14 research outputs found
Simple, affordable evaporative cooler to reduce food loss in developing countries
Cooling systems in developing countries have effects on health, hunger, food waste and the environment. Refrigerators are the best method for preserving food, but they are expensive, complex, energy-consuming, unsustainable for some countries. Therefore, there is an interest in simple, cheaper alternatives: evaporative coolers allow to raise the air humidity while reducing its temperature. The purpose of this work is to design and validate an evaporative cooling system that will allow storage of perishables, such as fruits and greens, extending their shelf-life. Our case study is focused on Senegal’s Tambacounda region. To crack the Senegalese market, an innovative business model has been thought, allowing the low-cost distribution of the cooler to the local population
Design, Construction and Commissioning of SGPR, the Fast Protection System of RFX
RFX, the largest machine for magnetic confinement of plasmas in the RFP line, is provided with a system named SGPR specifically designed for the machine global protection against fast faults which can develop in the plasma, in the windings, in the power supply circuits and in the control system. SGPR is a cabled logic HLL machine, able to organise in few tens of microseconds coordinated machine protection, dealing with more than forty fault signals and activating almost thirty protection commands. SGPR design, manufacture and test program conform the quality control criteria necessary to assure the required high reliability. After a careful and cumbersome commissioning work the system has assumed its protection role. Up to now it has been called to a number of interventions which, even if never due to major faults, have shown its capability of proper operation
Estrogenic potential of the Venice, Italy, lagoon waters
The exposure of the Venice lagoon (Italy) to endocrine-disrupting compounds (EDCs) from different sources was investigated. Spatial and time distribution of EDC concentrations were determined in four sampling sessions (December 200 I-May 2002) by solid phase extraction followed by high-performance liquid chromatography separation coupled with mass spectrometry detection via electrospray interface (SPE-HPLC-ESI-MS), which allowed identification of natural (estradiol, estrone) and synthetic estrogenic compounds, both steroidal (ethinylestradiol, mestranol) and nonsteroidal (benzophenone, bisphenol-A, nonylphenol, nonylphenol monoethoxylate carboxylate). No significant differences in the EDC distribution were observed between stations located near selected sources (raw sewage from the historical center of Venice, treated municipal and industrial effluents from sewage treatment plants, and areas undergoing the inflow of rivers). While synthetic nonsteroidal analytes were recorded in the I to 1,040 ng/L range (average concentration: 34 ng/L), steroidal EDC (estradiol, ethinylestradiol) concentrations were lower (1-125 ng/L; average concentration: 8 ng/L). The estrogenic activity of lagoon waters was estimated in terms of estradiol equivalent concentration (EEQ) by applying the estradiol equivalency factors (EEFs). Steroidal EDCs (estradiol, ethinylestradiol) contributed >97% to the total potential estrogenicity of the waters, which accounted for 4 to 172 ng/L (average: 25 ng/L), as total EEQs. These levels are likely to pose adverse effects on the Venice lagoon aquatic organisms
Determination of natural and synthetic estrogenic compounds in coastal lagoon waters by HPLC-electrospray-mass spectrometry
A new analytical method was developed for the simultaneous determination of estrogenic compounds of natural (estradiol, estriol, estrone) and synthetic origin, both steroidal (ethinylestradiol, mestranol) and non-steroidal (benzophenone, bisphenol-A, diethylstilbestrol, octylphenol, nonylphenol, nonylphenol monoethoxylate carboxylate), in environmental aqueous samples by high-performance liquid chromatography coupled with ion trap-mass spectrometry via electrospray interface (HPLC-ESI-IT-MS). Quantitative MS detection was performed in the negative mode for all compounds except mestranol and benzophenone, which were detected under positive ion conditions. Very low method detection limits (MDLs), between 0.1 and 2.6 ng/L, were achieved in coastal lagoon water samples, while the developed solid-phase-extraction (SPE) procedure permitted simultaneous recovery of all analytes from spiked water samples with yields >70% (7-11 RSD%), except estriol and benzophenone, which were recovered with 60% (9 RSD%) and 50% (11 RSD%) yields, respectively. The proposed method was applied to the analysis of Venice (Italy) lagoon waters, where average concentrations of selected compounds in the 2.8-33 ng/L concentration range were found