Effect of Jet Reynold’s Number on Nusselt Number for Convective Impingement Air Cooling on a Hot Plate

Studies were carried out to determine the Convective Heat Transfer Coefficient, h, under multiple jets of impinging cold air on a target heated flat plate. Tests were run with air- distribution plates with hole diameters, d, of 1.5mm, 2.0mm, 2.5mm and 3.0mm. The target plate is a carbon-steel flat plate of 6mm thickness, instrumented with a total of three Chromel-Alumel K-type thermocouples. The plate is electrically heated using a variable supply current input. Test were run at various cooling air flow rate G, between 1.0kg/m3, sec to 3.0kg/m3, sec. Distribution plate-to-target plate distance Z(mm), was varied between 100mm to 200mm. Heat input to the target plate Q Watt, was varied to give a heat flux rate between 10 to 100 watts. Results obtained were reduced and analyzed by evaluating for the dependence of h on the impingement jet diameter,Jet Reynolds Number, and the coolant mass flow rate G. Correlations were done, using the dimensionless parameters of Nusselt Number, Reynolds Number and Prandtl Number. Based on the results obtained, it is proposed that within the Reynolds Number range of 1500 to 2000, correlation may be made with:-   = 0.15Re0.58Pr0.33 Keywords: Reynold’s Number, Nusselt Number, Prandtl Number, Impingement, Cooling, Heat transfer Coefficien

Load frequency control using classical controllers

This paper presents a solution to the problem of load frequency control of a two area power system using PI and PID controllers. In electric power systems, the load demand varies at different times of the day and these load variations lead to changes in frequency of the power system. In an interconnected power system, the tie-line power also varies in addition to the frequency variations. These changes in frequency and tie-line power causes instability in the power system network and make it unreliable. Load frequency control therefore ensures that these changes in the tie-line power and frequency of the control areas are minimized with acceptable level of overshoot and settling time. The method used involves the modeling of the two area interconnected power system using Matlab/Simulink software, the PI and PID controllers were then tuned using the Ziegler-Nichols tuning rule and used to simulate the two area power system when a load change of 0.2pu occurred in control area one. The simulation results showed that both the PI and PID controllers were able to restore the changes in tie line power and frequency of the control areas caused by the change in load to their steady state values of zero but the PID controller has better dynamic performances of overshoot, rise time and settling time than the PI controller

Use of Mobile Phones for Research Among Undergraduates in Two Polytechnic Libraries in Imo State, Nigeria.

The study is titled ‘Use of Mobile Phones for Research among Undergraduates in two Polytechnic Libraries in Nigeria. The study seeks to establish if students who make use of the polytechnic libraries studied do use their mobile phones for research purposes, their reasons for preferring to use their mobile phones to traditional/conventional information resources as well as the constraints they encountered when accessing information. The survey method was adopted in data collection. The validated questionnaire were administered to the respondents within a period of week. Findings show that undergraduate students who use the polytechnic libraries studied make use of their mobile phones for research occasionally. It was revealed that lack of current/ relevant resources in libraries, saving of time and cost of travelling to other libraries for research, low level of satisfaction derived from available resources as well as lack of internet facilities in libraries are reasons why they make use of mobile phones for research. Also, high cost of downloading online resources, incompatibility of software/format of online resources as well as insecurity of sites which causes damages to the phones were identified as constraints students encountered when using mobile phones. The following were recommended in line with the findings of the study: use of anti-virus software, installation of internet facility in libraries, use of compatible phones/ software, saving of downloaded resources as well as use of mobile phones that are user friendly. The bottom-line of the paper is that the use of mobile phones has helped to improve students’ access to current and reliable information resources in tertiary institutions

Quadratic Time-dependent Quantum Harmonic Oscillator

We present a Lie algebraic approach to a Hamiltonian class covering driven, parametric quantum harmonic oscillators where the parameter set -- mass, frequency, driving strength, and parametric pumping -- is time-dependent. Our unitary-transformation-based approach provides a solution to the general quadratic time-dependent quantum harmonic model. As an example, we show an analytic solution to the periodically driven quantum harmonic oscillator without the rotating wave approximation; it works for any given detuning and coupling strength regime. For the sake of completeness, we provide an analytic solution to the historical Caldirola--Kanai quantum harmonic oscillator that, in a suitable reference frame, is just a time-independent parametric quantum harmonic oscillator.Comment: 22 pages, 4 figure

International Best Practice: Understanding the Core Difference between Medical Laboratory Science and Clinical Laboratory Medicine in Nigeria

