Investigating electrical response to water saturation of Agbada sandstone in an x-field Niger delta, Nigeria

In an attempt to characterize a reservoir in a field, importance is given to living models as it serves critical function in estimating if the reservoir under study is economically viable. Having a good knowledge of electrical response to reservoir rocks is important in characterizing and modeling the behavior of fluids at the subsurface. In this study, core plugs extracted from core barrels in a Niger Delta oil field were analyzed in the laboratory in order to determine the electrical properties of the samples and their relationship with each other and formation fluid. This was achieved by using a brine of a known concentration for simulation of core plugs. Results obtained show that for the unconsolidated sandstone, Formation resistivity factor increases with increase in confining pressure. This characteristic depends on the porosity of the Formation and type of fluid present. Resistivity values in a reservoir will increase with increase in capillary pressure and decrease with water saturation. Decrease in cementation exponent increases the rate of permeability in reservoir sand. However, resistivity values decrease with clay presence in reservoir sand

A robotic platform for high-throughput electrochemical analysis of chalcopyrite leaching

A novel robotic platform for combinatorial screening of ionic liquid-based Cu extraction from chalcopyrite with real-time, in situ monitoring of dissolved copper.</p

Antibacterial Potency of Allium sativum, Psidium guajava, Zingiber officinale Roots against the Food Poisoning Strains (Escherichia coli 0157:H7 and Staphylococcus aureus)

Escherichia coli 0157:H7 and Staphylococcus aureus are notorious food poisoning bacteria of great effect on human health. This study determined the phytochemical constituents of ethanolic, vacuum liquid chromatography (VLC) filtrates of Allium sativum (garlic), Psidium guajava (guava), Zingiber officinale (ginger) and their antibacterial activities on E. coli 0157:H7 and S. aureus. In a laboratory-based controlled experiment, the antibacterial and inhibitory activities of the VLC filtrates in doses of 0.01, 0.02, 0.04, and 0.08g/mL were investigated on E. coli 0157:H7 and S. aureus using the agar well diffusion method and compared with a standard antibiotic. The indices of the zone of inhibition on the agar plates were subjected to analysis of variance (p = 0.01). Phytochemical analysis revealed a high concentration of glycosides, steroids, tannins, terpenoids, and the absence of flavonoids in A. sativum. P. guajava root contained a high concentration of glycosides, steroids, tannins, and terpenoids. Z. officinale possessed a high concentration of alkaloids, glycosides, flavonoids, steroids, and terpenoids. Statistically, 0.02 g/mL of Z. officinale (12.0 mm) showed a significant result to 0.04g/mL of A. sativum (14mm) at p = 0.0049 and a higher inhibition index to 0.08g/mL of P. guajava. Inhibition by 0.02g/mL of P. guajava (8.8mm) was advanced than 0.04g/mL of A. sativum (6.3 mm) on S. aureus. Recommendable inhibition of 29.3 mm and 24.0 mm on E. coli 0157:H7 and S. aureus, respectively, were expressed by 0.08 g/mL Z. officinale, which was significant to the standard 0.04 g/mL of Neomycin (Positive control) at p = 0.0067. This study indicated a reliable antibacterial activity by Z. officinale than A. sativum and P. guajava, which might have been due to the high concentration of alkaloids and flavonoids. Nevertheless, A. sativum, P. guajava, and Z. officinale are normally used as fruit and food additives in the human diet, thus can be combined to prevent food poisoning by E. coli 0157:H7 and S. aureus and their exotoxins. Keywords:&nbsp;&nbsp;&nbsp; Allium sativum, Antibacterial activity, Escherichia coli 0157:H7, Psidium guajava, Staphylococcus aureus, Zingiber officinal

The dynamics of culture in Hope Eghagha's Death not a redeemer

No Abstrac

Unimpeded tunneling in graphene nanoribbons

We studied the Klein paradox in zigzag (ZNR) and anti-zigzag (AZNR) graphene nanoribbons. Due to the fact that ZNR (the number of lattice sites across the nanoribbon (N is even) and AZNR (N is odd) configurations are indistinguishable when treated by the Dirac equation, we supplemented the model with a pseudo-parity operator whose eigenvalues correctly depend on the sublattice wavefunctions for the number of carbon atoms across the ribbon, in agreement with the tight-binding model. We have shown that the Klein tunneling in zigzag nanoribbons is related to conservation of the pseudo-parity rather than pseudo-spin in infinite graphene. The perfect transmission in the case of head-on incidence is replaced by perfect transmission at the center of the ribbon and the chirality is interpreted as the projection of the pseudo-parity on momentum at different corners of the Brillouin zone

