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Open access

Mateusz Torbicki

Abstract

The conditional safety functions at the climate-weather particular states and the unconditional safety functions of the port oil piping transportation system area and the maritime ferry, the mean values and the variances of those systems unconditional lifetimes and other safety indicators are determined. Those safety indicators, considering impact of the climate-weather change process, are evaluated for the piping system operating at under water Baltic sea area and for the maritime ferry operating at Gdynia Port area.

Open access

Maciej Malicki and Bartosz Madejski

Abstract

To prevent failure of machine components it is necessary to measure material damage generated in a component throughout its entire lifetime. Damage can be quantified by means of damage parameters. This paper considers the usefulness of hardness measurements to evaluate damage parameter in Inconel 718. Vickers hardness tests were performed on a specimen with a variable cross section area after tensile testing. The specimen’s geometry enabled the evaluation of damage parameter in respect of hardness measurements made on one individual specimen.

Open access

Jan Grzeszczak, Łukasz Grela and Thomas Achter

Abstract

The paper covers problems of the owners of a fleet of long-operated conventional power plants that are going to be decommissioned soon in result of failing to achieve new admissible emissions levels or exceeding pressure elements design lifetime. Energoprojekt-Katowice SA, Siemens AG and Rafako SA presents their joint concept of the solution which is a 2on1 concept - replacing two unit by two ultra-supercritical boilers feeding one turbine. Polish market has been taken as an example.

Open access

Sourendra Sinha and Zenon Chaczko

Socionomic Modelling in Wireless Sensor Networks

The performance and efficiency of a Wireless Sensor Network (WSN) is typically subject to techniques used in data routing, clustering, and localization. Being primarily driven by resource constraints, a Socionomic model has been formulated to optimize resource usage and boost collaboration among sensor nodes. In this paper, we present several experimental results to ascertain the underlying philosophy of the Socionomic model for improving network lifetime of resource constrained devices - such as, sensor nodes.

Open access

Thorsten Wiesel, Bernd Skiera and Julián Villanueva

References Berger, P.D. and N.L. Nasr (1998), “Customer Lifetime Value: Marketing Models and Applications,“ Journal of Interactive Marketing, 12, pp. 17 - 30. Blattberg, R.C. and J. Deighton (1996), “Managing Marketing by the Customer Equity Test,“ Harvard Business Review, 74, pp. 136 - 144. Gupta, S. and D.R. Lehmann (2003), “Customer As Assets,“ Journal of Interactive Marketing, 17, pp. 9 - 24. International Accounting Standards Board (2004), “Framework for the Preparation and Presentation of

Open access

Philipp Schmitt, Bernd Skiera and Christophe Van den Bulte

Abstract

Marketers increasingly use word of mouth to promote products or acquire new customers. But is such companystimulated WOM effective? Are customers who are referred by other customers really worth the effort? A recent study clearly says “yes”. In a study of almost 10,000 accounts at a German bank, the referred customers turned out to be 25 % more profi table than customers acquired by other means. Over a 33-month period, they generated higher profi t margins, were more loyal and showed a higher customer lifetime value. The difference in lifetime value between referred and non-referred customers was most pronounced among younger people and among retail (as opposed to private banking) customers. The reward of € 25 per acquired customer clearly paid off. Given the average difference in customer lifetime value of € 40, this amount implied a return on investment (ROI) of roughly 60 % over a six-year period. The encouraging results of this study, however, do not imply that “viral-for-hire” works in each and every case. Referral programs would be most beneficial for products and services that customers might not appreciate immediately. Products and services that imply some kind of risk would also benefit to a more than average degree from referrals because prospects are likely to feel more confi dent when a trusted person has positive experiences. Companies should consider carefully which prospects to target with referral programs and how large a referral fee to provide.

Open access

Miroslava Ťavodová, Miroslav Džupon, Daniela Kalincová and Michaela Hnilicová

Abstract

Tools for crushing of undesirable advance growth and mulching wood are subjected to heavy wear in operation with the need for their frequent replacement shortly after deployment. It is important to address the problem of their wear due to price of tools, as well as the time necessary for their replacement. Tool life is shortened because of deformation taking place due to the loss of wolfram-carbide (WC) tips, what is an undesirable phenomenon. Solutions for increasing the tool lifetimes were designed on the basis of analysis of wear mechanisms that cause this deformation. Furthermore, effect of deformed layer was evaluated by measuring hardness and microhardness. It was found that there was a strain hardening the surface due to cyclic loading. Size and extent of deformation of the entire tool with the loss of material on the functional part were documented using an optical scanning sensor system. Effect of the deformation on the material structure change, as well as topography and extent of surface area affected by abrasive wear under impact loads, were assessed by means of light and electron scanning microscopy. On the basis of these analyses, an option for increasing the lifetime of exposed areas on the tool by application of hardfacing to increase the tool wear resistance was proposed. Prerequisite for extending their work lifetime in the field is creation of a sufficient coarse layer or multiple layers of wear resistant material at specific tool areas.

Open access

Neil R. Smalheiser

1 Introduction Don R. Swanson (1924–2012) was well appreciated during his lifetime as Dean of the Graduate Library School at University of Chicago, as winner of the American Society for Information Science Award of Merit for 2000, and as author of many seminal articles ( Figure 1 ). Don became Emeritus in 1996, but did not truly retire until around 2007, when he suffered a series of strokes. Around 10 years ago, Tanja Bekhuis (2006) wrote a review article that discussed Don’s contributions and their subsequent influence on bioinformatics and text mining

Open access

Miroslaw Rodzewicz

References Rodzewicz, M. (2008). Determination and extrapolation of the glider load spectra. Aircraft Engineering and Aerospace Technology , 80(5), pp. 487-496. Kensche, C., W. (2002). Proposal for a certification procedure of extended sailplane lifetime. Technical Soaring , 26(2), pp. 32-43. Rodzewicz, M. (2009). Fatigue evaluation of high-loaded aeronautical composite structures. Aircraft Engineering and Aerospace Technology , 81(5), pp. 452 - 460.

Open access

Giulia Maria Liosi, Francesca Giacobbo, Emanuele Pignoli, Mauro Carrara, Grazia Gambarini and Mario Mariani

Abstract

The Fricke xylenol orange (FX) gel system is a chemical dosimeter characterized by good sensitivity, linear dose response, tissue equivalence, no toxicity, easy preparation, reproducibility and low cost. Thanks to the presence of the gelatinous matrix, the system is particularly suitable to perform reliable 3D mapping of the absorbed dose spatial distribution via magnetic resonance imaging (MRI) or optical techniques. The aim of this work is to study in a systematic way the influence of the pre-irradiation storage procedure upon sensitivity, dose response stability and lifetime of use of a FX gel system made with gelatin from porcine skin subjected to homogeneous irradiation. For this purpose, different pre-irradiation storage procedures, in terms of temperature and duration of each storage step, were investigated. In order to evaluate the dose response stability, the optical analyses of the samples were performed up to 6 hours after irradiation. Moreover, the samples were irradiated at time intervals of 24 hours for up to 7 days after preparation in order to evaluate the system lifetime of use. Regardless of their thermal and temporal life, the samples show linear dose responses in the investigated dose range (3-24 Gy) and an increase of sensitivity with the time elapsed between preparation and irradiation. Among the three pre-irradiation storage procedures considered here, a procedure that provides the best dose response stability and lifetime of use was identified and recommended for further use. The analyzed dosimetric system possesses good properties that make it promising for medical application, particularly concerning the evaluation of pre-treatment plan quality assurance within the conformational external beam radiotherapy