Research and Design an Experimental Model for the Determination of Deposits Formation Mechanism in the Combustion Chamber

One of the important researches on fuel use in diesel engines is the basic study of deposits formation in engine combustion chambers. The process of creating deposits in the engine combustion chamber is a complex phenomenon causing many different problems. Therefore, it is necessary to study the mechanism of deposits formation and development in engine combustion chamber when using traditional diesel or biodiesel. The study of combustion chamber deposits in internal engines was conducted to understand the effects of deposits on the engine and how they were formed and developed. Most of the current studies on deposits are carried out using statistical results from vehicle’s engines. Testing on real engines requires a long time and long distance travel, which makes the cost of both tests very high, causes damage to the engine during deposits testing. Studying and finding a simpler, more cost-effective experimental model that meets the requirements of the deposits formation testing and assessing the factors that make up them are essential. An experimental model design to determine the formation mechanism of deposits in the combustion chamber is the key point of the paper. This study clarifies the deposits formation of fuel in the engine by using a method called a heated surfaces deposits formation testing (HSDFT) and simulate the accumulation and development of deposits in combustion chamber. This model will help researchers to initially build the database effectively to determine the deposits formation mechanism in the combustion chamber of diesel engines when using different fuel

On the Asymptotic Behavior of Solutions of Differential Systems

There are many studies on the asymptotic behavior of solutions of differential equations. In the present paper, we consider another aspect of this problem, namely, the rate of the asymptotic convergence of solutions.Асимптотичній поведінці розв'язків диференціальних рівнянь присвячено чимало досліджень. У даній роботі проблему розглянуто з іншого боку, а саме, з точки зору швидкості асимптотичної збіжності розв'язків

Technological Perspective for Reducing Emissions from Marine Engines

Climate change and adverse impacts on the ocean environment have recently received much attention in the shipping and marine economic sectors. Preventing pollution of the marine environment from land sources through the river or atmospheric water is only possible by applying clean industrial technologies without waste and methods for rational use of natural resources. Main technical facilities to protect the sea environment from the current pollution are used to remove toxic substances from waste sources of ships. The International Maritime Organization increasingly tightens regulations on emissions with marine transport fleets, especially emissions of NOx and SOx. Therefore, many countries in the world continually improve and develop marine diesel engines in the direction of reducing emissions with different technologies. It is a tremendous necessary to enrich the technological knowledge to select new energy equipment in shipbuilding because they play a vital role in ensuring emission standards throughout the life of the ship. Indeed, technology development orientation in coastal countries' marine industry with the initial study results on the use of extraction optimization measures, alternative fuels, and output emission control solutions, it shows that we can implement some technologies to achieve NOx and SOx reduction according to IMO regulations. This paper summarizes the most important recent development technologies in the world in the field of marine engines. Also, the authors assessed the possibility of applying these new technologies to fleets of coastal countries to meet environmental requirements

Nonparametric estimation of the fragmentation kernel based on a PDE stationary distribution approximation

We consider a stochastic individual-based model in continuous time to describe a size-structured population for cell divisions. This model is motivated by the detection of cellular aging in biology. We address here the problem of nonparametric estimation of the kernel ruling the divisions based on the eigenvalue problem related to the asymptotic behavior in large population. This inverse problem involves a multiplicative deconvolution operator. Using Fourier technics we derive a nonparametric estimator whose consistency is studied. The main difficulty comes from the non-standard equations connecting the Fourier transforms of the kernel and the parameters of the model. A numerical study is carried out and we pay special attention to the derivation of bandwidths by using resampling

EFFECT OF REDUCED CARBON SUPPLY ON ENHANCED BIOLOGICAL PHOSPHORUS REMOVAL AND DENITRIFICATION

Joint Research on Environmental Science and Technology for the Eart

Persistence probability of a random polynomial arising from evolutionary game theory

In this paper, we obtain an asymptotic formula for the persistence probability in the positive real line of a random polynomial arising from evolutionary game theory. It corresponds to the probability that a multi-player two-strategy random evolutionary game has no internal equilibria. The key ingredient is to approximate the sequence of random polynomials indexed by their degrees by an appropriate centered stationary Gaussian process.Comment: revised versio

Ultra high Performance Fiber Reinforced Concrete Panel Subjected to Severe Blast Loading

Experimental studies play a crucial role in shedding light on the dynamic behaviour of structures under blast loading. However, high costs and complicated technical requirements, particularly for full-scale structures, are still huge disadvantages to conduct such a series of tests. Hence, the finite element method is much needed to provide supplementary information to previous experiments and to enable further parametric studies without testing. This article presents a numerical investigation carried out to understand the behaviour of ultra high performance fiber reinforced concrete (UHPFRC) panels under severe blast loading. The authors designed a subroutine with eight numbers of solution-dependent state variables, 32 mechanical constants, integrated with the Abaqus program to analyze the dynamic behaviour of UHPFRC against multiple blast impacts, using the Johnson-Holmquist 2 damage model incorporating both the damage and residual strength of the material. The subroutine was validated by comparing the simulation results with test results. For the purpose of estimating the structural response of the UHPFRC panel subjected to blast loading, other studying scenarios were considered by varying input parameters, including the thickness of the panel, stand-off distance, and steel reinforcement bar volume. The variations in deflection, strain, and damage of the UHPFRC panel, as well as the steel reinforcement strain, were also evaluated. Through important obtained results, the UHPFRC panel is strongly recommended for a protective barrier installed in the vicinity of critical infrastructure against severe blast loadin