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International audience; When designing a Multi-Processor System-on-Chip (MPSoC), a very large range of design alternatives arises from a huge space of possible design options and component choices. Literature proposes numerous Design-Space-Exploration (DSE) approaches which mainly focus on cost optimization. In this paper, we present a DSE approach which mainly focuses on the reliability of the whole design. This approach is based on a meta-model of Multi-Processor System-on-Chips (MPSoCs) which integrates the reliability evaluation. We develop a tool that allows designers to describe and optimize their platform based on the proposed meta-model. The results obtained for an MPSoC is presented, including the improved overall reliability of the system thanks to the automatic selection of the fault tolerance strategies for each component.

Two β-galactosidases from Lactobacillus, including a heterodimeric LacLM type enzyme from Lactobacillus reuteri L103 and a homodimeric LacZ type β-galactosidase from Lactobacillus bulgaricus DSM 20081, were studied for immobilization on chitin using a carbohydrate-binding domain (chitin-binding domain, ChBD) from a chitinolytic enzyme. Three recombinant enzymes, namely, LacLM-ChBD, ChBD-LacLM, and LacZ-ChBD, were constructed and successfully expressed in Lactobacillus plantarum WCFS1. Depending on the structure of the enzymes, either homodimeric or heterodimeric, as well as the positioning of the chitin-binding domain in relation to the catalytic domains, that is, upstream or downstream of the main protein, the expression in the host strain and the immobilization on chitin beads were different. Most constructs showed a high specificity for the chitin in immobilization studies; thus, a one-step immobilizing procedure could be performed to achieve up to 100% yield of immobilization without the requirement of prior purification of the enzyme. The immobilized-on-chitin enzymes were shown to be more stable than the corresponding native enzymes; especially the immobilized LacZ from L. bulgaricus DSM20081 could retain 50% of its activity when incubated at 37 °C for 48 days. Furthermore, the immobilized enzymes could be recycled for conversion up to eight times with the converting ability maintained at 80%. These results show the high potential for application of these immobilized enzymes in lactose conversion on an industrial scale.

Medical literature abounds with reports of injuries and fatalities caused by arrows and crossbow bolts. Crossbows are of particular forensic and traumatological interest, because their mode of construction allows for temporary mechanical storage of energy. A newly developed type of pistol (Arcus Arrowstar), which belongs to the category of air and carbon dioxide weapons, discharges arrow-shaped bolts actuated by carbon dioxide cylinders. As, to the best of the authors' knowledge, literature contains no information on this uncommon subclass of weapons it is the aim of this work to provide the experimental data and to assess the trauma potential of these projectiles based on the ascertained physical parameters. Basic kinetic parameters of these carbon dioxide-actuated bolts (velocity v = 39 m/s, energy E = 7.2 J, energy density E' = 0.26 J/mm(2)) are similar to bolts discharged by pistol crossbows. Subsequent firing resulted in a continuous and fast decrease in kinetic energy of the arrows. Test shots into ballistic soap blocks reveal a high penetration capacity, especially when compared to conventional projectiles of equal kinetic energy values (like, e.g., airgun pellets). To conclude, these data demonstrate the high efficiency of arrow-shaped projectiles, which are also characterized by a high cross-sectional density (ratio of mass to cross-sectional area of a projectile).

The Surface Nanoscale Kirkendall Effect is an important part of the Kirkendall effect, and has special role in the formation of surface nano material configurations. It can also cause faults in interconnection contact systems, yet this kind of effect has not yet been identified and studied in detail. Based on the obtained experimental results, this paper proposes a formation mechanism and model of the mixed-surface nanoscale Kirkendall effect formed by the role of Au metal catalyst islands/strips on a GaAs surface using the thermal Vapor-Liquid-Solid method. The diffusion of Ga, As, O atoms and the absorption of O atoms from a low-vacuum ambient into Au droplets forming surface nanoscale Au/Ga/O clusters leaves behind vacancies and voids, this process results in the nanoscale Kirkendall effect. In addition, the outward diffusion of the surface nanoscale Au/Ga/O clusters leaving behind bare GaAs holes in place of the former Au island forms the surface Kirkendall effect. Consequently, the combination of the two mentioned effects forms a new kind of KE, the so-called Surface Nanoscale Kirkendall Effect. This effect is generated either partly or completely, depending on the technological conditions. Accompanying this effect, the different configurations of nanomaterials have grown in number. The outward diffusion of surface nanoscale Au/Ga/O clusters was caused by the concentration of surface cluster gradients, the weakening of chemical bonds due to the accumulation of vacancies, the porosity, and pit-etching beneath the Au island. The diffusivity of surface Au/Ga/O clusters is numerically estimated. Its values vary from 2 &times, 10&minus, 10 to 10&minus, 11 m2/s. Potential applications of the surface nanoscale Kirkendall effect, making use of its advantages, limitations and disadvantages, are also discussed and proposed.

