This paper investigates the effect of separated exhaust expansion chamber parameters on pressure oscillations in spark-ignited internal combustion (IC) gasoline engines. It is known that exhaust expansion chambers are becoming increasingly more popular among both – original equipment (OE) and aftermarket equipment (AE) exhaust system manufacturers for performance-oriented motorcycles equipped with mainly single cylinder engines, but the companies are reluctant to reveal any detailed principles of operation of the mentioned expansion chambers. The subject of this research is the type of expansion chamber (separate) as used on performance-oriented motorcycles, particularly its’ effect on exhaust pressure pulsations as different chamber volumes, locations and passage sizes are tested. Time-dependent computational fluid dynamics (CFD) analysis was carried out in Solidworks Flow Simulation environment on a simplified exhaust header pipe model imitating engine operation at full load and steady speed. Honda CRF450R motorcycle engine was used as the example and fully defined using a 1D engine performance calculator software to determine the combustion chamber pressure and exhaust valve lift at any given crankshaft position. Volume flow rate of exhaust gasses at the header pipe inlet was calculated based on engine parameters and operating speed. The average pressure values with respect to physical time were measured and graphed across the header pipe inlet cross-section. Eight different header pipe and exhaust expansion chamber combinations were modelled, tested, and results compared at low, medium and high engine speeds. It was found that the presence of exhaust expansion chamber tends to dampen the amplitude and decrease the frequency of pressure oscillations generated at the opening of the exhaust valve(s). Observations show that the addition of an expansion chamber as per design of performance-oriented motorcycles helps to decrease the negative effect of engine tuning while also dampening the positive effect.

The kinetics of plasma nitriding of CoCr alloy below temperatures of nitrides formation and mechanisms of nitrogen penetration are analyzed by proposed kinetic modeling in this article. Proposed nitrogen diffusion model is based on the trapping – detrapping (TD) model and developed taking into account the effect of the concentration dependent diffusivity of nitrogen, nitrogen adsorption on the surface of alloy and surface swelling process. The model indicates the influence of chromium atoms to nitrogen atoms diffusivity. The model consists of time and depth dependent diffusion, which is described by a partial differential equation, and it is solved by using Crank – Nicolson finite difference method. By fitting of experimental nitrogen depth profiles, it is shown that nitrogen diffusion coefficient varies with nitrogen concentration according to Einstein-Smoluchowski relation. Nitrogen depth profiles in plasma nitrided medical grade CoCr alloy (ISO 5831 – 12) at T = 400 °C for 1, 4 and 20 hours calculated on the basis of this model are in good agreement with experimental nitrogen profiles. Furthermore, the swelling process is showed and analyzed, derived the dependency of swelling rate on nitriding duration – the swelling rate is inversely proportional to the square root of nitriding duration. The obtained diffusion coefficient value and the swelling process rates satisfy the experimental data form Ref. The derived model explains physical processes during plasma nitriding and allows obtaining nitrogen depth profiles for any requisite nitriding duration.

One of the mechanisms for enhancing innovative processes in the industry is the application of the concept of the “four-link spiral”. In contrast to the 3-link spiral, this model as one of the most important components includes a “society”, acting as one of the actors of innovative transformations. Firstly, it is society that is the main consumer of innovative products being created and, thereby, establishes “requirements”, forming demands for the quality and parameters of future products; secondly, society, in turn, acts as the initiator and generator of innovations, forming the so-called “social capital” necessary for the implementation of directly innovative transformations. In this scientific work, the problems of the formation of a “smart specialization” strategy for the innovative development of the industrial sector of the national economic system based on the application of the four-link spiral concept are investigated. A system of quantitative indicators for assessing the innovative level of industrial development is presented. The experience of introducing the concept of a four-link spiral as a mechanism of innovative development of industry (on the example of the Republic of Belarus and the Russian Federation) is given. The aim of the article is to describe innovation processes in the Russian Federation and the Republic of Belarus and to develop an innovation transfer model.

