INSAT

This paper explores the comparative advantages and disadvantages of the simplest form of axial flux geometry, the single sided version, compared to the most common form of radial flux geometry with an inside rotor, when considering permanent magnet synchronous machines. A detailed literature review of comparisons is presented. New material is presented highlighting the benefits of single sided axial flux geometry. The constraints and assumptions made when comparing possibilities are discussed in detail, including a study of the biases these can introduce. The basis of this comparison is founded on constant electromagnetic airgap shear stress, being the product of electric loading and magnetic loading, and indeed the constancy of both of those factors. The metric used for comparison is simply that of the masses of the active materials, steel, copper, and magnet material. Examples are presented, including a machine which recently went into production in quantity. A range of lesser issues which are relevant when one is making a choice, are presented and discussed.

Formation of red pigment by Monascus purpureus via diauxic growth on glucose and ethanol in submerged culture was optimized based on inoculum preparation and culture medium. A vegetative inoculum was prepared from spores grown on ethanol. The optimized culture medium was low in phosphates, and had an initial pH of 5.5. The characteristics of Monascus purpureus grown on glucose and on ethanol were compared: the specific consumption rate of glucose (q G ) was higher than the specific consumption rate of ethanol (q E ), whereas the specific growth rate was greatest with ethanol. The specific production rate of red pigment (p OD ) and pigment yield (Y OD/s ) with glucose was twice that with ethanol. A novel fermentation process was developed with M. purpureus initially grown with controlled ethanol formation, and consumption of the latter during pigment formation.

The study regards para-nitrophenol (p-NP) removal by a mixed culture in a batch reactor under aerobic conditions performed at low ratio substrate (p-NP) to p-NP degrading microorganisms (0.09 < I 0 / (X B,PNP ) 0 < 0.80 g COD PNP g VS S À1 ). p-NP biodegradation was modelled with a dual-biomass kinetic including Haldane formalism. The purpose was to examine the effect of operating conditions of acclimation phases in the kinetic parameters estimated by respirometric measurements. The experiments were conducted with a series of successive additions of p-NP and a biogenic substrate (Ss) in different proportions (0 < R = Ss/I < 6.6). To place emphasis on decisive role played by frequency and amount of p-NP supply, a parallel was drawn with continuous processes, characterising acclimation cycles by different organic loading rate (207 < OLR < 1490 mg COD PNP l À1 d À1 ). During acclimation, results showed progressively decreasing half saturation constant (K PNP s ) values (11.4-1.21 mg COD l À1 ) whereas inhibition coefficient K PNP I increased (72.4-289 mg COD l À1 ), as the specific degradation rate increased. The inverse behaviour was observed during starvation periods. At the end of acclimation, higher values of growth yield (0.39 < Y PNP < 0.63 mg COD X mg COD À1 PNP ) and maximum growth rate (1.09 < l PNP max < 2.01 d À1 ) were obtained for cycles with low R.

The production of lignin peroxidase (LiP), manganese peroxidase (MnP) and lipases by Geotrichum candidum were performed in order to control the decolourisation and biodegradation of olive mill wastewater (OMW). Optimisation of different factors showed that dilution, carbon and ammonium concentrations significantly affected decolourisation and activities of ligniolytic peroxidases (LiP and MnP) on OMW. Moreover, addition of olive oil and agitation improved the lipase production. Batch and continuous OMW treatments in settler or bubble column bioreactors showed high COD and colour removal efficiencies of 60% and 50%, respectively. Lipolytic activity was greater in the batch bubble column whereas, LiP and MnP productions were improved in the settler. The performance of the continuous processes decreased with the decrease of hydraulic retention time (HRT). It has been shown that decolourisation and biodegradation decreased with an average of 40% and 45%, respectively, by decreasing the HRT from 4 d to 1.7 d. j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / b i o r t e c h phenolic fractions has been done. Optimal conditions for the production of simultaneous enzymes, LiP, MnP and lipases were also explored in batch and continuous cultures.

The performance of a submerged membrane bioreactor (SMBR) has been investigated for abattoir wastewater (AW) treatment. The chemical oxygen demand (COD) of permeate has not exceeded 25 mg L À1 providing an average COD removal of 98%. Microbiological analysis showed that the SMBR has allowed a complete removal of fecal coliforms, Listeria and Salmonella. A significant reduction in the excess biomass production was also observed. In fact, the yield of biomass production (Yobs) ranged between 0 and 0.106 g suspended solids/g COD removed.

