Numerical prediction of laminar nanofluid flow in rectangular microchannel

Numerical simulation of laminar nanofluid flow in Three-dimensional (3D) straight rectangular microchannel heat sink is carried out. In this study the behavior and effect of using pure water and Fe3O4-H2O as working fluids in the microchannel are examined. Fe3O4-H2O with volume fraction range of 0.4% - 0.8% are used in this simulation to evaluate the cooling performance of microchannel heat sink. Fluent, a Computational Fluid Dynamic (CFD) is used as the solver of simulation. A rectangular microchannel with hydraulic diameter of 86 µm and length of 10mm under the boundary condition of constant heat flux and uniform inlet velocity is set on this analysis. The Results of present work show that using Fe3O4-H2O as coolant resulted in to higher efficiency of heat transfer in microchannel heat sink in comparison to Pure water. However, using Fe3O4-H2O with 0.8% volume fraction provide a high heat transfer enhancement of 30% as compared to 0.4% and 0.6% volume fractions of the same Fe3O4-H2O. Numerical results show that increasing the thermal conductivity of working fluid can enhanced heat transfer. Therefore, it is equally important to note that the presence of nanoparticles could enhance the cooling of MCHS. Meanwhile, higher Nusselt number is found as fluid enters the channel inlet. This could be anticipated as a result of the development of thermal entry region at the channel and the values of Nusselt number tend to stabilize after fully develop region has been achieved

Preliminary field survey on Mycobacterium bovis infection in cattle herds using caudal fold intradermal tuberculin test in two Northeastern States of Nigeria

Aim: A survey was conducted to determine the prevalence of bovine tuberculosis (bTB) in two states of Northeastern Nigeria, namely Bauchi and Gombe States, between February 2010 and November 2014 using caudal fold tuberculin (CFT) skin test. Materials and Methods: A total of 5489 cattle were screened using single CFT in Bauchi and Gombe States. Of the 5489 cattle, 2116 cattle were from 189 herds in five testing areas in Bauchi State and 3373 cattle in 217 herds from five testing areas from Gombe State. Results: On the basis of the CFT, herd prevalence obtained was 56.08% in Bauchi and 55.29% in Gombe State, while the individual animal prevalence was 10.96% in Bauchi and 13.73% obtained in Gombe State. The prevalence based on the testing areas in Bauchi State, Alamari had the highest prevalence with 19.4 % and Disina the lowest with 9.0 %, while in Gombe State, Wakaltu had the highest prevalence with 20.9 % and Poshereng the lowest with 8.0 %. Cows were more likely to have tuberculosis lesions than bulls (p=0.0035) in Bauchi State, but there was no significant difference in Gombe State (p=0.166). However, a statistically significant association (p<0.05) was observed among the cattle age groups with cattle ≥4 years having higher odds for tuberculin reactivity compared to those below the age of 4 years in Bauchi State only. Conclusion: There is the need to strengthen routine meat inspection and public health awareness programs on the zoonotic nature of bTB among the abattoir workers and the herdsmen

Epidemiology of COVID-19 and Predictors of Outcome in Nigeria: A Single-Center Study.

There is a paucity of information regarding the epidemiology and outcome of COVID-19 from low/middle-income countries, including from Nigeria. This single-center study described the clinical features, laboratory findings, and predictors of in-hospital mortality of COVID-19 patients. Patients admitted between April 10, 2020 and June 10, 2020 were included. Forty-five patients with a mean age of 43 (16) years, predominantly male (87%), presented with fever (38%), cough (29%), or dyspnea (24%). In-hospital mortality was 16%. The independent predictors of mortality were hypoxemia (adjusted odds ratio [aOR]: 2.5; 95% CI: 1.3-5.1) and creatinine \u3e 1.5 mg/dL (aOR: 4.3; 95% CI: 1.9-9.8)

Solubility trapping as a potential secondary mechanism for CO2 sequestration during enhanced gas recovery by CO2 injection in conventional natural gas reservoirs : an experimental approach

This study aims to experimentally investigate the potential of solubility trapping mechanism in increasing CO2 storage during EGR by CO2 injection and sequestration in conventional natural gas reservoirs. A laboratory core flooding process was carried out to simulate EGR on a sandstone core at 0, 5, 10 wt% NaCl formation water salinity at 1300 psig, 50 °C and 0.3 ml/min injection rate. The results show that CO2 storage capacity was improved significantly when solubility trapping was considered. Lower connate water salinities (0 and 5 wt%) showed higher CO2 solubility from IFT measurements. With 10% connate water salinity, the highest accumulation of the CO2 in the reservoir was realised with about 63% of the total CO2 injected stored; an indication of improved storage capacity. Therefore, solubility trapping can potentially increase the CO2 storage capacity of the gas reservoir by serving as a secondary trapping mechanism in addition to the primary structural and stratigraphic trapping and improving CH4 recovery

