Challenges in the management of cervicofacial necrotizing fasciitis in a developing economy: our experience

Background: Necrotizing fascitis is uncommon but a life threatening cervico-facial infection, which is characterized by aggressive spread of inflammation and necrosis of the tissues. In our environment clinical presentation is often late and patient's management at this stage is very challenging. We present the challenges in the management of this lesion as experience in our centres.Methods: We carried out clinical evaluation on the management and treatment options amongst the 11 patients that presented with cervicofacial necrotizing fascitis at two tertiary hospitals in South east, Nigeria over a 3-year period from 2012 to 2015. The focus was on the management challenges which include diagnosis, lack of modern facilities and treatment options, associated co- morbidities such as retroviral disease and diabetes mellitus, financial constraint and incessant industrial action by the medical and allied workforce.Result: There were 7 males (63.6%) and 4 females (36.7%) giving a male-to-female ratio of 1.8: 1 aged between 27 – 78 years with a mean of 57.4 ± 17.9 years. All presented as emergency and were hospitalized. Six (54.5%) were treated successfully with mortality rate of 9.1% (one patient) recorded. Four (36.4%) were lost to follow up., two of which were referred as a result of industrial action while the other 2 were discharged against medical advice.Conclusion: Patients often presents late and with limited options of treatment in a depressed economy treatment is often very challenging. Since poor oral hygiene is a modifiable risk factor, emphasis on oral health care should be a preventable measure.Keywords: Cervicofacial, Necrotizing fasciitis, Challenges, Management, Developing econom

Effect of Particle Sized Clay Extender Pigment on Alkyd Paint Formulations

The effects of particle sizes on the properties of Ihitte-Uboma clay formulated alkyd paints have been studied. The clay particle sizes studied are 75, 150and 300 µm at clay contents 0 – 80 wt. %. Xylene was used as the solvent while TiO2 formulated alkyd paint served as reference alkyd paint in this study. The extender pigments were characterized using X-ray fluorescence and scanning electron microscope. The physic-chemical properties of the extender pigments were determined using ASTM measurements. The properties of the paint samples were evaluated according to ASTM. Results showed that the alkyd paints had higher viscosities which increased with increases in clay contents at the three clay particle sizes investigated. The drying properties of the paints were generally good. The dry film thicknesses of the formulated paints were in the range of 0.29 – 0.38 mm. The formulated paints exhibited moderate settling tendencies at the 75 µm clay particle size when compared with the other particles. There was no mildew formation observed on all the paint samples on exposure to rain and sunlight. Generally, all the paint samples exhibited good resistance to distilled water, 3 % H2SO4, and 3 % Na2CO3. The formulated paint samples were affected on 3 % NH3 immersion which resulted to wrinkles. The improved properties obtained from the clay formulated paints which include thermal and colour stability, viscosity, specific gravity

Modeling and Optimization of Performance of Four Stroke Spark Ignition Injector Engine

The performance of an engine whose basic design parameters are known can be predicted with the assistance of simulation programs into the less time, cost and near value of actual. This paper presents a comprehensive mathematical model of the performance parameters of four stroke spark ignition engine. The essence of this research work is to develop a mathematical model for the analysis of engine performance parameters of four stroke spark ignition engine before embarking on full scale construction, this will ensure that only optimal parameters are in the design and development of an engine and also allow to check and develop the design of the engine and it’s operation alternatives in an inexpensive way and less time, instead of using experimental method which requires costly research test beds. To achieve this, equations were derived which describe the performance parameters (sfc, thermal efficiency, mep and A/F). The equations were used to simulate and optimize the engine performance of the model for various engine speeds. The optimal values obtained for the developed bivariate mathematical models are: sfc is 0.2833kg/kwh, efficiency is 28.77% and a/f is 20.75. Keywords: Bivariate models, Engine performance, Injector engine, Optimization, Performance parameters, Simulation, Spark ignitio

Experimental Investigation on Effect of Head and Bucket Splitter Angle on the Power Output of A Pelton Turbine

