Experimental Determination of Elastic and Rupture Properties of Printed Ninjaflex

In this paper, the effect of the 3D printing procedure on the elasticity during fused deposition modeling (FDM) is investigated. The considered material with brand name Ninjaflex is a thermoplastic polyurethane. Uniaxial tension tests are performed to identify the material properties, specifically the Young’s modulus, the maximum stretch, the tensile strength and the material’s fracture toughness. The influence of geometric characteristics on the material properties is studied. From the experimental results the parameters of Ogden’s hyperelastic material model are derived. A finite element simulation of the uniaxial tensile test validates the values obtained from a conditional least-square fit. In conclusion, additional to the experimentally determined rupture properties, the elastic parameters adapted to a Neo-Hookean, a Money-Rivlin and an Ogden material model of Ninjaflex are presented

On the Elastic Modeling of Highly Extensible Polyurea

Polyurea is a soft and highly flexible material commonly used as protective coating on concrete or steel structures. Often subjected to abrasion and impact loading, numerical simulations of such structures require material models accounting for both stiffness and high extensibility of the coating. Hence, comparing several classical approaches with emphasis on efficiency and material stability, for impact simulations a Mooney-Rivlin model with μ1 = 6 MPa and μ2 = 1.5 MPa is suggested. Therefor material parameters from different sources are collected and, additionally, data from our uniaxial tension experiments are provided. The modeling is verified by comparison with a Taylor anvil impact experiment

Does Culture Impact Preferred Employee attributes in Complaint Handling Encounters?

Recently, Gruber et al.’s (2011) Kano study revealed that complaining customers in Saudi Arabia are less difficult to delight than UK customers. The present study investigates whether these differences are caused by different service sector development stages, as suggested in their study, or by cultural differences instead. Data were collected using Kano questionnaires from 151 respondents with complaining experience in Singapore. This country was chosen as it has a highly developed service economy (like the UK) but also a collectivistic culture (like Saudi Arabia). The analysis reveals that Singaporean customers show the same preferences as those in the UK. We consider this as a strong indicator for the suggested impact of the stage of service sector development rather than cultural differences on complaining customers’ preferences of frontline employee attributes. Our results support the findings by Gruber et al. (2011). By doing so, they surprisingly refute previous research which concluded that national culture plays a significant role in shaping customer expectations during complaint handling encounters. Our study especially corroborates the notion of a life cycle of quality attributes that had been found for goods and services and the preferred attributes of frontline employees dealing with customer complaints

Present state and future perspectives of using pluripotent stem cells in toxicology research

The use of novel drugs and chemicals requires reliable data on their potential toxic effects on humans. Current test systems are mainly based on animals or in vitro–cultured animal-derived cells and do not or not sufficiently mirror the situation in humans. Therefore, in vitro models based on human pluripotent stem cells (hPSCs) have become an attractive alternative. The article summarizes the characteristics of pluripotent stem cells, including embryonic carcinoma and embryonic germ cells, and discusses the potential of pluripotent stem cells for safety pharmacology and toxicology. Special attention is directed to the potential application of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) for the assessment of developmental toxicology as well as cardio- and hepatotoxicology. With respect to embryotoxicology, recent achievements of the embryonic stem cell test (EST) are described and current limitations as well as prospects of embryotoxicity studies using pluripotent stem cells are discussed. Furthermore, recent efforts to establish hPSC-based cell models for testing cardio- and hepatotoxicity are presented. In this context, methods for differentiation and selection of cardiac and hepatic cells from hPSCs are summarized, requirements and implications with respect to the use of these cells in safety pharmacology and toxicology are presented, and future challenges and perspectives of using hPSCs are discussed

The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes

How Global are Global Brands? An Empirical Brand Equity Analysis

The term 'global brand' has become widely used by the media and by consumers. Business week publishes annually its widely known ranking of the 'Best Global Brands' (with Coca-Cola as number 1 in the past years) and consumers on summer vacations purchase brands such as Heineken or Marlboro they are familiar with from their home country. Although media and consumers call these brands 'global' and centralized marketing departments manage these brands globally - are these 'global brands' really global? Are they really perceived everywhere in the same way by the customers? Can we talk about truly global brand equity? And if there were brand image differences between countries, which factors causes them? The authors conducted an empirical research during May and June 2009 with similarly aged University students (bachelor students at business school) in Germany (n=426) and Mexico (n=296). The goal was to identify if brand awareness rates differ between Germans and Mexicans, if the brand image of Apple iPod is perceived in the same way in Germany and in Mexico and what influencing factors might have an impact on any brand image discrepancy between the countries. Results prove that brand recall rates differ between the two countries (with higher rates in Mexico) as well as brand image attributes vary significantly (28 out of 34 brand image attributes are significantly different between Germany and Mexico), with Mexico showing higher levels of favorable brand image attributes. Key influencing factors on the different brand image perceptions are perceived quality, satisfaction and the influence of reference groups (such as friends and family). The results suggest that so-called 'global brands' are not perceived the same way in Germany and Mexico. As a consequence, brand management using standardized marketing instruments for its presumable 'global brands' might be better off with a more differentiated approach that takes account a specific local brand image