Mammographic screening patterns in Sokoto, Northwestern Nigeria

Background: Screening mammography is a radiographic examination of the breast performed for early detection of breast cancer in asymptomatic women. The American College of Radiology recommends that women should have mammography at the age of 40 years and annually thereafter. However, those who are at increased risk of breast cancer should start screening mammography earlier. These include patients with a strong family history of breast cancer or those who had radiotherapy to the chest wall. Objective: This study is aimed at evaluating the mammographic outcomes among 77 Nigerian females who had screening mammographic breast examination. Materials and Methods: From December 2010 and November 2012, 77 females had routine screening mammography in the department with the general electric alpha-RT machine with model number MGF-101 (manufactured 2010). All the participants had to fill a mammographic form consisting of variables such as age, sex, occupation, family history of breast cancer, tribe, contraception, parity and caffeine consumption, history of surgical intervention (lumpectomy, biopsy, and/or mastectomy), previous mammography, and last childbirth. Mediolateral-oblique and cranial-caudal views were done for the breast examination though additional were occasionally employed. Results: Seventy-seven females had screening mammography. The minimum age recruited was 40 years. The mammographic outcome for those who had screening was normal in 51 (66.2%) and abnormal in 26 (33.8%) participants. The abnormal mammographic outcomes were architectural distortion in either or both breasts in 13 (16.9%) participants, masses in either or both breast in 11 (14.3%) participants, while isolated calcification in either or both breast among 2 (2.6%) participants. Two (18.2%) of the subjects with masses had associated macrocalcification. No masses with malignant features were seen. Conclusion: Screening mammography was found out to be useful in detecting various forms of breast pathologies which were mostly breast masses, calcifications, and architectural distortions. Screening mammography is, therefore, advised yearly and routinely for women age 40 years and above

Antioxidant-based neuroprotective effect of dimethylsulfoxide against induced traumatic brain injury in a rats model

Traumatic brain injury (TBI) has been the result of neurological deficit and oxidative stress. This study evaluated the antioxidative neuroprotective property and learning and memory-enhancing effects of dimethyl sulfoxide (DMSO) in a rat model after the induction of TBI. 21 albino rats with 7 rats per group were used in this study. Group I was induced with TBI and treated with DMSO at 67.5 mg/kg orally once daily which started 30 min after the induction of TBI and lasted 21 days. Group II was induced with TBI but not treated while Group III was neither induced with TBI nor treated. Assessment of behavioral function (Learning and memory, anxiety and motor function), the level of an antioxidant enzymes and their gene expression (superoxide dismutase, catalase, glutathione peroxidase), the biomarkers of oxidative stress (malondialdehyde) and S100B levels as well as brain tissues histological studies were conducted. Administration of DMSO to rats with induced TBI has improved learning and memory, locomotor function and decreased anxiety in Group I compared to Group II. Moreover, the level of S100B was significantly (p < 0.05) lower in Group I compared to Group II. Treatment with DMSO also decreased lipid peroxidation significantly (p < 0.05) compared to Group II. There exists a significant (p < 0.05) increase in CAT, SOD, and GPX activities in Group I compared to Group II. Therefore, DMSO has demonstrated a potential antioxidative neuroprotective effect through its ability to increase the level of antioxidant enzymes which they quench and inhibit the formation of ROS, thereby improving cognitive functions

Polio eradication in Nigeria: evaluation of the quality of acute flaccid paralysis surveillance documentation in Bauchi state, 2016

Abstract Background Nigeria is the only country in Africa that is yet to be certified as polio free. Surveillance for acute flaccid paralysis (AFP) is the foundation of the polio eradication initiative since it provides information to alert both health managers and clinician that timely actions should be initiated to interrupt transmission of the polio virus. The strategy also provides evidence for the absence of wild poliovirus. This evaluation was performed to assess key quality indicators defined by the polio eradication program and thus to identify gaps to allow planning for corrective measures to achieve a polio-free situation in Bauchi state and in Nigeria at large. We conducted a cross-sectional descriptive study which involved a desk review of documents to authenticate the correctness and completeness of data, and a review of documented evidence for the quality of AFP surveillance. We interviewed Local Government Authority (LGA) surveillance officers and clinicians from focal and non-focal sites, along with caregivers of children with AFP and community leaders. The data were entered and analyzed in a Microsoft Excel spreadsheet. Methods We conducted a cross-sectional study of the AFP surveillance and documentation in eighteen of the twenty Local Government Areas (LGAs) of Bauchi State. We assessed the knowledge of the clinician at focal and non-focal sites on case definition of AFP, the number and method of stool specimen collection to investigate a case and types of training received for AFP surveillance. We verified AFP case investigations for the last three years: The caregivers (mothers) were interviewed to authenticate the reported information of AFP cases, the method used for stool specimen collection and feedbacks. Community leaders’ knowledge on AFP surveillance was also assessed. Data was entered and analyzed in excel spread sheet. Results Of the 18 LGA Disease Surveillance and Notification Officers (DSNOs), only 2 (11%) and 5 (28%) had reports of polio outbreak investigations and supervisory visits at the lower levels, respectively. Furthermore, only 6 (33%) and 7 (39%) of the DSNOs had minutes of meetings and surveillance work plans, respectively. Of the 31 AFP cases investigated, only 39, 26, 23, and 23% had correct and complete information for the birth day, birth month, date of onset of paralysis, and date of investigation, respectively. Seventy-one percent of the clinicians at the AFP focal sites knew the correct definition for AFP compared with only 30% at the non-focal sites. Of the 38 caregivers (mothers), 16 (42%) did not remember the day or month the AFP investigation was conducted. However, 95% gave a correct number of stool samples collected and 40% mentioned that the samples were collected 24 h apart. Feedback was not given to 26 (68%) of the caregivers. The majority (79%) of the community leaders knew how to recognize a case of AFP and knew that the stool was the specimen required for the investigation, but 21% did not know to whom they should report a case of AFP in their community. Conclusion This study revealed a gap in the quality indicators for polio eradication in the state, especially regarding knowledge and documentation for AFP surveillance at the operational level. Regular training of the DSNOs and focal persons, regular sensitization of clinicians, community education, supplies of reporting tools, and ensuring their judicious use will improve AFP surveillance in the state