Piloting VAKE (Values and Knowledge Education) in the Education for Practice of Nurses.

Imagine the following situation: You are a nurse for elderly people, going to the homes of your patients. A female patient tells you on our first visit after hospital discharge following a hip fracture surgery that she does not want to be at home, because she is not well enough to be alone and she needs therapy with oxygen in permanent basis until she recovers from a respiratory temporary infection situa¬tion. This kind of situations is the starting point for an educational sequence that ad-dresses both values (here: life, human dignity, respect, loneliness) and knowledge (different medical treatments, legal rules, etc.). The example shows how intensely interrelated the values and the facts are. Based on this example we introduce the constructivist didactical tool VaKE (Values and Knowledge Education) that permits to combine both issues, and present a pilot study using this method in the education of nurses.Tempus/LLAF; VAKEinfo:eu-repo/semantics/publishedVersio

Biofilm reactors

After presenting the concept of biofilms, reference is made to their importance in industry and health. Although biofilms are also well known for their deleterious effects (biofouling), emphasis is here given to the beneficial use of biofilms in wastewater treatment. The main types of biofilm reactors are briefly described and the role of support material in the adhesion and stability of biofilms is explained, taking into account the mechanisms involved in biofilm attachment. Practical procedures for the start-up of biofilm reactors are also mentioned. Biofilm growth processes are described together with their properties, structure and Performance. The advantages and disadvantages of biofilm reactors versus suspended biomass systems are discussed. The main equations of the diffusion-reaction model are developed from engineering science principles. Equations derived from the diffusion-reaction model to calculate the reactor volume are presented, together with experimental values of the kinetic parameters. Practical empirical expressions or rules-of-thumb used in the design of fixed biomass reactors are also given. An overall model to predict the growth rate of biofilms and their final thickness or mass is established. The main problems concerning biofilm reactor modelling are discussed and the "missing links" for an optimised design are identified

Co-composting cow manure with food waste: The influence of lipids content

Addition of an oily waste to a co-composting process of dairy cow manure with food waste, and the influence in the final product was evaluated. Three static composting piles with different substrates concentrations were assessed. Sawdust was also added to all composting piles to attain 60%, humidity at the beginning of the process. In pile 1, the co-substrates were the solid-phase of dairy cow manure, food waste and sawdust as bulking agent. In piles 2 and 3 there was an extra input of oily waste of 7 and 11% of the total volume, respectively, corresponding to 18 and 28% in dry weight. The results showed that the co-composting process was feasible even at the highest fat content. Another positive effect due to the oily waste addition was the requirement of extra humidity, due to the hydrophobic properties of this specific waste, which may imply reduced need of a bulking agent. Moreover, this study shows that composting can be a feasible way of adding value to fatty wastes. The three final composts presented very similar and suitable properties for land application.(undefined

A note on periodic solutions of some nonautonomous differential equations

We prove the existence of nontrivial periodic solutions of some nonlinear ordinary differential equations with time-dependent coefficients using variational methods.info:eu-repo/semantics/publishedVersio

Anaerobic co-digestion of coffee waste and sewage sludge

The feasibility of the anaerobic co-digestion of coffee solid waste and sewage sludge was assessed. Five different solid wastes with different chemical properties were studied in mesophilic batch assays, providing basic data on the methane production, reduction of total and volatile solids and hydrolysis rate constant. Most of the wastes had a methane yield of 0.24–0.28 m³CH4(STP)/kg VSinitial and 76–89% of the theoretical methane yield was achieved. Reduction of 50–73% in total solids and 75–80% in volatile solids were obtained and the hydrolysis rate constants were in the range of 0.035–0.063 dֿ¹. One of the solid wastes, composed of 100% barley, achieved a methane yield of 0.02 m³ CH4(STP)/kg VSinitial, reductions of 31% in total solids, 40% in volatile solids and achieved only 11% of the theoretical methane yield. However, this waste presented the highest hydrolysis rate constant. Considering all the wastes, an inverse linear correlation was obtained between methane yield and the hydrolysis rate constant, suggesting that hydrolysis was not the limiting factor in the anaerobic biodegradability of this type of waste.Fundação para a Ciência e a Tecnologia (FCT

Co-digestion of cow manure, food waste and intermittent input of fat

Pulses of oil were added to completely mixed reactors fed with dairy cow manure and food waste, after achieving a stable performance at an organic loading rate of 4.6 ± 0.1 gCOD/(lreactor day), an oily waste effluent from a canned fish processing industry was fed in the form of pulses. The oil concentration rose up to 9, 12, 15 and 18 gCODoil/lreactor, after the pulse feeding in the reactor. The highest fat concentration of 18 gCODoil/lreactor promoted a persistent inhibition in the process of the continuous reactor, although in batch assays, the reactor content evidenced a capacity to degrade more oil and to degrade the accumulated organic matter. All the other pulses had a positive effect in the methane production. From a practical point of view, this work demonstrates that controlled intermittent inputs of oil can enhance the methane production in a co-digestion of cow manure and food waste.Fundo Social Europeu (FSE) - SFRH/BD/18174/2004Fundação para a Ciência e Tecnologia (FCT)

