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Human cognition may be enhanced by energy drinks containing caffeine and/or other stimulants, which are thought to improve attentional as well as motor performance, and reduce reaction times. Due to the fact that literature shows that even low doses of caffeine may improve cognitive performance, we investigated an acute effect of a single dose of a caffeinated energy dietary supplement, on attention and motor responses by means of event related potentials. Healthy volunteers were examined in double blind, placebo controlled study. EEG recordings from 32 channels were performed in three sessions: before the supplementation (session 1), 30 min after the supplementation (session 2) and 90 min after the supplementation (session 3) in three tasks: visual P3, auditory P3, and motor task. Repeated measures ANOVA analysis showed reduced P3 amplitude increase after energy dietary supplementation (compared to placebo group) throughout all sessions (up to 90 min after consumption) in the visual task, and speeding the classification process observed as a decrease of P3 midpoint latency, but only 30 min after supplementation. The latter effect was present in both, but more pronounced in the visual task. Nonparametric cluster based permutation analysis showed one significant cluster in the placebo group from visual P3 task (approximately between 400 and 520 ms) over the centro‑parietal area, which was absent in the study group. Our results suggest that caffeinated energy dietary supplement containing only 55 mg of caffeine may enhance some attentional processes observed by changes in P3 features, but not in motor performance.

Since the adsorption chillers do not use primary energy as driving source the possibility to employ low temperature waste heat sources in cooling energy production receives nowadays much attention of the industry and science community. However, the performance of the thermally driven adsorption systems is lower than that of other heat driven heating/cooling systems. Low coefficients of performance are one of the main disadvantages of adsorption coolers. It is the result of a poor heat transfer coefficient between the bed and the immersed heating surfaces of a built-in heat exchanger system. The purpose of this work is to study the effect of thermal conductance values of sorption elements and evaporator as well as other design parameters on the performance of a re-heat two-stage adsorption chiller. One of the main energy efficiency factors in cooling production, i. e. cooling capacity for wide-range of both design and operating parameters is analyzed in the paper. Moreover, the work introduces artificial intelligence approach for the optimization study of the adsorption cooler. The ANFIS was employed in the work. The increase in both the bed and evaporator conductance provides better performance of the considered innovative adsorption chiller. The highest obtained value of cooling capacity is 21.7 kW and it can be achieved for the following design and operational parameters of the considered re-heat two-stage adsorption chiller: Msorb = 40 kg, t = 1300 s, T = 80oC, Csorb/Cmet = 50, hAsorb = 4000 W/K, hAevap = 4000 W/K.

Energy efficiency is one of the most important topics nowadays. It is strictly related to the problem of energy demand, energy policy, environmental pollution, and economic issues. Because of the technological development, using more advanced processes in almost every part of industry and increasing demands both for a high standard of living and simplification of processes, the energy demand is growing. This can be observed, e.g., in the building sector—air conditioning is present in almost every new building and people expect high quality thermal conditions. At the same time, many technological processes result in dissipating energy to the environment. Energy efficiency can be increased and operation costs reduced by using waste heat in other processes. One of the possibilities is to use sorption chillers to produce cool and desalinated water. Low temperature waste heat is not easy to utilize because of low energy potential. Using adsorption chillers in low temperature conditions allows utilizing waste heat and producing useful products in many regions of the world. The paper presents the results of experimental study carried out on three-bed adsorption chiller with desalination, using silica gel and water as the working pair. The chiller was equipped with plate-fin tube heat exchanger filled with silica gel with a grain size of 0.5–1.5 mm. The laboratory test stand included one evaporator, one condenser, and three separate tanks for water, desalinated water, and brine, respectively. The test stand scheme and description were presented. All results were obtained during a few hours test with stable temperature conditions in the range of 55–85 °C for the heating water.

