Slug front gas entrainment in gas-liquid two-phase flow in horizontal and near horizontal pipes

This thesis presents experimental studies relating to gas-liquid slug flows in horizontal and near-horizontal pipelines. In such flows, liquid-continuous regions (“slugs”) pass along the pipe separated by regions of stratified flow (“elongated bubbles”) (see Chapter 1). Gas may be entrained at the slug fronts and is subsequently discharged into the elongated bubble at the slug tail. The focus of the work described in this thesis is on this gas entrainment process. Specifically, the aim is to make objective measurements of the slug front gas entrainment rate. A review of the earlier work (see Chapter 2) showed a large diversity of results for slug front gas entrainment. This reflects the difficulty of doing objective experiments on this important parameter. In the work described here, two new techniques for determining gas entrainment rate were implemented and investigated, namely the three-way valve method and the bubble shrinkage method. All of the experiments described in this thesis were with air-water flows at near atmospheric pressure, though the techniques developed could be applied to other fluid pairs and to different pressures. The three-way valve method involves diverting a slug front to pass over a stratified liquid layer and to determine the gas pick-up rate at the slug front from the slug front propagation velocity. The experiments were carried out for a 32.8 mm pipe in the LOTUS facility (described in Chapter 3) and for a 78 mm pipe using the WASP facility (also described in Chapter 3). The experimental results are presented in Chapters 4 and 5 respectively and show that the gas entrainment rate per unit film width is similar for the two diameters and depends on the relative velocity between the slug front and the liquid film ahead of it. The results indicate entrainment rates which are within the range previously measured but which are above those calculated from the existing correlations. A new correlation for prediction of gas entrainment in slug flow in horizontal pipes was developed which adequately predicts previous gas entrainment work (repeated here using LOTUS facility). In the bubble shrinkage method, the aim is to measure the shrinkage rate (and hence the rate of loss of gas by entrainment) of an elongated bubble passing along a pipe in a liquid flow. Development work on this method is described in Chapter 6 and (though the test section lengths were not sufficient to measure shrinkage accurately), it could be deduced (from measurements of the slug front (bubble tail) velocity) that the results were consistent with the three-way valve experiments. The actual phenomena accompanying gas entrainment at the slug front in slug flow are extremely complex and this was demonstrated with high speed video photography using an Olympus i-SPEED 3 system (see Chapter 7). Depending on the actual conditions, the advancing slug front could be attached to or detached from the preceding liquid layer. There were significant differences in the phenomena observed depending on the nature of the preceding liquid layer (stratified flow, descending liquid film, and stationary liquid film)

Human rhinosporidiosis of the nasal cavity: a case report.

Rhinosporidiosis is a rare chronic granulomatous disease caused by Rhinosporidium seeberi. It is endemic in some parts of Asia and commonly involves the mucous membrane of the nose presenting with nasal obstruction, a nasal mass, and epistaxis. The main treatment for rhinosporidiosis remains surgical excision, although it may recur after excision. Rhinosporidiosis is a condition that clinicians should keep in mind when managing patients with nasal masses even in non-endemic areas. Case presentation: A 52-year-old housewife presented with a 9-month history of left progressive nasal obstruction and progressive enlarging left nasal growth associated with recurrent nasal bleeding and nasal discharge. She had a history of rearing animals and bathing in ponds as well as engaging in farming activities. Examination revealed a fleshy polypoid mass attached to the nasal septum by pedicle and filling the whole of the left nasal cavity covered with a mucopurulent nasal discharge with associated contact bleeding. She had endoscopic resection under local anaesthesia with cauterization of the base of the mass with a silver nitrate pencil. A histopathological diagnosis of rhinosporidiosis was made. Conclusion: Rhinosporidiosis is rare in our environment, its presentation mimics that of nasal tumours. Therefore, it should be part of the differential diagnosis; both clinicians and pathologists should have it at the back of their minds when managing patients with nasal masses even in non-endemic areas

CHALLENGES AFFECTING THE PERFORMANCE OF SMALL AND MEDIUM SCALE ENTERPRISES (SMEs) IN NIGERIA

Small and medium scale enterprises (SMEs) have been identified as the catalysts and builders for economic growth and national development for both developed and developing countries, particularly Nigeria. The objective of this study is to investigate the challenges affecting the performance of SMEs in Nigeria. This paper identifies the challenges affecting the performance of SMEs in Nigeria to include financial constraints, infrastructural problems, management problems, marketing problems, technological problems, corruption problem, lack of skill labour, government unfavourable fiscal policy and policy inconsistence’s, inadequate training, socio-cultural problem, strategic planning problem, multiple taxation, and location and business environment problem. But this study discovered that the major challenges that affect the performance of SMEs in Nigeria are finance, infrastructure and training among other challenges which this study adequately focused on. This study suggests that finance, infrastructure and training should be given adequate concentration. Thus, it is recommended that the government should make loan available for SMEs entrepreneurs, interest rate charge should be single digit instead of double digit, and the collateral demanded by the financial institutions before given out any financial assistance should be fear or the collateral should not be demanded when the project embark on can serve as the collateral. There is a need for the government to improve the existing infrastructure such as power supply, transportation, communication, water supply and roads in the country. Lastly, the SMEs entrepreneurs should inculcate the habit of training and developing their management and workforce to build a strong capacity for meeting the challenges of time to embrace and take advantage of development