Selective harvesting for seasonal fruits like apples requires intensive manual labour in a short period; however, due to the delicate property of the fruits, it cannot be performed with an existing commercial machine, which urged to be replaced by robots. The goal of this study is to introduce a framework for motion and hierarchical task planning which allows the manipulator to pick apples in the orchard. The hierarchical task planning assures that the manipulator performs the harvesting task in the higher control level in corporation with other components: sensors system, mobile platform while dealing with the complicated and uncertain environment. The motion planning provides the abilities to the manipulator: to avoid the obstacles, to reach the targets, and to perform the detaching movement elaborated from a limited number of predefined strategies. This motion and task planning framework has been successfully evaluated in simulation, and the real-time tests show that the harvesting task is accomplished with assured communication between sensing, planning and executing.

Removal of microcrystalline cellulose agglomerates in a dry-mixing system (lactose, 100 M) predominantly occurs via abrasion. The agglomerate abrasion rate potential is estimated by the Stokes abrasion (StAbr) number of the system. The StAbrnumber equals the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. Basically, the StAbrnumber concept describes the blending condition of the dry-mixing system. The concept has been applied to investigate the relevance of process parameters on agglomerate abrasion in tumbling blenders. Here, process parameters such as blender rotational speed and relative fill volumes were investigated. In this study, the StAbrapproach revealed a transition point between abrasion rate behaviors. Below this transition point, a blending condition exists where agglomerate abrasion is dominated by the kinetic energy density of the powder blend. Above this transition point, a blending condition exists where agglomerates show (undesirable) slow abrasion rates. In this situation, the blending condition is mainly determined by the high fill volume of the filler. © 2012 American Association of Pharmaceutical Scientists.

A novel fluidized bed bioreactor (FBBR) was designed by integration of anaerobic granular activated carbon and aerobic sponge reactors. This FBBR was evaluated at different sponge volume fractions for treating a synthetic wastewater. Polyester urethane sponge with cube size of 1 × 1 × 1 cm and density of 28–30 kg/m3 with 90 cells per 25 mm was used as biomass carrier. The results indicate that the FBBR could remove more than 93% of dissolved organic carbon (DOC). The highest nutrient removal efficiencies (58.2% PO4-P and 75.4% NH4-N) were achieved at 40% sponge volume fraction. The system could provide a good condition for biomass growth (e.g. 186.2 mg biomass/g sponge). No significant different performance in specific oxygen uptake rate was observed between 30, 40, and 50% sponge volume fractions.

The Etropy problem has been widely applied in the assessment and analysis of landscape ecology. Research results are just at the indicators, not able to describe the spatial distribution of the landscape. In this paper, we will simulate the results of the application Etropy problem in landscape assessment based on a GIS. A GIS is used to store the information of layers on landscape structure, indicator analysis and map-layer assessment. This is a new research direction, research results of Etropy problem will be simulated by the evaluation map. Research have been applied in Sa Pa area - one of Vietnam's most mountainous district. Research results shown the landscape diversity in the research area and landscape area identification to be conserved.

We present VIGO, a novel online Bayesian classifier for both binary or multiclass problems. In our model, variational inference for multivariate Gaussian distribution technique is exploited to approximate the class conditional probability density functions of data in an online manner. Besides being a conservative learner with a low number of updates compared with many other popular algorithms, VIGO algorithm can be updated in a minibatch of an arbitrary size which makes it robust with noise data. Experiments over a large number of UCI datasets demonstrate the advantage of VIGO with many state-of-the-art methods presented in LIBOL - a prevalent library for online learning algorithms.

