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Esta resenha analisa a obra de Daniel Gade Curiosity, Inquiry and the Geographical Imagination (2011). Esta obra, de profunda importância para Geógrafos e pesquisadores, aborda a questão da curiosidade e da investigação na imaginação geográfica. O autor utiliza-se de exemplos históricos de trajetórias profissionais e de pesquisa de geógrafos importantes e realiza um comparativo com as teorias da psicanálise e da filosofia.

Traditionally, the embodied energy of design choices which reduce operational energy were assumed to have a negligible impact on the life cycle energy of buildings. However with new buildings having considerably lower operational energy, the significance of embodied energy increases. A life cycle assessment of a population of house designs was conducted in a mild and mixed climate zone. It was determined not only that embodied energy dominates life cycle energy, but that the impact on embodied of design choices was of equal significance to the impact on operational energy., {"references":["Menoufi, K., et al., Evaluation of the environmental impact of\nexperimental cubicles using Life Cycle Assessment: A highlight on the\nmanufacturing phase. Applied Energy, 2012. 92: p. 534-544.","Pacheco, R., J. Ordóñez, and G. Martínez, Energy efficient design of\nbuilding: A review. Renewable and Sustainable Energy Reviews, 2012.\n16(6): p. 3559-3573.","Zhu, L., Hurt, R., Correia, D., Boehm, R., Detailed energy saving\nperformance analyses on thermal mass walls demonstrated in a zero\nenergy house. Energy and Buildings, 2009. 41(3): p. 303-310.","Cellura, M., Guarino, F., Longo, S., Mistretta, M., Energy life-cycle\napproach in net zero energy buildings balance: Operation and embodied\nenergy of an Italian case study. Energy and Buildings, 2014. 72(0): p.\n371-381.","Thormark, C., A low energy building in a life cycle—its embodied\nenergy, energy need for operation and recycling potential. Building and\nEnvironment, 2002. 37(4): p. 429-435.","Karimpour, M., Belusko, M., Xing, K., Bruno, F., Minimising the life\ncycle energy of buildings: Review and analysis. Building and\nEnvironment, 2014. 73(0): p. 106-114.","Treloar, G., Fay, R., Ilozor, B., Love, P., Building materials selection:\ngreenhouse strategies for built facilities. Facilities, 2001. 19(3/4): p. 139-\n150.","Saman, W., Whaley, D., Mudge, L.,Halawa, E. ,Edwards, J. , The\nintelligent grid in a new housing development in Project P6, F. Report,\nEditor 2011, CSIRO Intelligent Grid Research Cluster, University of\nSouth Australia.","Hammond, G.P. and C.I. Jones, Inventory of carbon and energy(ICE),\n2008, Sustainable Energy Research Team(SERT),Department of\nMechanical Engineering, Univeristy of Bath,UK: Bath."]}

Climate change is leading to an increased frequency and severity of heat waves. Spells of several consecutive days of unusually high temperatures have led to increased mortality rates for the more vulnerable in the community. The problem is compounded by the escalating energy costs and increasing peak electrical demand as people become more reliant on air conditioning. Domestic air conditioning is the primary determinant of peak power demand which has been a major driver of higher electricity costs. This report presents the findings of multidisciplinary research which develops a national framework to evaluate the potential impacts of heat waves. It presents a technical, social and economic approach to adapt Australian residential buildings to ameliorate the impact of heat waves in the community and reduce the risk of its adverse outcomes. Through the development of a methodology for estimating the impact of global warming on key weather parameters in 2030 and 2050, it is possible to re-evaluate the size and anticipated energy consumption of air conditioners in future years for various climate zones in Australia. Over the coming decades it is likely that mainland Australia will require more cooling than heating. While in some parts the total electricity usage for heating and cooling may remain unchanged, there is an overall significant increase in peak electricity demand, likely to further drive electricity prices. Through monitoring groups of households in South Australia, New South Wales and Queensland, the impact of heat waves on both thermal comfort sensation and energy consumption for air conditioning has been evaluated. The results show that households are likely to be able to tolerate slightly increased temperature levels indoors during periods of high outside temperatures. The research identified that household electricity costs are likely to rise above what is currently projected due to the impact of climate change. Through a number of regulatory changes to both household design and air conditioners, this impact can be minimised. A number of proposed retrofit and design measures are provided, which can readily reduce electricity usage for cooling at minimal cost to the household. Using a number of social research instruments, it is evident that households are willing to change behaviour rather than to spend money. Those on lower income and elderly individuals are the least able to afford the use of air conditioning and should be a priority for interventions and assistance. Increasing community awareness of cost effective strategies to manage comfort and health during heat waves is a high priority recommended action. Overall, the research showed that a combined approach including behaviour change, dwelling modification and improved air conditioner selection can readily adapt Australian households to the impact of heat waves, reducing the risk of heat related deaths and household energy costs.

