Conservation of building materials and the future of the built environment

Building uses a combination of materials resources ranging from clay to bronze. Some of these resources are widely available, but require substantial energy resources to process and distribute them as the volumes used are so great. Other resources, like copper, are in much smaller supply. The resources used in building need to be examined against the future resource limitations in their supply and the possibilities of recycling. The links between building and waste cycles will also be critical, as wastes from other processes can often be incorporated into the building process. Design for recycling has to be balanced against the advantages of design for longer life. Reversible cementitious processes could confer enormous advantages if the reversibility was safely controllable, but this represents a very formidable scientific problem. The advantages of composite materials need to be balanced against the difficulties of effective recycling, for example reinforced concrete. The building as an energy conservation device also needs more emphasis. The final section deals with the concept of the materials conservation city in a Utopian way. It is designed to stimulate constructive thinking about resource conservation and materials recycling.     

Mechanochemical removal of organo-chlorinated compounds by inorganic components of soil

The purpose of this work is to evaluate the catalytic efficiency of two metal oxides, ferrihydrite and birnessite and of a ferruginous smectite, towards organic molecules such as 4-chloroaniline (4-CA), pentachlorophenol (PCP), and five polychlorinated biphenyls (PCBs) characterised by different number and position of chlorine atoms. Mechanochemical dry contacts with light grinding between catalytic surfaces and pollutants have been carried out.

The efficiency of the mechanochemical removal was compared with batch experiments for the soluble compounds (PCP and 4-CA). The removal of 4-CA and PCP by the mechanochemical procedure resulted more effective than by batch contact in the presence of birnessite and ferrihydrite, particularly at higher pH (100% removal of 4-CA by birnessite in 30 min at pH 8.6 after the mechanochemical contact compared to 20% removal using the batch interaction at the same pH).

The mechanochemical contact of PCBs and birnessite produced a removal of pollutant that was a function of the number of chlorine atoms (complete removal of 2,2^′-dichlorobiphenyl in 10 days and a removal of 30% and 20% of 2^′,3,4-trichlorobiphenyl and 3,3^′,4,4^′-tetrachlorobiphenyl, respectively in 90 days) and of the position of chlorine atoms about the biphenyl rings (100% of 2,2^′-dichlorobiphenyl in 10 days, 84% of 3,3^′-dichlorobiphenyl in 15 days and 40% of 4,4^′-dichlorobiphenyl in 27 days).     

A statistics-based system for treatment plant operation

This paper describes work toward development of a convenient computer system to improve everyday operation and control of the wastewater treatment process. The goal is to help the operator detect the problems in the process and to select appropriate control actions. The system comprises subsystems for a data base management, data analysis including several statistical methods, and an expert advisory system. The statistical methods investigated include construction of external reference distributions, computation of moving averages, graphical methods, discriminant functions for early detection of upsets, and several kinds of control charts. The latter two methods are still under development and are not built into the system. Reference distributions are used to help define the fuzzy terms such as high and low for the conditions of the variables involved in the expert system control rules. The system is written in dBase-III and Lotus-123 and has a user-friendly interface for the communication between the user and the system.     

Effects of chronic exposure to radiofrequency electromagnetic fields on energy balance in developing rats

The effects of radiofrequency electromagnetic fields (RF-EMF) on the control of body energy balance in developing organisms have not been studied, despite the involvement of energy status in vital physiological functions. We examined the effects of chronic RF-EMF exposure (900 MHz, 1 V?m^?1) on the main functions involved in body energy homeostasis (feeding behaviour, sleep and thermoregulatory processes). Thirteen juvenile male Wistar rats were exposed to continuous RF-EMF for 5 weeks at 24 °C of air temperature (T _a) and compared with 11 non-exposed animals. Hence, at the beginning of the 6th week of exposure, the functions were recorded at T _a of 24 °C and then at 31 °C. We showed that the frequency of rapid eye movement sleep episodes was greater in the RF-EMF-exposed group, independently of T _a (+42.1 % at 24 °C and +31.6 % at 31 °C). The other effects of RF-EMF exposure on several sleep parameters were dependent on T _a. At 31 °C, RF-EMF-exposed animals had a significantly lower subcutaneous tail temperature (?1.21 °C) than controls at all sleep stages; this suggested peripheral vasoconstriction, which was confirmed in an experiment with the vasodilatator prazosin. Exposure to RF-EMF also increased daytime food intake (+0.22 g?h^?1). Most of the observed effects of RF-EMF exposure were dependent on T _a. Exposure to RF-EMF appears to modify the functioning of vasomotor tone by acting peripherally through α-adrenoceptors. The elicited vasoconstriction may restrict body cooling, whereas energy intake increases. Our results show that RF-EMF exposure can induce energy-saving processes without strongly disturbing the overall sleep pattern.     