Jeokimyasal verilerin saha dagilim desenlerinin belirlenmesi calismalarinda uzamsal kume ve aykiri degerler buyuk onem tasir. Bunlar, sadece cevherlesmenin temel ozelliklerini degil, ayni zamanda maden yataginin ve cevher mineralinin alansal dagilimini da karakterize ederler. Bu calismada, cok degiskenli verinin alansal dagilim deseni konusunda yeni bir yontem tanitilacak olup bu yontemde stabil Mahalanobis uzakligi ile lokal Moran’s I 1 degeri baz alinmistir. Uzamsal matriksi olustururken, araligi belirlemek uzere oncelikle Moran’s I uzamsal korelogrami kullanilmistir. Daha sonra, belirli bir elementler toplulugu icin stabil Mehalanobis araligi hesaplanmistir. Son olarak, hem uzamsal birlik derecesini olcmek hem de, uzamsal kume ve aykiri degerler dahil olmak uzere Cu, Au, Mo, Ag, Pb, Zn, As ve Sb birliklerinin uzamsal dagilim desenlerini belirlemek icin yersel Moran’s I 1 istatistigi uygulanmistir. Hem ham veri hem de Box-Cox donusum verisi uzerinde alti degisik olcekte (2km, 4km, 6km, 8km, 10km ve 12km) uzamsal desen analizi yapilmistir. Elde edilen sonuclar, Moran’s I 1 ve stabil Mahalanobis ile tanimlanan uzamsal kume ve uzamsal aykiri deger alanlarinin nesnel gerceklik ile uyum sagladiklarini, ayrica calisma alaninda bilinen maden yataklari ile de uyumlu bir iliski gosterdiklerini ortaya koymustur.

This paper evaluated a novel pilot scale electrocoagulation (EC) system for improving total phosphorus (TP) removal from municipal wastewater. This EC system was operated in continuous and batch operating mode under differing conditions (e.g. flow rate, initial concentration, electrolysis time, conductivity, voltage) to evaluate correlative phosphorus and electrical energy consumption. The results demonstrated that the EC system could effectively remove phosphorus to meet current stringent discharge standards of less than 0.2mg/L within 2 to 5min. This target was achieved in all ranges of initial TP concentrations studied. It was also found that an increase in conductivity of solution, voltages, or electrolysis time, correlated with improved TP removal efficiency and reduced specific energy consumption. Based on these results, some key economic considerations, such as operating costs, cost-effectiveness, product manufacturing feasibility, facility design and retrofitting, and program implementation are also discussed. This EC process can conclusively be highly efficient in a relatively simple, easily managed, and cost-effective for wastewater treatment system.

In the mining industry, conventional methods such as GPS and total station technology are used most extensively for data collection and in return used to compute volume of extracted materials (ore and waste). In situation where the ore body is bigger in size, and changes dynamically, the use of conventional method to measure volume of ore is not practicable and economically viable because of the workload involved, precision and accuracy of the survey and safety of workers. In this paper a method and work flow of ore heap volume measurement by using 3D laser scanning technique to acquire point cloud data was introduced. RiSCAN PRO and Geomagic studio was used to process the original data (registration, noise elimination, georeferencing, resampling etc.), 3D modeling and volume computations. A comparison on precision of geodetic control points coordinate measured by GPS receivers and 3D laser scanner was carried out. The results indicate that 3D laser scanning technique can effectively be applied to ore output volume measurement since it satisfies the requirement of ore volume measurement.

The membrane bioreactor system (MBR) with pre-treatment of sponge tray bioreactor (STB) was evaluated at different operating conditions for treating primary treated sewage (PTS). The result indicated the successful removal of DOC with the efficiency of higher than 95%. The highest nutrient removal efficiency of 83.6% (NH 4 -N) and 75.5% (PO 4 -P) was observed at sludge concentration of 330 mg/L. Specific oxygen uptake rate (SOUR) of activated sludge in MBR kept increasing up to 6 mg O 2 /g VSS h during stage IV. The sludge volume index (SVI) of less than 100 mL/g during the operation indicated the good settling property of the sludge. At highest sludge concentration of 5 g/L, trans-membrane pressure (TMP) was increasing dramatically during first 15 d up to 25 kPa; however it was only 6 kPa at lower sludge concentrations. It is concluded that the system showed the highest performance at stage III with sludge concentration of 330 mg/L.

