Comparison and Identification of Static Electrical Terminal Fuel Cell Models

Six steady-state fuel cell electrical terminal models are compared using experimental data from an Avista Laboratories SR-12 500 W proton exchange membrane (PEM) fuel cell. The paper begins by reviewing the physical effects in a fuel cell. The proposed electrical terminal models are introduced in terms of these physical effects, parameterized for identification and compared using the measured data.     

A chloride method for the determination of the enthalpy of steam/water mixtures discharged from geothermal wells

Chloride concentrations and pressures (or temperatures) in two points of a geothermal test line have been used to determine the enthalpy of the steam/water mixture discharged from Nisyros I geothermal well (Greece). The results are in agreement with those obtained by the Russell James method. The chloride method described in this paper is fast, requires cheap, portable equipment and is thus particularly suitable for short-term well testing during drilling or immediately after well completion, especially in steam-rich mixtures.     

Apple Juice Clarification With the Use of Honey and Pectinase

The clarification of apple juice with the use of honey and enzyme separately and in combinations was studied. The results indicated the existence of a synergistic effect upon the time of initial flocculation when honey was combined with pectinase enzymes. Changes in the rate of flocculation appeared to be an additive effect of enzyme concentration and/or honey concentration. The combined treatment of honey and enzyme was found to induce flocculation very fast as compared to enzyme alone at cold as well as warm temperatures. When used alone, the honey treatment produced a clarified juice with a viscosity similar to cider.     

Sulphiting agents in foods: some risk/benefit considerations

The current toxicological status of sulphiting agents is reviewed, including evidence of adverse reactions to sulphited foods by a sub-population of asthmatics. Against this background are assessed the applications and benefits of sulphiting agents in foods. It is concluded that further information is required to determine the magnitude of risk and that, in the interim, the controlled use of sulphiting agents is justifiable.     

Analysis of water inflows in the Donkin-Morien No. 3 tunnel,Sydney Coalfield,Nova Scotia

The analysis of piezometric levels, water inflows and hydrochemical data at the Donkin-Morien Development Project No. 3 tunnel has revealed a flow regime characterised by discontinuity networks rather than intergranular permeability. Above chainage 420 m, water inflows were encountered from a minor aquifer unit being recharged by percolation travelling down dip from outcrop. Below chainage 420 m, the inflows become predominantly more saline, with recharge occurring either vertically or down dip from seabed, while below chainage 500 m the disappearance of the aquifer unit resulted in no further inflows being encountered. A freshwater/saltwater interface was identified in the vicinity of chainage 420 m.     

Specifying transformer winter and summer peak-load limits

This paper presents a methodology for specifying the winter and summer peak-load limits for substation transformers that carry a temperature-sensitive load, taking into account the random nature of load and ambient temperature as well as their correlation. With this methodology, we can easily and accurately specify the peak-load limits for each substation transformer once the historical ambient temperature and load data are available. Also, we can collectively specify the peak-load limits for the transformer of each cooling type (OA, OA/FA, or OA/FA/FA) in a geographic region based on the mean and standard deviation of ambient temperatures in that region. Such peak-load limits are useful for power system planning.     

Monitoring, removal and risk assessment of cytostatic drugs in hospital wastewater.

Cytostatic agents are applied in cancer therapy and subsequently excreted into hospital wastewater. As these substances are known to be carcinogenic, mutagenic and toxic for reproduction, they should be removed from wastewater at their source of origin.In this study the fate and effects of the cancerostatic platinum compounds (CPC) cisplatin, carboplatin, oxaliplatin, 5-fluorouracil (5-FU) and the anthracyclines doxorubicin, daunorubicin and epirubicin were investigated in hospital wastewater. Wastewater from the in-patient treatment ward of a hospital in Vienna was collected and monitored for the occurrence of the selected drugs. A calculation model was established to spot the correlation between administered dosage and measured concentrations. To investigate the fate of the selected substances during wastewater treatment, the oncologic wastewater was treated in a pilot membrane bioreactor system (MBR) and in downstream advanced wastewater treatment processes (adsorption to activated carbon and UV-treatment). Genotoxic effects of the oncologic wastewater were assessed before and after wastewater treatment followed by a risk assessment.Monitoring concentrations of the selected cytostatics in the oncologic wastewater were in line with calculated concentrations. Due to different mechanisms (adsorption, biodegradation) in the MBR-system 5 - FU and the anthracyclines were removed < LOD, whereas CPC were removed by 60%. In parallel, genotoxic effects could be reduced significantly by the MBR-system. The risk for humans, the aquatic and terrestrial environment by hospital wastewater containing cytostatic drugs was classified as small in a preliminary risk assessment.