The deformation of carbide cutting tools

Under certain cutting conditions carbide tools can sustain a significant amount of permanent deformation and this may cause early tool failure. Tests were devised to investigate the deformation of three different grades of carbide, when machining steel (817M40, EN24) under a wide range of conditions. Each test was carried out on a continuous (60 seconds) and an incremental (5, 5, 10, 20 and 20 seconds) basis. This plan was adopted to investigate transient effects. During each test the cutting forces were measured with a dynamometer, and the boundary temperatures were measured at the tool/chip interface and the tool/shank interface. The permanent deformation took the form of bulging on the flank face and depression of the rake face. With low metal removal rates the deformation was minimal and the cutting edge was stable. High metal removal rates caused the tool to deform continuously and this gave an unstable cutting edge. It was deduced that within the tool there was a zone of material that had undergone plastic deformation. The rake and flank faces formed two external boundaries of this zone, the remaining boundary being within the tool body. For any particular set of cutting conditions, the amount of deformation for either the continuous test or the total of the incremental tests was essentially the same. A plane stress Finite Element (F.E.) model was developed to explain the effects of speed and feed in terms of temperature and stress and their variation with time. The F.E. model predicted that the values of both the transient and steady state thermal stresses were very low when compared with the mechanical stresses. The results from the cutting tests and the F.E. model suggest that the tool material continuously deformed under the applied mechanical stresses (cutting forces). Any contribution to the deformation from the transient thermal stresses was minimal and of a short duration

Physics Portfolios: A picture of student understanding

Traditionally, teachers assess students\u27 physics understanding through lab activities, responses to open-ended word problems, and tests. But there\u27s another way to measure student understanding, one in which students apply their learning to the world around them. This article shows how to implement student portfolios, which allow students to set goals they can monitor throughout the year and actively participate in assessment. When students build portfolios, they can evaluate and reflect on their own work, promoting engagement with the course and content (Danielson and Abrutyn 1997), and teachers can better assess students\u27 goal movement and see growth in students\u27 conceptual understanding. Portfolio assessment is a powerful motivator because students get to make choices (Tomlinson 1999), personalize learning goals, choose the assignments they want to include, and focus on areas of interest. Portfolios provide insight into students as individuals, revealing alternative conceptions and incomplete understandings (Danielson and Abrutyn 1997). Teachers can differentiate how students convey understanding based on readiness, interest, or learning profiles (Tomlinson 1999) and have opportunities to communicate with parents about student work (Nickleson 2004). The first author has implemented a physics portfolio project in two different general-level high school physics courses over the past six years. Students provide pictures of their understanding and make real-world connections as they learn, addressing the Next Generation Science Standards (NGSS) (Achieve Inc. 2013) and Common Core State Standards (CCSS) (NGAC and CCSSO 2010). Students reflect on their studies and goals for the course and provide evidence of their learning throughout the year, allowing the teacher to formatively assess both student progress and the course itself

Kinesthetic investigations in the physics classroom

Creating investigations that allow students to see physics in their everyday world and to be kinesthetically active outside of the traditional physics classroom can be incredibly engaging and effective. The investigations we developed were inquiry investigations in which students engaged in concrete experiences before we discussed the ab- stract concepts and derived the mathematical relationships. In this article, we describe the approach to inquiry used and an explanation of kinesthetic investigations in general. We then provide a description of several of the investigations and some examples of how students responded to them

Teacher\u27s Toolkit: Differentiating Inquiry

Differentiated instruction and teaching science as inquiry are two pedagogical approaches frequently discussed among science teachers. Teachers know these approaches are important but often have difficulty translating them into their classroom science instruction. This article describes how to differentiate a density investigation for variations in student readiness by varying the level of inquiry using an approach that is easily translated to experiments in any science content area

Exploring practices of science coordinators participating in targeted professional development

This study describes how district science coordinators supported teachers and implemented professional development in their districts following participation in the Science Coordinator Academy. This qualitative descriptive case study comprised three district science coordinators from three districts in a mid‐Atlantic state, as well as principals and teachers from those districts. Data sources, including observations, surveys, artifacts, and interviews, were analyzed using the framework method (Gale, Heath, Cameron, Rashid, & Redwood, 2013). District context, science coordinator background, and collaboration were salient factors that influenced coordinator practices and coordinators’ abilities to impact teacher change. We hypothesize that the development of a coaching relationship, facilitating collaboration among teachers, utilizing the characteristics of effective professional development, and promoting reflection through modeling and feedback may be the most important reflection‐growth model of instructional leadership (Blase & Blase, 1999) practices for science coordinators to enact when working with teachers

