Items

  • IMPROVE MARITIME EDUCATION TRAINING THROUGH ONLINE TEACHING

    Alexandra NIŢA; Gabriel RAICU
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    Online teaching is able to exclude the inconvenience of social life schedule, offering access to knowledge’s anytime, from any location. Another gain of this method is the ability of transmitting knowledge’s also for present students or former students interested in latest developments in maritime industry, and certainly for teachers and trainers, especially at the beginning of their lecturer careers. The present paper presents the online teaching system used by our university, for teachers and students, for former students, now officers onboard ships, to acess the latest information’s about technical development in maritime field. This system can improve the communications and interconnectivity between academic institutions and civil society, first as developer of knowledge’s and scientific research, second as beneficiary and applicants of these. The international work to improve maritime education and training (MET) has identified lack of access to quality learning material and tutors in many countries. It is assumed that increased use of information and communication technologies will be one major component for future quality improvement of maritime education and training.
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  • EXPERIMENTAL RESEARCH OF A JAMMING OVER A DIRECT SEQUENCE SPREAD SPECTRUM SYSTEM

    Zhelyazko K. NIKOLOV; Tsvyatko T. TSANEV; Miroslav Y. TSVETKOV
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    In this article an experimental research of a broadband noise jamming over GPS receivers is considered. Thelimitations of the effectiveness of the jammer in accordance with the distance is overviewed. In that case the power density levels of the signal and the noise at the input of each GPS receiver are compared.
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  • MODELLING OF THE REFRIGERATED SEAWATER SYSTEM ON BOARD OF FISHING VESSELS

    Feiza MEMET; Adrian SABAU; Darie TUDOR
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The fishing industry is a very competitive one. Professionals of this industry understood that making profit by offering quality is possible by using the best technology on board of the fishing vessels. Storing the catch in refrigerated water system brings many advantages to fishermens. This paper presents the flow sheet diagram of this cooling and storage system and its mathematical model. Are written balance equations, each component of the system being modeled as an object. These equations contain mass flows, pressure and enthalpies on the suction side and the discharge side of the components.The model allows to avoid an oversized system on board of fishing vessels.
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  • THEORY AND PRACTICE OF COMPLEX SAR OPERATIONS IN THE CONDITIONS OF THE BLACK SEA

    Boyan MEDNIKAROV; Peter DERELIEV
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The paper tries to define complex SAR operations as a specific form for providing high level of maritime safety and security in the Black Sea region. The main tasks of the research are to overview the complex SAR operations in the Black Sea; to give highlights in the theory of complex SAR operations and to cover some practical aspects of complex SAR operations in the Black Sea. The achievement of the goals of the complex SAR operations needs a set of complex capabilities. Their very important component, as a mental aspect of these capabilities, is the new SAR culture. Connected with this, the paper gives some directions for new educational and traning activities of the maritime universities.
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  • THE PREVENTIVE AND CONTROLLING MANAGEMENT OF THE BITUMEN POLLUTION IN THE MANGALIA PORT

    Florin IORDANOAIA
    10/1/2009
    Marine sciences and engineering ; Renewable energies ; Marine renewable energies and Sustenability ; Advanced technologies for MET ; Climate changes
    The new conditions from maritime transport have many implications for shipping companies, marine pollution and state or port authority. In Romania the imports of the bitumen are a new experience for our country until 1998. The Mangalia port has a new position in the maritime transports and the business of this domain is in development. But the bitumen represents the dangerous goods for the port area. In this paper is presented the problems and the preventive management at the ship and terminal
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  • A STUDY ON THE TURKISH REGULATIONS CONCERNING EMERGENCY RESPONSE AND INDEMNIFICATION OF DAMAGES ARISING FROM MARINE ENVIRONMENTAL POLLUTION

    Ilgin SEZER
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The issue of marine pollution is one of the main and important topics of maritime world. Following the principle of “Safe, Secured and Clean Seas”, several international regulations have been created by the international bodies, such as IMO. These international regulations are rapidly followed by internal regulations of many countries. Accordingly, Turkey enacted majority of the relevant international regulations into its domestic law, within a short time. Among these provisions, “The act Nrd. 5312 Relating to Emergency Response and Indemnification of Damages Resulted from Marine Environmental Pollution by Petroleum and Other Harmful Materials” and the “Regulation Regarding the Application of the Act Nrd.5312” have special importance for vessels, carrying Turkish and/or foreign flag, sailing in Turkish waters and calling any Turkish port and owners, managers and insurers of these vessels. The aim of the study is to give information on the above mentioned rules, together with an evaluation from the legal point of view.
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  • COMPARATIVE INVESTIGATIONS INTO NAVAL WELDED STEEL, METALLOGRAPHY AND MICROHARDNESS

