Gotowa bibliografia na temat „Liquid Blast Tube”

The combustion characteristics and emission from a gas turbine greatly depends on the spray characteristics. Pre-filming air-blast atomizers are commonly used in gas turbines due to their high spray cone angle and shorter atomization axial distance when compared to direct air-blast atomizers. Various numerical models are available in the open literature for predicting droplet characteristics. In the present study commercial code FLUENT 6.3 is used to predict the spray characteristics. The numerical results are validated against experimental results and further the spray characteristics in terms of radial Sauter mean diameter (SMD), mass flux distribution at varied axial distance and swirl number (S) have been discussed. The variation of predicted SMD with swirl number demonstrated a decrease in its value for each level of increase in the swirl number. Smaller droplets start to appear further downstream in addition to significant increase in radial spread of droplets. Negligible mass contribution from the smaller droplets at the boundary compared to that from bigger droplets at the centre was observed. Recessing the liquid tube at the exit of air nozzles showed a slight decrease in SMD. Recessing the liquid tube in the exit air nozzles results in a slight in SMD values, hence, the recessing of liquid post in the atomizer within certain limit might be beneficial not only helping in flame holding but also resulting in finer spray. The lessons learnt from this study on use of CFD for simulating the atomization process is highlighted.

DLR investigated forced combustion oscillations of two liquid fuel burners in a research combustion chamber at elevated pressures simulating idle conditions of aircraft engine combustors. The work was performed in collaboration with MTU Munich. An existing combustion chamber with optical access, capable to operate up to 20 bar, was upgraded with an air flow pulsator, that bypasses air from the combustor plenum to the exhaust with a sinusoidal massflow variation up to 700 Hz. Pressure transducers in the plenum and the flame tube monitored the forced disturbances. A photomultiplier recorded the OH* chemiluminescence of the flame. For the agreed operating conditions frequency scans of these values were registered. Additionally images of the OH* chemiluminescence were taken at selected frequencies and evaluated in a statistical manner, to separate turbulent and periodic behavior. From the analysis of the pressure data, it can be concluded, that serious thermoacoustic feedback was not observed for both burners. However, burner 2 with the flame detached from the wall exhibited a higher fluctuation level as burner 1 with the wall attached flame. A resonant behavior was observed near the characteristic frequency of the sound room comprised of plenum, flame tube, and burner nozzle as connecting passage. The chemiluminescence images show different modes of spatial fluctuation for the burners and for burner 2 they also vary with the operating condition.

Double skin composite (DSC) construction or Steel/concrete/steel sandwich construction (SCSS) is an innovative and relatively new form of composite construction that can be used in submerged tube tunnels, bridges deck, nuclear structures, liquid and gas containment structures, offshore and onshore structures, military shelters, and shear walls in buildings. The system consists of a plain concrete core sandwiched between two steel plates interconnected together by various types of mechanical shear connectors. The DSC construction perceives advantages that the external steel plates act as both formwork and primary reinforcement, and also as impermeable, blast and impact resistant membranes. The major duty of the shear connectors is to withstand longitudinal shear force and beam/slab separation, while in the bi-steel type where shear connectors are friction welded at both their two ends to two parallel steel plates, the longitudinal and transverse shear force, as well as plate buckling are resisted. The present paper highlights the previous prime researches concerning the subjects of SCSS composite construction, specifically on the conducted tests (push-out tests, tensile, direct shear tests, and bending tests) in which the components of partial interaction (uplift and slip forces) are resisted by various types of shear connectors.