The performance of a novel sponge-submerged membrane bioreactor (SSMBR) was evaluated to treat primary treated sewage effluent at three different activated sludge concentrations. Polyurethane sponge cubes with size of 1 × 1 × 1 cm were used as attached growth media in the bioreactor. The results indicated the successful removal of organic carbon and phosphorous with the efficiency higher than 98% at all conditions. Acclimatised sponge MBR showed about 5% better ammonia nitrogen removal at 5 and 10 g/L sludge concentration as compared to the new sponge system. The respiration test revealed that the specific oxygen uptake rate was around 1.0-3.5 mgO(2)/gVSS.h and likely more stable at 10 g/L sludge concentration. The sludge volume index of less than 100 mL/g during the operation indicated the good settling property of the sludge. The low mixed liquor suspended solid increase indicated that SSMBR could control the sludge production. This SSMBR was also successful in reducing membrane fouling with significant lower transmembrane pressure (e.g. only 0.5 kPa/day) compared to the conventional MBR system. Further study will be conducted to optimise other operating conditions.

The new attached growth sponge tray bioreactor (STB) was evaluated at different operating conditions for removing organics and nutrients from primary treated sewage effluent. This STB was also assessed when using as a pre-treatment prior to micro-filtration (MF) for reducing membrane fouling. At a short hydraulic retention time (HRT) of 40min, the STB could remove up to 92% of DOC and 40-56% of T-N and T-P at an organic loading rate (OLR) of 2.4kg COD/m3 spongeday. This OLR is the best for the STB as compared to the OLRs of 0.6, 1.2 and 3.6kg COD/m3 spongeday. At 28mL/min of flow velocity (FV), STB achieved the highest efficiencies with 92% of DOC, 87.4% of T-P, and 54.8% of T-N removal. Finally, at the optimal OLR and FV, the STB could remove almost 90% of organic and nutrient, significantly reduce membrane fouling with HRT of only 120min. © 2010 Elsevier Ltd.

Food-grade gene expression systems for lactic acid bacteria are useful for applications in the food industry. We describe a new food-grade host/vector system for Lactobacillus plantarum based on pSIP expression vectors and the use of the homologous alanine racemase gene (alr) as selection marker. A new series of expression vectors were constructed by exchanging the erythromycin resistance gene (erm) in pSIP vectors by the L. plantarum WCFS1 alr gene. The vectors were applied for the overexpression of β-galactosidase genes from L. reuteri L103 and L. plantarum WCFS1 in an alr deletion mutant of L. plantarum WCFS1. The expression levels obtained in this way, i.e. without the use of antibiotics, were comparable to the levels obtained with the conventional system based on selection for erythromycin resistance. The new system is suitable for the production of ingredients and additives for the food industry.

This study is set out to assess surface water quality of three groups of chemical (pH, COD, NH4+), of physics (TSS) and of microorganisms (Coliform) in the Cam Pha mining area, northeast Vietnam. GIS and hierarchical clustering technique were used for interpolation and grouping samples that have similar water quality, respectively. The results showed that surface water quality was heavily contaminated. All of indicators do not meet Vietnam's National Technical Regulations (NTR), especially COD and TSS beyond NTR about ten times at many locations such as TSS at Ha Rang stream, NH4+ at Cau Four River and COD at Khe Sim stream. The worst and best water quality was detected at Ha Rang and Khe Sim and Lep My, Khe Re, and Ong Linh streams, respectively. The results of this study demonstrated GIS and hierarchical clustering technique are effective methods for surface water quality assessments.

Influences of the symmetric Stone-Wales (SW) defect on the electronic transport properties of the zigzag graphene nanoribbons (ZGNRs) has been studied using $\it{ab}$ $\it{ initio}$ simulation based on density functional theory (DFT) combined with non-equilibrium Green's function (NEGF) technique. The calculated transmission spectra T(E) at various bias windows, device densities of states (DDOS), current characteristics as well as local density of states (LDOS) of the defective asymmetric and symmetric ZGNRs are presented in comparison of those for the pristine ZGNRs. It has been established the metallic character of the electronic transport in asymmetric ZGNRs, and in symmetric ones, the current has a semiconductor behavior, with negative differential resistance (NDR) effect. Symmetric SW defect, as a most unfavorable SW defect type for electric conductance, remarkably decreases the current values, but does not change the character of conductivity in both the asymmetric and symmetric ZGNRs. NDR has been explained by the altering by SW defect the number of frontier molecular orbitals entering bias windows.