    Constantin DUMITRACHE; Mihaela BARHALESCU; Adrian SABAU; Corneliu COMANDAR
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The purpose of this paper is to make comparative investigations of heat affected zones (HAZ) at naval welded structures in condition of normal welding (submerged arc welding– NW), ultrasonic welding (ultrasonic submerged arc welding– UW) and after thermal stress-relief (HT) and ultrasonic stress-relief (UT) methods. After welding this steel exhibits an uniform field of hardness, because it is low-alloy steel with a low carbon percent. The alloying elements can produce carbides and nitrides which may cause problems.Post weld heat treatment, such as thermal and ultrasonic stress relief methods reduces the residual stress field and solves the problems with improvement of mechanical characteristics.
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  • USING FLUENT AS AN EXPERIMENTAL STAND FLOW THROUGH A BROKEN BARRAGE

    Dinu DUMITRU ; Ovidiu CUPSA
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    In the paper we propose to use the FLUENT program as experimental stand. Why do we do this? It is often difficult and expensive to achieve a model. It is also difficult to calculate the phenomena in the nature scale using the FLUENT. So we calculated the physical parameters, using FLUENT on the model and we passed them, using the similitude criteria, in the nature. We illustrated the method with a spectacular example: the flow through a broken barrage. First, we established the model law, taking into account the physical magnitudes which influence the analyzed phenomena. Afterwards we calculated the scales of these physical magnitudes for normal similitude (a single geometrical scale). Using FLUENT we determined the values of the velocity and forces acting on the barrage (the unbroken part).Finally, we passed the “experimental” data in the nature by application of scale for physical magnitudes.
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  • BASIC DYNAMIC COUPLING EFFECT REGARDING THE MARINE ENGINE PROPULSION SYSTEMS

    Nicolae BUZBUCHI; Liviu STAN
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The purpose of the present paper is to be a tutorial one, intended to show the model of coupled torsional and longitudinal vibration of the marine engine shafting systems. Extension of the analytic method for a multi-dimensional system, modeling of typical marine propulsion plant, and results for some realistic examples are also presented and they show that neglecting the propeller coupling effect can result unprediction of vibratory response.
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  • AN EXPERIMENTAL METHOD OF INVESTIGATION OF AN ASYNCHRONOUS INDUCTION MOTOR’S MAGNETIC FIELDS

    Bohos APRAHAMIAN; Hristo RAEV
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The asynchronous induction motors are the most commonly used motors in ship electric drives. The investigation of their magnetic fields is an essential part of their working regimes exploring. The magnetic fields of an asynchronous induction motor are studied using an experimental method that enables the screening of the magnitude and the shape of the magnetic fields in the stator and in the rotor, separately and in joint action in different working regimes of the motor.
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  • THE EFFECT OF THE SEA WATER AS CORROSIVE ENVIROMENT ON THE SUPERFICIAL TREATED SAMPLES

    Mihaela BARHALESCU; Cornel MUNTEANU; Constantin DUMITRACHE; Adrian SABAU
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The experimental research was made on superficial layers laid-down through electrical sparking on the steel carbon OLC 45 samples, the used electrode being made from a corrosion resistant material (Copper). The probes being immersed 285 days in static sea water at the environments temperature. The superficial layers subjected to gravimetrical corrosion have been analyzed through optical metallographic microscopy, using the computers QX3 Intel Play microscope. The fine determining of the topography surfaces exposed to the action of the corrosive environment was made using the atomic force microscope (AFM).
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  • ECONOMICAL IMPLICATIONS OF THE NEW INTERNATIONAL COURT OF JUSTICE MARITIME DELIMITATIONS IN THE BLACK SEA

    Eugen BARSAN; ANECHITOAE C.; BARSAN F. V.; IORDANOAIA F.
    10/1/2009
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    In February 2009, the International Court of Justice pronounced its decision in the process on the Black Sea Maritime Delimitation (Romania vs. Ukraine) regarding delimitation of continental shelf and to the exclusive economic zone. The Decision puts a final end to a complex bilateral dispute which had been lasting for 42 years between Romania and Ukraine and which could not be resolved by any other means. Romania fulfilled thus its strategic objective in this file: drawing an equitable line, non-susceptible to interpretations and which allows the exploitation of the hydrocarbon resources from the area allocated to it by the International Court of Justice solution. The interesting point is how an international low decision, can end a half a century debate between two countries and to produce immediate economical effects. This new maritime boundaries will allow Romania to begin a systematic prospection of the area and extraction of oil and gas resources in location already certified. Quantification of these resources is still subject of debate between specialists, but on the existing data we tried to define the economic benefits of Romania for the near future.
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  • SHORT SEA SHPPING ALTERNATIVES IN FRONT OF THE ROAD ALTERNATIVE IN THE WESTERN MEDITERRANEAN

