Items

  • REPAIRING PISTON STEEL HEAD IN INTERNAL COMBUSTION SHIP ENGINE MITSUBISHI 60 LS BY MEANS OF FLUX-CORED ARC BUILT UP WELDING

    Hristo HRISTOV
    10/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    The proposed article describes the process of reparing piston steel head in internal combustion ship engine MITSUBISHI 60 LS by means of flux-cored arc built up welding. The technological sequence, of the recovery process, is completely described, the used consumables are listed, as well as the technological modes of welding. The main steps of the process are illustrated.
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  • AN ANALYSIS OF UNDERUTILISATION OF INLAND WATERWAY TRANSPORT IN NIGERIA

    Henry Kelechi ONYEMA; Uchenna Martin EMENYONU; Kingsley Olufemi AHMODU; Godfrey EMEGHARA
    10/1/2017
    5 citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    This research analyzes the effects of underutilization of inland waterway transport on Nigerian economy. It also scrutinized critically, the challenges negating the utilization of the inland waterway transport and its relative impacts on the Nigerian economy. Primary data were obtained from staff of Nigeria Inland Waterways Authority (NIWA) and Nigeria Port Authority (NPA). Data received, from 60 respondents identified constraining variables were subjected to Principal Component Analysis using the Principal component and orthogonal varimax rotation. The student t-test was used to test the statistical significance of the hypotheses, and they were all found to be not statistically significant, thus the null hypothesis were rejected. From our findings, the 15-item variables optimally weighted and summed based on the Kaiser criterion of eigenvalue cut-off of 1.0, there were 6 components that explained a cumulative variance of 91.917%, leaving 8.083% to other variables not included in the analysis. In conclusion, a well-developed and integrated inland waterway transport is a vital tonic for the economic development of Nigeria. With a better managed inland waterways, Nigeria can develop a regional trade within the West African subregion as the River Niger cut across Nigeria, Benin, Mali, and Guinea and emptied into the Atlantic Ocean. She can also boost her tourism potentials, through waterway recreational activities. This will definitely contribute to the Nigerian GDP and has the capacity to support the economy in the wake of dwindling oil prices.
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  • STOCHASTIC APPROACH TO OPTIMIZE THE SETTING OF RADIOLOCATION STATIONS AT REPAIR

    Evgeni GUGLEV; Yuriy DACHEV
    10/1/2017
    No citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    The structure of stochastic approximation methods is appropriate for realization in linear and non-linear stationary processes. Their application in optimization of pulses from radiolocation stations (RLS) is determined by the actual conditions of uncertainty (presence of noise and incomplete information about output data). Stochastic models of optimization are usually more adequate to real conditions with their choice of solution than determinate formulations of the extreme tasks. It applies to the optimization of impulse parameters that have static mode of operation of the electronic stage i.e., the circuit function is an algebraic equation. There is a simple and reliable algorithm enough to link the circuit function to the setting area of the existing element. Taking into account the nature of the respective real phenomena it is found that the most convenient method is the stochastic approximation. Practically, the degree of influence of the individual elements on the parameter of the set pulse, as well as the order of variation of the radio elements (R* and C*) is determined, which facilitates the practical realization of the algorithms at repair.
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  • GREEN ENERGY PROPULSION

    Catalin FAITAR; Novac IORDAN
    10/1/2017
    8 citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    Emissions from the shipping sector must be curbed in order to reduce air pollution and climate change impacts. The International Convention for the Prevention of Pollution from Ships (MARPOL) has stipulated mandatory technical and operation measures, which require more efficient maritime energy use and, simultaneously, less emissions. These regulations came into force in 2013. The industry itself has set targets to reduce carbon dioxide emissions by 20% by 2020 and 50% by 2050. Ship operators, therefore, need to consider cleaner fuel and power options, including the use of renewables, to meet these targets. Furthermore, rising bunker fuel prices, amid a globally volatile market, provide another compelling reason to scale up modern shipping solutions based on renewable sources and technologies.
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  • BEST PRACTICES FOR ESTIMATING EXTERNAL TRANSPORT COSTS

    Catalin FAITAR; Novac IORDAN
    10/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    Transport activities give rise to environmental impacts, accidents, congestion, and infrastructure wear and tear. In contrast to the benefits, the costs of these effects of transport are not fully borne by transport users. Without policy intervention, the so called external costs are not taken into account by transport users when they make travel decisions. Transport users are thus faced with incorrect incentives, leading to welfare losses.The next study gives a perspective to what it could be done
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  • DIGITАL АUDIO BROАDCАSTING FOR POSITION LOCАTION АT SЕА

