Fracture Toughness and Fatigue Crack Growth Rate Characterization of Inconel 718 Formed by Laser Powder Bed Fusion

Continuing improvement in the field of AM of metals provides the opportunity for direct fabrication of aerospace parts. AM was once used in large part for rapid prototyping but improvements in technology and increases in the knowledge base of AM materials has provided the opportunity for manufacture of AM parts for operational use. The ability to create low numbers of unique parts without having to invest in expensive tooling provides great economic incentive to utilize this technique. IN718 is the most common high temperature alloy used in the aerospace industry and lends itself readily to formation by LPBF. The superior strength of IN718 at temperatures up to 650°C and its excellent corrosion resistance make it the alloy of choice for compressor blades in jet turbines. Extensive data exists for conventionally produced IN718 but gaps in the data are present for AM material. Two of these gaps that are addressed by this research are FT and FCGR. A primary driver of the differences in behavior between conventionally manufactured and AM IN718 are the microstructural differences. Conventionally produced material has an equiaxed microstructure that provides isotropic material behavior. Conversely production by AM methods results in a highly directional microstructure related to the build direction of the part that drives anisotropy in material performance. It is hypothesized that a modified heat treatment that allows for re-crystallization of the columnar grains to grains that are more equiaxed will mitigate anisotropic material effects. This research will characterize the FCGR of AB, CHT, and MHT conditions. Results of FCGR indicate the the MHT is successful at reducing the overall FCGR of LPBF IN718. The standard heat treatment for wrought IN718 is shown to increase anisotropy in FCGR and give no improvement to the FCGR when compared to material in the AB condition

Creating a New Learning Model to Avoid Skills Gaps and to Fulfil the Future Needs of the Knowledge Society

In: A.J. Kallenberg and M.J.J.M. van de Ven (Eds), 2002, The New Educational Benefits of ICT in Higher Education: Proceedings. Rotterdam: Erasmus Plus BV, OECR ISBN 90-9016127-9The situation in the education institutions and the challenges for human resources activities inside companies changed rapidly the last years. It is not (only) because of the integration and use of new technologies. It is due to a general need to change the paradigm of new learning models (and theories) in accordance with new demands in the knowledge society. Strategic blended eLearning is an opportunity for institutions, universities and companies to utilise the “power” of technology for real social and educational change bringing benefits to all its users. Online education and learning can make a huge impact on the way companies and educational institutions do business. The Web can increase their potential significantly, giving them awareness on a larger scale and increasing or even creating revenue. From a corporate point of view it is recognised that in this day and age where use of technology and business methodologies are all relatively similar organisations need something more unusual to be considered “leading edge”. Creating a corporate university or online learning environment, can educate the people who work on the frontlines of a business. If they are well informed, impart a consistent message and feel valued they become positive ambassadors for the organisation, giving them a competitive advantage, increased productivity and an enhanced knowledge capital. Therefore it is in any case useful to be aware more clearly what the effects of strategic blended eLearning and the IT-integration can offer. The speech/workshop will highlight some of these effects looking at promising examples and methods and discuss the need of the creation of a new learning model. Furthermore the speech/workshop will argue, how this change can influence the requirements to all actors inside the “old” and “new” learning model

Localized Immunosuppressive Environment in the Foreign Body Response to Implanted Biomaterials

The implantation of synthetic biomaterials initiates the foreign body response (FBR), which is characterized by macrophage infiltration, foreign body giant cell formation, and fibrotic encapsulation of the implant. The FBR is orchestrated by a complex network of immune modulators, including diverse cell types, soluble mediators, and unique cell surface interactions. The specific tissue locations, expression patterns, and spatial distribution of these immune modulators around the site of implantation are not clear. This study describes a model for studying the FBR in vivo and specifically evaluates the spatial relationship of immune modulators. We modified a biomaterials implantation in vivo model that allowed for cross-sectional in situ analysis of the FBR. Immunohistochemical techniques were used to determine the localization of soluble mediators, ie, interleukin (IL)-4, IL-13, IL-10, IL-6, transforming growth factor-β, tumor necrosis factor-α, interferon-γ, and MCP-1; specific cell types, ie, macrophages, neutrophils, fibroblasts, and lymphocytes; and cell surface markers, ie, F4/80, CD11b, CD11c, and Ly-6C, at early, middle, and late stages of the FBR in subcutaneous implant sites. The cytokines IL-4, IL-13, IL-10, and transforming growth factor-β were localized to implant-adherent cells that included macrophages and foreign body giant cells. A better understanding of the FBR in vivo will allow the development of novel strategies to enhance biomaterial implant design to achieve better performance and safety of biomedical devices at the site of implant

The State of Women Veterans' Health Research: Results of a Systematic Literature Review

OBJECTIVE: Assess the state of women veterans' health research. DESIGN: Systematic review of studies that pertained specifically to or included explicit information about women veterans. A narrative synthesis of studies in 4 domains/topics was conducted: Stress of military life; Health and performance of military/VA women; Health services research/quality of care; and Psychiatric conditions. MEASUREMENTS AND MAIN RESULTS: We identified 182 studies. Of these, 2 were randomized-controlled trials (RCTs) and the remainder used observational designs. Forty-five percent of studies were VA funded. We identified 77 studies pertaining to the stress of military life, of which 21 reported on sexual harassment or assault. Rates of harassment ranged from 55% to 79% and rates of sexual assault from 4.2% to 7.3% in active duty military women and 11% to 48% among women veterans. Forty-two studies concerned the health and performance of military/VA women, with 21 studies evaluating sexual assault and posttraumatic stress disorder (PTSD) and their effect on health. Fifty-nine studies assessed various aspects of health services research. Eight studies assessed quality of care and 5, patient satisfaction. Twenty-five studies assessed utilization and health care organization, and findings include that women veterans use the VA less than men, that gender-specific reasons for seeking care were common among female military and veteran personnel, that provision of gender-specific care increased women veterans' use of VA, and that virtually all VAs have available on-site basic women's health services. Fifty studies were classified as psychiatric; 31 of these were about the risk, prevalence, and treatment of PTSD. CONCLUSIONS: Most research on VA women's health is descriptive in nature and has concerned PTSD, sexual harassment and assault, the utilization and organization of care, and various psychiatric conditions. Experimental studies and studies of the quality of care are rare