    F. Xavier MARTÍNEZ DE OSÉS; MARCEL·LA CASTELLS
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The full implementation of short sea shipping alternative faces a set of technical, administrative and legal obstacles, not seen as a real alternative at all. As shippers has not find always the most satisfactory service nor the best price that could motivate a modal shift. There is the need for balance the infrastructures, using tariff principles based on the necessity for reflect the exact external costs generated by the different infrastructures, the EU published in 1998 the White Paper on Fair Payment for Infrastructure Use: A Phased Approach to a Common Transport Infrastructure Charging Framework in the EU COM (1998) 466. This paper analyzes on selected multimodal transport chains with a sea leg, the pollutant emissions of dferent powered ships compared with the ones of their road alternative. These pollutant emissions will be translated to environmental costs, based on existing quantification databases. In some cases, the maritime transport provides savings in those costs against the truck, what would justify a kind of ecological bonus to be used by the administration to promote the sea option. The paper will conclude in a brief discussion on how the demand would react in front of a price bonus in the maritime sector.
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  • VIABILITY OF THE APPLICATION OF LIBR ABSORPTION MACHINES FOR AIRCONDITIONING ON BOARD OF A SHIP USING RESIDUAL ENERGY

    Santiago ORDÁS
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    In this paper, energetically and environmental-friend refrigeration machine is presentad. LiBr absorption machine is proposed for air conditioning purposes on board of a ship. The heat source used by the absorption machine is hot water, produced by the main engine scavenging air, when the ship is sailing, and the auxiliary engines exhaust gas, when the ship is anchored or in port. The use of absorption machines on board is viable from a economical and technical point of view.
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  • MODEL FOR NOX CALCULATION

    SABAU Adrian; STAN Liviu; DUMITRACHE Constantin
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    This paper describes the extension of the computer code make by author [1] to simulate nitric oxide formation. Complex kinetic mechanisms are applicable only for simple flame computations (e.g. one dimensional, laminar, etc.). For real turbulent flame calculations, their use is impractical, due to the complexity of the interacting processes (turbulence, radiation, heat transfer, etc.) which must be considered to obtain realistic results. A model derived by systematic reduction of multi-step chemistry is used in for the evaluation of the nitric oxide formation. This reduction is based on the partial equilibrium assumption of the considered elementary reactions using the extended Zeldovich mechanism describing the thermal nitrous oxide formation
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  • THE IMPORTANCE OF TRAINING IN LEADERSHIP IN MARITIME UNIVERSITIES

    RICARDO Rodríguez-Martos
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    There is a lack of training in managing and leadership for future captains and officers. On the other side, companies pay more attention of a good management that of a good leadership. This article tries to underlines the importance of leadership and also deals with the question about the possibility to combine managing with leadership. Another important question to face is if man can be trained to be a leader and which concepts should be learned in this case. how a manager can also becomes a leader and how leadership can and should be learned. It will be also made a reference to the special aspect of multicultural crews and finally some ideas about the topics that should be teached for training in leadership
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  • A DINAMIC CURRENT UNIT FOR GETTING SYMMETRY OF THRE FAZE ELECTRICAL POWER SYSTEM

    PETKO Petkov; GEORGI Stoilov; MARIN Nedev; VLADIMIR Chikov; GINKO Angelov
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    In the paper is subscribed a possibility of design and producing the electronic unit for dynamic current symmetrycity for three phase electrical distribution bar and system in cases of nonsymmetrical electrical loads. There is shown the investigated algorithm for control of the microprocessor’s unit. There is subscribed the results of experiment with the produced electronic microprocessor’s unit in real maintenance.
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  • COMPOSITE AND POLYMERIC MATERIALS USED IN NAVAL INDUSTRY

    Alexandra NIŢĂ
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    In the article [4] is published a mathematical model of optimization thermal stress-relief process which are conditioned by the plastic yield speed phenomenon. This new paper take in advance thermal stressrelief process and complete with overlapping ultrasonic stresses which is acting during cooling after welding process. In conformity with theory, Nevill and Brotzen [5] said that residual stresses are decreased because these overlapping stresses determined the altering of metallic yielding stress. In this article, using numerical method Runge-Kutta [1] is computed the overlapping ultrasonic stresses above welding residual stresses at OLC45 steel.
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  • AN ESTIMATING OF ELECTRICAL POWER FOR SUPPRESIOIN OF HARMONICS IN THE ELECTRICAL DISTRIBUTION BARS AND SYSTEMS WITH THE CURRENT IMPULSES INFLUENCE

    Marin NEDEV; Petko PETKOV ; VladimirCHIKOV; Ginko ANGELOV
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    There made an estimating of electrical power, needed for suppresion the high harmonics in the electrical power distribution systems by the active filters with appling of current impulses. These metod is based on summerising of instantaneous current value and current impulses with the constant pulse width from the special function generator. The mentioned method is compared to other known solutions for decreasing of high harmonics. There is an estimating of possibility of applying in the autonomic electric power system.
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  • ANALYSIS OF THE MOST OCCURED AND TYPICAL FAILURES OF SLOW SPEED MARINE DIESEL ENGINES (SSMDE) RELATED TO CRANKSHAFT (CS).