1991-2017 the Southeast coast of the Baltic Sea area, Lithuania, Latvia and Kaliningrad Region of the Russian coastal habitats was very intense, often chaotic variety of recreational facilities and areas of privatization and urbanization. These processes significantly influenced the character of the recreational landscape of Palanga, Jurmala and other resorts and coastal areas, as well as the expression of the urban structure and architecture of seaside towns, Ventspils, Liepaja, Giruliai, Melnragė, Karklė, Šventoji, Curonian Spit and other settlements. After a quarter of a century, some tendencies of the recreational environment and the evolution of the cultural landscape identity can be noticed. Recently, several projects for the improvement of recreational infrastructure and architectural environments have been implemented in Lithuania with the assistance of the European Union Structural Funds. Unfortunately, the results of the projects are not always positive. The planning of coastal settlements is often overlooked by good long-term planning experience. This article analyses the impact of changes in the quality of the Lithuanian recreational territorial system in the South-Eastern Baltic and the region’s recreational potential. Palanga resort areas dominated by architectural chaos and recreational quality of the environment tended to deteriorate, especially experts poorly assessed the central Basanavičiaus street. The changes in cultural landscapes are influenced by a whole range of methodological and practical factors: insufficiently effective research and modeling methods, unjustified privatization of state property, huge flows of individual automobiles, faults in the formation of recreational greenery. Based on the research of the recreational system of the coastal region of the long-term seaside, it can be concluded that in recent years the quality of the environment of many coastal zones of Lithuania has lost important qualitative components, deteriorated the quality of public spaces and increased urban and architectural chaos.

Artificial weathering is a widely used method for predicting wood behaviour during its service life. A study was carried out to compare the colour change of thermally modified aspen (Populus tremula L.) and grey alder (Alnus incana (L.) Moench) wood during natural solar and artificial ultra violet (UV) irradiation. Thermally modified wood specimens were exposed for 30 h to artificial UV irradiation at two different intensities, i.e.1.36 W m⁻² at 340 nm and 0.68 W m⁻² at 340 nm, as well as to solar irradiation outdoors and indoors. After 2.5, 5 and 10 h exposure, colour parameters and reflectance spectra (360–740 nm) were determined. Colour was expressed in accordance with the CIELAB colour model as colour parameters L*, a*, b*. The total colour change ΔEab was calculated from colour parameter differences ΔL*, Δa*, Δb*. The colour changes caused by solar and artificial UV irradiation had a similar pattern for both thermally modified hardwood species under study. Changes in the individual colour parameters in the course of the experiment altered their direction, which implies that discolouration of thermally modified wood is a complicated and dynamic process with various and different chemical transformations in wood chromophores. Colour and reflectance changes had similar trends for different intensities of the same type of irradiation, but they differed for various irradiation types – natural solar or artificial UV irradiation. Greater discolouration was detected for the specimens exposed to both solar irradiations - outdoors and indoors. The results suggest that the fluorescent lamps of the UVA-340 type, which only imitate well the sunlight UV spectrum from 290 nm to 365 nm, do not fully simulate the changes in thermally modified wood induced by solar radiation.

To survive in today's competitive environment, companies must continuously develop and offer customers new products. To increase the probability of a successful business case of investing in the development of a new product, careful attention must be paid to risk analysis in terms of the present value of future potential income. The article considers an example of the research work of the Latvia University of Life Sciences and Technologies, in the framework of which a technical and technological project was developed to produce a new product, like Mediterranean anchovy, from cheaper Baltic sprats. The main goal of this work is to explore the application multi-factor sensitivity and fuzzy real option analysis to the valuation of new product development project. The multivariate analysis of the sensitivity of the financial model of the greenfield production project described in this article revealed the main risk groups, as well as their degree of influence on the assessment of the Net Present Value of the project by a potential investor. The use of Fuzzy Real Option Valuation made it possible to evaluate the project with uncertain parameters, as well as to calculate the potential upside from preliminary refinement of parameters to eliminate negative scenarios. The described approach is applicable to risk assessment of new food product development and allows investors to make a more informed decision about participation in such projects.

The main aim of this paper is to fuzzify the kinetic parameters, which have crisp nature, in order to obtain the realistic and accurate results. In the present study, the variance, upper limit of ‘dE’ and the frequency factor are assumed to be fuzzy numbers. The Gaussian distribution is considered as the distribution function, f (E), of Distributed Activation Energy Model (DAEM). The membership and the non-membership functions are evaluated by the trapezoidal fuzzy number. Thermo-analytical data has been found experimentally with the help of TGA/DTG analysis. The approximated solution of DAEM is obtained with the help of asymptotic expansion.