Gender as a moderator between work-family conflict, job and family satisfaction

The study examined the effect of work-family conflict on job and family satisfaction among university junior staff in Ghana. It further tested the moderating role of gender on the relationship between work-family conflict dimensions and job and family satisfaction. A quantitative approach was adopted. A multi-stage sampling technique was employed to select 339 respondents. Descriptive and inferential statistics were used to analyse the data. The results revealed a negative effect of work-family conflict on both job satisfaction and family satisfaction. Further analysis showed that gender moderates the relationship between work-family conflict (FIW) and family satisfaction. Recommendations are made to the University authorities and employees on how to minimize the negative effects of work-family which can lead to better job and family satisfaction in this paper.Keywords: work-family conflict, job satisfaction, family satisfaction, gender, junior staf

Warfarin-induced skin necrosis: a rare condition

Warfarin induced skin necrosis is a rare debilitating and, in some cases, life-threatening complication. A 47-year-old male on life-long anticoagulation omits his medication and develops extensive skin necrosis of the left leg complicated by acute renal failure three days after restarting warfarin. Investigations reveal possible Protein S deficiency which is known to be a predisposing condition. Various mechanisms have been proposed as the underlying cause. He was managed on heparin, wound debridement and skin grafting. Warfarin was restarted concurrently with heparin. Knowledge of this complication will enable timely diagnosis and treatment

Clinicopathologic characteristics of early-onset breast cancer: a comparative analysis of cases from across Ghana

BACKGROUND: Breast cancer is the commonest cancer diagnosed globally and the second leading cause of cancer-related mortality among women younger than 40 years. This study comparatively reviewed the demographic, pathologic and molecular features of Early-Onset Breast Cancer (EOBC) reported in Ghana in relation to Late Onset Breast Cancer (LOBC). METHODS: A descriptive, cross-sectional design was used, with purposive sampling of retrospective histopathology data from 2019 to 2021. Reports of core or incision biopsy, Wide Local Excision or Mastectomy with or without axillary lymph node dissection specimen and matched immunohistochemistry reports were merged into a single file and analysed with SPSS v. 20.0. Descriptive statistics of frequencies and percentages were used to describe categorical variables. Cross-tabulation and chi-square test was done at a 95% confidence interval with significance established at p \u3c 0.05. RESULTS: A total of 2418 cases were included in the study with 20.2% (488 cases) being EOBCs and 79.8% (1930 cases) being LOBCs. The median age at diagnosis was 34.66 (IQR: 5.55) in the EOBC group (\u3c 40 years) and 54.29 (IQR: 16.86) in the LOBC group (≥ 40 years). Invasive carcinoma-No Special Type was the commonest tumour type with grade III tumours being the commonest in both categories of patients. Perineural invasion was the only statistically significant pathologic parameter with age. EOBC was associated with higher DCIS component (24.8% vs 21.6%), lower hormone-receptor-positive status (52.30% vs 55.70%), higher proliferation index (Ki-67 \u3e 20: 82.40% vs 80.30%) and a higher number of involved lymph nodes (13.80% vs 9.00%). Triple-Negative Breast cancer (26.40% vs 24.30%) was the most predominant molecular subtype of EOBC. CONCLUSION: EOBCs in our setting are generally more aggressive with poorer prognostic histopathological and molecular features when compared with LOBCs. A larger study is recommended to identify the association between relevant pathological features and early onset breast cancer in Ghana. Again, further molecular and genetic studies to understand the molecular genetic drivers of the general poorer pathological features of EOBCs and its relation to patient outcome in our setting is needed

Process modelling of sugar mill biomass to energy conversion processes and energy integration of pyrolysis