OBJECT Blast-induced neurotrauma (BINT), if not fatal, is nonetheless potentially crippling. It can produce a wide array of acute symptoms in moderate-to-severe exposures, but mild BINT (mBINT) is characterized by the distinct absence of acute clinical abnormalities. The lack of observable indications for mBINT is particularly alarming, as these injuries have been linked to severe long-term psychiatric and degenerative neurological dysfunction. Although the long-term sequelae of BINT are extensively documented, the underlying mechanisms of injury remain poorly understood, impeding the development of diagnostic and treatment strategies. The primary goal of this research was to recapitulate primary mBINT in rodents in order to facilitate well-controlled, long-term investigations of blast-induced pathological neurological sequelae and identify potential mechanisms by which ongoing damage may occur postinjury. METHODS A validated, open-ended shock tube model was used to deliver blast overpressure (150 kPa) to anesthetized rats with body shielding and head fixation, simulating the protective effects of military-grade body armor and isolating a shock wave injury from confounding systemic injury responses, head acceleration, and other elements of explosive events. Evans Blue-labeled albumin was used to visualize blood-brain barrier (BBB) compromise at 4 hours postinjury. Iba1 staining was used to visualize activated microglia and infiltrating macrophages in areas of peak BBB compromise. Acrolein, a potent posttraumatic neurotoxin, was quantified in brain tissue by immunoblotting and in urine through liquid chromatography with tandem mass spectrometry at 1, 2, 3, and 5 days postinjury. Locomotor behavior, motor performance, and short-term memory were assessed with open field, rotarod, and novel object recognition (NOR) paradigms at 24 and 48 hours after the blast. RESULTS Average speed, maximum speed, and distance traveled in an open-field exploration paradigm did not show significant differences in performance between sham-injured and mBINT rats. Likewise, rats with mBINT did not exhibit deficits in maximum revolutions per minute or total run time in a rotarod paradigm. Short-term memory was also unaffected by mBINT in an NOR paradigm. Despite lacking observable motor or cognitive deficits in the acute term, blast-injured rats displayed brain acrolein levels that were significantly elevated for at least 5 days, and acrolein’s glutathione-reduced metabolite, 3-HPMA, was present in urine for 2 days after injury. Additionally, mBINT brain tissue demonstrated BBB damage 4 hours postinjury and colocalized neuroinflammatory changes 24 hours postinjury. CONCLUSIONS This model highlights mBINT’s potential for underlying detrimental physical and biochemical alterations despite the lack of apparent acute symptoms and, by recapitulating the human condition, represents an avenue for further examining the pathophysiology of mBINT. The sustained upregulation of acrolein for days after injury suggests that acrolein may be an upstream player potentiating ongoing postinjury damage and neuroinflammation. Ultimately, continued research with this model may lead to diagnostic and treatment mechanisms capable of preventing or reducing the severity of long-term neurological dysfunction following mBINT.

Vibrio vulnificus is a ubiquitous marine bacterium frequently isolated from shellfish and associated with severe and often fatal disease in humans. Various control strategies to reduce the disease risk associated with V. vulnificus contamination in shellfish have been proposed. However, evaluating the efficacy of these control strategies is complicated because of the difficulty in distinguishing V. vulnificus from the high levels of background environmental Vibrio spp. The purpose of this research was to develop a model indicator V. vulnificus strain that could be readily differentiated from background microflora and used to facilitate the evaluation of processing efficacy. A spontaneous nalidixic acid–resistant strain of V. vulnificus (Vv-NA) was prepared from a wild-type parent (Vv-WT) using selective plating techniques. Vv-NA was very similar to Vv-WT with respect to biochemical characteristics, appearance on selective plating media, detection limits using most probable number and polymerase chain reaction, and growth rate. In comparative freeze inactivation studies on pure cultures, Vv-WT and Vv-NA had similar freeze inactivation profiles at −20°C (conventional freezing), at −85°C (cold blast freezing), and in liquid nitrogen (cryogenic freezing). In oyster homogenates artificially inoculated with Vv-NA, the organism was inactivated 95 to 99% after freezing, irrespective of freezing temperature. Thermal inactivation comparisons of pure cultures of Vv-WT and Vv-NA using the capillary tube method revealed statistically significant differences in D values at 47°C (2.2 versus 3.0 min, respectively) and 50°C (0.83 versus 0.56 min, respectively), but nearly identical values at 52°C (0.21 versus 0.22 min, respectively). However, these D values were notably higher than those reported by other investigators and hence provided a conservative means by which to evaluate thermal inactivation. In oyster homogenates seeded with Vv-NA, D values of 1.3 ± 0.09 min and 0.41 ± 0.01 min were obtained at 46°C and 48°C, respectively. This study demonstrated that Vv-NA is readily enumerated and could be used as a surrogate for evaluating the degree of V. vulnificus inactivation provided by freezing and thermal treatments of oyster homogenates.

