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Number of results: 14
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Abstract

This article explores caring through feeding as an important aspect of transnational family life, and analyzes the practices connected to sending food products home, supervising what the family eats, and changing consumption patterns. It focuses on Filipino migrants to the United States who maintain transnational ties with their families. With a history of colonial encounter, the United States has been a popular migration destination, and has also strongly influenced food consumption. The study shows the ways in which packages from abroad (balikbayan boxes) express love and care, and how they allow migrants to control food consumption of the family in the country of origin. By looking at the goods the immigrants put in the packages, and the way these are received, it is possible to uncover the dynamics of love, care, and intimacy in transnational families, which often translate into power, tensions, and control among family-members. The article analyses how food products sent in the packages work, bringing with them new ideas and practices, creating imaginaries of migration, and building the social prestige of the immigrant. Using the concept of “social remittances”, the article also shows the changing patterns of food consumption in the Philippines.
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Abstract

Describing the gas boiler fuel consumption as a time series gives the opportunity to use tools appropriate for the processing of such data to analyze this phenomenon. One of them are ARIMA models. The article proposes this type of model to be used for predicting monthly gas consumption in a boiler room working for heating and hot water preparation. The boiler supplies heat to a group of residential buildings. Based on the collected data, three specific models were selected for which the forecast accuracy was assessed. Calculations and analyses were carried out in the R environment using “forecast” and “ggplot2” packages. A good quality of the obtained forecasts has been demonstrated, confirming the usefulness of the proposed analytical tools. The article summary also indicates for what purposes the forecasts obtained in this way can be used. They can be useful for diagnosing the correct operation of a heat source. Registering fuel consumption at a level significantly deviating from the forecast should be a signal to immediately diagnose the boiler room and the heat supply system and to explain the reason for this difference. In this way, it is possible to detect irregularities in the operation of the heat supply system before they are detected by traditional methods. The gas consumption forecast is also useful for optimizing the financial management of the property manager responsible for the operation of the boiler room. On this basis, operating fees or financial operations with the use of periodic surplus capital may be planned.
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Abstract

The main aim of this article is to present the results of research on energy poverty conducted in Katowice and Bytom, two cities situated in the Silesian voivodeship [region] in Poland. The study attempted to verify whether the energy divide concept elaborated by Bouzarovski and Tirado Herrero (2015) has different undiscovered dimensions which result not only from the differences in energy prices and incomes between various regions, but also from other factors such as consumer behaviours. In discussions about the energy divide, this aspect of energy poverty has so far been rather neglected. The question remains whether the distinction between energy poverty levels of countries, regions, and other territories like cities is determined by consumer behaviours or only by income and energy prices. Katowice and Bytom seem to be perfect places to conduct such. The most important conclusions emerging from the presented research are: (a) low income does not affect the behaviour of people suffering from energy poverty, even though it theoretically should; (b) despite their difficult financial situation, low-income households do little to improve their situation; and (c) public policy should take into account in the spatial distribution of households affected by energy poverty other aspects, including non-income and behavioural factors and patterns of persons affected by energy poverty, which only deepen existing social inequalities rather than reduce them.
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Abstract

The aim of this study was to analyze diesel fuel consumption in Poland and identification of the causes of changes in the needs of individual sectors of the economy for this type of fuel. Time range of the researches covered from 2004 to 2014. Data from the Central Statistical Office (CSO) were the source material. In the years 2004-2014 diesel consumption in Poland was 111 553 thousand tons. In 2014 domestic consumption of diesel fuel was 11 203 thousand tons and it was more than 2 times higher than the level of consumption of this fuel in 2004. The highest consumption of diesel in Poland in the period took place in 2012. The increase in the consumption of diesel fuel in Poland had benefited from increased demand for diesel in transport, which became a result of an increased amount of transport services. The share of transport in the consumption of diesel fuel in Poland for the period 2004- 2014 was about 75%. Another area, which consumes the largest quantity of DF in Poland is agriculture. Consumption of this fuel in agriculture in the years 2004- 2014 increased by 7%. DF consumption in industry and the manufacturing sector it was variable. DF biggest consumption in these sectors of the economy in the period was recorded in 2004. The analyzes did not allow to identify the specific causes of changes in the use of DF in the industry and manufacturing. In transport it showed a relationship between the consumption of diesel fuel and the amount of transport work and the transported cargo.
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Abstract

In this article, an outline of the key questions connected with the essential problems of energy-consumption of air-stream moulding machines has been presented. Research results and calculations of requisite parameters appraisable of energy-consumption of air-stream moulding machines have been supplemented also by the data analysis of offer of the moulding machines manufacturers. The attention on constructional and technological factors which are favourable for the diminution of energy-consuming of the moulding process has been paid.
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Abstract

The predicted annual growth of energy consumption in ICT by 4% towards 2020, despite improvements and efficiency gains in technology, is challenging our ability to claim that ICT is providing overall gains in energy efficiency and Carbon Imprint as computers and networks are increasingly used in all sectors of activity. Thus we must find means to limit this increase and preserve quality of service (QoS) in computer systems and networks. Since the energy consumed in ICT is related to system load, ]this paper discusses the choice of system load that offers the best trade-off between energy consumption and QoS. We use both simple queueing models and measurements to develop and illustrate the results. A discussion is also provided regarding future research directions.
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Abstract