ENGLISH ABSTRACT: The sugar industry over the years has been producing sugarcane bagasse as part of the sugar milling process. Currently this sugar mill biomass is incinerated inefficiently as a means of their disposal to produce steam and electricity, which in most cases are only just enough to supply the energy required to run the mills, thereby leaving very little or no extra energy for sale to bring in extra income in addition to sales revenue from sugar. However, the recent instability and uncertainties in the price of sugar and the global call for a green and sustainable environment have necessitated the search for ways of making effective use of this biomass to supply sugar mill energy demands, while producing extra energy in the form of electricity and other energy products for sale and at the same time contributing towards environmental sustainability. The main objective of this work was to develop process models for the processing of sugar mill biomass into energy and energy products. Based on this, biomass to energy conversion process (BMECP) models have been developed for various process configurations of two thermochemical processes; Combustion and Fast Pyrolysis using the Aspen Plus® simulation software. The aim of process modelling was to utilizing sugar cane bagasse as an input energy source to supply the energy requirements of two sugar mill configurations (efficient and less efficient mills), while generating extra electricity and high valued energy products for sale. Four BMECP configurations; 30bar BPST, 40bar CEST, 63bar CEST and 82bar CEST systems were modelled for the combustion thermochemical process. For the fast pyrolysis thermochemical process, two process configurations: Pure Fast Pyrolysis BMECP and Partial Fast Pyrolysis BMECP were modelled. The former BMECP utilizes all available bagasse through fast pyrolysis to produce bio-oil and biochar alongside generating electricity as well as energy to run the sugar mill operations. In the latter BMECP model, only surplus bagasse after separation of the quantity needed to supply the sugar mill energy requirement and electricity production is used to produce bio-oil and biochar. The technical performance of the BMECP models have been analysed and compared based on steam and electricity production rates, process efficiencies and environmental impacts (based on CO2 savings). The effects of boiler operating pressure and bagasse moisture content on the performance of the combustion based BMECP models have also been investigated. Finally, detailed economic models have been developed using the Aspen Process Economic Analyzer (Icarus®) to assess the economic viability of the BMECP models and sensitivity analysis performed to study the response of the BMECP models to variations in economic parameters. Technical performance analysis shows the combustion based BMECP models perform better than the Pure Fast Pyrolysis and Partial Fast Pyrolysis BMECP models with regards to steam and electricity production, thereby giving them higher electrical efficiencies. The electricity generation rate has been shown to increase with increasing boiler operating pressure and decreasing bagasse moisture content while steam production rate has been shown to increase with decreasing bagasse moisture content and decreasing boiler operating pressure. Despite the lower electrical efficiencies of the fast pyrolysis based BMECP models, the analysis shows that their overall process efficiencies compare very well with those of the combustion based BMECP models due to the production of high energy value pyrolysis products. Based on common operating pressure and 50% bagasse moisture content, the Pure Fast Pyrolysis and the Partial Fast Pyrolysis models have proved to be more environmental friendly with hourly CO2 savings of 40.44 and 41.30 tons for the Partial Fast Pyrolysis BMECP and the Pure Fast Pyrolysis BMECP respectively based on a 300 ton of sugarcane/h (81 ton bagasse/h) plant size. From an economic point of view, biomass combustion based on the 63bar CEST BMECP model has proved to be the most economically viable option under current economic conditions. First order total capital investment estimate for this BMECP is about $116 million, producing NPV of$390 million at the end of a 20 year plant life and IRR of 34.51%. The Pure Fast Pyrolysis BMECP model is the least economic viable option. Sensitivity analysis shows this BMECP model is the most sensitive to changes in bagasse and electricity prices; recording -191.61/+446.86% change in NPV for a ±30% change in bagasse price and -91.5/+338.60% for a ±30% change in electricity price.AFRIKAANSE OPSOMMING: Die afgelope jare het suikerriet-afval (bagasse) by suikermeule ‘n belangrik byproduk van die suiker-industie geraak. Tans word hierdie afval of biomasse verbrand in die suikermeule se poging om stoom en elektrisiteit op te wek; maar die die proses is oneffektief. Die hoeveelheid energie wat opgewek word, is skaars genoeg om die suikermeule self aan die gang te hou; daar is feilik geen sprake ‘n surplus energie waaruit ekstra inkomste verkry kan word toevoegend