Refereed/Peer-reviewed Geopolymerreferstoalargegroupofnanoporous,nanoparticulatematerialsthatare synthesized by dissolution and polycondensation of aluminosilicates in basic solutions and can be made from a variety of starting materials, such as industrial waste ash, volcanic rock, or calcined clay. Geopolymers are X-ray amorphous, corrosion resistant, refractory, and made at ambient temperature and pressure similar to cements. In this study, potassium metakaolin-based geopolymer(KGP)composites containing alumina platelets and glass frit were fabricated, and the impact of heating temperature, dwell time, and heating/cooling rate on the microstructure was studied. The composites, heat treated up to 900◦C for up to20 h using heating/cooling rates of up to 1◦C/min, showed that the addition of alumina platelets prevented major microcracking and was also able to reduce linear shrinkage. Glass frit has been shown to heal microcracks formed during KGP dehydration and crystallization. The resulting material had an open porosity of less than 1% and a uniform surface glaze of 250μm thickness, while Oswald ripening of round closed pores occurred due to the migration of molten glass in the system.

Refereed/Peer-reviewed To achieve carbon neutrality there must be a significant increase in the proportion of renewable generation. Energy storage and demand flexibility will accommodate more solar and wind generation. Some energy markets in Australia, northern Europe and the USA have moved or are moving to a 5-min settlement period to increase energy flexibility. Commercial building's HVAC systems could capitalise on new market conditions through 5-min load shifting strategies that have negligible impact on occupant comfort. Here the effectiveness HVAC load shifting strategies for cost arbitrage in 5-min wholesale electrical energy markets are examined. Five strategies are compared using global zone setpoint adjustment and chilled water leaving setpoint adjustment. Results show significant energy flexibility can be achieved without violating occupant comfort. High priced 5-min settlement periods can be successfully coasted over with no HVAC energy consumption for temperatures under 36 °C. Over a 10 week period the case study achieved 14.2% energy cost savings.

Refereed/Peer-reviewed In this review article, waste materials (biogenic/non-biogenic) are focused as the flocculants for harvesting of algal biomass. Chemical flocculants are widely utilized for the effective harvesting of algal biomass at a commercial scale while the high cost is a major drawback. The waste materials-based flocculants (WMBF) are started to utilize as one of the cost-effective performance for dual benefits of waste minimization and reuse for sustainable recovery of biomass. The novelty of the article is articulated with the objective that presents an insight of WMBF, classification of WMBF, preparation methods of WMBF, mechanisms of flocculation, factors affecting flocculation-mechanism, challenges and future recommendations that are required for harvesting of algae. The WMBF are shown similar flocculation mechanisms and flocculation efficiencies as chemical flocculants. Thus, the utilization of waste material for the flocculation process of algal cells minimizes the waste load into the environment and transforms the waste materials into valuable resources.

Geopolymers (GP) are a class of X-ray amorphous, nanoporous, nanoparticulate materials that can be mixed, poured, and cured under ambient conditions. Typically, geopolymers are made using a Group 1 (G1) alkali activator such as sodium or potassium metasilicate and an aluminosilicate precursor. An analogous material to GPs is ordinary Portland cement because of the similarities in processing, however, the resulting microstructure is more similar to that of a glass. Geopolymers are more thermally stable than OPC and can therefore be used in a variety of thermal energy storage systems, as energy storage is an increasing global concern. In this study, potassium metakaolin-based geopolymer composites containing glass particles and alumina platelets were manufactured, heated in air, and exposed to molten sodium chloride or potassium chloride under an air atmosphere. Results showed the formation of an amorphous self-healing geopolymer composite (ASH-G) that could contain molten G1 chlorides for over 200 h without signs of macro or microscopic chemical degradation. The filling of cracks by glass particles in the composite after heating to 850 degrees C makes this material self-healing. It was found that the morphology of ASH-G composites was more affected by temperature and duration than contact with corrosive molten chlorides in air. Future works include investigating the effect of molten salt on mechanical properties during initial heating, after prolonged heating, and the material compatibility with other molten Group 1 chloride eutectics. Refereed/Peer-reviewed

