Comparison of fine and conventional blanking based on ductile fracture criteria

ABSTRACT A comparison between fine and conventional blanking is carried out in this paper. In the fine blanking process, V-ring indentation is applied to create hydrostatic pressure and prevent premature fracture in an undesired direction. Furthermore, a small clearance between the punch and die is employed along with a counterforce punch that causes concentrated strain in the sheared band region. A fracture mechanics oriented finite element procedure has been employed in this research work in order to obtain the fracture path. The fracture path is found according to the stress and strain histories which are calculated in each element. The numerical results have shown that the sheared edge quality in the blanking process is strongly influenced by the fracture path. In fine blanking, there are various parameters affecting the sheared edge quality and dimensional accuracy. The finite element calculation is carried out for an axisymmetric model. The commercial finite element code ABAQUS V6.2 is employed along with a controlling program that is written in Visual BASIC

Generating iPSCs with a High-Efficient, Non-Invasive Method-An Improved Way to Cultivate Keratinocytes from Plucked Hair for Reprogramming

Various somatic cell types are suitable for induced pluripotency reprogramming, such as dermal fibroblasts, mesenchymal stem cells or hair keratinocytes. Harvesting primary epithelial keratinocytes from plucked human hair follicles (HFs) represents an easy and non-invasive alternative to a fibroblast culture from invasive skin biopsies. Nevertheless, to facilitate and simplify the process, which can be divided into three main steps (collecting, culturing and reprogramming), the whole procedure of generating hair keratinocytes has to be revised and upgraded continuously. In this study, we address advancements and approaches which improve the generation and handling of primary HF-derived keratinocytes tremendously, e.g., for iPSCs reprogramming. We not only evaluated different serum- and animal-origin-free media, but also supplements and coating solutions for an enhanced protocol. Here, we demonstrate the importance of speed and accuracy in the collecting step, as well as the choice of the right transportation medium. Our results lead to a more defined approach that further increases the reliability of downstream experiments and inter-laboratory reproducibility. These improvements will make it possible to obtain keratinocytes from plucked human hair for the generation of donor-specific iPSCs easier and more efficient than ever before, whilst preserving a non-invasive capability

Generating iPSCs with a High-Efficient, Non-Invasive Method—An Improved Way to Cultivate Keratinocytes from Plucked Hair for Reprogramming

Various somatic cell types are suitable for induced pluripotency reprogramming, such as dermal fibroblasts, mesenchymal stem cells or hair keratinocytes. Harvesting primary epithelial keratinocytes from plucked human hair follicles (HFs) represents an easy and non-invasive alternative to a fibroblast culture from invasive skin biopsies. Nevertheless, to facilitate and simplify the process, which can be divided into three main steps (collecting, culturing and reprogramming), the whole procedure of generating hair keratinocytes has to be revised and upgraded continuously. In this study, we address advancements and approaches which improve the generation and handling of primary HF-derived keratinocytes tremendously, e.g., for iPSCs reprogramming. We not only evaluated different serum- and animal-origin-free media, but also supplements and coating solutions for an enhanced protocol. Here, we demonstrate the importance of speed and accuracy in the collecting step, as well as the choice of the right transportation medium. Our results lead to a more defined approach that further increases the reliability of downstream experiments and inter-laboratory reproducibility. These improvements will make it possible to obtain keratinocytes from plucked human hair for the generation of donor-specific iPSCs easier and more efficient than ever before, whilst preserving a non-invasive capability

Airline Travelers' Causal Attribution of Service Failure and Its Impact on Trust and Loyalty Formation: The Moderating Role of Corporate Social Responsibility

This study examines airline travelers' causal attribution (stability and controllability) and its impact on trust and loyalty formation and investigates the moderating role of corporate social responsibility (CSR) in this process. Based on a literature review, theoretical relationships between stability, controllability, CSR, trust, and loyalty were derived, and the moderating effects of CSR on relationships between stability/controllability and trust/loyalty were examined. To empirically test these theoretical relationships, quantitative data were collected from 271 airline passengers who experienced a service failure in the past year. The results provide support for effects of stability and controllability on trust as well as the effect of stability on loyalty. In addition, the perception of CSR had positive effects on trust and loyalty. Finally, a favorable CSR perception weakened the negative effects of a service failure on trust and loyalty, particularly when the failure was attributed to a stable cause. The results highlight the important role of CSR in service failure situations and have important implications for airline managers