Economic considerations and decision support tool for wastewater reuse scheme planning.

The reuse of upgraded wastewater for beneficial uses is increasingly adopted and accepted as a tool in water management. However, funding of schemes is still a critical issue. The focus of this paper is on economic considerations of water reuse planning. A survey of pricing mechanisms for reclaimed water revealed that most schemes are subsidised to a great extent. In order to minimise these state contributions to the implementation and operation of reuse projects, their planning should identify a least cost design option. This also has to take into account the established pricing structure for conventional water resources and the possibility of gaining revenues from reclaimed water pricing. The paper presents a case study which takes into account these aspects. It evaluates different scheme designs with regard to their Net Present Value (NPV). It could be demonstrated that for the same charging level, quite different amounts of reclaimed water can be delivered while still producing an overall positive NPV. Moreover, the economic feasibility and competitiveness of a reuse scheme is highly determined by the cost structure of the conventional water market.     

DISSERTATIONS AND THESES IN DRYING WRITTEN IN CZECHOSLOVAKIA IN THE PERIOD 1975 - 84

Research and development of drying processes and equipmect has a long tradition in Czechoslovakia (1). There are at least 10 top reoearch centers where drying of varicus materials has been studied. Remarkable attention to drying theory and application is also paid at Czechoslovak universities which yields numerous theses dealing with various aspects of the drying process. The total of 52 M.Sc. theses oriented to drying and/or dryers had been published in the last decade. Moreover, 22 Ph.D. theses were carried out in the same period. This represents an important source of theoretical and experimental results. However all theses had been mitten in the Czech or Slovak language, and therefore their wide international application is rather limited. They are summari-zed in the following list.     

Correlation of Mycobacterium avium subsp. paratuberculosis counts in gastrointestinal tract, muscles of the diaphragm and the masseter of dairy cattle and potential risk for consumers

Tissues of cattle intended for human consumption can be contaminated by Mycobacterium avium subsp. paratuberculosis (MAP). Although different studies attribute varying roles of MAP in Crohn's disease progression it is thought that the exposure of humans to this bacterium should in any case be minimised. In this study, we have collected samples of intestine, mesenteric lymph nodes, muscles of diaphragm (musculus diaphragma) and masseter muscles (musculus masseter) from twenty-five cows in a slaughterhouse. The infectious status of all animals was confirmed by culture of faeces. MAP was found in almost all the intestines and mesenteric lymph nodes examined, including three faecal culture-negative animals indicating intermittent shedding. As intestine is used for the traditional production of sausages, it is alarming that 84.2% of intestine samples were positive for MAP. F57 and IS900 real time PCR revealed MAP in 40 to 68% of diaphragms and 11.1 to 38.9% of masseters. A noticeable dependence of the probability of MAP positivity of faeces versus gastrointestinal tract (GIT) and of GIT and muscles was observed. Due to the changing behaviour of consumers, both of these muscles have started to be widely used in cuisine. Therefore, the results of this paper imply that the processing of cows with paratuberculosis in abattoirs without any precautions (restrictions) and the usage of meat for human consumption should be rethought.     

Surface‐active and associative properties of ionic polymeric surfactants based on carboxymethylcellulose

Polymeric biosurfactants were prepared by the transesterification reaction between rapeseed oil triacyl glycerides and carboxymethylcellulose (CMC). The reaction was performed in H₂O/N,N dimethylformamide (DMF) with potassium laurate as catalyst at various reaction conditions using microwave radiation as heating source. The structural features of the obtained water‐soluble CMC derivatives were characterized Fourier‐transform infrared (FT‐IR) spectroscopy and their behavior in dilute aqueous solutions was investigated by surface activity measurements, viscometry and with a polarity probe, the Coomassie Brilliant Blue dye. All derivatives showed a very low esterification extent and moderate surface tension lowering effect. Nevertheless, they exhibited significant emulsifying efficiency comparable to that of the synthetic surfactant, Tween 20. They establish hydrophobic associations in bulk solution while adsorbing on the air/water interface. The presence of hydrophobic substituents in CMC molecules enhanced the hydrophobicity resulting in higher emulsion stability than produced by Tween 20. The results suggested that suitable polymeric biosurfactants applicable as emulsifying agents can be prepared from CMC under microwave heating at low microwave power and reaction times in the range of few minutes, what represents a great advantage in comparison with transesterification reactions lasting up to 6 h at conventional heating. POLYM. ENG. SCI., 2011. ©2011 Society of Plastics Engineers.     

The specific chemical profile of Mediterranean propolis from Malta

Seventeen Maltese propolis samples were studied by GC–MS after silylation. They exhibited the typical Mediterranean chemical profile, rich in diterpene compounds (18–92% of TIC, GC–MS): 32 individual diterpenes were identified; 22 of them were present in each specimen. The other abundant compound group was that of sugars and sugar derivatives. In some samples, however, another compound group was observed (0–12% of TIC, GC–MS); the corresponding mass spectra were consistent with mono- and sesquiterpenyl esters of substituted benzoic acids. Two new propolis constituents of this group, daucane diterpene esters of hydroxybenzoic acids, were isolated. Their origin is suggested to be Ferula communis, as they are taxonomic markers for this species. All propolis samples were active against Staphylococcus aureus but only those with high concentrations of terpenyl esters showed antifungal activity against Candida albicans. The present results confirm that Mediterranean propolis is a valuable natural product with potential to improve human health.     

Synthesis and functionalization of superparamagnetic poly-?-caprolactone microparticles for the selective isolation of subpopulations of human adipose-derived stem cells

There has been a growing interest in using biofunctionalized magnetic particles for cell isolation. This paper describes the synthesis and characterization of magnetite-polymer (Fe₃O₄-poly-ɛ-caprolactone, magnetite-PCL) microparticles surface functionalized with amino and epoxy groups allowing easy covalent attachment of specific antibodies and subsequent ability to bind target cells. Particles with different sizes (4–135 µm), spherical shape and superparamagnetic behaviour (magnetite content of about 13 wt%) were obtained. The functionalized microparticles presented high protein-binding capacity (coupling efficiency of 47% for epoxy- and 71% for amino-functionalized particles) with a low level of non-specific binding. We have further investigated the influence of initial protein concentration, pH, ionic strength, temperature and incubation time on the capacity of amino-functionalized particles to bind protein molecules. The results showed that maximum protein coupling is rapidly achieved (≤5 h) at pH 5.5 and low ionic strength (0.05 M NaCl). Furthermore, when cultured in direct contact with osteoblast-like cells (Saos-2) or human-derived adipose stem cells (ASCs), the amino-functionalized particles did not affect the proliferation and morphology of the cells. As a proof of principle for the application of magnetic microparticles for cell isolation, CD105 (endoglin) antibody was coupled to the magnetic particle surface to bind subpopulations of human ASCs expressing the CD105 antigen. The isolation of CD105+ ASCs from a heterogeneous cell population was confirmed by flow cytometry analysis. Given the demonstrated potential of functionalized magnetite-PCL microparticles for selective cell isolation, we expect that these particles may be further applied in immuno-magnetic cell separation owing to their versatility and ease of surface modification.