This paper investigates through experiment, the effect of head and bucket splitter angle on the power output of a pelton turbine (water turbine), to improve the power generation by the use of efficient Hydro-electric power generation systems. Experiments were conducted on pelton turbine head conditions, high head and low flow with increased pressure delivered more energy on the bucket splitter which then generates a force in driving the wheel compared to the result obtained from low head and high flow operating conditions. The power output was maximum at 23o splitter angle followed by 21o, 15o, 10o and 3o using varied turbine speed (1700, 1400, 1200 and 1000rpm). The force generated by the bucket due to the splitter was increased as the turbine speed was increasing. The force generated by the bucket was increased (0 to 0.38N) due to the energy delivered to the wheel by the head, the turbine output increases from (0 to 7.47kW) which influences the output. This increase in the power output was as a result of their head conditions and the bucket splitter angle

Evaluation of Frictional Heat and Oil Cooling Rate in Mechanical Contact Due to Debris Formation

This paper evaluated experimentally, the amount of frictional heat generated in a Mitsubishi main journal bearing and the cooling performance of the lubricating oils A, B and C. The test rig used in this experiment is a mechanical apparatus that consists of mechanical drive, metal support, bevel gear, a rotating shaft and a bearing attached at its lower end. When the shaft was rotated by the mechanical drive of power 0.75kw and speed 1440rpm, the frictional force in journal bearing helped to convert the mechanical energy of the drive into frictional heat. The amount of heat absorbed from the surface of the journal bearing by the oil cooled the surface. The cooling rate of the oil was obtained at each time interval. The vibrating movement of the molecules helped to transfer the frictional heat to the lubricant and the calorimeter. This effect caused the temperature of the system to rise. The frictional heat generated at the contact increased linearly with the change in temperature in the mechanical contact which was absorbed differently in the three lubes, depending on their heat capacity and molecular movement. When there was no debris in the contact, the temperature changed within the range of 1.2-1.80C at interval of 3minutes in oil B, 10C in oil C and 0.8-1.20C in oil A. When there was sand debris in the contact, the temperature changed within the range of 2-2.50C at interval of 3minutes in oil B, 1.5-20C in oil C and 20C in oil A. Oil B has the best cooling performance based on the three local lubes used and was equally the most expensive. Mechanical failures like galling, fatigue and surface indentation occurred when the vibrational force (energy) of the molecules were greater than the binding force or energy of the atomic lattice of the bearing

Ameloblastoma of the jaws in children: an evaluation of cases seen in a tertiary hospital in South-Eastern Nigeria

Background: Ameloblastoma is one of the most common benign odontogenic tumours in Nigeria. It is considered uncommon in children. Materials and methods: This is a retrospective study of pediatric patients with histopathological diagnosis of ameloblastoma seen over seven years at the Oral and Maxillofacial Surgery Department of the University of Nigeria Teaching Hospital, Enugu, Nigeria. Relevant information was retrieved from patients’ records and data obtained were analysed using SPSS version 23, the chi-square test was used to compare qualitative variables, a p-value of <0.05 was considered as significant. Results: One hundred and thirty-six cases of ameloblastoma in all age groups were seen within the period. Thirty of the cases met the requirement. The mean age of the patients was 14.4 STD 2.03 (range from 10-17) years. Fourteen (46.7%) patients were male while 16 (53.3%) were female giving a ratio of 1:1.1. The duration of the lesion ranged from 3 months to 72 months (mean 15.07 months). Histologically, the follicular type (n=20, 66.7%) constitute the majority, while the clinical types were solid-multicystic (n=18, 60%) and unicystic (n=12, 40%). Enucleation was the treatment of choice in most (n=18, (60%)) of the patients. Conclusion: Ameloblastoma is relatively uncommon in children, especially those less than ten years of age. The solidmulticystic variety was the predominant type in the children studied. Most patients presented long after the onset of the tumour and enucleation with mechanical curettage produced satisfactory results in these patients. Keywords: Ameloblastoma, odontogenic tumour, children, resection, enucleation. Funding: None declare

MasakhaNER 2.0: Africa-centric Transfer Learning for Named Entity Recognition

African languages are spoken by over a billion people, but are underrepresented in NLP research and development. The challenges impeding progress include the limited availability of annotated datasets, as well as a lack of understanding of the settings where current methods are effective. In this paper, we make progress towards solutions for these challenges, focusing on the task of named entity recognition (NER). We create the largest human-annotated NER dataset for 20 African languages, and we study the behavior of state-of-the-art cross-lingual transfer methods in an Africa-centric setting, demonstrating that the choice of source language significantly affects performance. We show that choosing the best transfer language improves zero-shot F1 scores by an average of 14 points across 20 languages compared to using English. Our results highlight the need for benchmark datasets and models that cover typologically-diverse African languages