Development of Thermomechanical Model for the Analysis of Effects of Friction and Cutting Speed on Temperature Distribution around AISI 316L During Orthogonal Machining

In metal cutting,severe deformation takes place in the vicinity of the cutting edge of the high strain-rate and an increase in temperature is observed. Deformation behaviour of the work material in the primary and secondary zones is highly sensitive to the cutting conditions. Also, the frictional conditions between the tool and the chip and tool and the workpiece are highly complex and sensitive to the cutting conditions. As a result, the stresses and temperatures at tool-chip interface and around the cutting edge can be critically high in some cutting conditions and can cause excessive tool wear or premature tool failure. This research work focuses on the accurate prediction of the distribution of the process variables such as stresses and temperatures with the Finite Element (FE) Analysis to identify optimum cutting conditions, tool material, edge geometry and coating in order to help improve productivity and quality of machining operations. Effects of work material flow stress and interfacial friction at chip-tool interface on the accuracy of the predicated process variables in FE simulations are also analyzed. Specifically, friction models and cutting speed are varied to predict the effect on the temperature distribution, stresses and strain on the workpiece and tool chip during orthogonal cutting process. The result showed that an increase in coefficient of friction will cause an increase in thermal, force and mechanical variables during machining. Thus, the higher the coefficient of friction, the higher, the cutting forces, temperature, stress, and strain

Black Arts/West: A Theater Without a Home

In the 1960s, the civil rights struggle gripped much of the nation as Black people and African nations sought greater sovereignty at the personal and state level. The Black Arts/West theater company (BAW) was born into this atmosphere with an express purpose to “Educate, Enlighten and Entertain” (Barnett, 2001b). Over an 11-year span, BAW produced and performed over 100 plays in Seattle, while also teaching dance and acting as part of the Central Area Motivation Program (CAMP). Unfortunately, the theater struggled to establish a home and sustainable funding. How does a fledgling theater group of Black artists and activists match their artistic vision to a rapidly growing organization combatting historic racial discrimination, and the early stages of neighborhood gentrification? This case study establishes a timeline for significant BAW events, provides historical context, and investigates various reasons that led to its official closure in 1980

Process Based Analysis Of Fluvial Stratigraphic Record: Middle Pennsylvanian Allegheny Formation, North-Central WV

Fluvial deposits represent some of the best hydrocarbon reservoirs, but the quality of fluvial reservoirs varies depending on the reservoir architecture, which is controlled by allogenic and autogenic processes. Allogenic controls, including paleoclimate, tectonics, and glacio-eustasy, have long been debated as dominant controls in the deposition of fluvial strata. However, recent research has questioned the validity of this cyclicity and may indicate major influence from autogenic controls. To further investigate allogenic controls on stratal order, I analyzed the facies architecture, geomorphology, paleohydrology, and the stratigraphic framework of the Middle Pennsylvanian Allegheny Formation (MPAF), a fluvial depositional system in the Appalachian basin, to test for the dominant allogenic and/ or autogenic controls during deposition. A sedimentological process based approach has been used to analyze controls on the depositional reservoir quality of fluvial sandstone units. In this research, I utilized facies architectural analysis to identify four depositional styles for channel deposits of the MPAF. The depositional facies were used to identify paleoclimatic controls on fluvial sedimentary fill. I introduced a new, efficient numerical model to aid in channel geometry and paleohydrological modeling of the MPAF channels. The new numerical modeling method increased the accuracy of estimated channel geomorphology and hydrologic processes. I proposed a sequence stratigraphic framework, which utilized surfaces of floodplain paleosols and erosional channel bases, to correlate fluvial depositional packages across the Appalachian basin. The integration of facies architectural analysis and sequence stratigraphic allowed the differentiation of accommodation and controls on accommodation within vertically stacked deposits of the fluvial depositional system

Tools and metrics to characterize extreme climate events and evaluate climatic datasets over the Upper Colorado River Basin for societal applications

This study supports the Denver Water management goals by providing tools and metrics that are relevant for operational activities. The study focuses mainly on drought events, but with a slight mention of pluvial conditions over upper Colorado River basin (UCRB), the region that supplies water to Denver community. The study uses observed monthly minimum and maximum temperatures and monthly precipitation datasets (Climatic Research Unit; CRU and Precipitation-Elevation Regression on Independent Slopes Model; PRISM) and modeling outputs from 34 members of the Community Earth System Model Large Ensemble (CESM-LE) to monitor and characterize droughts over the region. With these datasets, we compute two multi-scalar moisture indices: standardized precipitation evapotranspiration index (SPEI) and standardized precipitation index (SPI) on a 36-month scale. We evaluate the capability of the CESM-LE to reproduce drought over the region using the more recently developed spatial verification tool, the Method for Object-based Diagnostic Evaluation (MODE) technique. In addition, the study examines the large-scale atmospheric circulation features associated with drought and pluvial conditions using reanalysis output. The results reveal the usefulness of these datasets, the drought indicators, and the spatial verification technique as important analytical tools to monitor and characterize extreme hydroclimatic conditions over UCRB

Alleviating higher education challenges through strategic integration of technology: a case of selected universities in Africa.

