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

The climatic performance of different ecological areas is determinant for agricultural production and its sustainability. The agriculture is closely related to climatic conditions as climate variability and climate change generate significant ef fects on agriculture. Analysis of climatic behavior of different ecological zones, are important to identify climate variations, but also phenomena related to climate change. The study of climate variations and the phenomena of climate change are important for agricultural activity, in order to adapt agricultural systems, implement mitigation strategies and adaptation to them. Organic farming systems offer the best solution in this regard. The nortthern western lowlands of Albania (Shkodra), is an area with significant agricultural activity and highly diversified, with a great potential for the implementation of organic farming systems. The analysis of the climatic variability of this area and the phenomena of climate change, will contribute to the orientation of agricultural activity towards organic systems in order to better adapt them to climatic variations and increase the sustainability of production.

Photovoltaic thermal system (PV-T) converts sunlight into electricity and heat simultaneously. The overall efficiency of these systems is higher than the efficiencies of PV panels and solar collectors together. In Albania energy production from photovoltaic systems has been promoted in the recent years. Albania’s Mediterranean climate conditions are very favourable for investment in renewable energy systems. In this study a stand-alone 280 W PV-T panel is considered with respect to thermal analysis of the system. The panel is installed at the terrace of the building University in Tirana, Albania. The aim of this work is to present the temperature profile of the panel, since there is a correlation between efficiency and temperature. In order to analyse the temperature distribution on the panel surface a series of experiments are carried out. Temperature variation vs. time for different water flow rate was performed. The inlet and outlet water temperature profile is drawn in this article.

The geographical distribution of plants in ecosystems and the limits of agronomic extention of plants cultivated in different areas are conditioned by the performance and climatic variabilities of these areas.The biological and productive behavior of plants in agricultural systems is determined by climate performance in general and in particular by the two main climatic parameters, temperature and precipitation.Their significant fluctuations, conditioned in recent years by climate change, are evident in the form of risky for agriculture such as prolonged droughts, severe shortages of rainfall, high summer temperatures in the form of heat waves, which further brings the effect of agronomic drought. In the thermal minimums, expressed in the form of frosts, there are observed fluctuations changes creating deviations from the average perennial performance of their occurrence. The study of thermal fluctuations, and in particular the study of the phenomenon of drought and its consequences, it is an important problem especially in areas with high agricultural character. Drought occurs when there is a shortage of rainfall for long periods, registering as a pluviometric deficit. Occurrence variations of this phenomenon are related to the rainfall cycle, but they should be considered in relation to potential climate change, especially in the Mediterranean basin where Albania is located. The study of climate variability and the identification of extreme climate phenomenas as well as the determination of thermal and pluviometric limits can be done through climate monitoring indicators. Albania’s western lowland area and particulary the Vlora area, which is under consideration on this study, is an agricultural area with a great diversity of cropping cultivations. Analyzing the climate behavior of this area will enable the design of suitable cultivation technologies as well as taking measures to minimize the damages to crop production from these factors.

This paper describes the process of drying baking soda in a pneumatic dryer. A description of a drying plant with honeycomb elements is provided. Due to the extensive work, only one part of the results of the study is presented, which is related to the material-energy balance, the calculation of the final humidity, the change of the air condition (humidity and temperature) in the bicarbonate drying process. Part of the research results related to the application of I-X – diagram in the drying process of Na HCO3 is presented

In this paper, a computer simulation of a new technology of thick-sheet rolling, including rolling in rolls with a relief surface followed by rolling on rolls with a smooth barrel to the desired size. The analysis of effective plastic deformation, hydrostatic pressure and temperature field was carried out according to the results of modeling. According to the results of the analysis of effective strain, maximum of processing in the first pass receives the ridge area, but after the second pass observed alignment distribution of this parameter over the cross section. The study of the temperature field showed that the greatest temperature difference in the cross section occurs when rolling in relief rolls, in the future when rolling in smooth rolls due to the increase in the contact surface area, this difference decreases. Analysis of hydrostatic pressure showed the presence of both compressive and tensile stresses in the deformation zone. Such distribution is caused by the presence of a relief surface after 1 pass in the further alignment of the strip profile, which occurs both in the longitudinal and transverse directions.

Given are the results of a comparative design analysis of the operating cycle and thermal stressed state of a piston in diesel engine 2F10,5/12 under rated power conditions. To reduce the thermoelastic stresses in the piston, the paper suggests using the modern method of managing the operating cycle – homogeneous mixing and combustion. Such an operating cycle reduces the maximum local temperature in the combustion chamber and the temperature gradients, thereby reducing the thermal load on the piston.

This paper discusses a heat pump subsystem within an existing high-temperature DH system located at a railway station in Omsk, Russia. The goal is to increase the efficiency of an existing high-temperature DH system by describing decentralized heat generation from an environmental point of view. We obtain a balance method whereby the heat loss (or the thermal energy loss) is expressed dependent on the supply and return temperatures so as to reduce operating costs of heat supply. The outcome of calculating the heat loss by this method is a relation that is valid typically for all DH networks. Findings beneath show that switching to a low-temperature DH can decrease operating costs and increase overall heat production efficiency. The reason for the latter is a known logarithmic heat flux-temperature correlation. This paper concludes that the idea of decentralized generation has a great potential for the future, as the implementation of this concept is closely related to a low-temperature DH.

