Browse

151 - 160 of 2,333 items :

  • Materials Sciences x
Clear All
Analysis of Engine Oils from Farm Tractors in the Aspect of their Change

Abstract

The paper presents results of research on selected physico-chemical parameters of engine oils from farm tractors based on the date of their change assumed by the user. 17 samples of used engine oil from farm tractors of various producers and with a varied exploitation course were analysed. Oils for research were collected during oil change, registering the service life of oil each time. They were obtained from service points that repair farm tractors in the region of Lublin Province. The studies were to verify whether a decision concerning oil change taken by tractor users after specific time of operation of an engine was good. Number of exceedings of the threshold values of parameters of engine oil which are responsible for correct lubrication were the basis for evaluation

Open access
Analysis of Gap Measurement of Various Dimensions of SERVAQUAL Model in context to Indian Banks

Abstract

To improve the reputation and customer loyalty, a benchmarking analysis is being carried out, which influences the perception of the service quality for banks. With the expansion of competitive interactions, the results can serve as a strategic tool to gain competitive advantage and customer satisfaction. Banks reveal the expectations and expectations of customers regarding the quality of selected services. The process creates and expands its reputation and builds customer loyalty. This research aims to compare the perception of the quality of four leading banks with logical comparisons.

Open access
An analysis of the causes of track twist at high speed of driving

Abstract

The research of railway track surfaces is aimed at improving the quality of railway infrastructure and providing the chance of improving the safety of driving. Therefore, it is advisable to constantly monitor track surface, but the research itself is not innovative because it is based on a known procedure. The crucial element are the techniques that allow to delve into the sources of problems. The aim of the article is to use the selected instruments of quality management to analyze the causes of track twist at high (180 km/h) speed of driving. The analysis of the causes of track twist was done on the basis of results from the measurement of one kilometer track section of the Krakow Glowny - Medyka route, which was made by using the TEC measuring device in April 2018. It was inferred that it is impossible to reach 180 km/h without track twist. In order to identify the causes of track twist it was proposed to use the selected sequence of quality management instruments, i.e.: brainstorming, Ishikawa diagram and the 5Why method. The identified causes of track twist include the abrasion of rail, scratches and exploitation point. The analysis and conclusions drawn from it may be useful in the analysis of other problems in railway transport as well as production and service industries.

Open access
Analysis of Traction Properties and Power of Wheels Used on Various Agricultural Soils

Abstract

The paper presents results of the research on traction properties of two tractor tyres used on two agricultural grounds. The first ground was a stubble and the second one cropland. The investigated tyres had the same structure (diagonal, with a traditional tyre tread but different external dimensions. The research was carried out in field conditions with the use of a stand aggregated with a farm tractor. Analysis covered traction efficiency, slide, towing power and power lost on the rolling resistance and wheel slide. Based on the obtained results it was concluded that on a ground with lower compaction, the values of power losses were higher and traction efficiency was lower. Moreover, it was proved that the value of the power lost for rolling resistance had a decisive impact on the values of traction efficiency

Open access
Cathionic corrosion inhibitors for protection of steel in chloride containing concrete pore solution

Abstract

Electrochemical chloride extraction from a reinforced concrete structure may be accompanied with an electrochemical injection of healing agents if such agents are positively charged and are able to migrate towards the activated reinforcement. Positive charge carried by nanoparticles or cathionic corrosion inhibitors might be the proper choice. Organic substances with a positive charge and their salts are mostly such inhibitors. The essential conditions for successful application of such corrosion inhibitors are their sufficient corrosion inhibition efficiency that was studied and evaluated and their stability of positive charge in chloride containing concrete pore solution.