tot inkomste uit die suiker verkope self. Die huidige onstabiele suikerprys en gepaardgaande onsekerhede sowel as die werêldwye oproep vir ‘n groen- en volhoubare omgewing, noodsaak ‘n nuwe soeke na effektiewe manier om die afvalmateriaal sinvol te verwerk. Die tipe effektiwiteit van verwerking waarna gesoek word moet die volgende uitkomste hê: verskaffing van genoeg energie tydens produksie aan die suikermeuele self; vervaardiging van ekstra energie in die vorm van eletrisieteit en ander energie produkte. Terselfder moet die ook bydra tot die volhoubaarheid van die omgewing. Die grootste gedeelte van hierdie navorsing is gewy aan die ontwikkeling van “proses modelle” om suikemeule afval (bagasse) te omskep in energie en energie-produkte. Om hierdie doel te bereik, is biomassa-tot-energie omskeppingsproses- modelle (BMECP) ontwikkel om verskeie proses konfigurasies van twee termo-chemiese prosesse, naamlik Verbranding (Combustion), en Vinnige Pirolise (Fast Pyrolysis) deur die gebruik van die ‘Aspen Plus®’- simulasie sagteware. Die doel van die proses modelering was om suikerriet biomassa as ‘n bron van energie te gebruik om weer die energie benodighehede van twee denkbeeldige suikermeule vas te stel; een meul is voorgestel as effektief, die ander as minder effektief. Terselfdertyd is gekyk na die hoeveelheid ekstra energie wat elkeen sou opwek en ander hoogs waardevolle energie produkte om te verkoop (bv. ‘bio-olies en bio-char’). Vier “BMECP” konfigurasies (voorstellings) 30bar BPST, 40bar CEST, 63bar CEST en 82bar CEST sisteme is gemodelleer vir die Verbranding termo-chemiese proses. In die geval van die Pirolise (Pyrolysis) termo-chemiese proses, is twee proses konfigurasies gemodelleer: 1. Suiwer Vinnige Pyrolyise BMECP en 2. Gedeeltelik Vinnige Pirolise BMECP. In die geval van eersgenoemde, word alle beskikbare ‘bagasse’ deur vinnige pirolise omskep om ‘bio-olie’ en ‘bio-char’ te vervaardig.Verder wek dit ook elektrisiteit op so wel as die nodige energie om die suikermeule te laat opereer. In die geval van die Gedeeltlike Vinnige Pirolise BMECP , moet daar eers genoegsame ‘bagasse’ opsy gesit word om die suikermeule van genoegsame energie te voorsien vir die volle funskionering daarvan en elektrisiteit-opwekking. Van die surplus of oorblywende ‘bagasse’ kan dan gebruik word om ‘bio-olie’ en ‘biochar’ te produseer. Die tegniese prestasie van al die BMECP modelle is geanaliseer en vergelyk ten opsigte van stoom en elektrisiteits-opwekking; proses effektiewiteit asook die impak op die omgewing ( gebaseer op CO2 –besparings). Die effek van stoomkettel-druk tydens operering asook die bagasse se vog-inhoud. Op die prestasie van die verbrandingsgebaseerde modelle is ook ondersoek. Laastens, uitgebreide ekonomeidese modelle is ook ontwikkel deur die gebruik van die ‘Aspen Process Economic Analyser (Icarus®)’. Sodoende is die ekonomiese vatbaarheid van die BMECP modelle ondersoek. Hierdie sagteware help ook met. Sensitiwiteits-analise in die bestudering van die terugvoer van die BMECP modelle tot veranderlikes in ekonomiese parameters. Rakende effektiwiteit, toon die uitslae dat die verbrandings-gebaseerde BMECP modelle beter vaar as die met betrekking tot stoom- en elektrisiteits-opwekking. Verbrandings-gebaseerde-modelle toon hoër elektriese effektiwiteit. Indien die vog-inhoud van die bagasse laag was en die tempo van stoomketel operasie druk verhoog is, het die tempo van elektriesiteits-opwekking ook gestyg. Ten opsigte van stoom daarenteen, het die stoom-opwekking tempo verhoog in die die vogl inhou van diebagasse laag was asook verminderde stoomketel operering druk. Ten spyte van die laer elektriese effektiewiteit van die Suiwer Vinnig- en Gedeeltelik Vinnig BMECP modelle, dui die analise aan dat hul proses effektiewiteit in die geheel Goed vergelyk met die van die verbrandings-gebaseerde BMECP modelle. Dit is toe te skryf aan die produksie van die hoë-energie draende pirolise produkte. Gebaseer op algemene operering druk van 50% ‘bagasse’ vog-inhoud, het die bogenoemde twee modelle bewys om meer omgewings-vriendelik te wees met uurlikse CO2-besparings. In die geval van Gedeeltelike Vinnige Pirolise BMECP, 40.44 en vir die Suiwer Vinnige Pirolise BMECP 41.30 gebaseer op ‘n 300 ton suikerriet/h (81 ton bagasse/h) plantasie-grote. Ten slotte, vanuit ‘n ekonomiese oogpunt, blyk ‘n biomassa verbranding gebaseer op die 63 bar CEST BMECP model die mees ekonomies-vatbare opsie onder huidige ekonomiese omstandighede. Eerste orde totale kapitale belegging beraming vir hierdie BMECP is ongeveer $116 miljoen, produksie NPV is$390 miljoen aan die einde van ‘n 20 jaar tydperk vir ‘n suikerriet-aanleg. IRP is 34.51%. Die Suiwer Vinnige Pirolise BMECP is die mins-ekonomiese vatbare model. Sensitiewiteits-analises het getoon dat hierdie BMECP model baie sensitief is ten opsigte van verandering in die pryse van bagasse en elektrisieteit; in die geval van NPV is veranderinge van -191.61/+446.86% aangedui op ‘n ±30% verandering in bagasse pryse. In die geval van elektrisieteitspryse, is ‘n sensitiewiteit van van -91.5/+338.60% op ‘n ±30% prysverandering getoon

