37 research outputs found
The Influence of Bleached Jute Fiber Filler on the Properties of Vulcanized Natural Rubber
Application of the multi-criteria navigational safety assessment method for the proposed variants of the designed waterway
The article presents an exemplary application of the multi-criteria navigational safety assessment method for the proposed variants of the designed waterway in order to verify it. This method comprehensively considers the most important environmental and technical aspects related to the implementation of the planned investment. The method can be used for the purposes of navigational analysis, i.e. an engineering document that meets the requirements of the regulation of the competent, which subject to agreement with the Director of the territorially competent Maritime Office
Possibilities for providing of professional practices on the training vessel Dar Mlodziezy
The article presents possibility of performing trainings on board of the Gdynia Maritime Academy's training ships. It has been described main rules of curriculum of practices, also included requirements of the timeline of the practice which were defined in proper law acts as well as applying of those requirements in accomplishment of practices on board of the ships. Paper presents statistics of the numbers of students trained on board of "Dar Mlodziezy" from the Gdynia Maritime University and from other Maritime Universities and schools. Based on the presented statistics data it has been analyzed possibility of the extension time of the trainings. Such analysis assay results from curriculum of the Maritime Academy in Gdynia and others maritime schools
Effect of the conditions of thermomechanical reclaiming of ground tire rubber on the properties of reclaimed rubber materials
Termomechaniczną regenerację miału gumowego (GTR) prowadzono przy użyciu współbieżnej wytłaczarki dwuślimakowej. Zastosowanie metody powierzchni odpowiedzi RSM (ang.: Response Surface Methodology) pozwoliło na scharakteryzowanie wpływu warunków termomechanicznej regeneracji odpadów gumowych (temperatury cylindra wytłaczarki, prędkości obrotowej ślimaków oraz wydajności wytłaczania) na przebieg procesu regeneracji (moment obrotowy) oraz właściwości otrzymanych regeneratów (zawartości ekstraktu acetonowego, zawartości frakcji zolowej, lepkości Mooneya, przyrostu momentów skrętnych, optymalnego czasu wulkanizacji). Stwierdzono, że najistotniejszym czynnikiem wpływającym na przebieg termomechanicznej regeneracji miału gumowego oraz na jakość otrzymanych regeneratów jest temperatura cylindra wytłaczarki.Thermomechanical reclaiming of ground tire rubber (GTR) was performed using a co-rotating twin screw extruder. Based on response surface methodology (RSM) the influence of reclaiming conditions (temperature of barrel, screw rotational speed, feed rate) on the processing (screw torque) and properties of reclaimed rubber (acetone extract content, sol fraction, Mooney viscosity, torque increment ΔM and optimal vulcanization time) were determined. It was found that barrel temperature is the main factor affecting the thermomechanical reclaiming process and quality of reclaimed rubber
Comparison of the Efficiency of Williamson and Anderson Turn Manoeuvre
The paper presents comparison of the ‘Person over board’ manoeuvres. The article was based on research con-ducted on a group of students of the Faculty of Navigation of Gdynia Maritime University. People involved in studies previously conducted on board training on school training ships: "Dar M?odzie?y" and "Horyzont II", but did not have experience as an officers. Research was carried on the Polaris Ships Bridge Simulator, located at the faculty of Navigation, of Gdynia Maritime University
Overview of definitions of maritime safety, safety at sea, navigational safety and safety in general
Safety, along with the issue of security, is the most substantial and critical issue to any society and nation of the mankind. The fact that human elements contribute dominantly, in particular, to the transportation – marine, air and road traffic – accidents requires not only the technical approaches, but also cultural configuration inherent to the accidents. This paper tries to incorporate Hofstede’s dimensions of national culture to identify possible interaction with accidents. It will be of help to figure out the need to consider the aspect of national culture to be efficient in dealing with policies for safer communities and nations
Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments
Reactive extrusion is a cost-effective and environmentally-friendly method to produce new materials with enhanced performance properties. At present, reactive extrusion allows in-situ polymerization, modification/functionalization of polymers or chemical bonding of two (or more) immiscible phases, which can be carried out on commonly used extrusion lines. Although reactive extrusion has been known for many years, its application for processing of bio-based polymer blends and composites is a relatively new direction of scientific research. This work presents a literature review on recent advances in the processing of bio-based polymer blends and composites via reactive extrusion. We described compatibilization mechanisms for different types of biodegradable polymeric materials based on: (i) aliphatic polyesters, (ii) aliphatic polyesters/starch and (iii) aliphatic polyester/natural rubber systems. A special attention was focused on conventional and dynamic cross-linking of bio-based polymer blends and composites as an effective way to prepare new materials with unique properties e.g. biodegradable thermoplastic elastomers or shape-memory materials. Advantages and limitations affecting future trends in development of biodegradable polymer blends and composites reactive extrusion are also discussed
Application of fluidal ashes as a component of cement slurry used in carbon dioxide injection wells - possibility analysis
One of the most important environmental issues bothering scientists nowadays are greenhouse gases, mainly carbon dioxide, and the possibility of limiting their emission and utilization. Many countries have been actively trying to limit the greenhouse gases emission, mainly carbon dioxide, and implement the Carbon Capture and Storage (CCS) technology for years. One of the essential aspects of geological injection is constant monitoring of carbon dioxide, especially its pressure and temperature. Those parameters have an impact on viscosity, density and phase alterations during the flow. It is of vital importance to maintain the supercritical state of the fluid because it is the most efficient way of CO2 storage. The negative impact of CO2 on the properties of the cement slurry may disturb the exploitation of the well and create considerable hazard for the geological storage of carbon dioxide. Therefore, the cement slurry should be appropriately selected and the role of CO2 in the development of technological properties of fresh and hardened cement slurry should be determined. The aim of this research is to select the most appropriate cement slurry composition exhibiting optimal properties with respect to the phase changes of carbon dioxide. The first part of the research consists in creating cement slurries of various compositions and investigating its thermal conductivity and sogginess under in-situ conditions. The second part concerns a possibility of utilization of fluidal ashes from combustion of lignite as a component of cement slurry