Introduction: International best practice (IBP) in the healthcare sector is an approach that is put in place globally, acceptable  standards to ensure patients’ safety while providing quality healthcare to the community. It achieves such standards by defining the job roles of various professionals in the healthcare sector. In the Nigerian healthcare sector, despite the clear definition of the job roles of the medical laboratory scientist and clinical laboratory physicians (pathologist) by the various Acts of Law of the Federal Republic of Nigeria that established these two professions, there seems to be a misapprehension of the differences between these two  professions. This study aimed to evaluate the knowledge of the health workers as it concerns the IBP on the scope of practice of medical laboratory science (MLS) and clinical laboratory medicine in Nigeria. Materials and Methods: Across-sectional, observational design was used for this prospective study involving 427 health workers from the six geopolitical zones in Nigerian and Abuja, using a proportionate sampling technique. It was facility‑based research usinga validated semi-structured self-administered questionnaire. Results: Over 50% of the participants believed that MLS was the same as clinical laboratory medicine. Two hundred and ten  participants (49.2%) did not know that analyses of samples in a clinical laboratory was the job responsibility of a laboratory physician. Conclusion: There was knowledge gap in the practices of both the MLS and the clinical laboratory medicine by health workers. Therefore, there is a need to create awareness through interprofessional education, workshops, and seminars to ensure understanding of job roles as this may promote harmony between these two professions in the health sector. Keywords: Clinical laboratory medicine, international best practice, medical laboratory scienc

Assessment of serum soluble intercellular adhesion molecule-1 and albumin in human immuno-deficiency virus-infected individuals with or without malaria parasite infection in Nauth, Nnewi, Nigeria

Background: Human immunodeficiency virus (HIV) co-infection with malaria is the main cause of morbidity and mortality in developing countries, including Nigeria. Both infections have impact on the disease severity and progression. Methods: This was a cross-sectional study aimed to determine the serum soluble intracellular adhesion molecule-1 (sICAM-1) and albumin in HIV/malaria-infected individuals attending the antiretroviral therapy (ART) clinic at Nnamdi Azikiwe Teaching Hospital, (NAUTH) Nnewi, Nigeria. 168 randomly selected individuals aged 18-65 years grouped into 42 HIV-infected individuals on ART, 42 HIV-malaria c-o-infected individuals on ART, 42 malaria-infected individuals, and 42 apparently healthy individuals (control) were included in the study. Serum sICAM-1 and albumin were determined using enzyme linked immunosorbent assay (ELISA) and bromocresol green technique respectively while CD4 T-cell count was obtained from the patients’ records. Results: The mean serum sICAM-1, albumin and systolic blood pressure (SBP) levels were significantly higher in HIV individuals with and without malaria infection when compared with control participants (p<0.05) respectively. The mean CD4 T-cell count was significantly lower in HIV/malaria co-infected individuals when compared with HIV infected individuals (p <0.05). A significant negative correlation was observed between CD4 count and sICAM-1 both in HIV infected individuals and HIV-malaria co-infection (p<0.05). Conclusions: The increased sICAM-1, SBP with decreased albumin levels suggests inflammatory and vascular changes with reduced hepatic synthesis which may result in endothelial dysfunction, adverse cardiovascular conditions, and disease progression.

Study of the Effects of Thermal Annealing on the Optical Band Gap of Nanocrystalline CoO Thin Films Prepared by Chemical Bath Deposition.

Nanocrystalline films of cobalt oxide have been prepared on glass slides by chemical bath deposition process. For deposition of CoO thin films, cobaltous chloride [CoCl2.6H2O] was used as cationic and ammonia [NH3] as anionic precursor in aqueous medium. In this process NaOH was used as complexing agent. X-ray diffraction, scanning electron microscopic [SEM] analysis have been used to study the films’ crystal structures, optical and solid state properties. We hereby present the effects of thermal annealing on the optical band gap of CoO thin films. The optical transition in the films is direct one. For the as- deposited film, the band gap is 2.1eV. This later decreased to 2.08eV, so that increased thermal annealing reduces the optical band gap of CoO. However,the energy gap cannot be said to be dependent on the annealing temperatures. These films could be used as  photovoltaic cells, sensors light emitting diodes and also in biomedical imaging. Key Words: Nanocrystalline CoO, Chemical Bath Deposition, Band Gap and                               Thermal Annealing

Validation of Wound-QoL Questionnaire among Patients with Acute Wounds in Enugu, South-east Nigeria

Globally, health related quality of life (HRQoL) has become an essential wound outcome measure in evaluating holistic care, clinical practice and research. In Nigeria, there is a dearth of validated studies on standardised instruments to assess quality-of-life in patients with acute wounds. This study validated the Wound-QoL questionnaire in Nigeria. It was a single-blinded randomized controlled study, carried out amongst 42 participants using simple blocked randomization to assign patients to different groups (Biodress, honey and povidone-iodine). Wound-QoL was used for data collection with due ethical consideration and data analysis. The median age of the participants was 32.5 years, with a slight male preponderance (52.4%). The global score was above 0.7 at both times tested with the subscale scores ranging from 0.420 to 0.754. The mean values for both Wound-QoL global scores (T0: 0.83, T1: 0.79) and two subscale scores (body: T0: 1.28, T1: 1.17, everyday life: T0: 0.61, T1: 0.58) decreased over time while the psyche subscale remained unchanged (T0: 0.53, T1: 0.53). On item selectivity, the global score was significantly correlated to each of the items and the subscales. This result showed that acute wounds affect patients’ quality of life. It also indicates that the Wound-QoL questionnaire has positive psychometric properties. The Wound-QoL is a valid and reliable tool in assessing quality of life of people with acute wounds in Nigeria. A large-scale study in different regions of the country is recommended bearing in mind the cultural differences