    Georgi DIMITROV
    10/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    Position locаtion rеfеrs to thе functionаlity аnd еvеnts thаt еstimаtе thе locаtion of а point of intеrеst. Dеvеlopmеnt of wirеlеss communicаtion tеchnology аnd widе usе of wirеlеss nеtworks hаvе mаdе locаtion-аwаrе аpplicаtions possiblе аnd nеcеssаry. Objеct positioning locаtion is аn еssеntiаl еlеmеnt in mаny аpplicаtions such аs nаvigаtion, trаcking, еmеrgеncy sеrvicе, locаtion bаsеd sеrvicеs аnd sеcurity. Position locаtion involvеs thе coordinаtеs of а tеrminаl thаt mаy bе in two or thrее dimеnsions аnd contаins informаtion such аs thе lаtitudе аnd longitudе. Thе position locаtion should idеаlly bе аvаilаblе еvеrywhеrе. Kееping trаck of objеcts cаn аssist whilе improving sаfеty аnd providing control еfficiеntly. This pаpеr is аn ovеrview thаt concеrns a method of utilizаtion of digitаl аudio rаdiobroаdcаting tеchnology for locаlizаtion purposеs whilе аt sеа. Thе dеscribеd mеthod rеlаtеs gеnеrаlly to position dеtеrminаtion аnd pаrticulаrly to position dеtеrminаtion using digitаl аudio broаdcаsting signаls (DАB). In-bаnd Onchаnnеl (IBOC) digitаl аudio broаdcаsting dеlivеrs bеsidеs еnhаncеd fidеlity аnd improvеd rеcеption, somе dаtа sеrvicеs. Thеsе digital sеrvicеs could bе utilizеd for position locаtion whеrе thеrе’s еnough covеrаgе not fаr from shorе.
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  • AWARENESS OF THE RISK PRESENTED BY THE RADON GAS AMONG PEOPLE IN CONSTANTA COUNTY (ROMANIA)

    Dănuț ARGINTARU; Eliodor CONSTANTINESCU; Valerica BABAN
    10/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    During the period November 2015 - May 2016, a radon awareness survey was conducted to measure awareness and knowledge about some characteristics and health hazards of radon among residents in Constanta County, Romania. Questionnaire data consisted of knowledge and risk perception about radon. A total number of 445 participants responded to the questionnaires. The survey found that only 41% respondents had heard of radon. This study shows the necessity to inform the population about the health risk posed by radon, the necessity of monitoring and mitigation methods of it.
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  • SAFE MOORING USING IMPROVED SHORE TENSION SYSTEM - ECONOMY OF ENERGY AND COSTS

    Mihail – Vlad VASILESCU
    4/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    The main focus of this article is the development and use safe, easy mooring system, with reduction of costs and energy. The operation of mooring a ship at port is extremely important and dangerous. It is very important to use a safe system for mooring, not to put people life’s in danger or even the ship. By using an improved system like Shore Tension we can reduce the costs of mooring for charters and owners, save people energy, save time. Quality of the lines used for mooring is very important, because with a damage one or a mooring line of poor quality, can appear accidents or even casualties. Improved Shore Tension System can be in future, the new system of mooring: safe, clean and easy.
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  • DETERMINATION OF RELIABILITY FEATURES USING BAYES’ THEOREM

    Mihaela TUROF
    4/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    Bayes' theorem is one of the fundamental theorems of probability, which determines the probability of events and objects belonging to a certain group. Reliability is considered in some sense a probability. To determine some characteristics of reliability, it is possible to use Bayes formula. Bayes' theorem can be used to review the likelihood of a specific event that already happened, it can be repeated again. Some examples of application of Bayes' theorem in the technical field are presented in this paper, attempting to explain why this theorem is called the inverse probability law: we can use condiţional probability to make a prediction in reverse and to improve our prediction of events.
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  • V-BELT TRANSMISSION DESIGN EFFICIENCY, USING MATHCAD PROGRAM

