The growing requirements for limiting the negative impact of all modes of transport on the natural environment mean that clean technologies are becoming more and more important. The global trend of e-mobility also applies to sea and inland water transport. This article presents the results of experimental tests carried out on a life-size, parallel diesel-electric hybrid propulsion system. The efficiency of the propulsion system was analysed for two modes of operation (electric and diesel) and for different engine speeds and loads. Analysis of the impact of using a hybrid propulsion system on fuel consumption was carried out on a case study vessel and for six actual journeys. The use of hybrid propulsion in "zero emission" mode enables up to four times higher energy efficiency when compared to a conventional drive, while reducing CO 2 emissions and air pollution to zero, as well as a hundred-fold reduction in noise emissions. High flexibility in the operation of such a drive enables the use of intelligent power control technology (smart propulsion). This article shows that the use of hybrid propulsion reduces the negative impact on the environment to a minimum and allows for a significant reduction in the vessel's operating costs.

The development of modern lithium batteries and propulsion systems now allows the use of complex propulsion systems for vessels of various sizes. As part of the research and implementation project, a parallel hybrid drive system was designed, built and then tested in the laboratory. The experimental studies conducted allowed for the measurements of power, fuel consumption and electric power distribution in various operating modes of the propulsion system. The research proves that in the analysed case, the hybrid parallel system meets the demand for electric energy during a typical cruise scenario, and thus there is no need to install a power generator on the yacht.

The development of modern technologies and their increasing availability, as well as the falling costs of highly efficient propulsion systems and power sources, have resulted in electric or hybrid propulsions systems’ growing popularity for use on watercraft. Presented in the paper are design and lab tests of a prototype parallel hybrid propulsion system. It describes a concept of retrofitting a conventionally powered nine meter-long vessel with the system, and includes results of power and efficiency measurements, as well as calculations of the vessel’s operating range under the propulsion of its electric motor. The concept of adding of a solar panels array was studied.

StreszczenieRozwój cywilizacji i ciągła poprawa jakości życia prowadzi do zmiany w zachowaniach prozdrowotnych. Siedzący tryb życia oraz nadmiar spożywanych kalorii powoduje nadmierny przyrost tkanki tłuszczowej, prowadzący do nadwagi i otyłości. W ciągu ostatnich kilku lat problem ten stale narasta, stając się epidemią XXI wieku w Polsce i na całym świecie. Cel pracy. Porównanie stylu życia dzieci z prawidłową masą ciała oraz dzieci z nadwagą i otyłością. Metody i pomiary. Badaniami ankietowymi objęto 232 dzieci w wieku 2,5-18 lat (80 dzieci z prawidłowa masą ciała i 152 dzieci z nadwagą i otyłością). Wyniki. Stwierdzono większą częstość występowania otyłości u rodziców dzieci z nadmierną masą ciała (60,13%). Dzieci otyłe rzadziej spożywały posiłki w domu w porównaniu z dziećmi z prawidłową masą ciała (62,50% vs. 37,50%) i jadły nieregularnie. Częściej również próbowały zredukować masę ciała (34,87 vs.1,25%) stosując diety niskokaloryczne. Wnioski. Nadwaga i otyłość stwierdzana u rodziców ma duży wpływ na występowanie nadmiernej masy ciała u dzieci. Posiłki przygotowywane i spożywane w domu przyczyniają się do kształtowania dobrych nawyków żywienio-wych.Endokrynol. Ped. 2016.14.1.54.29-35. © Copyright by PTEiDD 2016Key words overweight, obesity, lifestyle Abstract Introduction. The constant development of civilization and the continuous improvement of the quality of life lead to a change in healthy behaviors. A sedentary lifestyle and excess of calories contribute to an increase in fat tissue, leading to overweight and obesity. Over the past few years, this problem has been growing steadily and becoming an epidemic of the 21 st century in Poland and around the world. Objectives. Comparison of the lifestyle of children with normal weight and children with overweight and obesity. Materials and methods. The study included 232 children at the age 2,5-18 years (80 children with normal body weight and 152 children with overweight and obesity). Results. There was a higher incidence of obesity in parents of children with excessive body weight (60.13%) and less physical activity. Obese children rarely ate lunch at home, compared with children with normal weight (62.50% vs. 37.50%), and and had irregular mealtimes. They more often tried to reduce their body weight (34,87 vs.1, 25%) using low--calorie diets. Conclusions. Overweight and obesity observed in the parents has a major impact on the incidence of excessive weight with children. Meals prepared and eaten at home contribute to the development of good eating habits.

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This study compares the performance of a plain bearing, with a similar structure to a tail shaft stern bearing, lubricated with either mineral oil or an environmentally acceptable lubricant (EAL). The main characteristic of the bearing is its length/diameter ratio of <1. Measurements are carried out with the bearing operating under loads from 0.5 to 1 MPa and seven speeds ranging from 1 to 11 rev/s. The bearing lubricated with either mineral oil with a viscosity grade of 100 or an environmentally acceptable lubricant (EAL) with a viscosity grade of 100 or 150 is investigated according to the ISO standard. Bearing wear is simulated by increasing the clearance circle by 0.1 mm. According to the results obtained, the use of an EAL in place of mineral oil does not cause significant changes in the bearing performance, regardless of the value of the clearance radius. The pressure distribution in the oil film, bearing load carrying capacity, eccentricity and friction coefficient have similar values for the entire load and speed ranges considered, and the discrepancies in the results are within the range of the measurement errors. Only an increase in EAL viscosity causes significant changes in bearing performance and these changes comply with the general theory of lubrication.

The article presents the development of author’s concept of a diesel/hydraulic propulsion system for inland watercraft. Due to specific nature of vessel navigation on rivers, classical propulsion systems with shaft lines can be effectively replaced by systems with hydraulic power transmission. A solution is also presented of a hybrid design with extra electric port having the form of a pumping system driven from a battery of accumulators. Strong and weak points of the proposed solution are discussed and its energy efficiency is assessed.