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The purpose of this paper is to explore the designed cultural ecology of a hip-hop and computational science, technology, engineering, and mathematics (STEM) camp and the ways in which that ecology contributed to culturally sustaining learning experiences for middle school youth. In using the principles of hip-hop as a CSP for design, the authors question how and what practices were supported or emerged and how they became resources for youth engagement in the space.

The overall methodology was design research. Through interpretive analysis, it uses an example of four Black girls participating in the camp as they build a computer-controlled DJ battle station.

Through a close examination of youth interactions in the designed environment – looking at their communication, spatial arrangements, choices and uses of materials and tools during collaborative project work – the authors show how a learning ecology, designed based on hip-hop and computational practices and shaped by the history and practices of the dance center where the program was held, provided access to ideational, relational, spatial and material resources that became relevant to learning through computational making. The authors also show how youth engagement in the hip-hop computational making learning ecology allowed practices to emerge that led to expansive learning experiences that redefine what it means to engage in computing.

Implications include how such ecologies might arrange relations of ideas, tools, materials, space and people to support learning and positive identity development.

Supporting culturally sustaining computational STEM pedagogies, the article argues two original points in informal youth learning 1) an expanded definition of computing based on making grammars and the cultural practices of hip-hop, and 2) attention to cultural ecologies in designing and understanding computational STEM learning environments.

The purpose of this paper is to study the use of the additive manufacturing (AM) method, electron beam melting (EBM), for manufacturing of customized hip stems. The aim is to investigate EBM's feasibility and commercial potential in comparison with conventional machining, and to map out advantages and drawbacks of using EBM in this application. One part of the study concerns the influence on the fatigue properties of the material, when using the raw surface directly from the EBM machine, in parts of the implant.

The research is based on a case study of manufacturing a batch of seven individually adapted hip stems. The stems were manufactured both with conventional machining and with EBM technology and the methods were compared according to the costs of materials, time for file preparation and manufacturing. In order to enhance bone ingrowths in the medial part of the stem, the raw surface from EBM manufacturing is used in that area and initial fatigue studies were performed, to get indications on how this surface influences the fatigue properties.

The cost reduction due to using EBM in this study was 35 per cent. Fatigue tests comparing milled test bars with raw surfaced bars indicate a reduction of the fatigue limit by using the coarse surface.

The paper presents a detailed comparison of EBM and conventional machining, not seen in earlier research. The fatigue tests of raw EBM‐surfaces are interesting since the raw surface has shown to enhance bone ingrowths and therefore is suitable to use in some medical applications.

The purpose of this paper is to present an improved methodology for design of custom‐made hip prostheses, through integration of advanced image processing, computer aided design (CAD) and additive manufacturing (AM) technologies.

The proposed methodology for design of custom‐made hip prostheses is based on an independent design criterion for each of the intra‐medullary and extra‐medullary portions of the prosthesis. The intra‐medullar part of the prosthesis is designed using a more accurate and detailed description of the 3D geometry of the femoral intra‐medullary cavity, including the septum calcar ridge, so that an improved fill and fit performance is achieved. The extra‐medullary portion of the prosthesis is designed based on the anatomical features of the femoral neck, in order to restore the original biomechanical characteristics of the hip joint. The whole design procedure is implemented in a systematic framework to provide a fast, repeatable and non‐subjective response which can be further evaluated and modified in a preplanning simulation environment.

The efficacy of the proposed methodology for design of custom‐made hip prostheses was evaluated in a case study on a hip dysplasia patient. The cortical bone was distinguished from cancellous in CT images using a thresholding procedure. In particular the septum calcar ridge could be recognized and was incorporated in the design to improve the primary stability of the prosthesis. The lateral and frontal views of the prosthesis, with the patient's images at the background, indicated a close geometrical match with the cortical bone of femoral shaft, and a good compatibility with the anatomy of the proximal femur. Also examination of the cross sections of the prosthesis and the patient's intra‐medullary canal at five critical levels revealed close geometrical match in distal stem but less conformity in proximal areas due to preserving the septum calcar ridge. The detailed analysis of the fitting deviation between the prosthesis and point cloud data of the patient's femoral intra‐medullary canal, indicated a rest fitting deviation of 0.04 to 0.11 mm in stem. However, relatively large areas of interference fit of −0.04 mm were also found which are considered to be safe and not contributing to the formation of bone cracks. The geometrical analysis of the extra‐medullary portion of the prosthesis indicated an anteversion angle of 12.5 degrees and a neck‐shaft angle of 131, which are both in the acceptable range. Finally, a time and cost effective investment casting technique, based on AM technology, was used for fabrication of the prosthesis.