Boxwood (Buxus spp.) are commercially important evergreen ornamental plants with an annual market value of over $103 million in the United States. The recent U.S. incursion of boxwood blight disease caused by the fungus Calonectria pseudonaviculata (syn. Cylindrocladium pseudonaviculatum, Cy. buxicola) threatens the health and productivity of boxwood in both landscape plantings and nurseries. The first confirmed U.S. reports of the disease were made from Connecticut and North Carolina in November 2011 (2,4), followed by diagnoses in 10 additional states during 2012 and 2013. By August 2013, symptoms consistent with boxwood blight had been observed from B. sempervirens in Delaware, Maryland, New Jersey, and southeastern New York. Affected plants showed rapid onset of disease symptoms: dark brown to black spots or diffuse dark areas on leaves, followed by defoliation. Narrow, elongate black cankers also formed on current season shoots. Symptomatic stems and leaves were placed in petri dishes with moistened filter paper at 22°C for 3 days under continuous light. Conidiophores were excised, then placed on potato dextrose agar amended with streptomycin and neomycin (0.3 g/l). Resultant colonies showed dark brown pigmentation at the colony center surrounded by tan to reddish brown rings with white mycelia at the advancing edge. Conidia (n = 30 per isolate) were hyaline, cylindrical, rounded at both ends, with a single septum (45 to 76 × 4 to 6 μm; avg. 63 × 5 μm). Conidiophores (n = 20 per isolate) comprised a stipe, a hyaline septate stipe extension (length 119 to 192 μm; avg. 150 μm) and a terminal ellipsoidal vesicle (diameter 4 to 10 μm; avg. 7 μm). Based on morphological characteristics, the causal agent was identified as C. pseudonaviculata (1,4). Voucher specimens were deposited in the U.S. National Fungus Collections (BPI 892698 to 701). To verify morphological diagnosis, genomic DNA was extracted from fungal biomass grown in liquid cultures of yeast extract peptone dextrose media. A portion of the β-tubulin gene (TUB2) was PCR amplified and sequenced bi-directionally using primers Bta/Bt2b (3). BLASTn searches of NCBI GenBank databases using the TUB2 sequences (Accession Nos. KF785808 to 11) demonstrated 96 to 100% sequence identity with other C. pseudonaviculata isolates. To confirm pathogenicity, 5-month-old B. sempervirens and B. microphylla seedlings were spray-inoculated with a spore suspension of 1 × 104conidia/ml. One isolate from each state was independently tested with four replicates each. Non-inoculated water-sprayed plants served as negative controls. Plants were maintained in growth chambers at 22°C under constant light. Blight symptoms developed 4 to 5 days post inoculation. C. pseudonaviculata was re-isolated from inoculated plants; no symptoms or signs were observed from control plants. To our knowledge, this is the first report of C. pseudonaviculata in the states of Delaware, Maryland, New Jersey, and New York. This report demonstrates that C. pseudonaviculata is now widespread across the United States eastern seaboard, and represents a substantial threat to boxwood plants in North American landscapes and nurseries.References: (1) P. Crous et al. Sydowia 54:23, 2002. (2) D. F. Farr and A. Y. Rossman. Fungal Databases, USDA-ARS. Retrieved from http://nt.ars-grin.gov/fungaldatabases , 30 August 2013. (3) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (4) K. L. Ivors et al. Plant Dis. 96:1070, 2012.

