International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The building sector in our country has an important share of energy consumption. According to Eurostat data, final energy consumption in the residential sector was estimated about 35 % of the total consumption. On the other hand about 75% of the electricity consumption takes place in the building sector. It should be noted that currently this sector faces many challenge, as the quality of energy supply (heating) in public buildings and the residential sector remains at low rates. Nevertheless, reducing energy consumption is one of the main targets set in the National Energy Strategy 2018-2030. By 2030 this target suggests 15.5 % of the energy reduction. This study has at its core the assessment of energy consumption in a public building placed in the city of Durres. Determining the typology and thermophysical characteristics of the building is of primary importance. The evaluation of the energy performance of the building in the dynamic regime was carried out through the Hourly Energy Analysis (HAP) software. The implementation of energy efficiency measures is carried out taking into account the energy and cost criteria. A cost analysis of EE measures was performed using the dynamic Net Present Value method.

The city of Korça is situated in the South-East part of Albania. Korça’s climate is partly Mediterranean and Continental, characterized by cold winter and relatively hot summer. The average annual temperature is 10.6 oC, while the average rainfall is 720 mm. Heating of Korça is not an unknown issue, although it still remains unsolved despite many efforts in this sector. This paper shortly describes the building typology and their thermal characteristics in Korça. After defining the heating demand of the Korça city, where as input in the model are used demographic data, climate data, building typology and heating system. Energy scenarios for heating of the city rely on a
baseline scenario where wood is used as an energy source. Heat pump and natural gas energy scenario have been used for this comparative study. Energy and cost analysis for three scenarios are discussed in this paper.

Very popular among the environment activists and public authorities, the rolling highways prove to have a poor commercial viability. Therefore, the paper tries to find the reasons for this fact. The analysis starts with the descriptions of the technical solutions, then the traffic volumes recorded on different transport relations / countries are presented, together with the main findings from the European experience. The trends are explained considering the operational issues, the transport costs, the factors influencing the demand, the state support and the railway regulations, as well as the requirements of the customers. Special comments are focused on the Romanian experience, indicating the operational issues specific to Romania, the necessity for state aids with intensities of 45 – 60% from the costs, as well as the savings in external costs. The main conclusions are that the rolling highways are environmentally friendly, but costly and that they could develop only if the public authorities implement appropriate support measures and aids.

Welding is a manufacturing process, which uses heat or pressure to form a homogeneous weld when joining homogeneous or heterogeneous metal materials or thermoplastics. The last decade has been characterized by the intensive development of unconventional welding processes, which use friction as an energy source, and in developed countries have taken primacy over conventional welding processes. The modern welding process, known as Friction Stir Welding (FSW), offers many advantages over conventional Tungsten Inert Gas (TIG) and Metal Inert Gas (MIG) processes, both in terms of weld quality and environmental protection and in terms of saving time and materials needed to perform quality welding. This paper presents TIG, MIG and FSW welding technologies, with all the advantages and disadvantages, and the possibilities of their application in welding AA6082-T6 aluminum alloy (6xxx series), characterized by medium strength and outstanding corrosion resistance

The intensity of aging and wear of the components /aggregates and assemblies/ of the machines is different and hence the necessity of carrying out repair service interventions has different periodicity and volume.
A model has been developed to optimize the periodicity of maintenance of machine components, taking into account the losses from the underuse of their resource.
The influence of the parameters of the law and the economic indicators on the optimal periodicity of the maintenance was examined at the density of the distribution of work until failure to the Weibull distribution.

A key element in the machinery management policy is its rational use by optimizing the periodicity of maintenance and repairs. The influence of the numerical characteristics and parameters of the reliability indicators distribution on the optimal periodicity of the maintenance has been investigated. Analytical dependencies for determining the complex reliability indicators of the objects at the optimal periodicity of the prophylactics are proposed.