewer inpatient admissions but was associated with lower medical spending. These findings suggest the potential for meal delivery programs to reduce the use of costly health care and decrease spending for vulnerable patients
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