956 research outputs found

    A technique for the measurement of reinforcement fibre tensile strength at sub-millimetre gauge lengths

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    The strength of composite reinforcement fibres is normally measured on samples of much greater length than the actual residual fibre lengths found in many composite materials. This is due to a number of limitations of the standard techniques which are employed. We present a description of a technique which enables values for the tensile strength of composite reinforcement fibres at short gauge lengths to be obtained. The technique is based on an adaptation of a micro-mechanical test apparatus for fibre pullout measurements. Data is presented which was obtained at gauge lengths of 180-380 ”m on E-glass and S-2 glassŸ fibres taken from different chopped reinforcement products. The technique can be used at gauge lengths as short as 20 ”m. The data indicates that the values of average fibre strength in these products are significantly below the pristine glass strength values

    A modification of the mixed form of Richards equation and its application in vertically inhomogeneous soils

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    Recently, new soil data maps were developed, which include vertical soil properties like soil type. Implementing those into a multilayer Soil-Vegetation-Atmosphere-Transfer (SVAT) scheme, discontinuities in the water content occur at the interface between dissimilar soils. Therefore, care must be taken in solving the Richards equation for calculating vertical soil water fluxes. We solve a modified form of the mixed (soil water and soil matric potential based) Richards equation by subtracting the equilibrium state of soil matrix potential ψE from the hydraulic potential ψh. The sensitivity of the modified equation is tested under idealized conditions. The paper will show that the modified equation can handle with discontinuities in soil water content at the interface of layered soils

    Addressing challenges to teach traditional and agile project management in academia

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    In order to prepare students for a professional IT career, most universities attempt to provide a current educational curriculum in the Project Management (PM) area to their students. This is usually based on the most promising methodologies used by the software industry. As instructors, we need to balance traditional methodologies focused on proven project planning and control processes leveraging widely accepted methods and tools along with the newer agile methodologies. Such new frameworks emphasize that software delivery should be done in a flexible and iterative manner and with significant collaboration with product owners and customers. In our experience agile methodologies have witnessed an exponential growth in many diverse software organizations, and the various agile PM tools and techniques will continue to see an increase in adoption in the software development sector. Reflecting on these changes, there is a critical need to accommodate best practices and current methodologies in our courses that deliver Project Management content. In this paper we analyse two of the most widely used methodologies for traditional and agile software development – the widely used ISO/PMBOK standard provided by the Project Management Institute and the well-accepted Scrum framework. We discuss how to overcome curriculum challenges and deliver a quality undergraduate PM course for a Computer Science and Information systems curricula. Based on our teaching experience in Europe and North America, we present a comprehensive comparison of the two approaches. Our research covers the main concepts, processes, and roles associated with the two PM frameworks and recommended learning outcomes. The paper should be of value to instructors who are keen to see their computing students graduate with a sound understanding of current PM methodologies and who can deliver real-world software products.Accepted manuscrip

    Communication and leadership skills in the Computer Science and Information Systems curricula: A case study comparison of US and Bulgarian programs

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    In this paper we present results from our curriculum research on the behavioral educational topics being in the computer science (CS) and information systems (IS) academic programs in two countries USA and Bulgaria. Specifically, we address learning outcomes as they pertain to IT Project Management. Our research reveals that the two countries approach undergraduate education from different vantage points. The US universities provide a flexible general education curriculum in many academic areas and students have the opportunity to strengthen their soft skills before they enter the workforce. Bulgarian universities provide specialized education in main CS subject areas and the students are technically strong upon graduation. Is there a way to balance out this divergent educational experience so that students get the best of both worlds? Our paper explores this aspect and provides possible solutions

    A model based DC analysis of SiPM breakdown voltages

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    A new method to determine the breakdown voltage of SiPMs is presented. It is backed up by a DC model which describes the breakdown phenomenon by distinct avalanche turn-on (V01V_{01}) and turn off (V10V_{10}) voltages. It is shown that V01V_{01} is related to the 'breakdown voltage' that previous DC methods derive from simple reverse current-voltage measurements, while V10V_{10} is the 'real' breakdown voltage commonly obtained from complex gain-voltage measurements. The proposed method reveals how the microcell population distributes around V01V_{01} and V10V_{10}. It is found that if this distribution is assumed to be normal, then both voltages and even their standard deviation can readily be extracted from current-voltage curves. Measurements are in good agreement with the theoretical model

    Peracchi: What is the Right Result?

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    Young adults' perceptions of the implications of their hereditary, visual impairment: A Cape Town based study

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    In South Africa, approximately 600 000 individuals are visually impaired. Approximately onethird of genetic disorders and syndromes involves the eye, including conditions such as congenital cataracts, glaucoma, albinism, and retinal degenerative disorders. The transition into adulthood of visually disabled individuals is a crucial time, as it lays the foundation for their future. The aim of this research was to explore the level of understanding, perceptions and lived experiences of young adults aged eighteen to twenty-three who are visually impaired due to a genetic cause. A qualitative design, utilizing a phenomenological approach was used for this study. Fifteen participants were recruited through Athlone School for the Blind, the League of Friends of the Blind and Retina SA. In-depth interviews were conducted and data obtained was analysed using thematic analysis. Five themes were identified through this approach indicating the implications of having a genetic visual condition as perceived and experienced by these young adults. Most of the young adults experienced difficulty in understanding their condition and the genetic bases thereof and they had a strong desire to obtain clarity and knowledge via genetic counselling. The community was thought not to understand their situation either. They were unsure of the inheritance risks to future offspring and some indicated that they felt that this was a gamble they were unwilling to take, whilst others would have children. In some instances, their own visual impairment might create obstacles to raising children. Social interactions were greatly impacted and they felt isolated and tried to avoid unpleasant treatment, stigmatization and pity from the community. Intimate relationships were also noted as a challenge. Mobility is a major obstacle due to the incapacity to drive, as well as the lack of disability user-friendly public transportation and a daunting environment. They want to and feel that they can be independent and achieve the same things as sighted individuals, but society and life circumstances often create barriers to this. This research could assist in providing information to create more efficient, patient-centred genetic services and might be informative to various organizations about targeted support to provide these individuals and methods to assist their transition to adulthood
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