Kinesthetic Investigations in the Physics Classroom

Inquiry can be defined practically as “an active learning process in which students answer research questions through data analysis.”2 This simple definition of inquiry is based on the National Science Educational Standards and is easy for teachers to understand. The National Research Council (NRC) identifies the scientific practices that support inquiry and that students should be engaged in, including: question generation, experimental design, data analysis, creating explanations, argumentation, and communicating results.3 The investigations created encourage inquiry and require students to develop their scientific practices skills

Turning Missteps into Stepping Stones: Personal and Professional Growth as an Early Career Academic Librarian

This panel discussion will focus on the challenges and failures we have experienced as new and semi-new academic librarians. The all too familiar trend in libraries has been to do more with less: requests for library services have increased yet our budgets, time, and supplies have all decreased. While institutions have devised creative ways to adapt to new difficulties, including adopting new staffing models, the situation remains the same: we have been hired to do one job but inevitably end up doing much more. How did we as new librarians deal with systemic issues? How has it impacted our professional development (or lack thereof)? What did we learn or feel we failed at while coming into our own in this field? Our discussion will focus on shifts in working patterns, professional development (and the privilege that comes with being able to participate), the impact of institutional culture on “library work,” and proposals for success and change from the failures we have experienced. We also acknowledge that this is a panel of predominantly white, female-identified persons, and so our conversations are deeply rooted in systems of privilege. We are not speaking to the experiences of every librarian (nor should we aim to try), and we will also signal-boost counterspaces existing within our profession. This panel discussion will not be a venting session, but rather it is our hope to refocus the conversation to our experiences in the field and some possible solutions. Finally, we will consider how we have maintained professional direction and focus while allowing our career experiences to shape and inform us

Mothers' voices: hearing and assessing the contributions of 'birth mothers' to the development of social work interventions and family support

This paper focuses on interviews with ‘birth mothers’ who experienced successive losses of their children to public care in one local area of London, England. Interviews were conducted during a project partnership between a London borough and university staff, aiming to provide a localised, pilot support initiative which responded to mothers’ viewpoints. To ‘hear’ mothers’ own voices more clearly, we analysed interview transcripts using a methodology which separates out elements of how the interviewee tells her story, how she speaks about herself and about her relationships, taking into account surrounding social complexities and researchers’ reactions to the story. To explain how professionals could subsequently draw upon these ‘mothers’ voices’ for a pilot support initiative, we identify some key messages for professionals from these interviews, including: women wanting clear and honest communication between themselves and workers, and between staff; women often feeling ‘let down’ by professional procedures and court processes that were moving too fast for them to keep up; women wanting to be treated with more respect. Women respected some professionals but not others and this seemed to relate partly to personalities. Some mothers experienced being ‘left alone’ or ‘abandoned’ to deal with the aftermath of children’s removal and/or adoption

Active normal faults and coupled landscape response: bedrock variability in the southern Gulf of Corinth, central Greece

Fluvial erosion processes control landscape response to climatic and tectonic signals and its propagation into sedimentary basins. Considerable effort has gone into quantifying and modelling the effect of changes in uplift rates on fluvial erosion in bedrock rivers. However, current landscape models, based on stream power, tend to ignore the effects bedrock variability. The lack of available data relating rock strength to bedrock erodibility in fluvial settings has limited our ability to explore this question. Recent attempts at modelling to resolve this issue rely on indirect or theoretical rock strength properties. An alternative approach requires field measurements of rock strength together with geomorphological and tectonic constraints to quantify the effect of rock strength on river evolution. The Gulf of Corinth, central Greece, is one of the fastest extending rifts in the world and tectonic boundary conditions are well constrained. We (1) review published constraints on uplift along the active normal faults on the southern coast of the Gulf, and project uplift away from the faults into three catchments using a viscoelastic dislocation model; (2) test how channel width and slope vary in these rivers upstream of the active faults, and we use this data to estimate the distribution of stream power down-system; (3) systematically measure rock strength, using a Schmidt hammer, to constrain its effect on river response to uplift. All the rivers have knickpoints upstream of the active faults and we show they are responding transiently to active faulting. By assuming that our derived uplift rate equals stream power-driven erosion rate we calculate the erodibility, k, of bedrock. We demonstrate that stream powers in rivers crossing faults in the southern Gulf of Corinth correlate with rock strength and derive a non-linear power relationship between bedrock erodibility k and Schmidt hammer rebound. These findings highlight the need to incorporate bedrock variability into stream power erosion models