Fish like many living organisms have specific tolerant range of various environmental parameters, thus fish farming of specific types of fish species requires certain conditions that have to be reached. Moreover, the people that work in the fish farming ponds have to be engaged in all day activities to maintain the living fish habitat. Therefore, monitoring and taking actions to maintain the habitat’s sustainable environment for certain fish species inside of fishing ponds over distributed machine to machine communication, which will shorten the time needed for some basic actions, is the main motivation for this paper. In this paper we present an upgrade on a functional Internet of Things (IoT) system for monitoring fish farming ponds. The IoT system consists of various sensors that measure important factors of the water quality like temperature, light intensity or water level, as well as small board computer that processes the data and sends sound and visual notifications to the fish farming manager. The current system lacks the ability to process the data to the end-user via web or mobile platform. Due to remote distance of the fish farming ponds and their location dependence of clean fresh water, one solution of this problem is using expansion module like Wivity modem to enable the end users in real time to monitor and control certain aspects of the fish farming pond IoT system. Wivity modem allows user to communicate to the IoT system via WiFi connection, cellular, LoRaWAN or satellite communication; all in one product. Later on, this module can be integrated with IoT platforms including Japser, Microsoft Azure or Amazon Web Services. For future work, we plan to expand not only the applicable services on different platforms, but also add more control modules and sensors to the existing IoT system for specific fish species.

Horseradish peroxidase represents one of the most exploited enzymes in the process of enzymatic phenol removal from aqueous solutions. It has a catalytic ability over a broad pH range, temperature and contaminant concentration. In this study we have investigated the influence of pH and temperature on process of phenol removal by crude horseradish peroxidase from aqueous solution. Reaction was performed in the presence of low molecular polyethylene glycol (PEG 300) at different temperatures (4, 12, 17, 20, 25, 30, 35, 40 and 45 °C) and pH values (3, 4, 5, 6, 7, 8 and 9). Reaction was monitored by measuring of absorbance changes of the samples taken at certain time intervals from reaction mixture. Obtained results shown that phenol removal from aqueous solution increases by temperature increase up to 35 °C, after which this effect no longer exists. Also, phenol removal increases in the pH range of 3 – 7, while a further increase of pH value leads to the opposite effect. Based on this it can be concluded that phenol removal from aqueous solutions greatly depends of peroxidase activity, because this temperature and pH values represents the optimum values of peroxidase enzymatic activity.

Nano fluids is advantageous with high thermodynamic properties compared to pure fluids. In the last half century, rapid developments in production technology, which allows high-precision production of the micro heat exchangers and the use of the micro heat exchangers in different areas. These developments point researchers to enhance new methods in improving the heat transfer. One of these methods is; to improve fluid’s heat transfer by adding different particulates to the fluid. The nano fluids are the new type of heat transfer fluids that are made by adding nano particulates which has high thermal conductivity to a conventional fluid. Since the solid metal has a higher thermal conductivity than the basis fluid, the addition of the metallic particulates to the fluid increases the heat transfer of the mixture. In this study, for analyzing the temperature performance of fluids with Nano particulates; an experimental study was performed using water to determine the optimum mini channel length and mini channel diameter. Performance parameters are; channel length, tube mini channel diameter, the flow and the inlet temperature. According to the experimental results, the maximum temperature performance of the mini channel was found to be at L/D=250/3 (at Selcuk University condition). Therefore, with these results, the optimum mini channel length and mini channel diameter are determined for the high efficiency that is to be achieved by using nano fluids

The key issue to an automotive engine’s reliability and its durability is the quality of the lubrication system. The primary task of the lubrication system is to provide a continuous supply of filtered oil between two sliding surfaces. By using adequate lubrication oils will reducing friction between moving mechanical parts. Rheological characteristics of lubricating oil directly caused the friction losses due to internal engines mechanisms (piston group, valve train, fuel pump, crankshaft, bearings and seals, etc.). The main components of lubrication system has a poor lubrication during cold start up process of an IC diesel engine and thus is necessary a proper lubricating oil to full fit the complex demands of all engine components and subassemblies. The aim of this paper is experimental investigating of the influence for different classes lubricating oils characteristics and oil filters which are present in market of Republic of Kosovo, especially those with lower prices on engine oil pressure, temperature and flow during start up until the oil warms up some. The obtained results are taken from measuring device which is installed into Fiat passenger car with Spark Ignition Engine for different working regimes.

Measurements of linear thermal expansion coefficient (TEC) of a nanoporous metal carbide based carbon material were car-ried out. The values of linear thermal expansion coefficient in the range from 20°C to 300°C were obtained. The measured value of TEC are presented for this material for the first time.