In this study, a new combined inorganic–organic flocculant (CIOF) of FeCl3 and membrane performance enhancer (MPE50) was prepared and added to an aerated submerged membrane bioreactor (SMBR). The effects of CIOF on the performance of an aerated submerged membrane bioreactor (SMBR) were evaluated. The results indicated that the SMBR with CIOF addition could remove almost 100% total phosphate while eliminating over 90% ammonia (NH4-N) and dissolved organic carbon (DOC) during an 80-day of operation. The respiration tests revealed that the specific oxygen uptake rate (SOUR) was stable around 1.5–2.0 mg O2/gMLVSS h. The sludge volume index (SVI) of less than 100 mL/g during the operation showed the importance of CIOF on the improvement of settling properties of the sludge. Soluble carbohydrate concentration was also well correlated with DOC of the supernatant. CIOF was successful in the reduction of fouling of membrane as the membrane was only chemically cleaned after 53 days of operation.

Recombinant beta-galactosidase from Lactobacillus plantarum WCFS1, homologously over-expressed in L. plantarum, was purified to apparent homogeneity using p-aminobenzyl 1-thio-beta-d-galactopyranoside affinity chromatography and subsequently characterized. The enzyme is a heterodimer of the LacLM-family type, consisting of a small subunit of 35kDa and a large subunit of 72kDa. The optimum pH for hydrolysis of its preferred substrates o-nitrophenyl-beta-d-galactopyranoside (oNPG) and lactose is 7.5 and 7.0, and optimum temperature for these reactions is 55 and 60 degrees C, respectively. The enzyme is most stable in the pH range of 6.5-8.0. The K(m), k(cat) and k(cat)/K(m) values for oNPG and lactose are 0.9mM, 92s(-1), 130mM(-1)s(-1) and 29mM, 98s(-1), 3.3mM(-1)s(-1), respectively. The L. plantarum beta-galactosidase possesses a high transgalactosylation activity and was used for the synthesis of prebiotic galacto-oligosaccharides (GOS). The resulting GOS mixture was analyzed in detail, and major components were identified by using high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) as well as capillary electrophoresis. The maximal GOS yield was 41% (w/w) of total sugars at 85% lactose conversion (600mM initial lactose concentration). The enzyme showed a strong preference for the formation of beta-(1-->6) linkages in its transgalactosylation mode, while beta-(1-->3)-linked products were formed to a lesser extent, comprising approximately 80% and 9%, respectively, of the newly formed glycosidic linkages in the oligosaccharide mixture at maximum GOS formation. The main individual products formed were beta-d-Galp-(1-->6)-d-Lac, accounting for 34% of total GOS, and beta-d-Galp-(1-->6)-d-Glc, making up 29% of total GOS.

In this study, laboratory-scale anaerobic fluidized bed bioreactors (AFBBRs) using granular activated carbon as bedding material were employed for treating a primary treated sewage effluent (PTSE) with or without refractory organic pollutants (ROPs). A new starch based flocculant (NSBF) combining a nature starch based cationic flocculants and trace nutrients was prepared and applied in the AFBBR. The impact of NSBF on the performance of AFBBR was mainly evaluated in terms of organic and nutrient removal and microbial activity. Membrane fouling based on critical flux was assessed when the bioreactor used as pretreatment for microfiltration. The results indicated that the addition of NSBF in AFBBR (NSBF-AFBBR) not only attained improved organic (9-10%) and nutrient removal (10-20%), higher biomass growth (3.0 gbiomass/LGAC) and net bed expansion (18 cm), but also doubled the critical flux (from 15 L/m3 h to 30 L/m3 h) in the microfiltration system. In addition, NSBF-AFBBR could retain 10% better DOC removal efficiency at different recirculation rates for treating PTSE with ROPs. When increasing organic loading rate from 21.6 kg COD/m3 d to 43.2 kg COD/m3 d, NSBF-AFBBR achieved comparatively constant organic removal of 55% whereas the efficiency in AFBBR alone decreased dramatically from 47% to 34%. Thus, NSBF could act as a performance enhancer for AFBBR. © 2010 Elsevier B.V. All rights reserved.