Ecological adsorption technology is becoming a focus of attention by industry due to the utilization of low grade thermal energy sources for cooling production. It can be a promising part of sustainable development concept of the global economy. Therefore, research aiming at improving their performance i.e. Coefficient of Performance (COP) by optimizing the construction of sorption beds with a built in heat exchanger system is crucial. The heat transfer characteristics between the bed of porous media (sorbent) and surface of the heat exchanger system determine the heating power of an adsorption chiller. The HP increase can be obtained by heat transfer intensification due to the increase in the thermal conductivity of the sorbent layer in the vicinity of the heat exchanger’s surface. The novel modification of the sorbent layer structure is proposed in the paper in order to improve the heat transfer processes in the heat exchanger boundary layer. The analysis of desorption process conditions in the parametric model of a coated and fixed adsorption bed design is presented in the paper. The computational fluid dynamics (CFD) with conjugate heat transfer analysis is used to determine the crucial input parameters (temperature distribution in the sorbent bed) for further analytical calculations. The commercial code Ansys Fluent was used to perform numerical simulations. The developed computational model consisted of three subdomains representing heating water, heat exchanger material (copper) and sorbent (silica gel). The comparison of a novel coated design and a conventional fixed bed is discussed in the paper. The numerical analysis is based on experimental thermal conductivity measurements of the sorbent layer in different configurations, which were performed using Laser Flash Method.

Due to the progressive climate changes, increasing demand for cooling is observed. Therefore, ecological alternatives to conventional cooling systems based on electricity are analysed. One of the promising solutions are adsorption chillers which can be powered by low grade thermal energy sources such as waste heat, solar power and heat produced in cogeneration. However, contemporary adsorption chillers achieve lower COP (coefficient of performance) when compared to conventional electricity-driven compression refrigerators. Refrigeration capacity of the adsorption chiller is obtained with the use of thermal effects which occur during adsorption and desorption processes on porous media and the intensification of this phenomena is currently one of the most important research challenges. The paper presents development of guidelines to build novel coated construction of adsorption beds. The criterion for selection of optimum bed components in terms of improving COP of the adsorption chillers dedicated to air conditioning has been defined. Silica gel has been indicated as the most favorable sorbent for modification of the bed construction with glue.

The calcium looping (CaL) process usually employs a dual-fluidized bed (DFB) solid circulating unit. In the regenerator (calcinator or calciner), decomposition of CaCO3 proceeds. To supply the heat of decomposition, oxyfuel combustion of coal is conducted. However, since coal contains nitrogen, the NOx formation occurs during oxyfuel combustion. Because of the fact that NOx formation and destruction during combustion of solid fuels in a fluidized bed is a complex process, a predictive approach of NOx emissions has not yet been sufficiently recognized, especially during oxyfuel combustion conditions in the CaL systems. The paper introduces a regression-based method for the prediction of NOx emissions from a CaL DFB experimental unit. Effects of fuel type, excess oxygen feed, and NO addition to primary or secondary feed gas on NOx emissions in the regenerator were evaluated. The presented way constitutes a straightforward method to run a complementary technique in relation to other methods of data handling,...

Adsorption cycles have a distinct advantage over other systems in the ability to use low grade heat, especially waste heat of near ambient temperature. A Tri-bed twin-evaporator adsorption chiller constitute an innovative design in cooling production which allows more efficient conversion and management of low grade sources of thermal energy due to more effective way of utilization adsorptive abilities of the beds during a single work. Although it is the most effective way in chilled water production the complexity of the Tri-bed twin-evaporator adsorption chiller operation is still not sufficiently recognized and the improvement in cooling capacity (CC) of the cooler is still a challenging task. The paper introduces artificial intelligence approach for the optimization study of a Tri-bed twin-evaporator adsorption chiller using low-temperature heat from cogeneration. Genetic algorithms (GA) and artificial neural networks (ANN) are used to develop the model which allows estimating the behaviour of the adsorption heat pump. Cooling capacity (CC) as one of the main energy efficiency factor in cooling production is examined during the study for different operating sceneries. The presented non-iterative approach gives quick and accurate results as an answer to the input data sets. The CC of the chiller, evaluated using the developed model, is in good agreement with the experimental data. Maximum relative error between measured and calculated data is lower than ±10%. The developed model permits to study the influence of operating parameters on the cooling capacity of the chiller. For the considered range of input parameters the highest cooling capacity which can be obtained by the heat pump is equal 93.3 kW. The method constitutes an alternative, easy-to-apply and useful, complementary technique, comparing to the other techniques of data handling, including the complex of numerical and analytical methods as well as high costs of empirical experiments. The model can be applied for optimizations purposes and can constitute a sub model or a separate module in engineering calculations, capable to predict the CC of the Tri-bed twin-evaporator adsorption cooler, integrated into multigenerative systems.

