BALLAST WATER POLLUTION RISK ASSESSMENT IN THE BLACK SEA

Since the emergence of humanity, the marine environment has provided a safety net in many ways, has fostered socio-economic development, creating links between states, between continents. In the same time, it represents a priority source of food for a considerable percentage of the population. The same marine environment also creates solutions to current global problems, as a potential source of sustainable energy for the future. In recent decades, the stability of this ecosystem has been considerably shaken by the various types of pollution resulting from human activities. The Black Sea is not immune to these results from economic activities, such as the transport of goods by water, which creates the context for the migration of living organisms from one geographical region to another. The threat of ecosystems has been intensified by the process of globalization, by changing the natural food chains following the accidental introduction of non- indigenous marine life by discharging ballast water from ship tanks. Risk assessment to limit the effects of this biohazard problem is the first step in a normal regional chain of action..

AN ANALYSIS OF THE EFFECT OF THE BODY VIBRATIONS ON THE HUMAN PERFORMANCES

In this paper, we wanted to check if classical music can improve the intellectual and practical skills of those who work in very difficult conditions. For this, we exposed 44 male students, aged 21-24, with normal BMI (19-24), in perfect health, to four types of stressors, when there is classical music as a sic sound background and when we have no music. The stressors used were vibration, excessive temperature, and humidity as well as very strong light. Two pieces of music were chosen as background: "Eine Kleine Nachtmusik" (Mozart) and "Minuetto" (Boccherini). These 2 musical works were chosen because they are cheerful, optimistic, written in an alert rhythm, easily recognizable even if the audience is not music lovers. Students’ performance was measured using 3 tests: the Purdue Pegboard Test, the Stroop Color and Word Test and also Comparing of Names Test. The results show that neither Mozart's music nor Boccherini's music led to an improvement in student performances; on the contrary, better results were obtained when it was silence.

INVESTIGATIONS ON WEAR AND FRICTION IN THE SI ENGINE VALVETRAIN

The engine valvetrain system operating under conditions of insufficient oil lubrication, caused by incorrect installation of the gasket between the block and the head, was tested. The aim of the analysis was to determine the wear intensity and resistance to motion in camshaft bearings. A model was developed that includes a camshaft, bearings, tappet-valve-spring subassemblies and a part of the lubrication system. It was used to determine the bearing loads and the amount of oil supplied. The volumetric wear of the camshaft journals and bearing covers was measured. For the estimated engine run, the wear rate and resistance to motion were compared for the cases of the engine with correct and incorrect lubrication.

INFLUENCE OF ELEMENT SIZE IN A CASE OF IMPACT SIMULATION

This paper presents an analysis of data resulting from the same material constitutive model, based on experimental data and model developed by Johnson and Cook. The same case of impacting a cylindrical body on a perfectly rigid target was run with four different mesh size (2 mm, 1 mm, 0.5 mm and 0.25 mm). Here, the comparing criterion was the maximum value of von Mises stress and the authors pointed out that the finest mesh here presented is closer to reality. Depending on the case application the engineers could adopt a finer or coarse mesh, but not so coarse to denaturate the reality of body deformation and failure. How to decide? Having performant computer resources (hardware and software) and running several mesh in order to notice the convergence of one parameter or, more reliable, a set of criteria that could include qualitative resemblance with actual bodies as concerning failure and deformation, experimental dat on strain, yield and failure of the involved materials, values of stress and strain, at the same time moments. From this study the following conclusions were formulated: finer mesh presents a earlier failure in time and calculated a higher stress for these moment.

FLAMMABILITY TESTS ON HOT SURFACE FOR CASTOR OIL

For this paper, the authors studied the behavior of castor oil, when it accidentally reaches a hot surface. Thus, the lowest temperature at which castor oil ignited at least once in three tests and the highest temperature at which castor oil did not ignite in three tests were determined. To determine as accurately as possible these two temperatures, a total of 29 tests were performed. The procedure complies with ISO 20823:2018 Petroleum and related products -Determination of the flammability characteristics of fluids in contact with hot surfaces - Manifold ignition test.

POSSIBILITIES TO REDUCE POLLUTANT EMISSIONS IN NAVAL DIESEL ENGINES

The combustion process is, by far, the most important and complex process that takes place in engines. Its importance is given by the fact that it provides the flow of energy used in the engine and is the source of all pollutant emissions, the efficiency of the engine being directly influenced by it. The mechanisms of combustion are particularly complex and are not fully known even today, the most difficult problem being the mechanisms of mixture formation and the chemistry of the combustion process. Over time, depending on the evolution of knowledge in the field and computer technology, various mathematical models have been developed, which have. Emission estimation and theoretical verification, in the first phase, of the solutions applicable to in-service enginescould greatly reduce research and production costs, given that there are a variety of engines onboard ships and measurements in operation are very difficult.