The effects of polyurethane sponge size and type on the performance of an up-flow sponge bioreactor were studied using different sponge cube sizes (1 × 1 × 1 cm, 2 × 2 × 2 cm and 3 × 3 × 3 cm) and types of sponge (S28-30/45R, S28-30/60R, S28-30/80R and S28-30/90R). The reactors were operated under anaerobic conditions in an early stage and an aerobic condition in a latter stage. The results indicate that there was no significant difference in the organic and nutrient removal rates between sponge types. The medium size sponge (2 × 2 × 2 cm) had the best performance in terms of both biomass growth and pollutants removal. Under anaerobic condition, the COD, TN and TP removal efficiencies were up to 70%, 45% and 55%, respectively, and significantly improved under aerobic conditions (e.g. >90% TOC, 95% COD, 65% TN and 90% TP). The external biomass grew faster under anaerobic conditions while internal biomass was dominant under aerobic condition. © 2009 Elsevier Ltd.

The following paper researches into application of digital technology for explosives performance test, especially ballistic mortar test. The proposed approach provides a direct measurement of maximum throw angle of pendulum in ballistic mortar test. The measurement equipment for ballistic mortar (MEBM) is designed, produced, and applied in the defense industries in Vietnam. MEBM is developed and produced based on angle encoder, CPU S7 200, TD 200. With the new proposed approach, the measurement process, signal transfer, digital signal processing, data computing, and display are fully automatic. It overcomes the disadvantages of old approach, such as indirect measurement of throw angle, where measurement error depending on marker record, rule, and subjectivity of measurer. The testing and triggering detonator is integrated in MEBM.

This paper introduces a mechanism to learn optimal classifier combining algorithms for an ensemble system. By using a genetic algorithm approach that focuses on 3 objectives namely the number of correct classified observations, the number of selected features and the number of selected classifiers, optimal solution can be achieved after several interactions of crossover and mutation. We also employ the Ordered Weighted Averaging operator in which a weight vector is built by a Linear Decreasing (LD) function to find average values of outputs from combining algorithms. Experiments on 2 well-known UCI Machine Learning Repository datasets demonstrate benefits of our approach compared with other state-of-the-art ensemble methods like Decision Template, SCANN and all fixed combining algorithms in the ensemble system.

In this paper we introduce a novel approach for classifier and feature selection in a multi-classifier system using Genetic Algorithm (GA). Specifically, we propose a 2-part structure for each chromosome in which the first part is encoding for classifier and the second part is encoding for feature. Our structure is simple in the implementation of the crossover as well as the mutation stage of GA. We also study 8 different fitness functions for our GA based algorithm to explore the optimal fitness functions for our model. Experiments are conducted on both 14 UCI Machine Learning Repository and CLEF2009 medical image database to demonstrate the benefit of our model on reducing classification error rate.

2,5-diketo-D-gluconic acid reductase (2,5-DKG reductase) catalyses the reduction of 2,5-diketo-D-gluconic acid (2,5-DKG) to 2-keto-L-gulonic acid (2-KLG), a direct precursor (lactone) of L-ascorbic acid (vitamin C). This reaction is an essential step in the biocatalytic production of the food supplement vitamin C from D-glucose or D-gluconic acid. As 2,5-DKG reductase is usually produced recombinantly, it is of interest to establish an efficient process for 2,5-DKG reductase production that also satisfies food safety requirements. In the present study, three recently described food grade variants of the Lactobacillales based expression systems pSIP (Lactobacillus plantarum) and NICE (Lactococcus lactis) were evaluated with regard to their effictiveness to produce 2,5-DKG reductase from Corynebacterium glutamicum. Our results indicate that both systems are suitable for 2,5-DKG reductase expression. Maximum production yields were obtained with Lb. plantarum/pSIP609 by pH control at 6.5. With 262 U per litre of broth, this represents the highest heterologous expression level so far reported for 2,5-DKG reductase from C. glutamicum. Accordingly, Lb. plantarum/pSIP609 might be an interesting alternative to Escherichia coli expression systems for industrial 2,5-DKG reductase production.