The proposed design methodology helps to improve the fixation stability of the custom made total hip prostheses and restore the original biomechanical characteristics of the joint. The fabrication procedure, based on AM technology, enables the production of the customized hip prosthesis more accurately, quickly and economically.

The study aims to analyze the fretting phenomenon, manifested at the taper junctions of modular total hip prostheses (THP). Modularity of prostheses implies the micro-movement occurrence. Fractures can arise as a result of the fretting cracking of the prostheses components, affecting durability of modular THPs. Fretting corrosion is associated with the decrease in the clinical acceptance of hip modular implants.

Starting from the fretting phenomenon influence on modularity, monoblock THPs and prostheses with modular femoral head recovered from some review surgeries were investigated. Modular prostheses have a taper junction femoral head – femoral stem neck. Investigation consisted in the analysis of fretting wear and fretting corrosion, of the femoral heads’ taper and of the femoral stems’ trunnions.

The main result was that the micro-movement that provokes the fretting of the femoral head-femoral stem taper junction analyzed does not have the same direction. It is manifesting in the direction of the axis of the femoral head taper, around this axis or as a composed movement. The authors suspect that this is due to the different design of the taper. In this way, the inclination of the stem’s trunnion into the head hole has a different angular misalignment and may cause greater damages of the taper.

This result can be a starting point from the improvement of the future taper junctions design that will improve the quality, durability and modularity of THPs.

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE) applications in different fields of biomechanics between 1976 and 1991. The aim of this paper is to help the users of FE and BE techniques to get better value from a large collection of papers on the subjects. Categories in biomechanics included in this survey are: orthopaedic mechanics, dental mechanics, cardiovascular mechanics, soft tissue mechanics, biological flow, impact injury, and other fields of applications. More than 900 references are listed.

The purpose of this paper is to study the roughness effect on the fixation of taper junction components and surfaces wear in terms of taper surface design. The roughness of the femoral heads’ taper and of the femoral stems’ trunnions can influence the fretting wear of the taper junction.

It was analysed whether a microgrooved taper surface of the femoral stem trunnion improves the fixation and reduces the wear rate at the taper junction of the hip prosthesis. Two models have studied: a femoral head with a smooth tapered surface combined with a microgrooved stem trunnion and a femoral head with a smooth tapered surface combined with a trunnion that had a smooth surface of the tapered. To compare the wear evolution between these two models, a computerised finite element model of the wear was used.

The results obtained after analysis carried out during millions of loading cycles showed that the depth of the linear wear and the total material loss were higher for the femoral heads joined with microgrooved trunnions. The main conclusion of this paper is that the smooth surfaces of the taper and of the trunnions will ensure a better fixation at the taper junction, and therefore, will reduce the volumetric wear rates.

A higher fixation of the taper junction will reduce the total hip prosthesis failure and, finally, it will improve the quality and durability of modular hip prostheses.

To improve the quality of the additive manufacturing (AM) products, it is necessary to estimate surface roughness distribution in advance. Although surface roughness estimation has been previously studied, factors leading to the creation of a rough surface and a comprehensive test for model validation have not been adequately investigated. Therefore, this paper aims to establish a robust model using empirical data based on optimized artificial neural networks (ANNs) to estimate the surface roughness distribution in fused deposition modelling parts. Accordingly, process parameters such as time, cost and quality should be optimized in the process planning stage.

Process parameters were selected via a literature review of surface roughness estimation modelling by analytical and empirical methods, and then a specific test part was fabricated to provide a complete evaluation of the proposed model. The ANN structure was optimized by trial and error method and evolutionary algorithms. A novel methodology based on the combination of the intelligent algorithms including the ANN, linked to the particle swarm optimization (PSO) and imperialist competitive algorithm (ICA), was developed. The PSOICA algorithm was implemented to increase the capability of the ANN to perform much faster and converge more precisely to favorable results. The performances of the ANN models were compared to the most well-known analytical models at build angle intervals of equal size. The most effective process variable was found by sensitivity analysis. The validity of proposed model was studied comprehensively where different truncheon parts and medical case studies including molar tooth, skull, femur and a custom-made hip stem were built.

