Development and characterisation of a self-powered measurement buoy prototype by means of piezoelectric energy harvester for monitoring activities in a marine environment

<p class="Abstract">In the interest of our society, for example in Smart City but also in other specific backgrounds, environmental monitoring is an essential activity to measure the quality of different ecosystems. In fact, the need to obtain accurate and extended measurements in space and time has considerably become relevant. In very large environments, such as marine ones, technological solutions are required for the use of smart, automatic, and self-powered devices in order to reduce human maintenance service. This work presents a simple and innovative layout for a small self-powered floating buoy, with the aim of measuring and transmitting the detected data for visualization, storage and/or elaboration. The power supply was obtained using a cantilever harvester, based on piezoelectric patches, converting the motion of ripple waves. Such type of waves is characterized by frequencies between 1.50 Hz and 2.50 Hz with oscillation between 5.0 ° and 7.0 °. Specifically, a dedicated experimental setup was created to simulate the motion of ripple waves and to evaluate the suitability of the proposed design and the performance of the used harvester. Furthermore, a dynamic analytical model for the harvester has been defined and the uncertainty correlated to the harvested power has been evaluated. Finally, the harvested voltage and power have shown how the presented buoy behaves like a frequency transformer. Hence, although the used cantilever harvester does not work in its resonant frequency, the harvested electricity undergoes a significant increase.</p><p class="Abstract"><span lang="EN-US"><br /></span></p>

Decision Tool of Medical Endoscope Maintenance Service in Chinese Hospitals: A Conjoint Analysis

Background: Quality and cost of medical device maintenance are dominant factors influencing hospitals’ decision in choosing medical endoscope products. Effective and efficient medical device maintenance are also paramount for providing cost-effective and high quality of medical care. This research aims to facilitate decision-making at hospitals in choosing the suitable endoscope device and the associated maintenance service; it also aims to facilitate decision-making at suppliers to develop the right products and services to fulfill customer demands.Methods: A cross-sectional survey was undertaken in 50 Chinese hospitals, including primary and tertiary hospitals. Moreover, 65 medical staff and 56 medical engineers were recruited from 50 Chinese hospitals. A comprehensive set of attributes were defined and investigated. Conjoint analysis and orthogonal design were used for survey design and statistical analysis. Results: Attribute importance and utility values of decision-making factors were analyzed at the aggregate, occupation, and medical institution levels. (1) At the aggregate level, the most critical factor is "maintenance response" and the least important one is "maintenance efficiency". (2) At the occupation level, medical staff paid more attention to "maintenance response" and medical engineers paid more attention to "maintenance quality". (3) At the medical institution level, Primary hospitals paid more attention to "maintenance price", while tertiary hospitals paid more attention to "maintenance quality". Conclusions: In general, this study provides a more scientific decision-making tool to both hospitals in choosing maintenance service of medical equipment such as endoscopy, and it also helps manufacturers and suppliers improve the after-sales service.

Increasing life of pit dump truck motor-wheel gearboxes by introducing the monitoring of the actual technical condition

At present, Kuzbass coal strip mines pay great attention to improving quality performance of mining equipment operation, including reliability and durability of components and units. One of the ways of the performance improvement is decreasing number of unforeseen failures. To achieve this purpose a mine dump truck part diagnostics should be introduced into a maintenance service procedure. At the same time the process of diagnostics should not increase the machinery downtime, but effectively reveal a condition of motor-wheel gearboxes in the course of dump truck operation. The aim of the research is to increase the reliability and service life of motor-wheel gearboxes of large BelAZ dump trucks. Failure of a motor-wheel gearbox is a rare phenomenon, but the cost of a new gearbox can vary from 3.5 to 10 million rubles. That is why it is important to implement such methods of diagnostics, which allow revealing the condition of gearboxes in the shortest possible time and without disassembling corresponding units. Determination of the actual technical condition of motor-wheel gearboxes is possible by different methods: vibroacoustic; acoustic; thermal; physical and chemical analysis of spent operating materials. The studies showed that none of these methods can be used as a universal one. When justifying and selecting the most suitable method, different factors should be considered, including technological, or a combination of methods should be applied, which will reduce risks, but at the same time increase costs. It is necessary to develop a better diagnostic method based on the use of several methods simultaneously.

Strategic Formulation Analysis of Semi-Permanent Building Provider from Containers, "I-Cont."

PT. Karya Inti Abadi Kontainer, trademark ‘I-CONT,’ is a container modification company creating business stalls with modern, practical and economical containers. We are the solution for MSME business players, which is focusing on the food and beverage industry. Aside from that, we also provide services in membership from consultation, modification containers, delivery, maintenance, service until reselling and remodification. The strategy method uses the Value Proposition Canvas, IFE, EFE, VRIO, CPM, SWOT, IE, QSPM, Porter's Generic Strategy and Lean Business Canvas Model. The results of this analysis can help to determine a suitable business model for PT. Karya Inti Abadi. Keywords: Value Proposition Canvas, Porter's Generic Strategy, Lean Business Model Canvas, containers.

Validation of copula-based weather generator for maintenance model of offshore wind farm

This article discusses the aspect of modeling weather conditions in marine environment for implementation in the offshore wind farm domain. It is clear that harsh sea weather conditions influence many characteristics of any offshore installation. The accessibility to the infrastructure, maintenance procedures, failure ratios of components, energy provision levels, or utilization of vessels—are the examples of weather-related issues connected to the offshore wind industry. Regarding the growing popularity of digital twin methodology, authors present a novel view to generate weather data with copula-based method. The results obtained are compared to selected historical data and implemented into the maintenance model. The selected indicators of maintenance service are used for usability assessment of proposed copula-based method.