A pilot scale membrane bioreactor hybrid system (MBR-HS) was evaluated for municipal wastewater treatment. This novel system comprised of a granular activated carbon-sponge fluidized bed bioreactor (GACS-FBBR) followed by a submerge membrane bioreactor (MBR) with the capacity of 2 L/min. The results indicated that the MBR-HS could effectively remove 90% DOC and 95% NH4–N. PO4–P removal efficiency was remained stable at about 70% throughout the experiment. Specific oxygen uptake rate (SOUR) of activated sludge increased from 0.72 to 2.21 mg O2/gVSS h for the first 10 days and then followed by a steady stage until the end of experiment. Sludge volume index (SVI) was always below 50 mL/g, demonstrated an excellent settling properties of sludge. The system also showed an achievement in terms of low trans-membrane pressure (TMP) development rate. The TMP increasing rate was only 0.65 kPa/day, suggesting GACS-FBBR can be a promising pre-treatment for MBR.

The lacLM genes from Lactobacillus sakei Lb790, encoding a heterodimeric β-galactosidase that belongs to glycoside hydrolase family GH2, were cloned and heterologously expressed in Escherichia coli . Subsequently, the recombinant β-galactosidase LacLM was purified to apparent homogeneity and characterized. The enzyme is a β-galactosidase with narrow substrate specificity because o-nitrophenyl-β-D-galactopyranoside (oNPG) was efficiently hydrolyzed, whereas various structurally related oNP analogues were not. The K(m) and k(cat) values for oNPG and lactose were 0.6 mM and 180 s(-1) and 20 mM and 43 s(-1), respectively. The enzyme is inhibited competitively by its two end-products D-galactose and D-glucose (K(i) values of 180 and 475 mM, respectively). As judged by the ratio of the inhibition constant to the Michaelis constant, K(i)/K(m), this inhibition is only very moderate and much less pronounced than for other microbial β-galactosidases. β-Galactosidase from L. sakei possesses high transgalactosylation activity and was used for the synthesis of galacto-oligosaccharides (GalOS), employing lactose at a concentration of 215 g/L. The maximum GalOS yield was 41% (w/w) of total sugars at 77% lactose conversion and contained mainly non-lactose disaccharides, trisaccharides, and tetrasaccharides with approximately 38, 57, and 5% of total GalOS formed, respectively. The enzyme showed a strong preference for the formation of β-(1→6)-linked transgalactosylation products, whereas β-(1→3)-linked compounds were formed to a lesser extent and β-(1→4)-linked reaction products could not be detected.

Background Two sets of overlapping genes, lacLMReu and lacLMAci, encoding heterodimeric β-galactosidases from Lactobacillus reuteri and Lactobacillus acidophilus, respectively, have previously been cloned and expressed using the pSIP vector system and Lactobacillus plantarum WCSF1 as host. Despite the high similarity between these lacLM genes and the use of identical cloning and expression strategies, strains harboring lacLMReu produced about twenty-fold more β-galactosidase than strains containing lacLMAci. Results In this study, the plasmid copy numbers (PCN) of expression vectors pEH9R (lacLMReu) and pEH9A (lacLMAci) as well as the transcription levels of both lacLM genes were compared using quantitative PCR methods. Analyses of parallel fermentations of L. plantarum harboring either pEH9R or pEH9A showed that the expression plasmids were present in similar copy numbers. However, transcript levels of lacLM from L. reuteri (pEH9R) were up to 18 times higher than those of lacLM from L. acidophilus (pEH9A). As a control, it was shown that the expression levels of regulatory genes involved in pheromone-induced promoter activation were similar in both strains. Conclusion The use of identical expression strategies for highly similar genes led to very different mRNA levels. The data indicate that this difference is primarily caused by translational effects that are likely to affect both mRNA synthesis rates and mRNA stability. These translational effects thus seem to be a dominant determinant for the success of gene expression efforts in lactobacilli.

This study aims at evaluating the impacts of flocculant addition to a submerged membrane bioreactor (SMBR). Three types of common flocculants (FeCl3, PACl and chitosan) were tested based on the performance of organic and nutrients removal, respiration test and fouling control. The data showed that all of the flocculants not only could keep high removal efficiencies of DOC and COD (>90%) compared to SMBR alone, but also exhibited different advantages and disadvantages according to the properties of the flocculants. For instance, inorganic flocculants strongly affected the nitrification process and organic flocculant addition slightly reduced the phosphorus removal efficiency in SMBR. After adding FeCl3 and PACl, NH4-N removal decreased to 31.9% and 11.1%, while T-N removal dropped to 22% and 0.5% respectively. Although flocculants addition improved sludge settleability and oxygen transfer to some extent, organic flocculant obtained more stable sludge volume indexes (SVI) and specific oxygen uptake rates (SOUR) than those of inorganic flocculants. Inorganic flocculants, on the other hand, led to more reduction of soluble microbial products (SMP) present in mixed liquor and lower membrane fouling rates (1.3 and 2.6 kPa/day for FeCl3 and PACl respectively). © 2009 Elsevier B.V. All rights reserved.