    Mihaela TUROF
    4/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    The Mathcad interface allows users to combine a variety of different elements (mathematics, descriptive text, and supporting imagery) into the form of a worksheet, which is naturally readable. Because the mathematics are core to the program, the math is inherently live, dynamically recalculating as upstream values are altered. This allows for simple manipulation of input variables, assumptions, and expressions, which in turn update in real-time. The paper proposes the design by using Mathcad program of V-belt drives for speed reducer with a spur wheel stage.
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  • THE USE OF SIMULATION IN REMEDIAL INTERVENTIONS TO MARINE AREAS POLLUTED BY OIL

    Mirela-Iuliana SUNDRI; Mariana PANAITESCU; Fanel-Viorel PANAITESCU
    4/1/2017
    3 citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    Unloading of hydrocarbons into the marine environment has a signifiant economic impact for both the activities performed on the shores and exploiting the resources of the sea. In this context it is necessary to adopt a strategy and a national system of intervention to respond quickly and effectively in the event of a disaster caused by an accidental oil pollution in the area of the continental shelf or in the Romanian coastal belt. Quick resolution of such problems, as a result of work techniques developed as a result of simulations, reduces major negative consequences. In the present work was chosen using two simulation programs, HYSPLIT and ADIOS,both developed by NOAA, for forecasting events due to oil spills of the Black sea romanian coast and the choice of methods of remediation For simulations were used two types of oils: Abu-Dhabi and Horcon. The results of simulatios were: visualizing graphs oil removal, the charts of evaporated oil, the oil dispersing proces, the content of water in oil, the concentration of benzene in air. HYSPLIT and ADIOS programs for simulation the processes of removal oil discharged into the sea permit: making a prognosis; evaluation methods of remediation; the possibility of taking measures in advance to protect areas located at shore.
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  • VALIDATION OF THERMAL BALANCE EQUATION OF DIVER IN HYPERBARIC ENVIRONMENT AT SATURATION WITH HELIOX

    PhD student eng. Tamara STANCIU
    4/1/2017
    1 citation
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    I presented the validation of diver thermal balance equation in subsea hyperbaric environment at diving with air, in a previous paper. The same equation was validated, at saturation diving using Heliox breathing mixture, in the simulator of Laboratory Hyperbaric Diving Center. The subjects were separated into two groups of four: the first group dived in saturation with Heliox at 60msw “stage depth” and the second one at 30msw. I calculated, with equation (1.1), theoretically temperatures divers, after sinking into warm water (20 0C) and into cold water (17 0C). At the end diving temperatures were measured each subject, for each scenario diving (depth, water temperature, stationary time, thickness suit, etc.). Theoretically temperatures were compared with those obtained experimentally and the differences between theoretical and real values were 1 0C. The mathematical proposed model is valid for Heliox saturation diving in wet hyperbaric environment, up to 60 msw.
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  • MAGNUS EFFECT STUDIED WITH ANALYTICAL AND NUMERICAL METHODS

    Andrei Alexandru SCUPI
    4/1/2017
    5 citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    Different physical phenomena can be studied with the help of numerical programs. These programs are highly used in academic institutions for a better understanding of the phenomenon itself. A good correspondence between analytical representation and numerical representation is presented for different potential flows. The paper also presents a practical usage of potential flow when investigating the performance of an unconventional system that uses Flettner rotor for helping ship propulsion. The simulation, performed with CFD (Computational Fluid Dynamics) was made for different working conditions by varying the incidence angle.
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  • CONSIDERATIONS REGARDING DESIGNING 50 X 6 METERS SUSPENDED CROSSING

    Adrian POPA; Ionut Cristian SCURTU; Beazit ALI; Anastasia DUSE
    4/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    This paperwork is designing a suspended 50mx6m suspended crossing over a channel or a small river considering not only the design load but the response spectrum too.
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  • USE OF PRISMATIC CELL PANEL IN SHIPCONSTRUCTION

    Adrian POPA; Ionut Cristian SCURTU; Beazit ALI; Andreea JENARU
    4/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    This study was carried out starting from a real need: the possibility to create a fast rescue ship, able to operate in shallow waters in environments with explosive potential. That why, the idea of the designers was to use aluminium alloys in order to obtain a light boat. The hosed material is AL5083H116.
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  • A RISK OF CIBERNTICS IN THE BLACK SEA SYSTEMS

