All biological systems need reactive nitrogen, but historically it has been in short supply. [...] the end of the nineteenth century, the main agricultural source was fixation of N2 by symbiotic bacteria in legumes planted for that purpose, combined with careful recycling of the limited amount of nitrogen in manure.
Anthropogenic interference has resulted in climate change, ocean acidification, eutrophication and toxic pollution of the earth and it's ecosystems. The Earth System Analysis is an international research program on global environmental change to understand these processes in order to work towards global sustainability.
In the scope of this study, main pipe of the diffuser, risers, ports, internal and external environments forming the discharge system which is used in application are modelled by Finite Elements Analysis (FEA) program to obtain discharge and structural behaviour. The last two spans of the system (20 m) and four ports on these spans are investigated. While the diameter and geometry of the risers and ports remain constant, the diffuser pipe is modelled in three different ways. These are constant sectioned (Model 1), contracting with sharp edge entrance sectioned (Model 2) and gradually contracting sectioned (Model 3) respectively. Among them, only Model 1 is treated as Single Degree of Freedom (SDOF) system and it is simulated by FEA to verify FEA solver in the first place. After structural suitability is confirmed, rest of the models are analysed to determine reaction forces and stresses. The discharge is performed as unsteady external flow as well as steady external flow assumption which is widely used in external flow model in the literature. The discharge analyses are performed in two different ways to verify FEA program. Iterative method is accompanying to FEA program. As a result of this study, proper model for structural and discharge behaviour and external flow effects on discharge velocities are obtained.
The paper is analysing national and international legislation regarding the seafarer employment. Particular emphasis shall be placed on the fact, that there is insufficient legislation dealing with seafarer labour law in the Republic of Slovenia. On one hand we have the Employment Relationships Act under which the employment contract is concluded between employee and employer. This act determines additional commitments for the employer, which has to submit the contract with seafarer to the evaluation and to the registration. On the other hand there is a Maritime Code under which the employment contract is concluded between the seafarer and ship owner or other person acting on his behalf. Taking into account the national legislation we have to bear in mind the international legislation and especially consider the requirements arising from rules and standards agreed within the International Labour Organization.A comprehensive analysis of this issue presents solutions that the legislator could take into account when preparing employment of seafarer provisions, which need to be systematically, fairly, socially and legally oriented. There is no shipowner included in the maritime training process and consequently there is no system in place for the systematic employment of seafarers. The main goal of this analysis is to find out where the weaknesses are and what should be done better when implementing the Maritime Labour Convention.
The analysis of time records, coming from seakeeping experiments in irregular waves, is used to determine the occurrence of extreme events. The common procedure used for data analysis is to assume that the statistics of record's peaks is following two or three parameters Weibull distribution. For particularly severe sea states it can happen that the peaks assume a multi-modal distribution. In this case, a Weibull distribution is not suitable, also in the three parameters form, to reproduce the peaks population. That means some errors in the estimate of the extreme loads may occur, affecting consequently the vessel/structure design process. To overcome this source of error it is possible to use multi-modal distributions, or to change the peaks extraction technique, adopting a certain threshold. By using this second approach data should be fitted according to a Generalised Pareto distribution. Based on this theory, a data analysis procedure including the threshold selection is here proposed and tested on a set of time records coming from seakeeping model-scale experiments. The results are then compared with the standard Weibull approach.