Biosolids are organic by-products from wastewater treatment plants that contain valuable nutrients but also represent a pollution problem. The amount of heavy metals in biosolids at high concentrations prevents their use as fertilizers. The aim of the present study is to immobilize heavy metals in biosolids using phosphate amendments. Analytical-grade potassium dihydrogenphosphate (KH2PO4) was used as the source of phosphate, and its ability to reduce heavy metals in biosolids (200 g) was evaluated according to five additional phosphate quantities: Control (C) (without phosphate), P1 (1.45 g), P2 (2.9 g), P3 (5.8 g), P4 (10.15 g), and P5 (14.5 g). The effect of phosphate treatments on metal extractability was evaluated using the selective sequential extraction (SSE) method, and total metal concentrations were analyzed by the (US Environmental Protection Agency) EPA 6010 and EPA 3051 methods. The total and extractable level of metals showed that Cu, Zn and Pb were the predominant elements in the biosolids analyzed in this study (control). SSE results showed that, on average, over 80% of the total metals present in the biosolids were found in the organic (F4) and residual (F5) fractions for Cu and Zn; Fe–Mn oxide (F3), organic (F4) and residual (F5) fractions for Cd; exchangeable (F1) and residual (F5) fractions for Pb; and exchangeable (F1), organic (F4) and residual (F5) fractions for Ni. The addition of phosphate substantially decreased the amount of metals (Cu, Zn, Cd, Pb, and Ni) in biosolids after a 10-day period; however, the amount of removal varied between the examined analytical techniques.

The success of the chemotherapeutic treatment of hydatid disease is based upon the drug ability to operate on the germinal layer and on the protoscolices of the hydatid cyst interior at adequate concentrations for sufficient periods. The goal of this study was to evaluate the ability of the drug diffusion through the cyst membrane from sheep hydatid cysts and the increase of drug concentration in the cyst environment. In the first part of this work, the permeation behaviour through the hydatid cyst membrane was studied with five model molecules, having different molecular descriptors (logP, molecular weight, polar surface area ...) onto static Franz glass diffusion cells. A good correlation has been observed between the permeation coefficient and the partition coefficient, log P (r=0.951). In the second part, albendazole-loaded nanoparticles (about 300 nm) prepared by the emulsion solvent evaporation method have shown a sufficient entrapment efficiency (36.4 +/- 6.4%) to raise the apparent solubility of albendazole. The diffusion of drug from the nanoparticles across the hydatid cyst membrane was also improved compare to albendazole suspension. These results have shown the interest of the albendazole-loaded nanoparticles for the treatment of hydatid cysts in the future.

Background: Two overlapping genes lacL and lacM (lacLM) encoding for heterodimeric β-galactosidase from Lactobacillus reuteri were previously cloned and over-expressed in the food-grade host strain Lactobacillus plantarum WCFS1, using the inducible lactobacillal pSIP expression system. In this study, we analyzed different factors that affect the production of recombinant L. reuteri β-galactosidase. Results: Various factors related to the cultivation, i.e. culture pH, growth temperature, glucose concentration, as well as the induction conditions, including cell concentration at induction point and inducer concentration, were tested. Under optimal fermentation conditions, the maximum β-galactosidase levels obtained were 130 U/mg protein and 35–40 U/ml of fermentation broth corresponding to the formation of approximately 200 mg of recombinant protein per litre of fermentation medium. As calculated from the specific activity of the purified enzyme (190 U/mg), β-galactosidase yield amounted to roughly 70% of the total soluble intracellular protein of the host organism. It was observed that pH and substrate (glucose) concentration are the most prominent factors affecting the production of recombinant β-galactosidase. Conclusions: The over-expression of recombinant L. reuteri β-galactosidase in a food-grade host strain was optimized, which is of interest for applications of this enzyme in the food industry. The results provide more detailed insight into these lactobacillal expression systems and confirm the potential of the pSIP system for efficient, tightly controlled expression of enzymes and proteins in lactobacilli.