No abstract

Latent heat thermal energy storage is an attractive technique as it can provide higher energy storage density than conventional heat energy storage systems and has the capability to store heat of fusion at a constant (or a near constant) temperature corresponding to the phase transition temperature of the phase change material (PCM). This paper provides a state-of-theart review on phase change materials (PCMs) and their applications for heating, cooling and electricity generation according to their working temperature ranges from (-20℃ to +200℃). Four working temperature ranges are considered in this review: 1) the low temperature range from (-20℃ to +5℃) where the PCMs are typically used for domestic and commercial refrigeration; 2) the medium low temperature range from (+5℃ to +40℃) where the PCMs are typically applied for heating and cooling applications in buildings; 3) the medium temperature range for solar based heating, hot water and electronic applications from (+40℃ to +80℃); and 4) the high temperature range from (+80℃ to +200℃) for absorption cooling, waste heat recovery and electricity generation. Different types of phase change materials applied to each temperature range are reviewed and discussed, in terms of the performance, heat transfer enhancement technique, environmental impact and economic analysis. The review shows that, energy saving of up to 12% can be achieved and a reduction of cooling load of up to 80% can be obtained by PCMs in the low to medium-low temperature range. PCM storage for heating applications can improve operation efficiency from 26% to 66%, depending on specific applications. Solar thermal direct steam generation (DSG) is the most common electricity generation application coupled with PCM storage systems in the high temperature range, due to the capability of PCMs to store and deliver energy at a given constant temperature. The recommendations for future research are also presented which provide insights about where the current research is heading and highlights the challenges that remain to be resolved.

Research activity in the field of air pollution forecasting using artificial neural networks (ANNs) has increased dramatically in recent years. However, the development of ANN models entails levels of uncertainty given the black-box nature of ANNs. In this paper, a protocol by Maier et al. (2010) for ANN model development is presented and applied to assess journal papers dealing with air pollution forecasting using ANN models. The majority of the reviewed works are aimed at the long-term forecasting of outdoor PM10, PM2.5, and oxides of nitrogen, and ozone. The vast majority of the identified works utilised meteorological and source emissions predictors almost exclusively. Furthermore, ad-hoc approaches are found to be predominantly used for determining optimal model predictors, appropriate data subsets and the optimal model structure. Multilayer perceptron and ensemble-type models are predominantly implemented. Overall, the findings highlight the need for developing systematic protocols for developing powerful ANN models.

No abstract

configuration. In order to examine the performance quantitatively, the indoor airflow rate, supply and extract rates, external airflow and pressure coefficients were also measured. The CFD simulations were generally in good agreement (0 -20 %) with the wind tunnel measurements. Moreover, the smoke visualisation test showed the capability of CFD in replicating the air flow distribution inside the wind tower and also the test room.

Hot fusion is currently a difficult goal to accomplish due to the high temperatures required, which are difficult to achieve and also to be maintained. For these reason, it is much easier to try to achieve cold fusion, or a combined method. In this paper, the author will briefly present some original relationships for setting up a theoretical model for cold fusion. It will be determined the radius of a moving elementary particle and will be calculated the potential energy of the two adjacent particles. In addition, the necessary speed of the accelerated particles when they will collide to start cold fusion will be determined. The radius of an electron or a nucleus at rest is close to nano sizes. Because of this, static, the fusion working with nanoparticles. It was evaluated that dynamic nanoparticles dimensions are much smaller than when they are at rest.

No abstract

With the developments in virtual reality technologies, significant researches have been conducted for human response on indoor luminous environment using head-mounted display to replace those in real environment. However, the limited resolution and luminance values offered by the devices might affect the perceived appearance and high-order impressions in the simulated virtual environment. In this study, a simulated 3-dimensional virtual office was compared against a real one. Both settings presented similar physical and luminous conditions to twenty participants (N=20). The study investigated subjective and objective visual responses and participants' interaction with the virtual environment based on measurements of perceived presence. Subjective assessments included questions on luminous environment appearance (brightness, colour-temperature, distribution) and high-order perceptions (pleasantness, interest, spaciousness, excitement and complexity). Objective assessments measured contrastsensitivity and colour-discrimination tasks to assess visual performance across the two representation environments. Results showed no significant differences between the two environments based on the studied parameters, indicating a high level of perceptual accuracy of appearance and high-order perceptions. Minor physical symptoms related to the headset 2 use and high level of perceived presence were found, indicating the proposed methodology's capability to provide realistic immersive environments. Although attributes regarding scene quality: colours, details, and contrast were perceived significantly different to the real environment, objective tasks showed that similar contrast and colour appearance can be produced in the virtual environment with minor impact on fine-details due to limited resolution.Virtual reality maybe a promising alternative representation medium to investigate visual perceptions as the overall appearance of the scene can still be correctly acquired.