Cool roofs for passive cooling: performance in different climates and for different insulation levels in Italy

Roofs are severely hit by solar radiation in summer; hence the use of cool materials on the finishing layer provides a significant reduction in the heat flow entering the building, with sensible attenuation in the building cooling load. In this paper, a case study is presented, based on the dynamic simulation of an existing office building in Catania (southern Italy). Here, a part of the roof has been recently treated with a commercial cool paint, with the aim of improving thermal comfort in summer. Hence, the simulations represent a preliminary study that will allow assessing the expected effectiveness of the intervention. More in detail, the results of the simulations will be discussed in terms of both thermal comfort and energy savings, through the evaluation of parameters such as the roof surface temperature, the operative temperature and the cooling load for both conditions, i.e. with and without the cool paint. The paper also discusses the potential increase in the energy needs for winter heating, and looks at the overall annual balance in terms of primary energy; this is made by considering different climatic conditions and envelope characteristics. These aspects are usually not well highlighted in the current scientific literature.

Thermal and visual performance of real and theoretical thermochromic glazing solutions for office buildings

Thermochromic windows are able to modulate their transmittance in both the visible and the near-infrared field as a function of their temperature. As a consequence, they allow to control the solar gains in summer, thus reducing the energy needs for space cooling. However, they may also yield a reduction in the daylight availability, which results in the energy consumption for indoor artificial lighting being increased. This paper investigates, by means of dynamic simulations, the application of thermochromic windows to an existing office building in terms of energy savings on an annual basis, while also focusing on the effects in terms of daylighting and thermal comfort. In particular, due attention is paid to daylight availability, described through illuminance maps and by the calculation of the daylight factor, which in several countries is subject thresholds. The study considers both a commercially available thermochromic pane and a series of theoretical thermochromic glazing. The expected performance is compared to static clear and reflective insulating glass units. The simulations are repeated in different climatic conditions, showing that the overall energy savings compared to clear glazing can range from around 5% for cold climates to around 20% in warm climates, while not compromising daylight availability. Moreover the role played by the transition temperature of the pane is examined, pointing out an optimal transition temperatures that is irrespective of the climatic conditions.

Cool Roofs for improving thermal performance of EU office buildings: an investigation for different climates and building layouts

Cool materials are characterized by having a high solar reflectance r – which is able to reduce heat gains during daytime - and a high thermal emissivity ε that enables them to dissipate the heat absorbed throughout the day during night. Despite the concept of cool roofs - i.e. the application of cool materials to roof surfaces - is well known in US since 1990s, many studies focused on their performance in both residential and commercial sectors under various climatic conditions for US countries, while only a few case studies are analyzed in EU countries. The present work aims at analyzing the thermal benefits due to their application to existing office buildings located in EU countries. Indeed, due to their weight in the existing buildings stock, as well as the very low rate of new buildings construction, the retrofit of office buildings is a topic of great concern worldwide. After an in-depth characterization of the existing buildings stock in the EU, the book gives an insight into roof energy balance due to different technological solutions, showing in which cases and to what extent cool roofs are preferable. A detailed description of the physical properties of cool materials and their availability on the market provides a solid background for the parametric analysis carried out by means of detailed numerical models that aims at evaluating cool roofs performance for various climates and office buildings configurations. With the help of dynamic simulations, the thermal behavior of representative office buildings of the existing EU buildings stock is assessed in terms of thermal comfort and energy needs for air conditioning. The results, which consider several variations of building features that may affect the resulting energy balance, show how cool roofs are an effective strategy for reducing overheating occurrences and thus improving thermal comfort in any climate. On the other hand, potential heating penalties due to a reduction in the incoming heat fluxes through the roof are taken into account, as well as the aging process of cool materials. Finally, an economic analysis of the best performing models shows the boundaries for their economic convenience.

