• SOCIETY & ”INDUSTRY 4.0”

    Energy audit analysis in private residential apartment in Tirana city

    Industry 4.0, Vol. 7 (2022), Issue 2, pg(s) 79-82

    Recently, Albania as a developing country is focusing on the energy efficiency in residential and industry sector. Residential sector has very high contribution energy consumption in Albania due to many construction buildings without energy efficiency standards implementation. Most of the contribute city is Tirana where energy consumption in residential sector is very high in comparison to the other cities in Albania. Our research work will be focused on analysis of the energy audit on a private residence apartment which is located in the area of Tirana. The purpose of this paper is based on the relevant standards and norms to give appropriate recommendations for the implementation of energy efficiency which would increase the energy performance of this building.

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    Experimental analysis of creep behaviour of solder alloys at near eutectic point by using indentation test

    Industry 4.0, Vol. 6 (2021), Issue 6, pg(s) 225-228

    Eutectic solder alloys are widely used in the microelectronics industry. The phenomenon of creep and its mechanisms are important aspects that influence the performance of solder alloys. During the last two decades, a Pb – solder alloys is fast becoming a reality in lead free electronic products due to harmful caused as toxic material to environment and health, international legislative pressure and marketing. The replacement of Sn – Pb alloys with Sn-Ag-Cu (SAC) alloys needs reliable results for assuring the usage of this solder joints material in electronic industry. In this paper has been studied the creep behaviour of a group of alloy in the system Sn-Ag-Cu (SAC) near the eutectic point. In this research work we have used three different alloy samples which are 95, 5Sn-3, 8Ag-0,7Cu, 96, 5Sn-3, 0Ag-0,5Cu and 95, 46Sn-3, 58Ag-0,96Cu. Indentation technique has been conducted to study the creep behaviour of these three SAC alloys by determining the creep parameters at different temperatures. The temperature used was at room temperature 30oC until 100oC and the stress used was 64MPa-178MPa for the indentation diameter 1 mm and 0.5 mm. The experimental method and results of the creep parameters like activation enthalpy Q, the stress exponent n of the power law model and the parameter of the material A were briefly described in this paper. From the creep curves, constructed for alloys and considered loads, the values of creep stress exponent n were determined for the stud ied alloys.

  • Structure studding of recycling rubber materials through Infrared with ATR, DSC and Scanning electron Microscopy and energy dispersive analysis (SEM)

    Materials Science. Non-Equilibrium Phase Transformations., Vol. 7 (2021), Issue 1, pg(s) 27-30

    Tires are complex objects that consist of many different parts, each with a specific formulation, and include natural or synthetic polymers, carbon black, steel, dispersed oils, dispersed oils, sulfur for the vulcanization or bonding process, organic addit ives and inorganic, and even glass fibers. Their investigation poses a difficulty in identifying them, due to their complex structure. In the Tire
    Recycling Industry we encounter the problem of quality control, which is difficult due to the lack of solubil ity of rubber particles, as well as the limited technical means of these industries. The study aimed to investigate the structure and composition of recycled tires, used in artificial turf / grass as fillers.
    The study focused on the development of standard investigation methods using three instrumental and analytical techniques, as well as the study of morphological changes they have undergone during the recycling process and the impact of additives on them. The aim of this scientific search is studying the structure rubber these materials are recycled, that is one of the most important issues, especially in Albani. Through FT-IR with ATR Analysis, is a analysis technique that provides information about the chemical bonding or molecular structure of materials, Differential Calorimetry DSC and Scanning Electronic microscope (SEM) equipped with the system of
    dispersive of energy spectroscopy (EDS).

  • INNOVATIVE SOLUTIONS

    Investigation of rubber granules used in artificial turf systems with FTIR spectroscopy with ATR system and DSC

    Innovations, Vol. 9 (2021), Issue 4, pg(s) 171-173

    The purpose of this study was to investigate the structure of recycled tires which are used in artificial turf/ grass as infi ll materials. One of the most important issues, especially in Albania is proving that these materials are recycled. In this paper it is presented the FTR with ATR system methods analyses. That will provide info regarding the combining material in rubber granules, for the investigation of their structure, it was used the spectroscopy method, with vibration infrared and Fourier FTIR transformation equipped with ATR system, a method which enables analysis of samples of thick surface, without any prior preparation. The scanning of samples was done with wavelength from 4000-400 cm-1. At the same time was possible to see the changes in the micro-structure of the tires by using the Differential scanning calorimetry (DSC) analyses.

  • MATERIALS

    Post welding residual stress in P91 alloy steel

    Machines. Technologies. Materials., Vol. 15 (2021), Issue 2, pg(s) 73-78

    The chromium-molybdenum steel pipe P91 is widely used in the power plants construction, because they can withstand higher temperatures and operating pressures, in order to increase operating efficiency and output. This material has a complex microstructure which is extremely vulnerable to convert into Austenite form near the temperature for heat treatment. During the welding procedure should be very carefully, because otherwise the residual stress installed post welding will reach high values. A series of experimental studies was carried out, which has shown the development in the magnitude of transverse and longitudinal residual stresses and the values in both directions were determined. For but welded joints the residual stresses in the three direction were measured and the results are reported here. For measuring was used the hole drilling method through “measuring balls” or electrical strain gauge. Except the experiments the finite element method was used to determinate the value and the distribution of the residual stresses. The experimental and FEM results were compared between them and no discrepancy was found.