This paper presents several improvements in surface roughness distribution modelling including a more suitable method for process parameter selection according to the design criteria and improvements in the overall surface roughness of parts as compared to analytical methods. The optimized ANN based on the proposed advanced algorithm (PSOICA) represents precise estimation and faster convergence. The validity assessment confirms that the proposed methodology performs better in varied conditions and complex shapes.

This research fills an important gap in surface roughness distribution estimation modelling by using a test part designed for that purpose and optimized ANN models which uses purely empirical data. The novel PSOICA combination enhances the ability of the ANN to perform more accurately and quickly. The advantage in using actual surface roughness values is that all factors resulting in the creation of a rough surface are included, which is impossible if other methods are used.

This paper aims to argue that providing youth of color with opportunities to explore content while reflecting on and sharing mental health concerns is an under-focused dimension of teaching and learning that has the potential to positively impact these students’ academic achievement in science, technology, engineering and mathematics (STEM) disciplines

This paper used a qualitative study to interrogate a teaching/learning model through a hip-hop-based science program.

Because urban youth of color are traditionally most disengaged in STEM and also the ones who are the least likely to seek or be provided with mental health tools/services, it is suggested that there is a connection between their low academic achievement and the absence of opportunities for them to address emotions that impact their academic success. Furthermore, if these youths come from communities where mental health stressors are highly prevalent, and teaching is most restrictive, a model for teaching that considers practices that address both their academic and mental health needs becomes necessary.

This work does not intend to devalue or undermine the role of school counselors or traditional teachers. It is believed that the role of the school counselor or social worker when youths identify themes that go beyond the scope of personal challenges is significant and that these professionals should be made available when engaging in this type of work. It is also believed that the educator who may not be privy to hip-hop can successfully engage in this type of activity with STEM students. Finally, the use of science as an exemplar for engaging in this work does not indicate that the other STEM disciplines cannot or should not explore this type of model.

The paper outlines a model that other educators/researchers may use and suggests ways that this brand of research may be implemented by scholars across the country.

Through the implementation of the hip-hop-based science program as an intervention in science classrooms, students are provided the opportunity to bolster science content knowledge and knowledge of self. In addition, utilizing the hip-hop-based science program created an avenue for teachers to develop better understanding of students and their full socioemotional selves. This is especially necessary in STEM education where perceptions of students’ decisions to not engage in the disciplines are directly related to our collective unwillingness to present the subject matter in a way that goes beyond the glorification of its stoic and “old white” history.

This paper suggests a new dimension of STEM research through an exploration of hip-hop culture and youth emotions.

This chapter challenges the notion that Black males in science, technology, engineering, and mathematics (STEM) are missing from the discipline and proposes a model that presents underrepresentation as a function of Black males being both intentionally undiscovered and/or deliberately disconnected from particular academic disciplines. Our work offers a tangible and implementable yet aligned theory/method/exemplar for supporting the STEM genius of Black males through a hip-hop development (HHD) approach that aligns with a unique pedagogical method rooted in hip-hop culture.

In this chapter, we describe a hip-hop based science program as an intervention that combats STEM undiscovery and disconnectedness. We suggest that this program (through its theoretical and methodological roots) provides a set of practices that have the potential to bolster both academic content knowledge and knowledge of self. We argue that this program supports the development of the students' full socioemotional selves – which is a necessary prerequisite to pursuing academic content knowledge.

Black Panther depicted a positive representation of Black culture. The film transcended Black minds to believe in power, excellence, and intelligence. Black youth posted images on social media using the Wakanda pose as a symbol of pride. The film not only countered the stereotypical generalized ideologies of African culture, values, and customs, but it capsized false narratives by including the historical context of Black scientist with a female character. Articles summarizing depictions of Black Panther and its influence on Black youth assert that the character of Shuri and her perfection of the sciences contributed to pathways for young Black girls to join science, technology, engineering and mathematics (STEM) programs. Other factors contribute to the increase of Black girls in STEM programs, but the image of Shuri's character in a position of power of the sciences pinpoints representation as key to cerebral pictures and reflections of Black female excellence in the sciences. However, representation is minimal among Black male youth in STEM programs.

Although it is true that African American male youth have Black male representation in media through sports figures, rappers, and hip-hop artists, inquiring minds need to know that Black male representation in the sciences and mathematics is the formula to how young minds view themselves and their relation to the world. Accordingly, this underrepresentation of Black male youth in STEM programs leads to the big “what if” question. If LeBron James conducted a critical analysis using physics and mathematics to make a 3-point shot, then what is the likelihood that young Black males' interest in the STEM programs would increase?