Effect of LCFA content in the co-digestion of manure and food waste

The influence of the lipid content in the mesophilic co-digestion of food waste with cow manure was evaluated. An oily waste was used to simulate the lipid content of food waste. Four reactors with four different concentrations of fat were run in parallel. An oily effluent was added in pulses to simulate different fat contents. The control reactor R1 received no additional fat and R2, R3 and R4 received an increasing input of oil on days 49, 56 and 84 which corresponded to 6, 25 and 36% of Fat COD/total COD in R2, 9, 38 and 46% Fat COD/total COD in R3 and 13, 51 and 55% Fat COD/total COD in R4. The performance was evaluated through the measurement of methane production, effluent soluble chemical oxygen demand (COD), effluent volatile fatty acids, long chain fatty acids (LCFA), total and volatile solids removal. Using single factor analysis of variances (ANOVA) no statistical differences were detected in the reactors performance, in terms of pulse response. The exception was the LCFA adsorbed onto the solid matrix. Hence, R1 only presents palmitic acid (C16:0) adsorbed onto the solid matrix and R2, R3 and R4 presents C16:0 along with stearic (C18:0). The values detected of these two acids were always lower than 25 gCOD/kgTS and no other significant differences were found between the four reactors performance. The added fat was in this case, apparently retained in the reactor in the form of floating yellowish aggregates. The results indicate that cow manure presents a good buffer capacity to overcome the different lipids input of the FW.Fundação para a Ciência e Tecnologia (FCT) - SFRH/BD/18174/2004.Fundo Social Europeu (FSE

Fate of LCFA in the co-digestion of cow manure, food waste and discontinuous addition of oil

Different concentrations of oily waste were added in a discontinuous mode and recurrently to anaerobic continuous stirred tank reactors fed with cow manure and food waste. Four continuous stirred tank reactors were run in parallel. A control reactor (R1) received no additional oil and R2, R3 and R4 received increasing concentrations of oil in two different experimental approaches. First, the lipids composition was forced to change suddenly, in three moments, without changing the total chemical oxygen demand (COD) fed to the reactors. The only long chain fatty acid (LCFA) detected onto the R1 solid matrix was palmitic acid (C16:0). Nevertheless in the solid matrix of R2, R3 and R4 C16:0 and stearic acid were detected. For occasional increase in the oil concentration up to 7.7 gCODoil/Lreactor (55% OilCOD/TotalCOD) no statistical differences were detected between the reactors, in terms of methane production, effluent soluble COD, effluent volatile fatty acids and total and volatile solids removal. Therefore this experiment allowed to conclude that cow manure–food waste co-digestion presents sufficient buffer capacity to endure solid-associated LCFA concentration up to 20–25 gCOD-LCFA/kgTS. In a second experiment higher concentrations of oil were added, raising occasionally the concentration in the reactors to 9, 12, 15 and 18 gCODoil/Lreactor. All pulses had a positive effect in methane production, with the exception of the highest oil pulse concentration, that persistently impaired the reactor performance. This experiment demonstrates that threshold values for LCFA and C16:0 accumulation onto the solid matrix, of about 180–220 gCOD-LCFA/kgTS and 120–150 gCOD-C16:0/kgTS, should not be surpassed in order to prevent persistent reactor failure, as occurs in some full scale co-digestion plants.Fundo Social Europeu (FSE)Fundação para a Ciência e a Tecnologia (FCT

Low-cost fermentative medium for biosurfactant production by Streptococcus thermophilus A

Interest in biosurfactants has increased considerably in recent years, as they are potential candidates for many commercial applications in the petroleum, pharmaceuticals, biomedical and food processing industries. Biosurfactants have several advantages over chemical s urfactants including lower toxicity and higher biodegradability, and effectiveness at extreme temperatures or pH values. In spite of the advantages, fermentation must be cost competitive with chemical synthesis and many of the potential applications that have been considered for biosurfactants depend on whether they can be produced economically. The use of alternative molasses medium (sucrose content 20 g/L, supplemented with 3 g/L yeast extract and 5 g/L peptone) for biosurfactant production by Streptococcus thermophilus A was studied. Suitable models were established to describe the response of the experiments pertaining to glucose or sucrose consumption, cell growth and biosurfactant production. Conventional synthetic M17 broth was used as control experiments. The replacement of M17 broth by cheaper molasses medium resulted on an increase about 1.4 times in the mass of produced biosurfactant (mg) per gram cell dry weight and a 80% medium preparation costs reduction.In con clusion, the results obtained showed that molasses medium can be used as a relatively inexpensive and economical alternative to conventional synthetic medium for biosurfactant production by S. thermophilus A

Low-cost fermentative medium for biosurfactant production by probiotic bacteria

Potential use of alternative fermentative medium for biosurfactant production by Lactococcus lactis 53 and Streptococcus thermophilus A was studied. Suitable models were established to describe the response of the experiments pertaining to glucose, lactose or sucrose consumption, cell growth and biosurfactant production. Synthetic media MRS and M17 broth were used as control experiments. When the synthetic media were replaced by cheaper alternative media, as cheese whey and molasses, fermentations were carried out effectively with high yields and productivities of biosurfactant. An increase about 1.2–1.5 times in the mass of produced biosurfactant per gram cell dry weight and 60–80% medium preparation costs reduction were achieved, for both strains. In conclusion, the results obtained showed that supplemented cheese whey and molasses media can be used as a relatively inexpensive and economical alternative to synthetic media for biosurfactant production by probiotic bacteria, thus an attractive alternative as many of the potential applications for biosurfactants depend on whether they can be produced economically.Fundação para a Ciência e a Tecnologia (FCT