Poly[(R)-3-hydroxy butyrate] Melt Processing: Strategy for Prevention of Degradation Reactions

Poly[(R)-3-hydroxy butyrate] (PHB) as well as all the components of the poly[(R)-3-hydroxy alkanoate]s (PHAs) family tend to degrade during processing at temperatures above their melting point via a hydrolytic mechanism induced by moisture attack and a concerted reaction mechanism induced by temperature. Therefore, the PHAs stabilization in the molten state is particularly important for production of biodegradable ecocompatible plastic items of commercial value. In order to refrain the indicated negative degradation effects, PHB was melt processed in a torque rheometer in the presence of a polymeric carbodiimide agent. Processed specimens were characterized by using FTIR, GPC, DSC, TGA and tensile properties. GPC analysis showed that the increase of the additive content in the formulation resulted in an increase of PHB molecular weight. However, decreasing in PHB thermal stability, glass transition temperature and mechanical properties, was observed with the increase of the additive amount. This behaviour most likely arises from the formation of new chemical structures promoted by the presence of the additive aimed at preventing the onset of hydrolitic processes.     

Effectiveness of control strategies against Botrytis cinerea in vineyard and evaluation of the residual fungicide concentrations

This investigation was undertaken to test different control strategies against Botrytis cinerea vineyards. Two commercial vineyards, “Barbera” and “Moscato,” located in Piedmont (Northern Italy) were divided into seven plots and treated with different combinations of fungicides including fenhexamid, pyrimethanil, fludioxonil + cyprodinil, iprodione, and boscalid, a new carboxamide compound. An integrated strategy including a chemical (pyrimethanil) and a biocontrol agent (Trichoderma spp. t2/4ph1) was also included. At harvest, the percentage of bunches and berries attacked by B. cinerea and the concentration of the chemical fungicides were determined. All the pesticide residues at harvest were below the maximum residue level (MRL), except when two applications of pyrimethanil per season were applied. Boscalid was the most effective active ingredient against B. cinerea among the tested chemicals. When boscalid application was followed by a treatment with pyrimethanil, its efficacy was similar to that shown by two treatments of pyrimethanil. However, this second strategy was not feasible due to the risks of resistance development in the pathogen and to the residue accumulation as indicated by the analysis.     

Material and energy recovery in integrated waste management systems: a life-cycle costing approach

A critical assumption of studies assessing comparatively waste management options concerns the constant average cost for selective collection regardless the source separation level (SSL) reached, and the neglect of the mass constraint. The present study compares alternative waste management scenarios through the development of a desktop model that tries to remove the above assumption. Several alternative scenarios based on different combinations of energy and materials recovery are applied to two imaginary areas modelled in order to represent a typical Northern Italian setting. External costs and benefits implied by scenarios are also considered. Scenarios are compared on the base of the full cost for treating the total waste generated in the area. The model investigates the factors that influence the relative convenience of alternative scenarios.     

Noninvasive characterization of the Trecate (Italy) crude-oil contaminated site: links between contamination and geophysical signals

The characterization of contaminated sites can benefit from the supplementation of direct investigations with a set of less invasive and more extensive measurements. A combination of geophysical methods and direct push techniques for contaminated land characterization has been proposed within the EU FP7 project ModelPROBE and the affiliated project SoilCAM. In this paper, we present results of the investigations conducted at the Trecate field site (NW Italy), which was affected in 1994 by crude oil contamination. The less invasive investigations include ground-penetrating radar (GPR), electrical resistivity tomography (ERT), and electromagnetic induction (EMI) surveys, together with direct push sampling and soil electrical conductivity (EC) logs. Many of the geophysical measurements were conducted in time-lapse mode in order to separate static and dynamic signals, the latter being linked to strong seasonal changes in water table elevations. The main challenge was to extract significant geophysical signals linked to contamination from the mix of geological and hydrological signals present at the site. The most significant aspects of this characterization are: (a) the geometrical link between the distribution of contamination and the site’s heterogeneity, with particular regard to the presence of less permeable layers, as evidenced by the extensive surface geophysical measurements; and (b) the link between contamination and specific geophysical signals, particularly evident from cross-hole measurements. The extensive work conducted at the Trecate site shows how a combination of direct (e.g., chemical) and indirect (e.g., geophysical) investigations can lead to a comprehensive and solid understanding of a contaminated site’s mechanisms.     

The influence of per offspring investment (POI) and starvation on larval developmental plasticity within the palaemonid shrimp,Palaemonetes varians

At the inter-specific level, per offspring investment (POI), degree of abbreviated development, and lecithotrophic potential all increase with increasing latitude and freshwater penetration among crustaceans. These traits are considered adaptations to conditions of decreasing growth potential. We hypothesise that this relationship between POI and abbreviated development also occurs at the intra-specific level. We studied the caridean shrimp, Palaemonetes varians, to investigate the hypothesis that under food-limited conditions, higher POI enables development through fewer larval instars. Under starvation stress, larvae from broods of greater POI (measured as hatchling brood average dry weight, DW) generally developed through fewer larval instars. With increasing starvation period, larval development time increased, whilst larval growth rate, juvenile DW, juvenile carbon mass, and juvenile carbon:nitrogen (C:N) ratio all decreased. Larval development time generally decreased with increasing brood average dry weight. In contrast, larval growth rate, juvenile DW, juvenile carbon mass, and juvenile C:N ratio all increased with increasing larval brood average DW. The relationship between POI and larval instar number (abbreviation of development) reported here is consistent with that at the inter-specific level and supports the concept that macro-ecological trends in development modes at the inter-specific level may be driven by selection occurring on POI at the intra-specific level.