Introduction: There are numerous methods of isolating and detecting organisms that are similar and closely related; one of the most reliable method is molecular typing of 16S rRNA. Apart from being omnipresent as a multigene family, or operons; it is evolutionarily stable; the 16S rRNA gene (1,500 bp) is large enough for informatics purposes. Materials and Method: This study employed molecular sequencing of 16S rRNA by Sanger method to reveal the specific organisms’ nucleotides and blasting (BLASTn) to show the similarities between the resulting organisms and existing organisms. The 16S rRNA remains the best choice of identification process for bacteria because of its distinguishing sizes and evolutionary stability. Results: All isolates were Gram positive rods and were positive in Biochemical tests such as oxidase, catalase, citrate, and protease but were in turn negative in coagulase and indole test tests. On sensitivity test; 80% of all the isolates were resistant to common antibiotics except ciprofloxacin and ceftriaxone. Based on the sequence difference in the variable region (V1) of 16S rRNA as observed from the molecular sequencing results; four isolates out of ten were identified. Six were different strains of B cereus. Others isolates include: wiedmannii, thuringensis, toyonensis and pseudomycoides. Sequence analysis of the primer annealing sites showed that there is no clear‐cut difference in the conserved region of 16S rRNA, and in the gyrB gene, between B. cereus and B. thuringiensis strains. Phylogenetic analysis showed that four isolates showed high similarity to each other; hence the limited number of deletions when subjected to alignments by maximum neighborhood joining parsimony using MEGA X software. B. toyonensis, B. wiedmannii and thuringensis were distantly related. Introduction Authors Pathogens cause illness and death in some countries and it also causes infections and gastrointestinal diseases in other countries thereby causing public health concern. Pathogens are organisms capable of causing diseases. Reliable methods are needed for the detection of pathogens due to pathogen evolution as a result of new human habits or new industrial practices. Microbial classification of organisms ranges from genus to specie level depending upon the technique used either phenotypic or genotypic. Presently, molecular methods now obtain advances to allow utilization in microbiology [1]. There are numerous molecular methods which are of fast and simple application to the detection of pathogen. Among the pathogens involved in human health, Bacillus cereus is interesting due to their ability to survive in various habitats [2]. The genus Bacillus is aerobic or facultative anaerobic bacteria, gram positive spore forming rod shaped bacteria. Which can be characterized by two morphological forms, the vegetative cell which range from 1.02 to 1.2 um in width and from 3.0 to 5.0 in length, it can be straight or slightly curve, motile or non-motile, and the endospore (the non-swelling sporangium). The genus Bacillus is been characterized by the presence of endospore, which is not more than one per cell and they are resistant to many adverse environmental conditions such as heat, radiation, cold and disinfectants. It can also respire either in the presence or absence of oxygen [3]. Cell diameter of Bacillus cereus, sporangium and catalase test do not allow differentiation, where as important in differentiation among B. anthracis, B. cereus, B. thuringiensis can be considered by parasporal crystals and the presence of capsule. [4] Showed a B. thuringiensis strain capable of producing a capsule resembling that of B. anthracis. Most species of the genus display a great kind in physiological characteristics such as degradation of cellulose, starch, pectin, agar, hydrocarbons, production of enzymes and antibiotics and other characteristic such as acidophile, alkalinophile, psychrophile, and thermophile's which allows them to adapt to various environmental conditions [5]. In differentiating between species of the genus Bacillus it was difficult at early attempts when endospore formation and aerobic respiration were the main character used for classification. As reported by many authors that at molecular method level, the differentiation between B. thuringiensis and B. cereus is also very difficult. cereus can survive at the temperature between 4°c and 55°c. The mesophile strains can grow between the temperature of 10°c and 42°c, while psychotropic strains can survive at 4°c, whereas other strains are able to grow at 52 to 55°c. B. cereus vegetative cells grow at pH between 1.0 and 5.2. Heat resistant strain can survive and multiply in wet low acid foods in temperature ranging from 5 to 52°c. The survivability of B. cereus spores at 95°c decreases when the pH level decreases from 6.2 to 4.7 [6]. B. cereus can grow in the presence of salt with concentration up to 7.5% depending on the pH value. thuringiensis possesses a protein crystal that is toxic to insects. This toxin protein was first known as parasporal crystalline inclusion but was later referred to as π - endotoxin or in other ways known as insecticidal crystal protein [7]. Strains of B. thuringiensis bacteria possess a wide range of specificity in various orders of insects such as Lepidoptera, dipteral, coleoptera. These strains of bacteria produce crystalline proteins known as cry protein during sporulation. When B. thuringiensis infects an insects, it will cause the insect to loose appetite, enhances slow movement and over time the insect will die due to crystals of proteins that have been dissolved in the insect's stomach. In the cultivation of vegetable crops, the plant can be attack by many types of pests. Hence, in overcoming pest attacks farmers often use pesticides that contain active synthetic materials. Many negative effects arise