The use of metallic periodic structures was considered for melting rate enhancement of a phase change material (PCM) contained in a rectangular enclosure isothermally heated from the side. The critical (optimized) cell size, or pore size, of a periodic structure with fixed porosity, realising the shortest melting time by maximizing the convection and conduction heat transfer rate into the PCM, was studied. Furthermore, the effects of material properties (copper, aluminium, nickel, and stainless steel), enclosure length, wall-melting temperature difference and porosity were numerically investigated. It was observed that increasing porosity and/or reducing thermal conductivity enlarged the critical cell size (i.e. the optimal cell size that minimizes the melting time). The critical PPIs (pores per inch) of copper and aluminium periodic structures for all studied porosities were 10; for nickel, the critical values were 10 PPIs for porosity values of 0.75, 0.8 and 0.85 while it reduces to 5 PPI for the highest porosity considered here being 0.95. Interestingly, showing a different trend, the critical PPI of stainless-steel structures was 5 for the lowest porosity (0.75) and reduced to 3 for higher porosities. The results clearly demonstrated localised melting which was observed in all periodic structures except for the 10 PPI stainless-steel case. Scattered melting islands are observed as opposed to a moving interface when ϕ=(dp/L)αligament/αPCM>1. For such cases, localized melting occurs and the PCM is melted at the ligaments away from the heated wall before the melt front reaches those ligaments.

The study reveals the effect of interstage pressure with the consideration of gas cooler outlet temperature on the cooling performance of an operating CO2 heat pump system currently in use at a dairy plant. Based on the numerical model and CO2 properties, it was found that the maximum mass fraction of liquid allocated for cooling can be achieved in the middle of the operating range of interstage pressure when the enthalpy at the location of the gas cooler outlet is between 341 kJ/kg. K and 399 kJ/kg. K (that is, the gas cooler outlet temperature is between 37.34 °C and 43.02 °C with a fixed discharge pressure of 85 bar), however, the maximum liquid fraction can be achieved at the upper limit of the pressure when the enthalpy is less than 341 kJ/kg. K and can be achieved at the lower limit of the pressure when the enthalpy is higher than 399 kJ/kg. K, respectively. In the comparative study on fixed and variable interstage pressure, it was found that there is small difference in cooling COP when the gas cooler outlet temperature is lower than 38.5 °C , while the COPs with variable interstage pressures surpass those with fixed pressures when the gas cooler outlet temperatures are even higher.

This study established a methodology for designing a cascade latent heat thermal energy storage system. The latent heat thermal energy storage has been investigated by numerous researchers as an energy-dense and lower cost alternative to the two-tank molten salt sensible heat thermal energy storage for concentrated solar power plants. However, in order to achieve a high storage efficiency without decreasing the efficiency of the receiver and power block, many design restrictions should be applied in the design, including the total storage capacity, charging/discharging rate, charging/discharging period and the temperature difference of heat transfer fluid between the inlet and outlet of the storage system for both the charging and discharging process. There is no methodology or guideline currently available in the literature to design such a storage system. Therefore, a new methodology has been proposed, and it was successfully demonstrated in a case study. To achieve the final design, three major steps are involved: preliminary design, coarse optimization and fine optimization. Though intensive simulation is needed, the proposed methodology is appropriate to design the cascade latent heat thermal energy storage system Refereed/Peer-reviewed

The next generation of concentrated solar power plants will need to operate at higher temperatures (> 700°C) so that better efficiencies and lower costs can be achieved. One such design that may be able to achieve this is with sodium as the heat transfer fluid (HTF) and phase change materials (PCMs) as the storage medium. To ensure safe design it is imperative that the consequences of failure are known. Therefore, in the current study, the failure of such a system is investigated by mixing molten PCM into liquid sodium using a custom-built rig. Using this rig, it was possible to introduce molten PCM (Na2CO3−K2CO3) into sodium at 750°C and view the interaction. When combined, it was found that no violent reaction was observed, indicating that a failure in the storage system would not cause detrimental failure if the PCM was to mix with the sodium. Furthermore, the decomposition of the PCM releasing CO2 (potentially reactive with sodium) was studied Refereed/Peer-reviewed

