Equal Channel Angular Extrusion Characteristics on Mechanical Behavior of Aluminum Alloy

Materials strengthened by conventional methods such as strain hardening, solute additions, precipitation and grain size refinement are often adopted in industrial processes. But there is limitation to the amount of deformation that these conventional methods can impact to a material. This study focused on the review of major mechanical properties of aluminum alloys in the presence of an ultrafine grain size into polycrystalline materials by subjecting the metal to an intense plastic straining through simple shear without any corresponding change in the cross-sectional dimensions of the sample. The effect of the heavy strain rate on the microstructure of aluminum alloys was in refinement of the coarse grains into ultrafine grain size by introducing a high density of dislocations and subsequently re-arranging the dislocations to form an array of grain boundaries. Hence, this investigation is aimed at gathering contributions on the influence of equal channel angular extrusion toward improving the mechanical properties of the aluminum alloys through intense plastic strain

Breast cancer receptor status assessment and clinicopathological association in Nigerian women: A retrospective analysis

Background: Breast cancer markers are becoming increasingly important in breast cancer research due to their impact on prognosis, treatment and survival. The present retrospective study was carried out to quantify the proportion of estrogen (ER), progesterone (PR), and human epithelial receptor 2 (HER2) expressions and their association with tumour grade, age, and tumour size in breast cancer patients in Nigeria. Materials and methods: The paraffin embedded tissue sections were analysed for breast cancer markers using monoclonal antibody SP1 for ER and SP2 for PR and polyclonal antibody ErbB2 for HER2. Results: A total of 286 breast cancer paraffin wax tissue sections were analysed for ER, PR and HER2 expression. Of all the tissue samples examined, 20 (7%) were ER-positive, 6 (2.1%) were PR-positive, 11 (3.8%) were HER2-positive whereas 248 (87%) were triple-negative breast carcinoma. ER- and PR-positivity was associated with early grade I and II tumours (P 50mm (P < 0.0001). Conclusion: A small proportion of Nigerian women with breast cancer are ER/PR-positive which are associated with less aggressive, better prognosis and benefit from endocrine therapy. An even smaller proportion of patients with aggressive tumors were HER2-posivite but responsive to Herceptin treatment. Unfortunately, a very high proportion of cases were triple-negative which is associated with very aggressive tumours and no targeted treatment, which may explain the high mortality rates from breast cancer in Nigeri

Morphological spectrum and epidemiological profile of ovarian tumours in black West African women at Lagos state university teaching hospital, Ikeja, Nigeria

Background: This study was done to evaluate the histological types, frequency and age distribution of ovarian tumours in Lagos State University Teaching Hospital (LASUTH), Ikeja, Lagos State. This study also aims to classify ovarian tumours in this centre according to the World Health Organisation (WHO).Methods: A retrospective, descriptive hospital study of all ovarian specimens that were sent to the department of pathology and forensic medicine, LASUTH between 1st January, 2011 and 31st December, 2019 was done. Relevant data composed of the age distributions and histopathological types were extracted from the departmental information system and filed documents. The data was analysed using the IBM-SPSS version 25.0.Results: There were 198 cases of ovarian tumours. The mean age at diagnosis of ovarian tumours was 34.6±15.3 years. Unilateral ovarian tumour was observed in 91.9%% of cases while bilateral disease was seen in 8.1%. Primary ovarian tumours constitute 97.0% of all diagnosed tumours of the ovary. Germ cell tumour was the most frequently diagnosed ovarian tumour; and teratoma was the most common, representing 91.2% of germ cell tumours and 47.0% of all ovarian tumours. Primary ovarian cancer peaked at the 6th decade of life and metastatic ovarian cancer was infrequently seen. Serous carcinoma is the most commonly diagnosed ovarian cancer.Conclusions: Ovarian tumour presents most frequently at the 4th decade of life, and germ cell tumour is the most common

Histopathology of bladder carcinomas: an eight year retrospective study at Lagos state university teaching hospital, Ikeja, Nigeria

Background: This study was undertaken to evaluate the histological types, frequency, age and sex distribution of bladder carcinoma in Lagos State University Teaching Hospital (LASUTH), Ikeja, Lagos state. This study aims to classify bladder carcinoma in this centre according to the World Health Organisation/ International Society of Urological Pathology.Methods: An eight-year retrospective study of all bladder carcinomas specimens that were sent to the department of Pathology and Forensic Medicine, LASUTH between 1st January, 2011 and 31st December, 2018 was done. Relevant data consisting of the age and sex distributions as well as histopathological types were extracted from the departmental information system and filed documents. The data was analysed using the IBM-SPSS version 25.0.Results: There were 87 cases of bladder tumours, out of which 55 (63.2%) were bladder carcinomas. The mean age at diagnosis of bladder carcinomas was 56.9±13.9 years. Sex distribution has male to female ratio of 1: 1. Urothelial carcinoma predominates as the most common histological type.Conclusions: Bladder carcinoma presents most frequently at the 5th decade of life, with a slight male preponderance