The progress in environmental investigations such as the analysis of building arrangements in an urban environment could not have been expanded without the use of computational fluid dynamics (CFD) as a research tool. The rapid development of numerical models results in improved correlations to results obtained with real data. Unfortunately, the computational domain discretization is a crucial step in CFD analysis which significantly influences the accuracy of the generated results. Hence an innovative approach to computational domain discretization using polyhedral elements is proposed. The results are compared to commonly applied tetrahedral and hexahedral elements as well as experimental results of particle image velocimetry (PIV). The performed research proves that the proposed method is promising as it allows for the reduction of both the numerical diffusion of the mesh as well as the time cost of preparing the model for calculation. In consequence, the presented approach allows for better results in less time.

More efficient use of the primary energy contained in fuels translates into tangible earnings for power plants while reductions in the amounts of fuel burned, and of non-renewable resources in particular, certainly have a favourable impact on the natural environment. The main aim of the paper is to investigate the contribution of theuse of adsorption chillers to improve the production energy efficiencyin combined cycle gas turbine. Simulation calculations were performed using Sim tech's IPSEPro software.

According to predictions, electricity consumption in developed countries will increase three times by 2020 compared with 1970. In contrast, in developing countries, where the population may double by 2020 relative to 1970, there may even be a twentyfold increase in electricity consumption [1]. Other sources predict that increases in electricity demand by 2030 will be approx. 2 ÷ 3% a year. With such a high rate of development of the world economy, the electricity demand will be increasing. Thus, using only renewable sources to satisfy the demand for energy is insufficient and will remain so in the near future. Coal will remain the predominant fuel used to produce electricity. One of the ways to reduce the adverse effect of fossil fuels on the natural environment is to increase the efficiency of use of primary energy. Electricity production is associated with large losses, including in the form of heat which can be used to produce cold with adsorption chillers that can be powered by low-temperature heat. The paper presents the possibility to employ adsorption chillers in power units in order to increase the efficiency of electricity production. Simulation calculations were performed using Sim tech’s IPSEPro software.

AIMS The aim of this study was to isolate and identify potentially pathogenic strains of Yersinia enterocolitica in water samples collected from the upstream section of the Drweca River in Poland. METHODS AND RESULTS Thirty-nine water samples were collected. Strains were isolated, identified with the use of the API(®) 20E test kit (Biomerieux, Marcy l'Etoile, France) at 37°C, serotyped and subjected to a molecular analysis. Multiplex PCR was carried out to amplify three virulence genes: ail, ystA and ystB. Fragments of ail and ystA genes were not identified in the genetic material of the analysed strains. The ystB gene was identified in four strains. Yersinia enterocolitica strains of biotype 1A, which contain the ystB gene, may cause gastrointestinal problems. CONCLUSIONS In our study, Y. enterocolitica strains of biotype 1A/ystB with serotypes 0 : 3, 0 : 5 and 0 : 8 were identified in samples collected from the Drweca River which flows through the areas protected by Natura 2000, one of the largest networks of nature conservation areas in the European Union. The presence of Y. enterocolitica in the Drweca River indicates that the analysed bacteria colonize natural water bodies. SIGNIFICANCE AND IMPACT OF THE STUDY Most research focuses on food or sewage as a source of Y. enterocolitica infections. Little is known about the occurrence of this pathogen in natural waters. Our results show that natural waters are also a potential threat to human and animal health.

Forecasts to 2030 indicate that demand for electricity will increase from 2% to 3% per year, and due to the observed high rate of development of the world economy, energy demand will continue to increase. More efficient use of primary energy has influence on reduction emissions and consumption of fuel. Besides, reducing the amount of fuel burned, it reveals a beneficial effect on the environment. Since extraction-back pressure turbines have some limitations, including the restriction of electricity production due to limited heat consumption in summer. The paper discusses the possibilities of integrating the adsorption aggregate with a combined cycle gas turbine and its impact on the operation of all devices. Simulations are performed on Sim tech IPSEPro software. The obtained results confirm that the adsorption aggregate, using a low grade of thermal energy, does not affect the operation of the gas and steam cycle and allows the production of electricity at a constant level. The calculated chemical fuel energy utilisation factor was 85.7% in cogeneration and 75.6% in trigeneration. These factors indicated a reduced utilisation of chemical fuel energy; however, this reduction is caused by a lower COP for adsorption chillers. Besides, the adsorption aggregate additionally generates chilled water for air conditioning or other technological processes, which stands for an added value of the innovative concept proposed in the paper.