Thermochemical biomass upgrading for co-gasification with coal

Thesis (PhD)--Stellenbosch University, 2018.ENGLISH SUMMARY: Lignocellulosic biomass is considered as a sustainable and renewable fuel source with the potential to substitute or partially replace coal in applications such as gasification for energy generation due to its sustainable carbon as well as its potential to reduce greenhouse gas emissions. However, raw biomass differs significantly from coal in terms of several important fuel properties, such as low energy density, high moisture, oxygen and volatile matter contents. Due to this the co-utilization of raw biomass with coal in gasification systems has been shown to result in the increase in the production of oxygenated volatile compounds (tar precursors) which impacts negatively on the quality of the gasification products and causes critical operational problems. This challenge has limited the development of biomass-based gasification processes. Hence to ensure the effective and efficient utilization of lignocellulosic biomass with coal, an upgrading process is required to improve some biomass properties to make them more similar to that of coal. The approach of this work consists in a thermal pretreatment in order to generate char products with reduced oxygen and volatile matter contents. The overall aim of the study therefore was to use thermochemical technologies (torrefaction and slow pyrolysis) as methods to pretreat lignocellulosic biomass feedstocks; pine (PN), bamboo (BB), corn cob (CC) and corn stover (CS) to produce upgraded biomass feedstocks (char), with reduced oxygen content as well as improved fuel properties, comparable to coal for use in co-gasification. For this task the study was divided into several objectives. The initial part focused on the characterization of the lignocellulosic chemical composition of the various biomass feedstocks. Next the types and quantities of oxygenated volatile products produced during the devolatilization of raw biomass feedstocks were studied. For this objective a novel analytical method incorporating the use of Thermogravimetric Analysis, thermal desorption and Gas Chromatography–Mass Spectrometry (herein referred as (TGA-TD/GC-MS) was developed and used to analyse and quantify the oxygenated volatile products. The analysis of the volatile composition data by means of principal components analysis (PCA) showed a clear correlation between lignocellulose chemical composition and the type and quantities of oxygenated volatile compounds produced during biomass devolatilization. The influence of thermal pretreatment conditions (temperature and time) on the structural transformation of raw biomass and on the volatile evolution mechanism of the resulting char during subsequent char devolatilization was also studied. Thermal pretreatment was done within the temperature range of 250-400 oC and hold time at pretreatment temperature of 30 and 60 min. It was observed that the temperature had a more profound effect than hold time during thermal pretreatment. The distribution of char devolatilization products was shown to be consistent with the extent of biomass transformation during thermal pretreatment. The biomass composition, particularly cellulose crystallinity, had an impact during thermal pretreatment. It was shown that for biomass feedstock with high degree of crystallinity such as PN a higher temperature (>300 oC) was required to achieve significant cellulose degradation. Hence char produced from such feedstock at temperature ≤300 oC generated high amount of anhydrosugar and furan volatiles during the char devolatilization. With the aim of using pretreated biomass with coal for co-gasification, biomass chars produced at different pretreatment temperatures were compared to coal in terms of fuel properties (proximate and elemental composition and Higher Heating