Browse

31 - 40 of 159 items :

  • Mechanical Engineering x
  • Materials Sciences, other x
Clear All
RPAS Satellite Communication Channel Based on IEEE 802.11b Standard

Abstract

Original models of RPAS communication channels based on IEEE 802.11b Standard, including both Base Station transmission within the Radio Line of Sight, and through the satellite using Beyond Radio Line of Sight, were built. Dependencies of the Bit Error Rate on the Signal-Noise Ratio for different payload data rates were obtained. Transponder nonlinearity and Base Station antenna diameter impact were analysed.

Open access
Ship Noise Level Analysis Based on the International Regulations

Abstract

The target of analyse was to determine the exposure levels to the staff on the vessel and ensure adequate measures are in place to minimize the exposure when necessary. Noise levels through the vessel will be compared to the noise code detailed in section 2 of this report. The measurement data results obtained at this survey will be analysed against the codes, as shown below. In addition, the measurement result table has the readings from 2007 during sea trials at the shipyard, Brodogradilište d.o.o. – Split. The analyse is to measure the exposure levels, through the accommodation and machinery spaces to determine the risk to staff working in these areas as well as making recommendations that could reduce the exposure levels.

Open access
Turbine Blade of Gas Turbine Engine Additional Unloading by Changing the Layout of the Gravity Centre of the Shroud Shelf

Abstract

The article describes the impact of the gas turbine engine low-pressure turbine blade shroud shelf on the blade profile stress position. Attention is focused directly on the impact of the location of the gravity centre of the shroud shelf on blade stress distribution at the three most critical points of the profile. The paper describes the details of the calculation and the required expressions provided, as well as the results of the calculation example with clear graphical dependencies.

Open access
Bending fatigue strength coefficient the low carbon steel with impurities

Abstract

The article discusses the results of a study investigating the effect of the number of fine non-metallic inclusions (up to 2 μm in size) on the fatigue strength of structural steel during rotary bending. The study was performed on 7 heats produced in an industrial plant. Fourteen heats were produced in a 100 ton oxygen converter. All heats were subjected to vacuum circulation degassing.

Steel sections with a diameter of 18 mm were hardened and tempered at a temperature of 200, 300, 400, 500 and 600°C. The experimental variants were compared in view of the applied melting technology and heat treatment options. The heat treatments were selected to produce heats with different microstructure of steel, from hard microstructure of tempered martensite, through sorbitol to the ductile microstructure of spheroidite. The results were presented graphically, and the fatigue strength of steel with a varied share of non-metallic inclusions was determined during rotary bending. The results revealed that fatigue strength is determined by the relative volume of fine non-metallic inclusions and tempering temperature.

Open access
Context of production engineering in management model of Value Stream Flow according to manufacturing industry

Abstract

The popularity of visual management in the lean concept is caused by the possibility to apply it in solving different kind of issues related to reduce waste or process planning. The adaptations of VSM is focused on stream flow, identifying waiting and productive times in accordance to material and information flow. In this paper five basic areas of value stream flow management have been presented and characterized. Discussion under the 5 areas on the VSM process included identifying the dominant stream in the area and the range of factors affecting the flow of the stream. Based on an observation of processes in the manufacturing industry and a literature review, the graphic model of mutual cooperation between value stream areas (1-5) has been presented.

Open access
How can people be convinced to buy electric cars? – case of Slovenia

Abstract

Electric cars represent a promising energy-and carbon-efficient alternative to internal combustion engine cars. However, as mobility behaviour is highly habitual, convincing people to switch from conventional cars to electric is challenging. In the following research, which was carried out in the past years in Slovenia, an attempt was made to determine what influences people’s buying habits and what would motivate them to buy an electric car. It appeared that the most relevant factor for not purchasing electric cars is, firstly, its overall too high price, and, secondly, short driving ranges. Different studies, as well as the results of the following research have revealed that there is no single measure which would dramatically increase the demand for electric cars. The solution is to combine different measures or strategies like Top – Down and Bottom – Up, where both the government and car industry should come across.

Open access
Keeping Higher Education Aligned with the Requirements and Expectations of the Knowledge-Based Economy

Abstract

Paper describes the procedure for developing academic programs which are properly aligned to the requirements of the knowledge-based economy. The paper also addresses the continuous quality improvement (CQI) process with the CQI loop closing on the program level and the course level. This process is needed to make continuous adjustments to an academic program, so that the program is always aligned to the constantly-changing needs of the economy. Paper also discusses the system of mutual dependency between the academic program and external partnership like local industry, secondary schools, local government, local community, regional business incubator center, other educational institutions, alumni and industrial advisory council. The ongoing collaboration with external partners allows the program to prosper and grow.

Open access
LEAN Production issues in the organization of the company - the first stage

Abstract

Today’s market determinants and most importantly, very dynamically changing customer requirements significantly shortened the product life cycle. This situation reflects in companies by common extension of the assortment offered and personalised serial production. The result of a flexible approach to market changes is the implementation of LEAN concept, which, both in terms of management and production aims to develop efficiency within an organisation, which will then enable quick and dynamic response to changes in the environment. The popularity of LEAN concept (in management and production) among managers comes from its universality and a wide range of instruments used to maximise the use of existing potential. The main assumptions of LEAN concept are aimed at the maximum use of an organisation’s resources, defining the activities necessary to execute an order and identifying the areas generating losses and then minimising them and eventually eliminating. LEAN concept is based on flagship-main tools for identification and modernisation of processes, the difficulty in using them results from the need to recognise and select the most effective ones that meet the expectations of a given organisation. The article presents issues related to the first stage of implementing LEAN concept in a company’s structures, i.e. identification of opportunities and selection of appropriate tools.

Open access
Problems of Polish enterprises in the field of innovation

Abstract

Innovative activity of enterprises in Poland is mostly generated by European funds that concern boosting European regions based on its significant resources and new technologies. Polish enterprises development within innovations is based mainly on accumulating new products and new technologies that improve organization and increase sale of products and services. Papers presents research findings that concern problems resulting from the innovations implementing in Polish enterprises comparing with European results. There is presented European Innovation Index providing a comparative assessment of the innovation performance at the country level of the EU Member States and the Regional Innovation Scoreboard (RIS) that presents results of innovative activity in Polish and European enterprises including regional data from the Community Innovation Survey (CIS).

Open access
Review of Policies for Promotion of Electric Vehicles

Abstract

This paper presents the review of policies and their possible effects for promoting the use of electric vehicles. Suggestions on faster implementation of electric vehicles can also be identified within best practices from abroad. Various countries have adopted different policies to promote the use of electric vehicles which include fiscal or other forms of incentives that would persuade people into buying electric vehicles. Possible effects are hard to determine since many variables affect a consumer’s purchasing decisions. That is why identification of policies that have proven to be successful and those that have not achieved projected results and should be improved is necessary. Research has shown that countries with most promising policies for promotion have the biggest share of electric vehicles and invest the most in their promotion (fiscal incentives).

Open access