Bioclimatic design of buildings considering heating requirements in Italian climatic conditions. A simplified approach

This paper presents a parametric approach to the definition of a proper building shape compared to the building heating requirement in the very first stage of the design process. A new simplified index is introduced, namely the south exposure coefficient C_fs. In fact, as far as bioclimatic architecture is concerned, the relationship between buildings and natural environment is very important both for the control of indoor comfort conditions and energy requirements. The building shape is a fundamental aspect of this relationship. Usually, in thermal behavior analysis this parameter is considered only from the point of view of compactness. This is a reductive approach, because two buildings with the same coefficient could have different shapes and so a different thermal behavior. Some aspects such as orientation, openings, exposure to atmospheric agents and natural elements must also be strictly considered. Moreover, in scientific literature no indications are given to designers who operate in mild and warm climate conditions. This is why the results of a research activity focused on heating requirements of buildings with different shapes and laid in the Italian territory are presented. Monthly calculations have been performed following the quasi-steady-state method suggested in the European standard. Outputs show that better results in the building energy performance can be achieved considering a bioclimatic (though simplified) approach since the very beginning.     

Infrared thermovision technique for the assessment of thermal transmittance value of opaque building elements on site

Due to new regulations in the field of energy saving, international standards concerning energy requirements of buildings have been developed. In this field, during the design phase, one of the most important parameters to be considered is the value of heat losses coefficient through the envelope. Anyway, very often a great difference is experienced between predicted performance of building elements as calculated using the methods prescribed in technical standards, and the one considering as-build conditions, particularly in the field of building renovation where the envelope thermal transmittance value must be measured on site. Till now, the only method accepted by international standards is the heat flowmeter (HFM) that presents some restriction and some uncertainty in the results. In this study a faster and less invasive method is proposed, the infrared thermovision technique (ITT) whose full potentiality has never been investigated yet, in order to acquire quantitative data of real thermal transmittances of the building envelope in a quasi-steady state condition. The theoretic background is presented together with the application in three case studies. The results indicate that, following a specific methodology, it is possible to record significant data useful to perform a proper assessment of energy performance of existing buildings.     

Diversity of stress responses in dairy thermophilic streptococci

Exponential and stationary phase cells of 56 strains of the dairy Streptococcus species S. thermophilus, S. macedonicus and S. salivarius, were exposed to acid, osmotic, oxidative and heat stresses to investigate the diversity of their responses. Three strains of dairy related streptococci, Lactococcus lactis ATCC11454, Enterococcus faecium DSM20477 and Enterococcus faecalis DSM20478, were included for comparison purposes. Acid and heat adaptation and cross-protection to stress were studied in ten strains with different stress response patterns. Cell death and the changes in protein expression were evaluated by plate counts and Sodium Dodecyl Sulfate Polyacrilamide Gel Electrophoresis, respectively. All strains of all species were highly tolerant of osmotic stress. With a few exceptions, acid and oxidative treatments reduced the number of viable cells by > 5 log units but responses to heat stress were more variable. For some, but not all strains, stationary phase cells were more resistant to some or all stresses. Matrix cluster analysis was used to group strains on the basis of their pattern of stress response in seven clusters. Significant associations between the sources of strains and stress resistance were found for acid and oxidative stresses. Adaptation to stress during the exponential phase enhanced the survival of acid and heat stressed cells from 1 to 60,000-folds, but a detrimental effect of adaptation on cell viability was evident for oxidative and osmotic stresses for three strains. Adaptation and entry into the stationary phase resulted in significant changes of protein bands whose estimated molecular masses corresponded with those of proteins (DnaK, GprE, GroEL, and GroES) involved in the general stress response but no statistically significant correlation between stress response and band intensity was evident.     

Solar cooling in the food industry in Mexico: A case study

In Mexico efforts are being made to promote the use of solar energy for cooling in the Agro-Food Industries (AFI), 120 industries were contacted in order to assess the solar cooling potential application in the sector. One case study was selected among the visited potential end users according to the size of the facility, the information available and their willingness to collaborate in the present project. Data from the industry was used to select the appropriate solar cooling concept and therefore the collector’s typology, and the absorption cooling system. Moreover, the operation of the system was simulated in order to define the optimal size of the collector field required. The proposed cooling system was composed by a Fresnel concentrating collector field to activate a series of air cooled single-effect ammonia–water absorption chillers. The cooling system simulation was carried out with the Transient Systems Simulation Programme (TRNSYS) which allowed to model the collector system that fulfill the required load. The calculated saved electricity was around 19% of the total consumption, this small fraction is due to the fact that the selected facility is operating continuously with very large refrigeration capacities. The specifications of the simulated solar cooling system are presented.     

Spatio‐Temporal Control of Dynamic Topographic Patterns on Azopolymers for Cell Culture Applications

Cell response to exogenous cues is the result of a complex integration of multiple biochemical/biophysical signals, which might occur simultaneously and might be characterized by specific spatial and temporal patterns. Among these signals, surface topography plays an important role in affecting cell functions and fate. However, the current understanding of the interplay between cells and topography relies on static environment. Here the intrinsic light‐responsive properties of azopolymers and the versatility of laser‐based confocal microscope technique is exploited, aiming to induce spatio‐temporal dynamic topographic changes in situ during cell culture. Diverse patterns can be designed on cell‐populated azopolymer films with high control on time, space, and on‐off signal modification. The technique proposed in this study enables the development of synthetic platforms that finely control cell orientation and migration both in time and space. The results may pave the way to unravel complex processes involved in cell‐topography interactions, thus allowing to define the spatio‐temporal features that most effectively influence cell functions.     

Antioxidant capacity,ascorbic acid,total phenols and carotenoids changes during harvest and after storage of Hayward kiwifruit

The influences of harvest time and storage on the quality indices and nutritional content of kiwifruit were evaluated. Antioxidant capacity, ascorbic acid, total phenol content, carotenoids, soluble solids content and flesh firmness were determined in kiwifruit gathered at two different time (T1: 17-11-2005 and T2: 24-11-2005) and stored at 0 °C, for 2 or 6 months (S1 and S2, respectively). At the end of the cool storage, fruits were maintained for a week at 25 °C (S1 + 7d and S2 + 7d).