Open access
CdO-Fe3O4 nanocomposite with enhanced magnetic and photocatalytic properties

Abstract

Pure CdO nanopowder and CdO-Fe3O4 nanocomposite were synthesized by a cost effective chemical method, and the samples were characterized by XRD, SEM, TEM, FT-IR, UV-Vis-NIR and PL. Also, magnetic and photocatalytic properties of the synthesized samples were studied. XRD patterns of the composite confirm the presence of diffraction peaks related to both CdO and Fe3O4. EDX spectrum confirms the presence of the elements Cd, O and Fe in the composite. Peaks related to Cd–O and Fe–O bonds were observed respectively at 688 cm−1 and 592 cm−1 in the FT-IR spectrum. The paramagnetic behavior of pure CdO becomes ferromagnetic when coupled with Fe3O4. The composite exhibited a high photodegradation efficiency of 92.85 % against the degradation of methylene blue dye under visible light radiation.

Open access
Chemical Threats in Thermally Processed Traditional Food and Possibilities of Their Reduction

Abstract

The objective of the paper is to review the present state of knowledge on health threats that occur as a result of some thermal processing of food products. Depending on the type and properties of raw materials and conditions of processes, carcinogenic, mutagen and genotoxic substances may be formed out of them, which may be treated as a process contamination. They are produced in processing plants, where their content is obligatorily controlled and organic, as well as in the conditions of food production in gastronomic units and households. The paper emphasises the second area of food processing, in particular, house-holds and popularised grilling processes, where there are no other possibilities of control of the threat level and awareness of people who prepare food and consumers is insufficient. The paper presents the most often occurring hazardous compounds, the most important regulations and admissible limits of consumption, as well as principles of thermal processing in a safe manner, and possibilities of limiting the levels of those substances in products

Open access
Comparison of temperature dependence of internal damping of selected magnesium alloys

Abstract

The research is focused on the study of the temperature dependence of the internal damping of selected magnesium alloys with different contents of aluminium - AZ31 and AZ61. These alloys are currently widely used in various types of industry, mainly in the automotive industry. It belongs to a group of materials called HIDAMETS because they have excellent damping properties. The internal damping of the samples was measured on a unique ultrasonic device constructed at Žilina University in Žilina. Specimens were measured at baseline in the temperature range from 25 °C to 400 °C. Changes in internal damping caused by varying aluminium contents in investigated alloys were noted. As the aluminium content increases, maximum internal damping is achieved due to the formation, growth and subsequent dissolution of the continuous precipitate in the microstructure.

Open access
Comprehensive Aviaton System of Flying Crew Improving Safety in the Aircraft Operation

Abstract

The article describes 10 known programmes of practical flight training in military aviation – specialization: Multi-Mission Tactical Jet Pilot, which is the highest level of military pilot training in all types of military and civil aviation – comparable only to the level of training and experience of the pilot-instructor of the Military Aviation School. The presented comparison was developed on the basis of literature research from the point of view of, among others, an aircraft operation engineer and a pilot-instructor.

Open access
Contract Brewing – Production-Oriented Cooperation in Craft Brewing Industry

Abstract

The objective of the paper is to analyze the cooperation in craft beer manufacturing in Poland and to identify the specificity of this phenomenon from the perspective of enterprise management. The sales of craft beers in Poland are growing rapidly. Craft beers have about a 0.5% share in the total beer sales value in Poland. The popular practice in the industry is contract brewing. It is an interesting phenomenon in the field of cooperation of enterprises which can be classified and analyzed as a form of: economic cooperation (generally), production cooperation, outsourcing, network and virtual organization and also coopetition. It is a specific business model. Contract brewing is a complex problem the specificity of which emerges on several levels. Firstly, there is a special way to emerge in the market of craft beers, even while not possessing significant funds by the entrepreneur. Secondly, it is a form of cooperation in the field of production which unites efforts on the side of both the customer and the contractor since it is not limited to normal outsourcing of production to an external entity but involves physical production capacity of the contractor and technological know-how of both cooperation parties. Thirdly, it is firmly embedded in human relationships. Fourthly, it can generate coopetitive relations since the brewery accepting the order may conduct its own activity related to production and sales of beer under its own brand.

Open access