  • MACHINES

    Analysis of sinking of GRP pipe string DN 1600

    Machines. Technologies. Materials., Vol. 15 (2021), Issue 1, pg(s) 15-21

    The aim of this research it was the installation of a discharge sea water pipeline DN 1600 of GRP (glass-reinforced plastic) material in Vlore Bay. The analysis of the sinking of the pipe string has been carried out by using CAESAR II software and considering different load cases. The calculation was carried out for static condition (sustained load) and transient condition (occasional load). In consideration were taken the allowable stress due to bending for pipe and allowable stress for joint subjected to freezing. From the calculation it was evident that the most critical effect on the GRP pipe has done by the position of Concentrated Force due to the presence of sledge (approx.. 2 tons), not disassembled from the string after moving in the position from the shore. In these cases, where the central crane has been maintained fixed or moved downward, the maximum bending stress on the pipe was 12.03 MPa. According to the verification carried out for pipe wall in the transient condition (occasional load) the stability was good and for the joint, was shown, in the worst scenario, a bending stress 158% of the allowable one. In this case it is possible to have the crack of the resin used for the freezing of the joint but not the failure of the system joint + pipe that can withstand without, failure, a stress 3 times greater than the allowable stress for pipe according to EN1796.

  • Quality Control of the Concrete Pavement Constructions for Mother Theresa Airport

    Materials Science. Non-Equilibrium Phase Transformations., Vol. 6 (2020), Issue 3, pg(s) 88-89

    Nowadays, roads and airports are the most used ways of communication to connect people to each other inside and outside of Albania. Based on it, infrastructure has been a key parameter to develop economy and social life of Albania. The request of the people to use the roads and airports is increasing every year which has made the government to concentrate on the infrastructure improvement and development. The most common problem comes from Mother Theresa airport due to non-formal management control. Due to it, our research work will be focused on the quality control of the concrete pavement constructions of the Mother Theresa Airport.

  • MACHINES

    The strenous state of the contact at the sliding – flip pairs

    Machines. Technologies. Materials., Vol. 14 (2020), Issue 7, pg(s) 258-261

    The exact determination of strain on the load application area, regards to changing material or shape is one of the main problems of the mini structure constructions, which it does not interfere with the classical methods of linear elasticity. The main purpose of this article is to demonstrate accomplishments in the knowledge of linear elasticity with different mathematical methods, in order to penetrate into the area or into the contact lining, taking into consideration the friction between the bodies in contact. The methods and hypotheses are related to the analysis of different classical half-plane problems in loads of different types of linear elasticity. This material shows a clear original solution of the strained state in the contact area including the surface lining; it serves as a solution to the various contact plan problems. The details and the elements of the vehicles are part of a broad field, which should be optimized considering different analytical solutions and using various computer programs. These solutions can be installed in their structure. Classical methods in the details apply only when the hypotheses on studied subjects are being met, such as Material Resistance studying the Rod. A detail with a length of ten times greater than the transverse dimension. That’s the reason why extreme problems or problems out of the different hypotheses are solved and proven in practice with the most creative and sophisticated methods. The solution given in this article is an important contribution to constructive calculations, which is also associated with other works carried out by me on the friction coefficient on the flip-flop slippery contact.

  • MACHINES

    A fuzzy logic-based Anti-Lock Braking Systems

    Machines. Technologies. Materials., Vol. 14 (2020), Issue 2, pg(s) 58-60

    In today’s automobile industry, the need to adjust the speed of the vehicle and stabilize the wheels control is still a task due to road conditions and traffic. The Anti-lock Braking System (ABS) is a tool used in automobiles to prevent wheels from locking while brakes are pressed. The objective of this work is the maintenance of the wheel slip value to a desirable slip ratio as the vehicle model is simulated using a fuzzy logic controller. The analyses are made based on the slip ratio, angular velocity and stopping time.

  • MATHEMATICAL MODELLING OF TECHNOLOGICAL PROCESSES AND SYSTEMS

    Mechanical and hydraulical stability of the offshore composit structure

    Mathematical Modeling, Vol. 4 (2020), Issue 1, pg(s) 22-25

    The aim of this research it was the installation of an intake sea water GRP (glass-reinforced plastic) structure in Vlore Bay. A detailed study about the extreme wave condition offshore was carried out by the SWAN (Simulating Waves Nearshore) model. Then the mechanical structure stability calculation was performed with AxisVM8, a finite element modeler & solver. Conservative hypothesis were taken, such as to use the max static pressure value as per energy balance calculation on the sea waves. The program Fluid Flow was used to model the pipe line end with pipe chimney connections. The scope of the calculation was primarily to balance fluid flows in each chimney in order to match the range of 0, 2 – 0, 25 m/s velocity at each chimney entrance. The result of the mechanical and hydraulically stability verification for the sea water intake structure take in consideration it was positive and this structure was installed successfully.