Steel Sheet Applications and Integrated Heat Management

Increasing energy use has caused many environmental problems including global warming. Energy use is growing rapidly in developing countries and surprisingly a remarkable portion of it is associated with consumed energy to keep the temperature comfortable inside the buildings. Therefore, identifying renewable technologies for cooling and heating is essential. This study introduced applications of steel sheets integrated into the buildings to save energy based on existing technologies. In addition, the proposed application was found to have a considerable chance of market success. Also, satisfying energy needs for space heating and cooling in a single room by using one of the selected applications in different Köppen climate classes was investigated to estimate which climates have a proper potential for benefiting from the application. This study included three independent parts and the results related to each part have been used in the next part. The first part recognizes six different technologies through literature review including Cool Roof, Solar Chimney, Steel Cladding of Building, Night Radiative Cooling, Elastomer Metal Absorber, and Solar Distillation. The second part evaluated the application of different technologies by gathering the experts’ ideas via performing a Delphi method. The results showed that the Solar Chimney has a proper chance for the market. The third part simulated both a solar chimney and a solar chimney with evaporation which were connected to a single well insulated room with a considerable thermal mass. The combination was simulated as a system to estimate the possibility of satisfying cooling needs and heating needs in different climate classes. A Trombe-wall was selected as a sample design for the Solar Chimney and was simulated in different climates. The results implied that the solar chimney had the capability of reducing the cooling needs more than 25% in all of the studied locations and 100% in some locations with dry or temperate climate such as Mashhad, Madrid, and Istanbul. It was also observed that the heating needs were satisfied more than 50% in all of the studied locations, even for the continental climate such as Stockholm and 100% in most locations with a dry climate. Therefore, the Solar Chimney reduces energy use, saves environment resources, and it is a cost effective application. Furthermore, it saves the equipment costs in many locations. All the results mentioned above make the solar chimney a very practical and attractive tool for a wide range of climates.

Carbohydrates and fat for training and recovery

An important goal of the athlete's everyday diet is to provide the muscle with substrates to fuel the training programme that will achieve optimal adaptation for performance enhancements. In reviewing the scientific literature on post-exercise glycogen storage since 1991, the following guidelines for the training diet are proposed. Athletes should aim to achieve carbohydrate intakes to meet the fuel requirements of their training programme and to optimize restoration of muscle glycogen stores between workouts. General recommendations can be provided, preferably in terms of grams of carbohydrate per kilogram of the athlete's body mass, but should be fine-tuned with individual consideration of total energy needs, specific training needs and feedback from training performance. It is valuable to choose nutrient-rich carbohydrate foods and to add other foods to recovery meals and snacks to provide a good source of protein and other nutrients. These nutrients may assist in other recovery processes and, in the case of protein, may promote additional glycogen recovery when carbohydrate intake is suboptimal or when frequent snacking is not possible. When the period between exercise sessions is  <8 h, the athlete should begin carbohydrate intake as soon as practical after the first workout to maximize the effective recovery time between sessions. There may be some advantages in meeting carbohydrate intake targets as a series of snacks during the early recovery phase, but during longer recovery periods (24 h) the athlete should organize the pattern and timing of carbohydrate-rich meals and snacks according to what is practical and comfortable for their individual situation. Carbohydrate-rich foods with a moderate to high glycaemic index provide a readily available source of carbohydrate for muscle glycogen synthesis, and should be the major carbohydrate choices in recovery meals. Although there is new interest in the recovery of intramuscular triglyceride stores between training sessions, there is no evidence that diets which are high in fat and restricted in carbohydrate enhance training.

Ecophysiology of avian migration in the face of current global hazards

Long-distance migratory birds are often considered extreme athletes, possessing a range of traits that approach the physiological limits of vertebrate design. In addition, their movements must be carefully timed to ensure that they obtain resources of sufficient quantity and quality to satisfy their high-energy needs. Migratory birds may therefore be particularly vulnerable to global change processes that are projected to alter the quality and quantity of resource availability. Because long-distance flight requires high and sustained aerobic capacity, even minor decreases in vitality can have large negative consequences for migrants. In the light of this, we assess how current global change processes may affect the ability of birds to meet the physiological demands of migration, and suggest areas where avian physiologists may help to identify potential hazards. Predicting the consequences of global change scenarios on migrant species requires (i) reconciliation of empirical and theoretical studies of avian flight physiology; (ii) an understanding of the effects of food quality, toxicants and disease on migrant performance; and (iii) mechanistic models that integrate abiotic and biotic factors to predict migratory behaviour. Critically, a multi-dimensional concept of vitality would greatly facilitate evaluation of the impact of various global change processes on the population dynamics of migratory birds.