    Nikolay PETROV; Fanel-Viorel PANAITESCU; Mariana PANAITESCU
    4/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    Cybernetics consider the machines, living organisms and sea society as a organizing comprehensive form (system) – sea risky system that naturally historical or artificially reaches a certain level of organization according to relevant quality fixed structure or level of complexity. Basic laws and principles of cybernetics are inextricably linked to the reliability of functioning cybernetic systems. Cybernetics (cyber society) consider the objects as a system, not as a control system of a general nature, but as a system of defined set of general and specific structural and functional properties (presence in the world of living systems and social structures).
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  • HIGH PERFORMANCE CONTROLLABLE PITCH PROPELLERS

    Beazit ALI; Adrian POPA; Gheorghe ICHIMOAIEI; Levent ALI
    4/1/2017
    No citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    In order to maximize the design of the Controllable Pitch Propellers for low acoustic signature is necessary to analyse more aspects the general features of propeller and the effect of air emission, the effect of cavitation by using different computer programme which can stimulate a lot of parameters developed on the model on scale and on the full scale model. The result made possible a new way for improvement of design techniques to obtain more and more less noisly Controllable Pitch Propellers.
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  • ESTIMATED PROPULSION OF SMALL SCALE HYDROFOIL SHIPS

    Beazit ALI; Adrian POPA; Gheorghe ICHIMOAIE; Levent ALI
    4/1/2017
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    This paper presents an original procedure for estimating the propulsion of small scale hydrofoil ships. This procedure has enabled the development of a computer program that can predict both those types of ship propulsion regime imposed at a quasi-stationary speed and the march regime on wings. The calculation software obtained may serve to design any type of hydrofoil ship. The input data are read in a network that has access throughout the development of the program. In the end, the program outlines for the two march regimes of the ship which the study has been carried on, the drag resistance curve depending on the speed.
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  • CAVITATION AROUND PROPELLERS EQUIPPED WITH ENRGY SAVING DEVICES

    Mihail – Vlad VASILESCU
    10/1/2016
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    The main focus of this article is the development and use of clean renewable energy sources – energy saving devices, on ships. These mechanisms improve the propulsion performance and lower the fuel consumption of the ship using reaction fins for low-speed full ships and stator fins for high-speed slender ships. By using CFD - fluid flow computer program, we analyzed and evaluated the cavity propellers on ships equipped with energy-saving mechanism, including keel and rudder. This helps in understanding the flow characteristics such as pressure distribution on the propeller that would otherwise require many hours of effort and experimental analysis. The result is a high degree of propeller optimization and of the mechanism with the role of energy saving. The main reason of this article is to try to reduce cavitation around the propeller and show a modality for reducing ship pollution, so the quantity of fuel used, that mince, to reduce the price of transportation and it becomes a method of saving money for the ship owners and charters.
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  • CONSTRUCTION TESTING OF AN OFFSHORE PIPELINE USING NUMERICAL METHODS

    Liviu – Constantin STAN
    10/1/2016
    1 citation
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    The production of oil and gas from offshore oil fields is, nowadays, more and more important. As a result of the increasing demand of oil, and being the shallow water reserves not enough, the industry is pushed forward to develop and exploit more difficult fields in deeper waters. In this paper, there will be deployed the new design code DNV 2012 in terms of checking an offshore pipeline as compliance with the requests of this new construction code, using the Bentley Autopipe V8i. The August 2012 revision of DNV offshore standard, DNV-OS-F101, Submarine Pipeline Systems is supported by AutoPIPE version 9.6. This paper provides a quick walk through for entering input data, analyzing and generating code compliance reports for a model with piping code selected as DNV Offshore 2012. As seen in the present paper, the simulations comprise geometrically complex pipeline subjected to various and variable loading conditions. At the end of the designing process the Engineer has to answer to a simple question: is that pipeline safe or not? The pipeline set as an example, has some sections that are not complying in terms of size and strength with the code DNV 2012 offshore pipelines. Obviously those sections have to be redesigned in a manner to meet the conditions.
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  • VALIDATION OF DIVER’S THERMAL BALANCE EQUATION IN SUBSEA HYPERBARIC ENVIRONMENT AT AIR DIVING