Value), with particular attention given to the composition of oxygenated volatile compounds generated during the devolatilization stage. The result of the study showed that chars produced at temperature ≥350 oC had fuel properties comparable to that of coal. In addition these chars produced mainly aromatic hydrocarbons and phenolics during devolatilization which were similar to the volatiles generated from coal under identical conditions. Hence the pretreatment temperature of at least 350 oC is recommended when considering coal substitution, while 400 °C could be considered in the case of samples with high lignin (softwood) or high inorganic contents. Finally, the reactivity of the biomass chars under gasification condition was investigated. The devolatilization characteristics and CO2 gasification kinetics of biomass/char (produced at 350 oC) and coal at different blend ratios were studied. The devolatilization characteristics of char were found to follow the profile of coal especially at blend ratios of 10 wt% and 20 wt% with no particular synergy detected, while the kinetic parameters were also comparable. This work confirmed the potential of the use of thermally pretreated biomass chars for coal substitution in gasification process and brought decisive insights for the implementation of future tests at pilot scale.AFRIKAANS OPSOMMING: Lignosellulosiese biomassa word beskou as ’n volhoubare en hernubare bron van brandstof met die potensiaal om steenkool heeltemal of gedeeltelik te vervang in toepassings soos vergassing vir energie generasie. Hierdie beskouing is as gevolg van die lignosellulosiese biomassa se koolstof en sy potensiaal om groenhuisgasuitlate te verminder. Nogtans verskil biomassa van steenkool in terme van verskeie brandstofeienskappe, soos lae energiedigtheid, hoë voginhoud, hoë suurstofinhoud, en hoë vlugtige-materiaal-inhoud. Daarom was dit bevind dat die gesamentlike gebruik van biomassa met steenkool in vergassing sisteme ’n toename in oksigeneerde vlugtige verbindings (teer-voorgangers) tot gevolg het, wat ’n negtiewe impak op die kwaliteit van die vergassingprodukte het en kritiese bedryfsprobleme veroorsaak. Hierdie uitdaging beperk die ontwikkeling van biomassa-baseerde vergassing sisteme. Dus, om die effektiewe en doeltreffende gebruik van biomassa met steenkool te verseker, word ’n opgegradeerde proses benodig om sommige van die biomassa einskappe te verbeter om meer soos die van steenkool te wees. Die benadering in hierdie werk bestaan uit ‘n termiese voorbehandeling om houtskool produkte met verminderde suurstof en vlugtige-materiaal inhoud te genereer. Die algehele doelwit was dus om termochemiese tegnologie (uitdroging en stadige pirolise) as metodes te gebruik vir die voorbehandeling van lignosellulosiese biomassa grondstowwe: denne (PN), bamboes (BB), mieliestronk (CC), en mieliestrooi (CS) om opgegradeerde biomassa grondstof (houtskool) te produseer, wat verminderde suurstofinhoud sowel as verbeterde brandstofeienskappe vergelykend met die van steenkool het, vir die gebruik in gesamentlike vergassing. Vir die taak is die studie in verskeie doelstellings verdeel. Die aanvanklike gedeelte het gefokus op die karaktarisering van die lignosellulosiese chemiese samestelling van die verskeie biomassa grondstowwe. Volgende is die tipes en hoeveelhede oksigeneerde vlugtige produkte wat tydens die verwydering van vlugtige komponente uit rou biomassa grondstowwe verkry is studeer. Vir hierdie doelstelling was ’n nuwe analitiese metode ontwikkel wat die gebruik van Termogravimetriese Analise, termiese-desorpsie en Gas-Chromatografie-Massaspektrometrie (verwys na as TGA-TD/GC-MS) insluit. Die metode was gebruik om die oksigeneerde vlugtige produkte te analiseer en te kwantifiseer. Die analise van die data oor die vlugtige komponente samestelling is gedoen met hoofkomponente-analise (PCA) en dit het ’n duidelike