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

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

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

Living between languages: The politics of translation in Leila Aboulela’s Minaret and Xiaolu Guo’s A Concise Chinese-English Dictionary for Lovers

This is the author's final draft post-refereeing as published in The Journal of Commonwealth Literature 2012 47: 207 DOI:10.1177/0021989412440433. The online version of this article can be found at: http://jcl.sagepub.com/content/47/2/20

Race, colonial history and national identity: Resident Evil 5 as a Japanese game

Resident Evil 5 is a zombie game made by Capcom featuring a White American protagonist and set in Africa. This paper argues that approaching this as a Japanese game reveals aspects of a Japanese racial and colonial social imaginary that are missed if this context of production is ignored. In terms of race, the game presents hybrid racial subjectivities that can be related to Japanese perspectives of Blackness and Whiteness where these terms are two poles of difference and identity through which an essentialised Japanese identity is constructed in what Iwabuchi calls “strategic hybridism” (Iwabuchi, 2002). In terms of colonialism, the game echoes structures of Japanese colonialism through which Japanese colonialism is obliquely memorialised and a “normal” Japanese global subjectivity can be performed

Permanence, Temporality and the Rhythms of Life : Exploring Significance of the Village Arena in Igbo Culture

The village arena (or ‘square’ or ‘Otobo’ in Nsukka Igbo) is at the physical and socio-cultural centre of Igbo life, in southeast Nigeria. It is a space where intangible Igbo cultural heritage is played out, and also serves as a virtual museum where heritage materials are kept. The arena performs its roles in two very different ways: as a sacred space hosting initiation rites and religious rituals; and as a profane space for meetings and ceremonies. Either way, these uses see the arena transition between permanency and temporality, following routines and rhythms which themselves give the practices meaning and significance, and contribute to their inscription on the landscape. This paper explores the complexities associated with these village arenas with a particular focus on their socio-cultural, political, economic and religious functions through time, as well as the way those complexities are manifest in material cultures that serve to characterize the village arena

Global Perspectives on Task Shifting and Task Sharing in Neurosurgery.

BACKGROUND: Neurosurgical task shifting and task sharing (TS/S), delegating clinical care to non-neurosurgeons, is ongoing in many hospital systems in which neurosurgeons are scarce. Although TS/S can increase access to treatment, it remains highly controversial. This survey investigated perceptions of neurosurgical TS/S to elucidate whether it is a permissible temporary solution to the global workforce deficit. METHODS: The survey was distributed to a convenience sample of individuals providing neurosurgical care. A digital survey link was distributed through electronic mailing lists of continental neurosurgical societies and various collectives, conference announcements, and social media platforms (July 2018-January 2019). Data were analyzed by descriptive statistics and univariate regression of Likert Scale scores. RESULTS: Survey respondents represented 105 of 194 World Health Organization member countries (54.1%; 391 respondents, 162 from high-income countries and 229 from low- and middle-income countries [LMICs]). The most agreed on statement was that task sharing is preferred to task shifting. There was broad consensus that both task shifting and task sharing should require competency-based evaluation, standardized training endorsed by governing organizations, and maintenance of certification. When perspectives were stratified by income class, LMICs were significantly more likely to agree that task shifting is professionally disruptive to traditional training, task sharing should be a priority where human resources are scarce, and to call for additional TS/S regulation, such as certification and formal consultation with a neurosurgeon (in person or electronic/telemedicine). CONCLUSIONS: Both LMIC and high-income countries agreed that task sharing should be prioritized over task shifting and that additional recommendations and regulations could enhance care. These data invite future discussions on policy and training programs

Two Concepts of Basic Equality

It has become somewhat a commonplace in recent political philosophy to remark that all plausible political theories must share at least one fundamental premise, ‘that all humans are one another's equals’. One single concept of ‘basic equality’, therefore, is cast as the common touchstone of all contemporary political thought. This paper argues that this claim is false. Virtually all do indeed say that all humans are ‘equals’ in some basic sense. However, this is not the same sense. There are not one but (at least) two concepts of basic equality, and they reflect not a grand unity within political philosophy but a deep and striking division. I call these concepts ‘Equal Worth’ and ‘Equal Authority’. The former means that each individual’s good is of equal moral worth. The latter means that no individual is under the natural authority of anyone else. Whilst these two predicates are not in themselves logically inconsistent, I demonstrate that they are inconsistent foundation stones for political theory. A theory that starts from Equal Worth will find it near impossible to justify Equal Authority. And a theory that starts from Equal Authority will find any fact about the true worth of things, including ourselves, irrelevant to justifying legitimate action. This helps us identify the origin of many of our deepest and seemingly intractable disagreements within political philosophy, and directs our attention to the need for a clear debate about the truth and/or relationship between the two concepts. In short, my call to arms can be summed up in the demand that political philosophers never again be allowed to claim ‘that all human beings are equals’ full stop. They must be clear in what dimension they claim that we are equals—Worth or Authority (or perhaps something else)