This paper proposes an analysis of the effect of vertical position of the pivot point of the inverted pendulum during humanoid walking. We introduce a new feature of the inverted pendulum by taking a pivot point under the ground level allowing a natural trajectory for the center of pressure (CoP), like in human walking. The influence of the vertical position of the pivot point on energy consumption is analyzed here. The evaluation of a 3D Walking gait is based on the energy consumption. A sthenic criterion is used to depict this evaluation. A consequent reduction of joint torques is shown with a pivot point under the ground.
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Abstract

The paper presents a theoretical analysis of the effect of electric car performance characteristics on vehicle energy consumption and driving range. The test object was a Nissan Leaf electric vehicle. The characteristic curves of basic and additional resistance to motion (sum of rolling resistance and air resistance and inertia resistance or grade resistance, respectively) were applied to the model characteristic curve of electric motor torque of the tested vehicle. Based on that, the graphs describing the relationships between vehicle energy consumption and vehicle speed were made (for specific values of car acceleration / acclivity grade) as well as the relations between vehicle driving range and its traction properties. It was concluded that the use of performance characteristics significantly increased the vehicle’s energy consumption and decreased the available vehicle’s driving range.
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Abstract

The paper presents the simulation analysis determining the effect of tyre energy efficiency class on fuel consumption of a passenger car. Calculations were made assuming the wheel movement on a dry and smooth asphalt road surface. The tests based on a simulation model were performed on 61 types of tyres, being characterised by different sizes and energy efficiency classes. Different values of rolling resistance coefficient were adopted (in accordance with energy efficiency classes), also, the values of basic and additional resistance to motion were determined. Based on them, engine speeds and load torque corresponding to respective specific fuel consumption were estimated. This parameter allowed the relationship between average mileage fuel consumption and tyre energy efficiency class to be determined on the basis of the NEDC test.
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Abstract

The sustainable management of energy production and consumption is one of the main challenges of the 21st century. This results from the threats to the natural environment, including the negative impact of the energy sector on the climate, the limited resources of fossil fuels, as well as the unstability of renewable energy sources – despite the development of technologies for obtaining energy from the: sun, wind, water, etc. In this situation, the efficiency of energy management, both on the micro (dispersed energy) and macro (power system) scale, may be improved by innovative technological solutions enabling energy storage. Their effective implementation enables energy storage during periods of overproduction and its use in the case of energy shortages. These challenges cannot be overestimated. Modern science needs to solve various technological issues in the field of storage, organizational problems of enterprises producing electricity and heat, or issues related to the functioning of energy markets. The article presents the specificity of the operation of a combined heat and power plant with a heat accumulator in the electricity market while taking the parameters affected by uncertainty into account. It was pointed out that the analysis of the risk associated with energy prices and weather conditions is an important element of the decision-making process and management of a heat and power plant equipped with a cold water heat accumulator. The complexity of the issues and the number of variables to be analyzed at a given time are the reason for the use of advanced forecasting methods. The stochastic modeling methods are considered as interesting tools that allow forecasting the operation of an installation with a heat accumulator while taking the influence of numerous variables into account. The analysis has shown that the combined use of Monte Carlo simulations and forecasting using the geometric Brownian motion enables the quantification of the risk of the CHP plant’s operation and the impact of using the energy store on solving uncertainties. The applied methodology can be used at the design stage of systems with energy storage and enables carrying out the risk analysis in the already existing systems; this will allow their efficiency to be improved. The introduction of additional parameters of the planned investments to the analysis will allow the maximum use of energy storage systems in both industrial and dispersed power generation.
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Abstract

The paper presents selected issues related to the development of international coal markets. World consumption of coal dropped for the second year in a row in 2016, primarily due to the lower demand from China and the US. The share of coal in global primary energy consumption decreased to 28%. World coal production accounted to 3.66 billion toe and it was lower by 6.2% when compared to the previous year. More than 60% of this decline took place in China. The decline in global production was more than four times higher than the decrease in consumption. The sufficiency of the world resources of coal are estimated at 153 years – that is three times more than the sufficiency of oil and gas resources. After several years of decline, coal prices increased by 77% in 2016. The current spot prices are at the level of $80/ton and are close to the 2014 prices. In the European market, after the first half of the year, coal prices reached the level of around 66% higher than in the same period of the last year. The average price in the first half amounted to PLN 12.6/GJ, which is close to the 2012 prices. The share of spot trade in the total purchase amount accounted to approx. 20%. Prices in futures contracts can be estimated on the basis of the Japan-Australia contracts prices and prices in supplies to power plants located in Germany. On average, the prices in supplies to these power plants were higher by approximately 9% in the years 2010 – 2016 and prices in Australia – Japan contracts were 12% higher than CIF ARA prices in 2017. Global energy coal trade reached about 1.012 billion tons in 2016. A decline by 4.8% is expected in 2019 primarily due to the expected reduction in demand in major importing countries in Asia.
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Abstract

The article presents the results of selected energy parameters calculations, carried out for the recorded values of instantaneous voltages and currents in the three-phase power supply of the model vibratory unit. The parameters were the values of active and apparent power taken from the drive consisting of two electric motors supplied by the inverter for selected frequency settings and directly from the power grid. In addition, calculations of tgφ power factor values were made to evaluate the compensation of reactive power consumption in the tested power systems. Measurements and calculations lead to the conclusion that if the frequency of the inverter output voltage rises, the active and apparent power consumed by the model vibratory drive unit increases. The active and apparent power for setting the output frequency of the inverter from 50 Hz was less than the active and apparent power taken by the model vibratory unit that was powered directly from the power grid. The power factor tgφ in the power supply system was approximately 6, except one case (f = 30 Hz).
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