Worldwide tendencies in the scope of environmental protection demonstrate the requirement for the limited carbon dioxide emission, that influences on the development of greenhouse effect. As a result of coal as a basic fuel used in the professional power industry, this industry sector is the greatest CO2 polluter and it means that works on the reduction of carbon dioxide in such industry are completely justified. In the IPSEpro programming environment, a reference block model for a conventional coal power station was elaborated, including the CO2 separation unit basing on the adsorption methods with the CO2 preparation installation to liquid state. Simulation researches were conducted with means of numeric techniques, that enabled the system analysis for the CO2 separation unit with the CO2 preparation system to the liquid state, as well as analysis was made for the use of chiller systems, basing on the adsorption technology for waste heat use originating from the compression of CO2 in a cascade system, as well as for potential opportunities for further exploitation of the produced chilled water in the CCS cycle. We analysed in these papers the opportunities for chiller systems application, based on the adsorption chillers in the CCS installation used for the reduction of CO2 emission in the coal power station and its influence on the operation of a power station cycle.

A distinct advantage of adsorption chillers is their ability to be driven by heat of near ambient temperature. However the performance of the thermally driven adsorption systems is lower than that of other heat driven heating/cooling systems. It is the result of a poor heat transfer coefficient between the bed and the immersed heating surfaces of a built-in heat exchanger system. The aim of this work is to study the effect of thermal conductance values as well as other design parameters on the performance of a re-heat two-stage adsorption chiller. One of the main energy efficiency factors in cooling production, i.e. cooling capacity (CC) for wide-range of both design and operating parameters is analyzed in the paper. Moreover, the work introduces artificial intelligence (AI) approach for the optimization study of the adsorption cooler. The Adaptive Neuro – Fuzzy Inference System (ANFIS) was employed in the work. The developed ANFIS model can be applied for optimizations purposes and may constitute a submodel or a separate module in engineering calculations, capable to predict the CC of the re-heat two-stage adsorption chiller.

Adsorption heat pumps are becoming increasingly popular. Due to their design, they enable application of low-temperature heat sources. Evaporators for adsorption chillers make one of the basic design elements determining the correct operation of these devices. The specificity of operation in low pressures and temperatures is the reason why their design significantly differs from that of conventional evaporators. The pluralities of existing solutions as well as the lack of a systematic review of them cause difficulties in correct evaluation and choice of design. The paper presents the current state of art as well as a review of the existing solutions of evaporators used in adsorption heat pumps. The purpose of the review research is to present various solutions of evaporators as well as indicating their advantages and disadvantages in order facilitate the choice of the optimal design.

Long-term forecasts indicate that the annual increases in electricity demand by 2030 will be approx. 2 ÷ 3% a year. At present, 40% of the world's electricity is produced using coal-fired power plants. Forecasts indicate that coal will still be the predominant fuel used to produce electricity and thus any actions aimed at increasing the efficiency of electricity production are purposeful. Enormous amounts of waste heat, which is not sufficiently used, are released during the process of electricity production. One of the ways to manage it is to use refrigeration systems based on adsorption chillers which would use waste heat to generate cold that would be employed for air-conditioning or process purposes. In this paper, the cycle of a conventional coal-fired power plant was modelled and then the possibilities of using waste heat for generation of cold as well as the impact of a chiller on the operation of a power unit were analysed using IPSEpro software.

The simultaneous production of electricity, heat and cooling, the so-called trigeneration, allows for substantial savings in the chemical energy of fuels. More efficient use of the primary energy contained in fuels translates into tangible earnings for power plants while reductions in the amounts of fuel burned, and of non-renewable resources in particular, certainly have a favourable impact on the natural environment. The main aim of the above-described project was to analyse the influence of use adsorption contacted to conventional CHP power plant. An adsorption chiller is an item of industrial equipment that is driven by low grade heat and intended to produce chilled water and desalinated water. Adsorption chillers ACH can by used for utilization heat from many industrial process where temperature medium is too low for use absorption chillers. In this article modelled the cycle of a conventional heat power plant integrated with an adsorption chiller-based plant. Multi-variant simulation calculations were performed using IPSEpro simulation software.