verwantskap gewys tussen lignosellulosiese-chemiese-samestelling en die tipe en hoeveelhede oksigeneerde vlugtige verbindings wat produseer word tydens die verwydering van vlugtige komponente uit biomassa uit. Die invloed van termiese voorbehandeling kondisies (temperatuur en tyd) op die strukturele verandering van rou biomassa en op die vlugtige komponent evolusie meganisme van die resulterende houtskool tydens die opvolgende verwydering van vlugtige komponente uit die houtskool uit, was ook gebestudeer. Termiese voorbehandeling was gedoen binne die temperatuuromvang van 250-400 oC en hou-tyd by voorbehandelingstemperatuur van 30 en 60 min. Dit was opgemerk dat temperatuur ‘n groter effek as hou-tyd gehad het tydens termiese voorbehandeling. Dit was gewys dat die verspreiding van produkte van die verwydering van vlugtige komponente uit die houtskool uit ooreenstem met die mate van biomassa verandering tydens termiese voorbehandeling. Die biomassa samestelling, veral sellulose kristalliniteit, het ‘n impak gehad tydens termiese voorbehandeling. Dit was bevind dat vir ‘n biomassa grondstof met ‘n hoë graad van kristalliniteit, soos PN, was ‘n hoër temperatuur (>300 oC) benodig om beduidende sellulose degradasie te behaal. Gevolglik het die houtskool geproduseer van sulke grondstowwe by temperature <300 oC, hoë hoeveelhede anhidriese suikers en furan vlugtige komponente gegenereer tydens die verwydering van vlugtige komponente vanuit die houtskool. Met die doelwit om voorbehandelde biomassa te gebruik in die gesamentlike vergassing met steenkool, was biomassa-houtskool, geproduseer by verskillende voorbehandelingstemperature, vergelyk met steenkool in terme van brandstofeienskappe (algemene en elementele samestelling en Hoër Verbrandings Waarde), met spesifieke aandag aan die samestelling oksigeneerde vlugtige verbindings wat gegenereer is tydens die verwydering van vlugtige komponente. Die resultaat van die studie het gewys dat houtskool geproduseer by temperature ≥350 oC, brandstofeienskappe vergelykbaar met die van steenkool gehad het. Daarbenewens het die houtskole hoofsaaklik aromatiese koolwaterstowwe en fenole geproduseer tydens die verwydering van vlugtige komponente, wat soortgelyk was aan die vlugtige komponente gegenereer van steenkool onder identiese kondisies. Daarom word die voorbehandelingstemperatuur van ten minste 350 oC aanbeveel wanneer steenkoolvervanging oorweeg word, terwyl 400 oC oorweeg kan word in die geval van monsters met hoë lignien (sagtehout) of hoë anorganiese inhoud. Laastelik was die reaktiwiteit van biomassa houtskool onder vergassingtoestande ondersoek. Die eienskappe tydens die verwydering van vlugtige komponente en die CO2 vergassings-kinetika van biomassa/houtskool (geproduseer by 350 oC) en steenkool by verskillende vermengingsverhoudinge was gebestudeer. Dit was gevind dat die eienskappe van houtskool tydens die verwydering van vlugtige komponente dieselfde profiel as steenkool volg veral by vermengingsverhoudinge van 10 wt% en 20 wt% en geen spesifieke sinergie was opgemerk nie, terwyl die kinetiese parameters ook vergelykbaar was. Die werk het die potensiaal van die gebruik van termiese voorbehandelde biomassa houtskool in die vervanging van steenkool in vergassing prosesse bevestig en beslissende insigte voortgebring vir die implementering van toekomstige toetse op toetsskaal

JAMESTOWN INTERVIEWS

Interviews of community members</p

QOL Dataset

EORTC QLQ scores</p

Jamestown Transcripts.rar

Transcripts of Focus Group Discussions and Key Informant Interviews on Breast Cancer Knowledge in Jamestown community in Accra</p

Transcripts from Jamestown

Transcripts of Focus group discussions and Key Informant Interviews</p

Comparison of combustion and pyrolysis for energy generation in a sugarcane mill

Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)IngenieursweseProsesingenieurswes