Climate-driven impacts of prey abundance on the population structure of a tropical aquatic predator

In the present study we explore how annual variation in climate (late wet-season rainfall) affects population demography in a gape-limited obligate piscivorous predator, the Arafura filesnake Acrochordus arafurae in the Australian tropics. These aquatic snakes display extreme sexual dimorphism, with body sizes and relative head sizes of females much larger than those of males. Two consecutive years with low rainfall during the late wet season reduced the abundance of small but not large sized fish. Although snake residual body mass (RBM, calculated from a general linear regression of ln-transformed mass to ln-SVL) decreased after the first year with low prey availability, it was not until the second year that reduced prey abundance caused a dramatic decline in filesnake survival, and hence in population numbers. Thus, our results suggest that most snakes survived the first year of reduced prey abundance, but a successive year with low prey availability proved fatal for many animals. However, the effects of prey scarcity on RBM and survival fell disproportionately on some size classes of snakes. Medium-sized animals (large males and intermediate-sized females) were affected more dramatically than were small or large snakes. We attribute the higher survival of small snakes to their lower energy needs compared to medium-sized individuals, and the higher survival of large snakes to the continued abundance of large prey (mainly large catfish). Two successive years with low abundance of smaller sized prey thus massively modified the size-structure of the filesnake population, virtually eliminating large males and intermediate-sized females. Our field data provide a clear demonstration of the ways in which stochastic variation in climatic conditions can have dramatic effects on predator population demography, mediated via effects on prey availability.

Optimum design and analysis study of stand-alone residential solar PV microgrid

Today’s power system network has become more complex and it has more responsibilities and challenges to provide secure, reliable and quality energysupply to the communities. A small entity of electrical network known as Microgrid (MG) is more popular nowadays to enhance reliablity and secure level of energy supply, in case of any energy crisis in the utility network. The MG can also provide clean energy supply by integrating renewable energy sources effectively. TheMG with small scale solar photovoltaic (PV) power system is more suitable to provide reliable and clean energy supply for remote or urban communities in residential level. This paper presents the basic analysis study of stand-alone solar photovoltaic (PV) MG power system which has been developed with the aid of Matlab - Simulink software, on the basis of residential load profile and solar exposure level in a particular area of Geelong, Victoria State. The simulation result depicts the control behavior of MG power system with optimum sizing of PV (4.385 kW)and battery storage (480Ah/48V) facility, fulfills daily energy needs in residential load level. This study provides a good platform to develop an effective and reliable stand-alone MG power system for the remote communities in the near future.

Contribution to the chemoreception capacity of juvenile Loggerhead sea turtles (Caretta caretta, L.)

Loggerhead sea turtle juveniles (Caretta caretta), pelagic stage, are found in waters of Madeira archipelago. Pelagic turtles are in the main growth phase of their life cycle and consequently higher energy needs. However, knowledge about the ecology of pelagic loggerhead sea turtles is still quite rudimentary, mainly about the mechanisms that lead them to find food in the vast ocean. Studies with other pelagic species, such as procellariiform birds, revealed that the olfactory system play an important role for the detection of feeding areas, through the detection of concentration peaks of DMS (dimethylsulfide), a scent compound that naturally exists in the marine environment and it is related to areas of high productivity. Based on the assumption that loggerhead sea turtles use a similar mechanism, behavioural experiments were conducted in order to analyze the chemoreception capacity to DMS (airborne chemoreception - theoretically responsible for the long distance detection of areas with food patches; and aquatic chemoreception - theoretically responsible for the short distance detection of preys). The first step was to observe if pelagic loggerheads demonstrate sensitivity to DMS and the second was to verify if they really use the DMS, in natural conditions, as an airborne cue to find areas where food patches might be available. Four juveniles of loggerhead sea turtles were tested in captivity and three wild turtles in the open ocean. The results of airborne chemoreception experiments in captivity revealed that one turtle clearly demonstrated sensitivity to DMS and the sea experiments confirmed this result. However, the experiments were not conclusive on the question whether the pelagic turtles actually use the DMS as an airborne cue to detect long distance food patches. In aquatic chemoreception experiments was not observed sensitivity to DMS by the three sea turtles tested. In the classical conditioning experiment, where DMS and food were given nearly at the same time revealed that after a certain period of time, the sea turtle tested did not associated the DMS stimulus with a possible food reward. The main cause of mortality of loggerhead sea turtles in Madeira waters is due to the accidental capture (bycatch) by deep pelagic longlines fishery which the target species is the black-scabbard (Aphanopus carbo) fish. Chub mackerel (Scomber japonicus) is one of the baits used in this fishery. Aquatic chemoreception experiments were conducted in order to evaluate the attractiveness of the chub mackerel for sea turtles. For the three sea turtles tested, the results showed that in 90% of the cases the sea turtles were extremely attracted by the underwater smell of this fish.

