Global natural resources are affected by several causes such as climate change effects or unsustainable management strategies. Indeed, the use of water has been intensified in urban buildings because proliferation HVAC (Heating, Ventilating and Air Conditioning) systems, for instance cooling towers, where an abundant amount is lost during evaporation process. The measurement challenging, so a v...

The influence of annealing time on temperature range of martensitic phase transition (ΔT(A-M)), thermal hysteresis (ΔThys), magnetic hysteresis loss (ΔMhys), magnetic entropy change (ΔS(M)) and relative refrigeration capacity (RC) of the Mn-rich Ni43Mn46Sn11 melt spun ribbons have been systematically studied. By optimal annealing, an extremely large ΔS(M) of 43.2 J.kg(-1)K(-1) and a maximum RC ...

Glass-forming ability GFA as defined by a critical cooling rate Rc to vitrify a liquid upon solidification is a complex function of many parameters. Some of the parameters, such as liquid-crystal interfacial energy, temperature-dependent liquid viscosity, and influence of heterogeneities, are crucial but their accurate experimental determination is challenging. Here, instead of relying on the e...

Cooling towers provide an ideal environment for microbial growth and have been attributed as a source for accumulation and dissemination of pathogenic organisms, especially Legionella pneumophila [1,2]. Since Legionella infections have frequently been traced to contaminated aerosols generated at distances over 6 km, cooling systems have a potential risk for public health. Inhalation of Legionel...

Our survey of cooling tower water demonstrated that the highest density of legionellae, >/=10 CFU/100 ml, appeared in water containing protozoa, >/=10 MPN/100 ml, and heterotrophic bacteria, >/=10 CFU/100 ml, at water temperatures between 25 and 35 degrees C. Viable counts of legionellae were detected even in the winter samples, and propagation, up to 10 CFU/100 ml, occurs in summer. The counts...

In June and July 2008, two office workers were admitted to a Dublin hospital with Legionnaires' disease. Investigations showed that cooling towers in the basement car park were the most likely source of infection. However, positive results from cooling tower samples by polymerase chain reaction (PCR) did not correlate with subsequent culture results. Also, many employees reported Pontiac fever-...

This paper presents an engineering application of optimization method for energy conservation in condenser water loop operation in HVAC (Heating, Ventilation and Air Conditioning) systems. Based on the analysis of component model characteristics and interactions within the cooling tower and between towers and chillers, an objective function, which minimizes the operating costs through optimal s...

In the paper a detailed analysis of the dynamic response of a cooling tower shell to mining tremors originated from two main regions of mining activity in Poland (Upper Silesian Coal Basin and Legnica-Glogow Copper District) was presented. The representative time histories registered in the both regions were used as ground motion data in calculations of the dynamic response of the structure. It...

The control logic of frequency adjustment for pump and cooling tower fan has been presented in this paper, based on the operation mode of a chiller with one pump and one cooling tower. Optimum outlet water temperature control of cooing tower has been put forward through analysis and comparison among factors influencing it based on measured data. A mathematical model of energy consumption has be...

6.5 kV level IGBT (Insulated Gate Bipolar Transistor) modules are widely applied in megawatt locomotive (MCUs) traction converters, to achieve an upper 3.5 kV DC link, which is beneficial for decreasing power losses and increasing the power density. Reverse Conducting IGBT (RC-IGBT) constructs the conventional IGBT function and freewheel diode function in a single chip, which has a greater flow...