Doctor of Philosophy. University of KwaZulu-Natal, Durban.The higher education sector in Africa is evolving and information technology continues to play a key role in driving these changes. Information and communications technologies are improving the creation and transmission of knowledge. This is attributed to the way people learn and create ideas as well as disseminate information within the educational environment and in the public sphere. In this study, an exploratory research was conducted to identify and understand the challenges and opportunities associated with information technology integration in higher education. A survey of 592 staff at the University of Lagos, Nigeria, the University of KwaZulu-Natal, South Africa and University of South Africa was undertaken to address the research problem. The study makes use of a blend of theoretical frameworks to provide the foundation for identifying, proposing, planning and suggesting information technology strategies that can be integrated into higher education to alleviate higher education challenges in order to enhance teaching and learning outcomes. The three models used are: The Change Management Model; Model of Technology Adoption in the Classroom; and the Diffusion of Innovation Theory. The study evaluates the role of ICTs in higher education and also identified issues, challenges and instances of ICT strategic integration in higher education institutions at the selected universities in Africa. In the process of understanding the strategic integration of information technology in higher education institutions at the selected universities, the study identified what was considered successful technology integration strategies, what were not as successful, and why this was the case. The study further identified the factors that influence information technology integration in higher education. Having identified the limitations to technology integration and the significance of information technology in higher education at the selected universities, the study proffered recommendations and proposed a strategic framework. The framework offers strategies for the integration of information technology into higher education which can be used to alleviate higher education challenges, enhance teaching and learning outcomes, sustain the integrated information technologies and achieve ICTs promised benefits to higher education

Strategic capabilities and sustainability of SMMEs in Gauteng: a case of Roodepoort area in Johannesburg.

Masters Degree. University of KwaZulu-Natal, Durban.Despite the interventions of South African government on SMMEs, there is still a huge challenge in ensuring that SMMEs are sustainable. SMMEs plays a major role in the sustenance of the South African economy. However, the lack of access to the necessary capabilities has led to the close down of many small businesses. Therefore, to achieve continuous success and low failure rate in SMME sector, there is need for the knowledge and awareness on the essential strategic capabilities for business sustainability. The challenges faced by SMMEs should also be carefully examined and monitored in order to provide lasting solutions. This research adopted the Sustainable Business Model (SBM) as the theoretical framework underpinning the concept and structure of the study. The SBM was used in the study as a foundation for identifying and suggesting the integration of strategic capabilities for the sustainability of SMMEs. This study performed an exploratory research analysis through quantitative research method to understand the level of awareness and adoption of various strategic capabilities within the SMME industries. The study investigated and identified the various key strategic capabilities available for SMMEs’ sustainability. The research also investigated challenges that SMMEs face in applying and performing the business actions/strategies for sustainability of their businesses. The study further examined the impact of adopting and performing business actions/strategies for the sustainability of SMMEs. In the process of understanding the essential strategic capabilities for sustainability of SMMEs, the findings of the study identified various essential strategic capabilities available within SMMEs. These essential strategic capabilities are in form of business strategies and process improvement actions. The cohesion of these two factors when effectively applied, ensures profitability and sustainability of SMMEs. Hence, recommendations were proposed on strategies that will ensure business sustenance over a long period. The study recommends and suggests that government support and intervention programmes should be effectively implemented to support SMMEs. Large organisations were encouraged to network and partner with SMMEs in order to enhance flexibility in organisational structure of large companies to accommodate business relationships with SMMEs. The study further recommends that SMMEs should build Business-to-Consumer (B2C) relationships in order to establish trust between SMMEs and their clients. Lastly, governments were encouraged to be consistent in their labour laws and implement low tax rates to ensure sustainability of SMMEs