    Julian MOSKOV
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    This report is a description of the case with main engine MAN 8L42MC, in which case, known by the experience, a failure related to turning round the crankshaft main journal from 1st to 7th movement is ascertained. Registering the problem is realized by means of the ship Mean Indicated Pressure (MIP) system. The deviations in the operation characteristics of the engine cylinders are indicated. Conclusions are reached and the procedure on restoring the engine normal operation mode is described with the purpose of diagnostics and avoiding similar failures in future.
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  • SOME ASPECTS REGARDING THE LNG OFFSHORE TERMINALS

    Feiza MEMET; Ender ASYALI
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    The important role of natural gas as a primary fuel in the energy industry led to the increase of its transportation on board the ships. This kind of transportation is made under the form of Liquefied Natural Gas (LNG), on board of special vessels, called LNG carriers which are equipped with cryogenic tanks. LNG carriers deliver it to terminals for storage and re-gasification, after which LNG is supplied to consumers from the LNG production plant, situated offshore. This paper presents the vaporization technology based on open-rack vaporizers (ORV), a modern technology for LNG terminals. Also, is discussed the environmental aspect connected with the construction of the terminal.
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  • THE OFF-SHORE PETROLEUM TERMINALS IMPACT ON THE MARINE ENVIRONMENT

    R. HANZU-PAZARA
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    In the present days the energy request at the world level is growing-up. This increasing needs a necessity of more quantities of basic fuel, especially oil and coal. To satisfy the industrial and civil requirements and to cover the necessary quantities the transport field, mainly the maritime transport increase the transport capacity of their units. For the oil transport at sea, the tanker ship capacity has been expended from around 30,000 tones up to over half a million tones. These developments of maritime transport capacities impose to be developing new operational capacities. The operational capacities, the terminals, are difficult to be expend and improve when are placed in a limited space as harbors. This aspect conduct to necessity to create new terminals, placed outside of port area, in open sea, with possibility to receive and operate ships with tonnage more over the harbor terminals possibilities. This positioning in the open sea area has the risk of damaging the environment higher than port terminals. In the present paper will be presented some aspects of the impact on marine environment of the off-shore petroleum terminals.
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  • THE RAMSEY ALGORITHM

    ENG. Gabriela - Simona DUMITRESCU
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    This algorithm improved the best bounds known for approximating the independent set and graph coloring problems and prove that the approaches used to date to obtain such results can not be improved much further. I start with the Ramsey algorithm for finding independent sets in graphs, which is actually a schema of algorithms parameterized by the pivoting function applied, similar to the greedy algorithm. It has the property that its solution on any graph is at least as large as the one the corresponding greedy algorithm finds. The algorithm Ramsey is related to a classical problem in extremal graph theory [1].
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  • COMPUTATIONAL ULTRASONIC STRESS-RELIEF PROCESS

    Constantin DUMITRACHE; Corneliu COMANDAR; Mihaela BĂRHĂLESCU; Adrian SABĂU
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    In the article [4] is published a mathematical model of optimization thermal stress-relief process which are conditioned by the plastic yield speed phenomenon. This new paper take in advance thermal stressrelief process and complete with overlapping ultrasonic stresses which is acting during cooling after welding process. In conformity with theory, Nevill and Brotzen [5] said that residual stresses are decreased because these overlapping stresses determined the altering of metallic yielding stress. In this article, using numerical method Runge-Kutta [1] is computed the overlapping ultrasonic stresses above welding residual stresses at OLC45 steel.
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  • SAINT VENANT EQUATIONS: AN ATTEMPT TO MODEL A TSUNAMI WAVE PROPAGATION

    DELEANU Dumitru
    04/01/09
    Marine sciences and engineering; Renewable energies; Marine renewable energies and Sustenability; Advanced technologies for MET; Climate changes
    By means of the homotopy analysis method, the solution of the unidimensional Saint Venant equations are obtained in this paper. These equations are a commonly accepted governing approximation for Tsunami wave propagation in the deep ocean as well as near-shore regions which include inundations. The dependent variables are the fluid heigh and the fluid velocity field. Analytical results agree well with the basic features of the tsunami waves. Numerical results are also presented and shown graphically.
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