RBF Model for the Mass Loss of a Brass in Cavitation Field

This article aims at presenting the model of the mass loss of a brass sample in ultrasonic cavitation field in saline water. The experiments done for data collecting was performed in three scenarios. In the first one, the high frequency generator worked at three power levels - 80 W, at the second one - at 120 W, and in the third one - at 180 W. The Model has been built using the series of the mass loss on surface.

Researches on Soot Filtration Process by Comparing Simulation and Experimental Tests

In this paper, the main objective of using numerical simulation was to highlight and analyse details that are very difficult to highlight through experimental tests. The development of the simulation model was also done for predictive purposes. In other words, after validation of the model, it can be used to estimate the filter load in other conditions than the experimental ones, respectively to evaluate how the particulate filter affects the operation of the internal combustion engine. In order to achieve the desired result, the creation of the model was done in two stages, the first stage was the creation of a model containing all the components of the engine, except the particle filter in order to identify the parameters of the combustion process and pollutant emissions - model validated on the basis of the indicated pressure curves, and the second stage was to complete the initial model with a particle filter and validate it from the point of view of the pressure drop, respectively of the engine performance, the aim was to obtain a trend, respectively values similar to the experimental ones.

Analysis of the Wear Process of the Elements in the Braking System of Heavy Trucks

Today's commercial vehicles work in a very competitive environment, in an extremely active economic market and the requirements for the delivered performance make it imperative to study in detail each component element. In practice, all these aspects are found in the process of wearing the elements of different systems. Moreover, major changes are expected for the near future of motor vehicles in order to improve the ecological balance both by reducing the pollutant emissions of the propellants and by improving the percentage of recyclability and reduction of waste from maintenance (liquids and solutions such as oils, antifreeze or solutions with different detergents). In order to identify solutions to improve the mentioned problems, the current study analyses the types of wear identified in the elements of the braking system of commercial vehicles and their main factors of influence. The study is based on data obtained during analysis during operation for a number of trucks with different configurations.

Drone Detection Using Image Processing Based on Deep Learning

The objective of this experimental research is to identify solutions to detect drones using computer vision algorithm. Nowadays danger of drones operating near airports and other important sites is of utmost importance. The proposed techniques resolution pictures with a good rate of detection. The technique is using information concerning movement patterns of drones.

Determination of Porosity in Fluidized-Bed Carburized P/M Compacts Using an Image Software Analysis

The aim of this research was to study the porosity in carburizing in fluidized-bed on sintered alloys produced by powder metallurgy route using an image analysis software and to compare the obtained results with the conventional method for porosity measurements. Porosity is a measure of the void fraction in a material. The total porosity is defined by the ratio of the volume of void space to the total bulk volume of the material, expressed as a percentage. Development of digital images and computer software lead to a new and suitable method to determine the porosity of powder metallurgy materials.

Research on Some Freshwater Fish Catalase Activity - As a Potential Biomarker for Environmental Pollution

In the last decade studies show that water pollution is a very serious problem, especially since the degree of water pollution plays a key role in the growth and fish multiplication. As a biomarker of environmental pollution, antioxidant enzymes such as catalase (CAT; EC 1.11.1.6) play an essential role in preventing the harmful effects of heavy metals in the tissues of fish. These researches were carried out to investigate the effect of various environment conditions and some pollutant agents on oxidative stress in some aquatic organisms. The enzymatic assay of CAT (in fish organs, e.g., liver, kidney, gill, intestine and brain, as well as in mixture of these organs) was carried out according to standard enzyme assay protocol. The results showed decrease of CAT activity: the enzymatic activity was 35.89 ± 1.02 µmol H2O2/min/mg protein to pH 7 and 6.59 ± 0.47 µmol H2O2/min/mg protein to pH 12. More, the enzymatic activity was 38.1 ± 0.3 µmol H2O2/min/mg protein to pH 3. Also, the catalase activity increased with 23 enzymatic units to a less dissolved oxygen concentration (6.2877 mg/L). Furthermore, this study indicated that heavy metals, such as Cr, Cu and Zn can inhibit biochemical reactions in various organs of fish. During exposure duration of the fish to a mixture of metal ions the catalase activity decreases from 35.89 ± 1.02 µmol H2O2/min/mg protein to 23.51 ± 2.85 µmol H2O2/min/mg protein. On the other hand, as a result of the response of the enzyme system, the catalase activity increases to 36.25 ± 3.22 µmol H2O2/min/mg protein.

CFD Modeling of Aerodynamic Car Brake Cooling System

The objective of this experimental research is to identify solutions for an optimal cooling of the disks. The aerothermal brake cooling calculation is used to determine how the brake cooling process evolves. The techniques for simulating the dynamics of the CFD fluid allow us to simulate the cooling of the brakes in air current and then to compare the results obtained in the wind tunnel.

Analysis of the Influence of Pesticides on the Soil in an Agricultural Area

The paper presents an analysis of the soil in an agricultural area, to determine the influence of pesticides on the soil where agricultural production is carried out. For the research of the soil quality, were analysed areas, for harvesting soil samples. On the samples collected were determined, the amount of nitrates and nitrites from the soil, were determination of heavy elements from soil composition, soil pH and it was observed of the impact of pollutants on the soil.

The Impact of Various Fuels on Particulate Emissions for a Compression Ignition Engine Equipped with a Diesel Particulate Filter

The aim of this research was to highlight the impact of using different types of fuels on particulate emissions and also on the operation on particulate filters on diesel engines. For all the results obtained from the experimental tests, comparative studies were performed to find the optimal fuel mixture that can be used in order to obtain the optimal performance of the particle filter, without affecting the engine performance. Following the initial tests performed without DPF, the case with the highest smoke emission value (2000 1/min) was identified. For this case, continuous measurement tests were then performed. For this reason, a more detailed analysis was made only for this case.

On the Corrosion of Two Types of Bronzes Under Cavitation

This article contains the results of the experiments concerning the mass loss of two types of bronze in seawater in the cavitation produced by ultrasound generated by a high-frequency generator. The mass loss models are presented for the experimental conditions when the generator worked at different powers - 80 W, 120 W, and 180 W. In all scenarios, the results show that the bronze with Sn has the highest mass loss in the cavitation field.