Modeling and Simulation of Hydrogen Storage Device for Fuel Cell Plant

The article reviews a brief literature on the modeling of hydrogen storage device for fuel cell. Different dimensional approaches in modeling hydrogen absorption/desorption in a metal hydride reactor for use in fuel cell are summarized. Mathematical modeling equations involved are also stated. The effect of various operating parameters such as temperature, concentration, viscosity, thermal conductivity and time on the gas is also verified. The importance of various simulation software with reference to their major functions is also identified. The review concludes on the opportunities and challenges with the use of hydrogen as an alternative renewable energ

Eclampsia: A Five-year Retrospective Review in Sagamu, South-West Nigeria

Context: Eclampsia is one of the leading causes of maternal and perinatal morbidity and mortality in developing countries. This is the result of poor health-seeking behavior of pregnant women and inadequate comprehensive emergency obstetric services. This study reviewed the presentation and management of eclampsia in Sagamu over a 5‑year period. Aims: This study aims to determine the prevalence, pattern of clinical presentation and fetomaternal outcomes of eclampsia. Settings and Design: This was a retrospective study conducted in Olabisi Onabanjo University Teaching Hospital Sagamu, Ogun state. Subjects and Methods: Relevant information was retrieved from case notes of all patients who presented with eclampsia from January 2014 to December 2018. Data were analyzed using SPSS version 21. Results: Out of the 4656 deliveries, there were 45 cases of eclampsia giving a prevalence of 0.97%. The modal age was 20–24 years. Majority were&nbsp; unbooked 41 (91.1%) and 29 (64.4%) of the women were nulliparas. Antepartum eclampsia was commonest occurring in 36 women (80%). The most common premonitory symptom was headache occurring in as high as 37 women (82.2%). Most of the patients 37 (84.4%) had an abdominal delivery. There were two maternal mortalities (4.4%) and four perinatal deaths (8.9%). There was no statistically significant association between factors such as booking status, type of eclampsia, mode of delivery and parity, and the fetal outcome (APGAR score at 1 min). Conclusions: Eclampsia is still one of the preventable causes of maternal and perinatal mortality in our environment. The prevalence of eclampsia in sagamu was 0.97%. Improved health-seeking behavior, antenatal care monitoring, and prompt diagnosis and management of preeclampsia will invariably reduce the prevalence of eclampsia. Keywords: Eclampsia, maternal, morbidity, mortality, perinata

Analysis of the variability of airborne particulate matter with prevailing meteorological conditions across a semi-urban environment using a network of low-cost air quality sensors.

The concentrations of fine and coarse fractions of airborne particulate matter (PM) and meteorological variables (wind speed, wind direction, temperature and relative humidity) were measured at six selected locations in Ile Ife, a prominent university town in Nigeria using a network of low-cost air quality (AQ) sensor units. The objective of the deployment was to collate baseline air quality data and assess the impact of prevailing meteorological conditions on PM concentrations in selected residential communities downwind of an iron smelting facility. The raw data obtained from OPC-N2 of the AQ sensor units was corrected using the RH correction factor developed based k-Kohler theory. This PM (corrected) fast time resolution data (20 s) from the AQ sensor units were used to create daily averages. The overall mean mass concentrations for PM2.5 and PM10 were 213.3, 44.1, 23.8, 27.7, 20.2 and 41.5 μg/m3 and; 439.9, 107.1, 55.0, 72.4, 45.5 and 112.0 μg/m3 for Fasina (Iron-Steel Smelting Factory, ISSF), Modomo, Eleweran, Fire Service, O.A.U. staff quarters and Obafemi Awolowo University Teaching and Research Farm (OAUTRF), respectively. PM concentration and wind speed showed a negative exponential distribution curve with the lowest exponential fit coefficient of determination (R2) values of 0.08 for PM2.5 and 0.03 for PM10 during nighttime periods at Eleweran and Fire service sites, respectively. The relationship between PM concentration and temperature gave a decay curve indicating that higher PM concentrations were observed at lower temperatures. The exponential distribution curve for the relationship between PM concentration and relative humidity (RH) showed that PM concentrations do not vary for RH 80 % for both day and nighttime. The performances of the MLR model were slightly poor and as such not too reliable for predicting the concentration but useful for improving predictive model accuracy when other variables contributing to the variability of PM is considered. The study concluded that the anthropogenic and industrial activities at the smelting factory contribute significantly to the elevated PM mass concentration measured at the study locations