A CROSS-SECTIONAL STUDY OF THE PREVALENCE OF SICKLE CELL DISEASE AMONG CHILDREN OF UNDER THE AGE OF FIVE YEARS AT HERI MISSION HOSPITAL IN BUHIGWE DISTRICT – KIGOMA, TANZANIA

Background:  Sickle cell disease has become a common inherited hemoglobin disorder. Various reports have shown that a high mortality rate of children under five years of age was reported in the year 2022 in Tanzania. This research aimed to determine the prevalence of sickle cell disease (SCD) amongst children under five years of age and their family history at Heri Mission Hospital in Buhigwe District, Kigoma.  Methods:  A convenient cross-sectional study was carried out to enroll 204 children under the age of five years at Heri Mission Hospital. The collected data were subjected to analysis of variances using the statistical package for Social Sciences (SPSS) version 28.0.1.0 software (SPSS Inc., USA). The Chi-square test was utilized in comparing proportions and frequency of occurrence of Haemoglobin (Hb) in the variables at P &lt; 0.05 as the significance of variance.  Results:  The prevalence of SCD among children under five years was 28.3% (103/364). Among the positively tested with SCD, the majority were female at 71.7% (65/91), whereas males were 28.3% (26/91). Family records of the children with SCD showed that the proportional of SCD was significantly higher among family members with SCD 73.1% (38/52) than none SCD (14/52) 26.9% (X2 = 7.513, P &lt; 0.05).  Conclusion:  The findings in this research showed a high rate of SCD amongst children under five years, and the family history of the victims showed it’s inheritable.  Recommendation:  Health awareness and proper mitigation strategies need to be addressed on how to curb the SCD in Buhigwe District and Tanzania as a country

Very high energy gamma rays from the Crab Nebula

Observations of the Crab pulsar using the atmospheric Cerenkov technique were conducted for 22 hours. The light curve obtained shows a single peak at approximately the position of the expected main peak with a significance level of 3.2 sigma. The pulsed flux above 200 GeV is 2.5 + or - 0.8 x 10 to the 11th power cm(-2)s(-1)

Field enhanced electron mobility by nonlinear phonon scattering of Dirac electrons in semiconducting graphene nanoribbons

The calculated electron mobility for a graphene nanoribbon as a function of applied electric field has been found to have a large threshold field for entering a nonlinear transport regime. This field depends on the lattice temperature, electron density, impurity scattering strength, nanoribbon width and correlation length for the line-edge roughness. An enhanced electron mobility beyond this threshold has been observed, which is related to the initially-heated electrons in high energy states with a larger group velocity. However, this mobility enhancement quickly reaches a maximum due to the Fermi velocity in graphene and the dramatically increased phonon scattering. Super-linear and sub-linear temperature dependence of mobility seen in the linear and nonlinear transport regimes. By analyzing the calculated non-equilibrium electron distribution function, this difference is attributed separately to the results of sweeping electrons from the right Fermi edge to the left one through the elastic scattering and moving electrons from low-energy states to high-energy ones through field-induced electron heating. The threshold field is pushed up by a decreased correlation length in the high field regime, and is further accompanied by a reduced magnitude in the mobility enhancement. This implies an anomalous high-field increase of the line-edge roughness scattering with decreasing correlation length due to the occupation of high-energy states by field-induced electron heating.Comment: 20 pages and 6 figure

Superconductivity driven by magnetic instability in CeCu2Si2

The coexistent of superconductivity (SC) with antiferromagnetism (AFM) and ferromagnetism (FM) as U ?? is studied in CeCu2Si2 on application of the Exact Diagonalization technique to the Single site Impurity Anderson Model and the Periodic Anderson Model. The results obtained show that magnetic instability is the key to understanding superconductivity in Heavy Fermion compounds as increasing the onsite coulomb repulsion, U, suppresses all ferromagnetic tendencies and enhances superconductivity. The results obtained here is in qualitative agreement with the inelastic neutron scattering experimental results obtained by Stockert et al (2011) on increasing the copper content in CeCu2Si2. U in this theoretical study behaves as Cu in the inelastic neutron scattering experiment. Keywords: Heavy fermion, antiferromagnetism, superconductivity, ferromagnetism, singlet state energy, triplet state energy