Treatment of olive mill wastewater by different biological process led to an important decrease of organic compounds but the black coloration due to the recalcitrant phenolic compounds persists. Experimental design using fractional factorial plan showed that, among the seven studied factors, yeast extract, dilution and glucose exhibited a positive effect on Pediococcus pentosaceus growth and treated olive mill wastewater (TOMW) decolourisation. Optimization of influent factors showed that 2.5 and 1 g/l are the suitable concentrations of glucose and yeast extract, respectively. Optimum TOMW decolourisation was reached when TOMW was diluted to 2.5 initial OD390 value. The growth of P. pentosaceus on TOMW led to high molecular weight phenolic compounds removal as shown by the sephadex G-50 chromatogram. Simple phenolic compound removal was also observed. Bacterial growth on TOMW induced an ecological removal of recalcitrant phenolic compounds without chemical sludge production.

The effects of different extracting solvents, used in two extraction methods, on the total polyphenol contents of Quercus coccifera L. and Juniperus phoenicea L. fruits were studied. The antioxidant and antibacterial activities of these extracts were evaluated. Water and organic solvents, used individually, such as acetone and chloroform, or in mixtures: acetone/water/acetic acid (90/9.5/0.5) and ethyl acetate/methanol/water (60/30/10), significantly affected total polyphenol content. The antioxidant activity of these extracts was investigated by the widely used ABTS Å+ method and the b-carotene bleaching test. The results showed that solvents with different polarities had significant effects on antioxidant activity. A few of these extracts are as strong as some common synthetic antioxidants. Extracts were also tested for their antibacterial effects on spoilage and pathogenic bacteria. Results showed that acetone/water/acetic acid extracts exhibited the highest antibacterial activities against all tested germs. It is also noteworthy that the Gram-positive bacteria, Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212, were inhibited more easily than were the Gram-negative ones. Since a strong correlation between polyphenol contents and biological activities was noted (correlation ranging between R 2 = 0.76 and R 2 = 0.84), we suggest the use of these extracts to prevent the deterioration of stored foods by bacteria, if any resulting organoleptic effects are acceptable.

Near one hundred isolates of Lactobacillus paraplantarum, Lactobacillus pentosus and Lactobacillus plantarum from table olives were studied. Strains were genotyped by rep-PCR. Although the technique failed to differentiate some isolates at the species level, it proved a robust and easy procedure that could be useful for distinguishing between related strains of L. paraplantarum, L. pentosus and L. plantarum from a large pool of unrelated strains of these species. A PCR-based screening revealed the presence of the plantaricin encoding genes plnA, plnB, plnC, plnD, plnE/F, plnF, plnI, plnJ, plnK, plnG and plnN in most isolates of the three species. Sequences of bacteriocin genes present in L. paraplantarum and L. pentosus were homologous to L. plantarum genes. Through a discriminating analysis of the bacteriocin gene profiles, it was possible to establish a relationship between the origin of isolation and the LAB isolates, regardless of species.

The essential oils (EOs) extracted from the aerial parts of cultivated Salvia officinalis L. and the berries of Schinus molle L. were analysed by gas chromatography-mass spectrometry (GC-MS) and 68 and 67 constituents were identified, respectively. The major constituents were 1,8-cineole (33.27%), β-thujone (18.40%), α-thujone (13.45%), borneol (7.39%) in S. officinalis oil and α-phellandrene (35.86%), β-phellandrene (29.3%), β-pinene (15.68%), p-cymene (5.43%) and α-pinene (5.22%) in S. molle oil. In its second part, the present study was conducted to evaluate the in vitro antimicrobial activity of both studied EOs. For this purpose, paper disc-diffusion method and broth microdilution test were used. The discdiffusion method showed significant zone of lysis against all the pathogens studied (gram-negative and gram-positive bacteria, yeast). These activities remained stable after six months, and decreased approximately by 20% after one year of storage of the EOs at 4 to 7°C. On comparing the efficiency of both EOs, S. officinalis EO exhibited higher antibacterial activity against the majority of strains and especially against Candida albicans (two fold more active according to the inhibition zones values). The minimal inhibitory concentrations (MICs) were reported between 4.5 mg/ml and 72 mg/ml on nutrient broth. The particular chemotype of each EO may be involved in its specific antimicrobial behaviour. Furthermore, the inhibitory effect of these EOs were evaluated against two foodborne pathogens belonging to Salmonella genus, experimentally inoculated (10 3 CFU/g) in minced beef meat, which was mixed with different concentrations of the EO and stored at 4 to 7°C for 15 days. Although the antibacterial activities of both EOs in minced beef meat were clearly evident, their addition had notable effects on the flavour and taste of the meat at concentrations more than 2% for S. molle and 1.5% for S. officinalis. One solution to the abovementioned problem may be the use of combinations of different food preservation systems. In this context, each of the EOs has been used along with low water activity (addition of NaCl) in addition to low refrigeration temperatures. Results on the Salmonella growth showed that some combinations could be recommended to eliminate germs from minced raw beef. By using this method, a stable and, from a microbiological point of view, safe meat can be produced without substantial loss in sensory quality. Results obtained herein, may suggest that the EOs of S. officinalis and S. molle possess antimicrobial activity, and therefore, they can be used in biotechnological fields as natural preservative ingredients in food and/or pharmaceutical industry.