A ternary molten chloride has been suggested as a high temperature (550-720 °C) sensible heat storage medium for a two-tank system. An effective thermal insulation is proposed to provide an opportunity for the fabrication of both the hot and cold storage tanks from lower cost metals, e.g. A240-347H, by maintaining the tank wall below 500 °C. To achieve this, the hot storage tank mainly comprises of inner shell (11.4 cm of a refractory brick as liner (KX-99®), 30 cm of insulation brick) and outer metal shell, where 5 cm of frozen layer of PCM800 (NaCl), and 5 cm of ceramic wool fill the annular space between the shells. Another layer of ceramic wool was introduced at the outer side of the metal shell to keep the temperature lower than 60 °C. ANSYS Fluent was used for the numerical study of the cool down behavior of the system during idle period when tank is quarter-filled. The heat transfer modes were considered as radiation and natural convection heat transfer from the hot molten salt at 720 °C, conduction through the solid layers and convection heat transfer from the outer shell to the environment at 15 °C. The results showed that the proposed insulation system including a frozen layer of PCM800 maintains the temperature at the metal wall lower than 500 °C, and lower than 60°C at the outer side of the tank. Apart from the insulation property of the frozen layer of PCM800, it absorbs any leak of hot molten salt, acting as a barrier between salt and the metal shell. The thermal performance analysis provide an insight into the benefits of the multilayer insulation. Refereed/Peer-reviewed

In the current study a novel geopolymer created from waste materials (namely fly ash and black slag) has been characterised as a potential high temperature thermal energy storage material option. Several geopolymer samples have been fabricated and characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Additionally, the density and heat capacity have been determined. Lastly, the cost of the material and packed bed system was estimated showing that the geopolymer-based systems are potentially 35% cheaper than the traditional 2-tank molten salt systems. This research was performed as part of the Australian Solar Thermal Research Institute (ASTRI), a project supported by the Australian Government, through the Australian Renewable Energy Agency (ARENA). The work was partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER)). The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). GREA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. This project has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under Grant agreement Nº PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES). Aran Solé would like to thank Ministerio de Economía y Competitividad de España for Grant Juan de la Cierva, FJCI-2015-25741. The authors would also like to acknowldege the Diopma group from the University of Barcelona thanks the funding by the Spanish Government (RTI2018-093849-B-C32), and the Catalan Government for the quality accreditation (2017 SGR 118).

Latent heat thermal energy storage systems working at higher temperatures around 800 °C are considered as a promising alternative in conjunction with the sCO2 Brayton cycle for the next generation of concentrating solar power plants. At higher temperatures, a detailed thermo-mechanical analysis of the system is crucial, particularly during a melting/charging process with a high temperature difference (50-100 K) between the solid phase change material (PCM) and heat transfer fluid. Here, the melt path formation of a high temperature PCM in a horizontal shell and tube system is investigated. Three different levels of modelling were conducted. The results of the study showed that the melted PCM around the tubes connect and form a path after about 50 seconds, which provides a way for the high temperature PCM to flow through. This imposes a temperature gradient along the tubes preventing a localised hot spot and high thermal stresses. Refereed/Peer-reviewed

For design and optimization purposes, understanding the performance characteristics of different configurations of PCM systems during charging and discharging processes is crucial, particularly for thermal storage in CSP. A numerical study using FLUENT has been performed to explore and compare the characteristics and behavior of PCM in different shell and tube configurations; namely counter flow and parallel flow in vertical and horizontal orientations. These designs have been compared with that of an alternative design using plate fins. The main practical advantage of the alternative design is decoupling the PCM location from the path of flow of the heat transfer fluid that reduces the constraints on the materials. Confined heating/cooling pipes in a channel at the bottom of the PCM enclosure makes it more flexible to match the required working pressures, and simplifies the design and material (PCM/plate) selection. This is a significant issue as higher temperatures and pressures are being required for improving the overall solar thermal system performance. Based on the same heat transfer area, amount of PCM and input energy, a performance comparison was determined based on exergy maximization. Using sodium nitrate as the PCM, the results show a higher heat transfer rate for the vertical arrangement of plate fins compared to the counter flow shell and tube configurations, as well as a more uniform heat transfer rate compared to all shell and tube arrangements for both the charging and discharging processes. The proposed design leads to less redundant PCM, as well as a smaller and more cost effective PCM system as a heat storage unit. Overall, the vertical plate fin configuration maximizes the useful heat that can be extracted for a given amount of heat and PCM, which has direct applicability to thermal storage solutions for CSP and other applications. Moreover, its modular design facilitates the selection and optimisation for different scales and applications e.g. as a heat storage for electricity production or as a protection system for a receiver from high thermal stresses in a CSP plant. Refereed/Peer-reviewed