A questão do petróleo em terras indígenas: uma análise constitucional à luz do desenvolvimento sustentável

Recognizing the need to preserve a national ethnic minority, the Constitution, inspired by the pluralistic values of the Constitutional Law State, stipulated a series of rights and guarantees for the conservation of indigenous cultural singularity, disciplining in article 231 the Indians right to maintain their social organization, customs, languages, beliefs and traditions, as well as safeguarding the rights to the lands they traditionally occupy, and the exclusive use of the wealth existing in them, premise of ensuring their physical and cultural continuity, breaking decisively with the paradigm the assimilation of the Indian national civilization. However, despite the Indian policy of ethnic and cultural preservation, the Constitution allowed the exploitation of minerals in aboriginal territory, incorporated herein hydrocarbons, provided they meet certain predetermined requirements, leaving it to the legislature the discipline of ordinary matter. However, this law has not yet been published, with some projects in the National Congress, leaving thus precluding the indigenous subsurface oil exploration until the enactment of enabling legislation. Meanwhile, this paper carries out an integrated analysis of the constitutional protection of ethnic and cultural uniqueness of indigenous peoples, Convention Nº 169 of the International Labour Organization and the bill presented by Deputy Eduardo Valverde, in an attempt to consolidate sustainable development practices in the sector, through developing a system of social and environmental responsible oil exploration, aligning with national energy needs to maintain a balanced environment and preservation of socio-cultural organization of a minority so weakened and beaten over five centuries of domination

Extração enzimática de óleo e produção in situ de biodiesel a partir da Moringa oleífera Lam

With the growth and development of modern society, arises the need to search for new raw materials and new technologies which present the "clean" characteristic, and do not harm the environment, but can join the energy needs of industry and transportation. The Moringa oleifera Lam, plant originating from India, and currently present in the Brazilian Northeast, presents itself as a multi-purpose plant, can be used as a coagulant in water treatment, as a natural remedy and as a feedstock for biodiesel production. In this work, Moringa has been used as a raw material for studies on the extraction and subsequently in the synthesis of biodiesel. Studies have been conducted on various techniques of Moringa oil extraction (solvents, mechanical pressing and enzymatic), being specially developed an experimental design for the aqueous extraction with the aid of the enzyme Neutrase© 0.8 L, with the aim of analyzing the influence variable pH (5.5-7.5), temperature (45-55°C), time (16-24 hours) and amount of catalyst (2-5%) on the extraction yield. In relation to study of the synthesis of biodiesel was initially carried out a conventional transesterification (50°C, KOH as a catalyst, methanol and 60 minutes reaction). Next, a study was conducted using the technique of in situ transesterification by using an experimental design variables as temperature (30-60°C), catalyst amount (2-5%), and molar ratio oil / ethanol (1:420-1:600). The extraction technique that achieved the highest extraction yield (35%) was the one that used hexane as a solvent. The extraction using 32% ethanol obtained by mechanical pressing and extraction reached 25% yield. For the enzymatic extraction, the experimental design indicated that the extraction yield was most affected by the effect of the combination of temperature and time. The maximum yield obtained in this extraction was 16%. After the step of obtaining the oil was accomplished the synthesis of biodiesel by the conventional method and the in situ technique. The method of conventional transesterification was obtained a content of 100% and esters by in situ technique was also obtained in 100% in the experimental point 7, with a molar ratio oil / alcohol 1:420, Temperature 60°C in 5% weight KOH with the reaction time of 1.5 h. By the experimental design, it was found that the variable that most influenced the ester content was late the percentage of catalyst. By physico-chemical analysis it was observed that the biodiesel produced by the in situ method fell within the rules of the ANP, therefore this technique feasible, because does not require the preliminary stage of oil extraction and achieves high levels of esters