Safety analysis of interchange functional areas

Limited access facilities, such as freeways and expressways, are generally designed to the highest standards among public roads. Consequently, these facilities demonstrate crash, injury, and fatality rates that are significantly lower than other road facility types. However, these rates are generally elevated in the immediate vicinity of interchanges due to increases in traffic conflicts precipitated by weaving, merging, and diverging traffic. Given the extensive costs involved in interchange construction, it is important to discern the expected operational and safety impacts of various design alternatives. To this end, the objective of this study was to analyze the safety performance within the functional areas of interchanges. The study involves the integration of traffic crash, volume, and roadway geometric information using data from 2010 to 2014 from the state of Iowa in order to assess the relationships between these factors and frequency of crashes within the interchange functional area. Separate analyses were conducted for the freeway mainline and ramp connections. Safety performance functions (SPFs) were estimated for the interchange mainline and ramps using negative binomial regression models, and random effects models were estimated to account correlation in crash counts at the same location over time. The results from this study suggest that speed limit and interchange configuration have a significant impact on crash rates. Lower ramp advisory speeds (10 mph to 35 mph) were associated with fewer crashes on-ramps. Off-ramps were also associated with elevated crash risk in comparison to on-ramps and freeway-to-freeway ramps. Comparison SPF models were also developed using Iowa-specific data to relate the outcomes of these simple SPFs with Florida-specific SPFs and the national default SafetyAnalyst SPFs with varying results

Haematological and sperm count changes following Exposure to Hyptis suaveolens, Cleome viscose and Urena lobata in rats

The plants Hyptis suaveolens, Clome viscosa and Urena lobata are herbs commonly found growing in pasture and also used as medicinal plant in Nigeria. They were suspected to be toxic following a pilot toxicity study, and their toxic effects were thus evaluated on haematological parameters and sperm count of albino rats. The crude aqueous extract of the leaves of these plants were administered orally for 28 days and the haematological analysis of the rats treated with Cleome viscosa showed a significant decrease (p0.05) in the erythrocyte indices, white blood cell count and differentials. The neurophils number also increased significantly (

Production of Biodiesel from Soybean Oil Using Calcium Oxide and Cow Bone as Catalysts

Biodiesel was produced from the transesterification of soybean oil using calcium oxide and cow bone (an animal waste bone that contains hydroxyapatite, a calcium phosphate mineral) as heterogeneous catalysts. The soybean oil used was characterized using gas chromatography mass spectrometer (GCMS) and the cow bone catalyst produced was characterized using X-ray diffractometer (XRD) and X-ray fluorescence (XRF) spectrometer. The effects of the variation of methanol/oil mole ratio (9–15), catalyst concentration (10–20 wt/wt%) and reaction temperature (55–65 °C) on biodiesel yield during the transesterification of soybean oil with methanol was investigated. Reaction time of 3 hours and stirring rate of 500 rpm were kept constant. It was observed that the calcination of cow bone catalyst (at 800 °C) enhanced its conversion to apatite [Ca5(PO4)3OH] and increased the yield of biodiesel obtained. Biodiesel yield results revealed an optimum condition of methanol/oil mole ratio of 9, catalyst concentration of 15 wt/wt% and reaction temperature of 55 °C. Also, the results obtained showed that the performance trends of the two catalysts used were similar. And the close values of highest biodiesel yields obtained when the two heterogenous catalysts were used separately (yields of 94.8 and 92.2% using calcium oxide and calcined cow bone catalysts respectively) implies that the use of low-cost and readily available calcined cow bone catalyst is a promising alternative to CaO catalyst

Agroclimatic Zonning of Nigeria Based on Rainfall Characteristics and Index of Drought Proneness

Nigeria, a country in sub-Saharan West Africa that depends largely on rainfall distribution for its agricultural practices has been categorised into three major climatic zones based on its rainfall characteristics and drought-proneness analysis. The data used comprises of daily rainfall of thirty years (1983 to 2012) for the thirty-eight climatic stations spread over the country. Rainfall characteristics such as onset dates, cessation dates, length of rainy season and rainfall amount within the seasons for thirty years were extracted over each of these stations for the analysis. Rainfall distribution during the rainy season was also investigated by using two-state Markov chain analysis of order one and two. The result is useful in making some pre-sowing decisions such as site selection for a particular crop and specie selection for a particular zone. The first zone has earliest rainfall onset dates, latest cessation dates and hence, having longest length of rainy season in the country. It also has the highest (lowest) Markovian probability of a wet (dry) week after a previously wet week and hence least prone to drought occurrence. Therefore, this zone is tagged “rain-forest” (Guinea). Followed closely is the zone II which is the “Savannah” and lies on the north of the zone I. On the northern part of zone II is the zone III with the shortest length of rainy season termed “Sahel”. Despite the fact that Sahel zone has the latest onset, earliest cessation and hence shortest length of rainy season, it is most prone to drought occurrence, while Savana has moderate values between those of zones I and III. Keywords: Rainfall onset, rainfall cessation, length of rainy season, drought-proneness, zones