WEAR OF SPHERICAL JOINTS OF THE VEHICLES STEERING SYSTEMS. VIBRATIONS AND THEIR ROLE IN DIAGNOSIS

Motor vehicles have an important role in our lives, the need for mobility making them present in daily activities. In a more open world, people want to be able to move, not only more and more, but also increasingly better. In the current context of the intensification, both nationally and internationally, of road transport, the need for safe traffic traffic is a primary objective for the operation of motor vehicles. Combining vehicle technology enhancements with an improved driver training, with a better road infrastructure design and an enforcement of existing traffic regulations is an important goal for society in order to increase road safety. During the operation of the vehicles, their component systems interact both with each other and with the external environment and these interactions are generating variations of some technical state parameters. As a result, there is a continuous change in the technical state of the vehicles, which causes variations in the dynamic, economical, air pollution, ergonomic, comfort and safety performances. This pape analyzes the vibrations of the steering system components, under different operating conditions and according to the technical state of the spherical joints. The measurements were made using a 4-channel digital recorder DA20-RION, with data processing software DA-20 VIEWER and a triaxial accelerometer Brüel & Kjær, type 4321. The paper highlights the possibility of monitorin the technical state of the spherical joints, analyzing the vibrations produced under different driving conditions of the vehicles and, at the same time, it opens the perspective of the implementation of intelligent devices to ensure the early detection of these failures.

THE IMPACT GENERATED BY SARS-COV-2 VIRUS ON THE AIR QUALITY IN THE CONSTANTA PORT AREA

The effect that the shipping industry has on the air quality in the areas adjacent to the ports, where it carries out loading and unloading operations, it is already known. In the new global context generated by the spread of the SARS-CoV-2 virus, the economy was affected. Due to the measures that many states have taken to limit the spread of this virus among people, the production activity has been stopped in many economic sectors and consequently, the freight industry by sea has also been affected. Measures that have been taken in the navigable sector in Romania are known, but also worldwide. In the perspective of reducing the density of ships in ports, the evolution of some parameters of air quality in the area of Constanta County will be followed. This evolution will be correlated with the evolution of the volume of port calls of international ships to the port services in the port of Constanta and presented in this study

MULTICRITERIAL ANALYSIS OF THE ROMANIAN COASTAL ZONE MANAGEMENT

The coastal zone is a mixed anthropogenic and environmental area (socio-ecological system) characterized by the significant variety of morphological conditions, land uses, which significantly change in time and space.Natural systems located on the border between the terrestrial environment and the marine environment are characterized by a morphological, ecological and dynamic variety, which changes over short and medium periods of time, under the influence of climatic factors and taking into account from the tidal effect every two hours to wind erosion or wave-related phenomena. In this paper, the authors will choose the optimal approach of strategic management that aims to analyze and evaluate these options by addressing economic, social and environmental factors. The multifactorial approach must consider a careful analysis of stakeholders in a coastal area, having in mind that each area has its peculiarities and needs to be treated separately. When developing the approach for analyzing and evaluating strategic options, the authors will consider the sectorial plans designed for the coastal area, as well as the local, regional and national development plans.

ASPECTS REFERRING TO FATIGUE TESTING OF EPOXY POLYMERIC MATERIALS

Concomitant with the development of new technologies in usage of renewable energies and with the necessity of replacing metal, epoxy polymeric materials are becoming more frequently used. Their main advantages are the reduced weight, high mechanical and corrosion resistance, the possibility to recover, recondition and reutilise the components. Thus, they become suitable for various industries, such as: automobile manufacturing, wind turbine blades, naval industry etc. Increased fragility and low resistance in initiating and developing cracks lead to varied fatigue performance. One way of reducing these disadvantages is to test fatigue in order to observe and analyse its manifestation, before projecting components. This paper presents tests carried on cylindrical epoxy polymeric samples. The samples were manufactured through casting in tubular moulds because of great advantages of this method. The manufacturing time is short, the material usage is maximised and after casting, the samples are smooth and don’t have sharp edges. Hence, the risk of unwanted concentrated stress is eliminated. The testing means assessing the samples to variable loading in rotating bending. For a better precision of test results, it is very important that his method could be accurately repeated with samples, preparing them in similar conditions. The results are used to draw Wohler`s curve using stress-number of cycles (S-N) as coordinates, specific to the tested material. Finally, the level of maximum stress of a material that resists fatigue, without having any ulterior damage can be determined.