Balanço energético de um forno túnel de cerâmica estrutural convertido de lenha para gás natural

In energy systems, the balance of entrances, exits and losses are fundamental to rationalize the energy consumption, independently of the source (sun, natural gas, wind, water, firewood or oil). This estimate is important so much in the phase of project of the facilities, as in the exploration or operation. In the project phase it indicates the energy needs of the process and the contribution of the energy in the cost of the product and the capacity of storage of the fuel and in the operation phase it allows to evaluate the use of the energy in the process of it burns, showing the weak points that should suffer intervention to improve the efficiency. With this tool, it can be implemented routines of calculation of thermal balances in ovens of it burns of structural ceramic, in way to generate an optimized mathematical model for application in the current and promising structural ceramic brazilian industry. The ceramic oven in study is located in the metropolitan area of Natal (Rio Grande do Norte) and it is a continuous oven of the type wagons tunnel, converted of firewood for natural gas and it produces blocks of red ceramic. The energy balance was applied in the oven tunnel before and after the conversion and made the comparisons of the energy efficiencies (it burns to the firewood and it burns to natural gas), what showed that the gaseous fuel is more efficient when we burn structural ceramic in ovens tunnels. When we burn natural gas, the requested energy is smaller and better used. Tests were accomplished in the burned product that showed the best quality of the burned brick with natural gas. That quality improvement makes possible to accomplish new interventions for the most rational use of the energy in the oven tunnel of the Ceramic in study and in the industries of structural ceramic of the whole Brazil, that need control tools of burning and of quality

The floral nectary of Hymenaea stigonocarpa (Fabaceae, caesalpinioideae): Structural aspects during floral development

Background and Aims Considering that few studies on nectary anatomy and ultrastructure are available for chiropterophilous flowers and the importance of Hymenaea stigonocarpa in natural 'cerrado' communities, the present study sought to analyse the structure and cellular modifications that take place within its nectaries during the different stages of floral development, with special emphasis on plastid dynamics.Methods For the structural and ultrastructural studies the nectary was processed as per usual techniques and studied under light, scanning and transmission electron microscopy. Histochemical tests were employed to identify the main metabolites on nectary tissue and secretion samples.Key Results The floral nectary consists of the inner epidermis of the hypanthium and vascularized parenchyma. Some evidence indicates that the nectar release occurs via the stomata. The high populations of mitochondria, and their juxtaposition with amyloplasts, seem to be related to energy needs for starch hydrolysis. Among the alterations observed during the secretory phase, the reduction in the plastid stromatic density and starch grain size are highlighted. When the secretory stage begins, the plastid envelope disappears and a new membrane is formed, enclosing this region and giving rise to new vacuoles. After the secretory stage, cellular structures named 'extrastomatic bodies' were observed and seem to be related to the nectar resorption.Conclusions Starch hydrolysis contributes to nectar formation, in addition to the photosynthates derived directly from the phloem. In these nectaries, the secretion is an energy-requiring process. During the secretion stage, some plastids show starch grain hydrolysis and membrane rupture, and it was observed that the region previously occupied by this organelle continued to be reasonably well defined, and gave rise to new vacuoles. The extrastomatic bodies appear to be related to the resorption of uncollected nectar.

The Brazilian experience of sugarcane ethanol industry

Biomass has gained prominence in the last few years as one of the most important renewable energy sources. In Brazil, a sugarcane ethanol program called ProAlcohol was designed to supply the liquid gasoline substitution and has been running for the last 30 yr. The federal government's establishment of ProAlcohol in 1975 created the grounds for the development of a sugarcane industry that currently is one of the most efficient systems for the conversion of photosynthate into different forms of energy. Improvement of industrial processes along with strong sugarcane breeding programs brought technologies that currently support a cropland of 7 million hectares of sugarcane with an average yield of 75 tons/ha. From the beginning of ProAlcohol to the present time, ethanol yield has grown from 2,500 to around 7,000 l/ha. New technologies for energy production from crushed sugarcane stalk are currently supplying 15% of the electricity needs of the country. Projections show that sugarcane could supply over 30% of Brazil's energy needs by 2020. In this review, we briefly describe some historic facts of the ethanol industry, the role of sugarcane breeding, and the prospects of sugarcane biotechnology.

Sustainable bioenergy: a framework for decision makers

Includes bibliography