    PhD student eng.Tamara STANCIU
    10/1/2016
    No citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    The solution of diver’s thermal balance equation in subsea hyperbaric environment was validated by experimental diving with air breathing, in the simulator of Laboratory Hyperbaric Diving Center. They were calculated theoretically end temperatures of divers submerge in heat water (21-22 0C) and cold water (15-17 0C), with equation (1.3). They were measured temperatures of end diving, for each subject, in each scenario diving (depth, water temperature, stationary time, thickness suit, etc.). Theoretically temperatures were compared with those obtained experimentally and the differences between theoretical and real values were 0.1 – 0.5 0C. The mathematical proposed model is valid for diving in hyperbaric environment simulated wet, up to 60 m depth and for air breathing gas unit diving.
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  • A METHOD FOR FLOW MODELLING OF VULNERABLE AREAS

    M. PANAITESCU; F.V. PANAITESCU; I.A. ANTON; C. ANTON
    10/1/2016
    4 citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    This paper presents the floods of the waters on Timis River in compliance with the provisions of the legislation from Romania correlated with that of the European Union modelling in MIKE11 software. Flooding that occurs in the Banat basin is a natural and frequent phenomenon on the water courses in this catchment area, where 1,085 km of the water courses are dammed and there are also numerous hydrotechnical and water management works. Although these works are well made and are intended to protect against floods, a review of these natural phenomena occurring in Banat highlights the fact that over a period of approximately 250 years, major flooding has occurred with a frequency of about once every 30 years, and in some cases these phenomena occur every few years, for example the floods of 2005 which occurred just five years after the floods of 2000. In almost every month in 2005 (February-September), throughout Romania, river water volumes exceeded the capacity that water defences were built to handle. The most important floods in Banat occurred in April. In April 2005 heavy rains were recorded in the Banat region: Oraviţa (226.4 mm), Resia (205.3 mm), Lugoj (201.2 mm), Caransebeş (200.6 mm). These rain falls exceeded reviously recorded maximum monthly levels. This rainfall combined with snow melt – the thickness of snow layers in the mountains at that time exceeded one meter (Ţarcu - 126 cm, Semenic - 26 cm) – led to historically significant flooding from April to September 2005, affecting extensive areas and resulting in casualties and significant property damage. In this paper we present a method of flow modelling (for year 20050) which can use with the same tools for another vulnerable areas.
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  • DATA OF POLLUTION ON SURFACE WATER AND GROUNDWATER

    Elvidan Mariana NICHITA; Mariana PANAITESCU; Fanel-Viorel PANAITESCU
    10/1/2016
    No citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    In this paper we investigate the impact of pollution on the surface water and groundwater. For this, we collect samples from Harbour Tomis Constanta, South Mamaia, Siutghiol Lake, Tabacarie Lake , water from a fountain and water which proves from stink. We analised the physical and chemical parametres of all samples. Finally, the results demonstrated that water samples from areas North Mamaia, Harbour Tomis, Siutghiol Lake, Lake Tabacarie have the values of quality indicators higher that values from Water Pollution Technical Standards. The samples from fountain and from stink are not polluted. So, we can talk about pollution of those waters resulting from the activities undertaken by people of course, because of the attraction of these areas.
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  • THE SHORTEST PATH PROBLEM WITH UNCERTAIN INFORMATION IN MARITIME TRANSPORT ROUTING

    Tomasz NEUMANN
    10/1/2016
    1 citation
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    The purpose of this paper is to find a solution for route planning in a maritime transport networks, where the costs of tracks, factor of safety and travel time are ambiguous. In this paper author propose a hybrid routing algorithm with Ant Colony Optimization.
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  • COMPARATIVE PERFORMANCE ANALYSIS OF R134a AND R290/R600a REFRIGERANTS IN A VAPOR COMPRESSION REFRIGERATION CYCLE

    Feiza MEMET
    10/1/2016
    No citations
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced; technologies for MET; Climate changes
    Vapor compression technology is used in the majority of space cooling and food refrigeration applications. Refrigerated ships and marine branches, such as merchant, naval, fishing or cruise-shipping are used to transport perishables. This system is running in several situations on R134a, a HFC refrigerant having excellent thermodynamic and thermo-physical properties, but an adverse environmental impact, considering its global warming potential. This paper deals with a theoretical performance study of a vapor compression refrigeration system working with the pure refrigerant R134a and a mixture, R290/R600a (50% / 50%), considering the effect of the main factors that affect the coefficient of performance: interior tube diameters, working pressures and inlet water temperatures. Are highlighted cases in which the performance when using the mixture is higher than the one when using R134a.
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