Two novel sulfate-reducing bacterial strains, designated E-2 T and IMP-2, were isolated from geographically distinct locations. Strain E-2 T was recovered from marine sediments near Sfax (Tunisia), whereas strain IMP-2 originated from oilfield production fluids in the Gulf of Mexico. Cells were Gram-negative, non-sporulated, motile, vibrio-shaped or sigmoid. They were strictly anaerobic, mesophilic and moderately halophilic. Sulfate, sulfite, thiosulfate and elemental sulfur served as electron acceptors, but not nitrate or nitrite. H 2 (with acetate as carbon source), formate, fumarate, lactate, malate, pyruvate, succinate and fructose were used as electron donors in the presence of sulfate as terminal electron acceptor. Lactate was oxidized incompletely to acetate. Fumarate and pyruvate were fermented. Desulfoviridin and c-type cytochromes were present. 16S rRNA gene sequence analysis of the two strains showed that they were phylogenetically similar (99.0 % similarity) and belonged to the genus Desulfovibrio, with Desulfovibrio indonesiensis and Desulfovibrio gabonensis as their closest phylogenetic relatives. The G+C content of the DNA was respectively 60.4 and 62.7 mol% for strains E-2 T and IMP-2. DNA-DNA hybridization experiments revealed that the novel strains had a high genomic relatedness, suggesting that they belong to the same species. We therefore propose that the two isolates be affiliated to a novel species of the genus Desulfovibrio, Desulfovibrio marinus sp. nov. The type strain is strain E-2 T (5DSM 18311 T 5JCM 14040 T ).

For the 1st time, 4 olive cultivars, the Meski, Chemlali, Besbessi, and Tounsi, from the Tunisian market were investigated to evaluate the phenolic compounds' contribution in nutritional value of table olives. From the Meski cultivar, we have chosen 4 different samples to evaluate differences within the same cultivar. Basic characteristics and total phenolic content were evaluated in flesh and kernel. The highest value of flesh phenolic content was observed in sample M4 of the Meski cultivar; however, the lowest value was observed in the Besbessi cultivar and they were 1801 and 339 mg GA/100 g dry weight, respectively. The main simple phenolic compounds identified in flesh extracts are hydroxytyrosol, tyrosol, and vanillic acid. Oleuropein was not detected in any samples. The antioxidant activity of Tunisian olive flesh varies between 212 and 462 μM TEAC/g of dry weight. Antioxidant activity of olives was related to their phenolic content but we found a low correlation between phenolic content and TEAC.

This study evaluated the anaerobic degradation of landfill leachate and sulfate reduction as a function of COD/(SO 4 2− ) ratio in an upflow anaerobic fixed-bed reactor. The reactor, which was inoculated with a mixed consortium, was operated under a constant hydraulic retention time (HRT) of 5 days. We investigated the effect of COD/(SO 4 2− ) ratio variation on the sulfate reduction efficiency, hydrogen sulfide production, chemical oxygen demand (COD) removal, conductivity, and pH variation. The best reactor performance, with significant sulfate reduction efficiency and COD removal efficiency of 91% and 87%, respectively, was reached under a COD/(SO 4 2− ) ratio of 1.17. Under these conditions, microscopic analysis showed the abundance of vibrios and rod-shaped bacterial cells. Two anaerobic bacteria were isolated from the reactor sludge. Phylogenetic studies performed on these strains identified strain A1 as affiliated to Clostridium genus and strain H1 as a new species of sulfate-reducing bacteria affiliated to the Desulfovibrio genus. The closest phylogenetic relative of strain H1 was Desulfovibrio desulfuricans, at 96% similarity for partial 16S RNA gene sequence data. Physiological and metabolic characterization was performed for this strain.