Coexistence of Kaposi sarcoma and Molluscum contagiosum on the same site in a HIV-AIDS patient: A very rare occurrence

Introduction: There have been numerous reported opportunistic infections among HIV/AIDS patients. However, coexistence of Kaposi sarcoma and Molluscum contagiosum on the same site is a rare finding. Case presentation: A 37-year-old man poorly adherent to antiretroviral therapy presented with Molluscum contagiosum and Kaposi sarcoma occurring simultaneously on numerous skin lesions around mid-2017 at Usmanu Danfodiyo University Teaching Hospital, Sokoto State, Nigeria. Management and outcome: The patient was counselled and re-initiated on a second-line highly active antiretroviral therapy regimen. The patient’s lesions resolved three months later. Discussion: The case is presented to improve the index of suspicion among clinicians and pathologists on such rare occurrences

Combined treatment of domestic and pulp and paper industry wastewater in a rice straw embedded activated sludge bioreactor to achieve sustainable development goals

The pulp and paper industry has been recognized as one of the largest users of water worldwide. Water is used in nearly every step of the manufacturing process. It generates significant amounts of wastewater and leftover sludge, creating several problems for wastewater treatment, discharge, and sludge disposal. Adopting the most effective and economical treatment techniques before discharging wastewater is therefore crucial. Thus, this study aims to evaluate the performance of the activated sludge bioreactor system (ASBS) for the treatment of pulp and paper industry wastewater (PPIW). The PPIW was characterized. During the experiment, the domestic and PPIW wastewater were run at a fixed HRT of 1 day. Subsequently, the ASBS was evaluated by varying the HRT and OLR. The HRT was varied in the range of 3, 2, and 1 day. At a fixed HRT of 2 days, the maximum and minimum COD removal were 88.4 and 63.2%. Throughout the study, the ASBS demonstrated higher treatment efficiency in terms of COD removal. First order, Grau second order, and modified Stover Kincannon biokinetic models were applied for the study. The biokinetic investigation shows that the modified stover kinetic model was more appropriate for the description of the experimental data in terms of microbial growth parameters. Thus, the kinetic coefficients obtained in this study could be used for the bioreactor scale-up. The study has also proven that the biosorbent made from biomass waste can potentially help preserve non-renewable resources and promote zero-waste attainment and principles of a circular bioeconomy

CHRONIC KIDNEY DISEASE AMONGST SICKLE CELL ANAEMIA PATIENT AT THE UNIVERSITY OF MAIDUGURI TEACHING HOSPITAL, NORTH EASTERN NIGERIA: A STUDY OF PREVALENCE AND RISK FACTORS

ABSTRACT Introduction: Involvement of the kidneys in patient with sickle cell anaemia is a well recognized chronic complication of this disorder. The index study seeks to determine the prevalence of chronic kidney disease in patients with homozygous sickle cell disease (HbSS) and to identify risk factors associated with its development. Methodology: The subjects consisted of adolescents and adults with HbSS recruited sequentially from the adult haematology outpatient clinic and Day care ward of the unit. Clinical variables including age of diagnosis of SCA, frequency of vaso-occlusive crisis and transfusion therapy, as well as laboratory data including haematological profile, renal function test were obtained from routine blood result. The glomerular filtration rate was estimated (eGFR) using the ‘modification of diet in renal disease’ (MDRD) formula.. Results: Two hundred and eighty-four HbSS patients were recruited. The prevalence of CKD amongst them was 38.9%.  Further stratification of the patients based on eGFR showed that sixty-nine (26.8%) had hyperfiltration; 35 (13.6%) stage 1 CKD; 53 (20.6%) stage 2 CKD; 61 (23.7%) stage 3 CKD; 30 (11.7%) stage 4 CKD and 9 (3.5%) had end stage renal disease. There was significant association between eGFR and clinical parameters such as age (r -0.353, p=0.000), SBP (r -0.148, p= 0.021), DBP (r -0.213, p=0.001) and total number of blood received (r -0.276, p=0.000); and laboratory parameters such as  PCV (r 0.371, p=0.000); urea ( r 0.527, p=000 ); creatinine (r 0.625, p=0.000) and uric acid  ( r -0.419, p=0.000). Conclusion The present study has revealed a high prevalence of CKD amongst patients with SCA in this region. Various clinical and laboratory predictors of eGFR were also identified. Monitoring and detection of early stages of these groups of patients may allow for interventions which may delay progression into advance stages and ESRD

Global, regional, and national incidence, prevalence, and years lived with disability for 328 diseases and injuries for 195 countries, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

As mortality rates decline, life expectancy increases, and populations age, non-fatal outcomes of diseases and injuries are becoming a larger component of the global burden of disease. The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of prevalence, incidence, and years lived with disability (YLDs) for 328 causes in 195 countries and territories from 1990 to 2016

Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed