Heats of Immersion of Uranium Oxides in n-Nitropropane III.

Heats of wetting· of uranium oxides with different O / U ratios were measured in n-nitropropane and these heats were found to decrease with increasing oxygen content of the oxide\u27s. This behaviour was compared with the opposite t endency in water. It was concluded that a definite amount of U03 is relatively easily formed on the surface of U02 at lower temperatures

Determination of phthalates in plum spirit and their occurrence during plum spirit production

Phthalates are ubiquitous environmental contaminants that, due to their lipophilicity, migrate more readily into beverages with higher ethanol content. The aim of this work was to study the occurrence of phthalates in samples during the plum spirit production and in the final product, plum spirit manufactured by registered producers from five European countries, using gas chromatography-mass spectrometry (GC-MS). A decreasing trend of mean values was observed for diethyl phthalate (DEP), di-iso-butyl phthalate (DiBP), and di-n-butyl phthalate (DBP) as the distillation process went on. Levels of benzyl-butyl phthalate (BBP) and di-(2-ethylhexyl) phthalate (DEHP) increased in the distillation phase compared to concentrations in the preceding phases. In commercial plum spirits, DEHP and DiBP were detected in the highest concentrations. Results also indicated that a moderate daily consumption of plum spirit does not pose a health risk regarding the Tolerable Daily Intake of BBP, DEHP, and DB

10.34: Creep properties of grade S275JR steel at high temperature

The paper describes an ongoing research project which aims to determine the creep properties of European steel Grade 275JR. The purpose of the research is to develop a reliable temperature‐, stress‐ and time‐dependent creep model for this alloy, since there is very little information available in the scientific community regarding its creep properties. The research within the project is focused on a series of stationary creep tests, which will be used to obtain time‐dependent creep strains in the temperature range 400–600°C. The stress range for which the creep evolution is studied in this project is between 25% and 90% of the value of the stress at 0.2% strain at any particular temperature level. Comparisons between the creep output for the alloy analysed and existing creep data are presented in the paper

Reconstruction of geomagnetic event as observed in Northern Adriatic region and Its correlation with GPS single-frequency positioning deviations

Space weather effects are generally recognized as causes of degradation of satellite positioning, navigation and timing (PNT) services. We analyze GPS position estimation error during a geomagnetic storm, focusing on manifestations of geomagnetic processes. The position estimation error was analyzed in terms of GPS coordinates’ deviations (latitude, longitude and height) from their reference values. The storm’s impact was studied in the Northern Adriatic region where GPS observables from two Global Navigation Satellite System (GNSS) reference stations were analysed. Geomagnetic indices were elaborated, comprising readings from interplanetary, magnetospheric and geomagnetic observatories. Total Electron Content (TEC) on both stations was computed using dual frequency GPS pseudorange observables. The experiment was to reconstruct the movement of geomagnetic disturbances entering the geospace, reaching the earth’s surface. The aim was to correlate possible space weather manifestation on satellite positioning performance in terms of positioning error. Regularities in changes in positioning deviations were identified with relation to influential indices. The research offered a possibility of experimental positioning deviations assessment as well as forecasting. Evaluation of generated rudimentary Classification and Regression Trees (CART) models showed that the risk of satellite positioning errors could be assessed and predicted considering absolutes, as well as changes in values of geomagnetic indices. During the research process, several activities emerged as preferable continuation of the work, with the aim of further development of predictive models and the complement of space weather scenarios and their consequences on navigational systems. Along with summarized results, they are outlined in the conclusion section

Navigation with ECDIS: Choosing the Proper Secondary Positioning Source

The completion of ECDIS mandatory implementation period on-board SOLAS vessels requires certain operational, functional and educational gaping holes to be solved. It especially refers to positioning and its redundancy, which represents fundamental safety factor on-board navigating vessels. The proposed paper deals with primary and secondary positioning used in ECDIS system. Standard positioning methods are described, discussing possibilities of obtained positions’ automatic and manual implementation in ECDIS, beside default methods. With the aim of emphasizing the need and importance of using secondary positioning source in ECDIS, positioning issue from the standpoint of end-users was elaborated, representing a practical feedback of elaborated topic. The survey was conducted in the form of international questionnaire placed among OOWs, ranging from apprentice officers to captains. The result answers and discussion regarding (non)usage of secondary positioning sources in ECDIS were analysed and presented. Answers and statements were elaborated focusing not only in usage of the secondary positioning system in ECDIS, but in navigation in general. The study revealed potential risks arising from the lack of knowledge and even negligence. The paper concludes with summary of findings related to discrepancies between theoretical background, good seamanship practice and real actions taken by OOWs. Further research activities are pointed out, together with planned practical actions in raising awareness regarding navigation with ECDIS

Raising awareness on cyber security of ECDIS

In the maritime transport, the Electronic Chart Display and Information System (ECDIS) has been developed into a complex computer-based ship critical operational technology system, playing central roles in the safe ship navigation and transport. While ECDIS software maintenance is regulated by the International Maritime Organization (IMO) ECDIS performance standards and related circulars, underlying software and hardware arrangements are implemented by ship-owners and supported by ECDIS equipment manufacturers. In this paper, we estimate ECDIS cyber security in order to study the origin of ECDIS cyber security risks. A set of ECDIS systems is examined using an industry-leading vulnerability scanning software tool, and cyber threats regarding the ECDIS backup arrangement, underlying operating system and third party applications are studied

Overreliance on ECDIS technology: A challenge for safe navigation

The Electronic Chart Display and Information System (ECDIS) became the central navigational tool on modern ships. The system comprises numerous navigational and other components, each of them with its limitations and reliability. Due to ECDIS's revolutionary features, navigators are tempted to place excessive reliance on the system. Such reliance on it as a sole navigational aid is undoubtedly a problematic issue. The proposed paper is a segment of a systematically carried out research among ECDIS stakeholders. ECDIS EHO (Experience, Handling, and Opinion) research aims through research activities based on a user-centred approach to develop and improve the educational framework. The overreliance on the ECDIS system motivated the proposed research, which focused on system users' opinions and practice regarding confirmation of the accuracy of information displayed on ECDIS, particularly concerning positional sensors. Analysis of answers collected by the ECDIS EHO questionnaire represents a backbone of the research supported by previous achievements. The answers have been categorized and discussed, revealing certain worrying aspects referring to the system's positional error experienced by users. Furthermore, preferred methods of cross-checking ECDIS information have been identified and have differed among respondents based on their rank on board. Additionally, answers indicate certain doubts between users’ interpretation of the best confirmation method and the actual selection of the used method. The importance of cross-checking navigational data in avoiding overreliance and maintaining situational awareness has been presented in the conclusion chapter and the proposal for further work