from the folly use of chemical pesticides. Among the negative effect is the increase of pest population, resistance, death of natural enemy population and increase in residue level on Agricultural product which makes it unsafe for public consumption [8]. Therefore, it is necessary to find an alternative method in the control of crop pest. The best alternative that can be done is to replace the chemical insecticide with biological control which involves the use of living things in the form of microorganisms. In these profiling microbial communities, the main objective is to identify which bacteria and how much they are present in the environments. Most microbial profiling methods focus on the identification and quantification of bacteria with already sequenced genomes. Further, most methods utilize information obtained from entire genomes. Homology-based methods such as [1–4] classify sequences by detecting homology in reads belonging to either an entire genome or only a small set of marker genes. Composition-based methods generally use conserved compositional features of genomes for classification and as such they utilize less computational resources.Using the 16S rRNA gene instead of whole genome information is not only computational efficient but also economical; Illumina indicated that targeted sequencing of a focused region of interest reduces sequencing costs and enables deep sequencing, compared to whole-genome sequencing. On the other hand, as observed by [8], by focusing exclusively on one gene, one might lose essential information for advanced analyses. We, however, will provide an analysis that demonstrates that at least in the context of oral microbial communities, the 16S rRNA gene retains sufficient information to allow us detect unknown bacteria [9, 10]. This study aimed at employing 16S rRNA as an instrument of identification of seemingly close Bacillus species. Abbreviations BLAST, Basic Local Alignment sequence Tools; PCR, Polymerase Chains reactions; rRNA, ribosomal RNA; Material and methods T Sample collection. Soil samples were collected from three sources from Rice, Sugar Cane, vegetables and abandoned farmland in January 2019. The samples were labeled serially from Sample 1 to Sample 10 (S1 to S10). Bacterial culture: A serial dilution of 10 folds was performed. Bacterial suspension was diluted (10-10) with saline water and 100 μl of bacterial suspension werespread on Nutrient Agar plate and incubated for 24 hours. Bacterial colonies were isolated and grown in Nutrient Broth and nutrient agar. Other microbiological solid agar used include: Chocolate, Blood Agar, EMB, MacConkey, Simon citrate, MRS Agar. Bacteria were characterized by conventional technique by the use of morphological appearance and performance on biochemical analysis [11]. Identification of bacteria:The identification of bacteria was based on morphological characteristics and biochemical tests carried out on the isolates. Morphological characteristics observed for each bacteria colony after 24 h of growth included colony appearance; cell shape, color, optical characteristics, consistency, colonial appearance and pigmentation. Biochemical characterizations were performed according to the method of [12] Catalase test: A small quantity of 24 h old culture was transferred into a drop of 3% Hydrogen peroxide solution on a clean slide with the aid of sterile inoculating loop. Gas seen as white froth indicates the presence of catalase enzyme [13] on the isolates. DNA Extraction Processes The extraction processes was in four phase which are: Collection of cell, lyses of cell, Collection of DNA by phenol, Concentration and purification of DNA. Collection of cell: the pure colonyof the bacteria culture was inoculated into a prepared sterile nutrient broth. After growth is confirmed by the turbidity of the culture, 1.5ml of the culture was taken into a centrifuge tube and was centrifuge at 5000 rpm for 5 minutes; the supernatant layer was discarded leaving the sediment. Lyses of cell: 400 microns of lyses buffer is added to the sediment and was mixed thoroughly and allow to stand for five minutes at room temperature (25°c). 200 microns of Sodium Dodecyl Sulfate (SDS) solution was added for protein lyses and was mixed gently and incubated at 65°c for 10 minutes. Collection of DNA by phenol; 500 microns of phenol chloroform was added to the solution for the separation of DNA, it was mixed completely and centrifuge at 10,000 rpm for 10 minutes. The white pallet seen at the top of the tube after centrifugation is separated into another sterile tube and 1micron of Isopropanol is added and incubated for 1hour at -20°c for precipitation of DNA. The DNA is seen as a colorless liquid in the solution. Concentration and purification of DNA: the solution was centrifuge at 10,000 rpm for 10 minutes. The supernatant layer was discarded and the remaining DNA pellets was washed with 1micron of 17% ethanol, mixed and centrifuge at 10,000 rpm for 10 minutes. The supernatant layer was discarded and air dried. 60 micron TE. Buffer was added for further dissolving of the DNA which was later stored at -40°c until it was required for use [14]. PCR Amplification This requires the use of primers (Forward and Reverse), polymerase enzyme, a template DNA and the d pieces which includedddATP, ddGTP and ddTTP, ddNTP. All this are called the master mix. The PCR reactions consist of three main cycles. The DNA sample was heated at 940c to separate the two template of the DNA strand which was bonded by a hydrogen bond. Once both strand are separated the temperature is reduced to 570c (Annealing temperature). This temperature allows the binding of the forward and reverse primers to the template DNA. After binding the temperature is raised back to 720c which leads to the activation of polymerase enzyme and its start adding d NTPs to the DNA leading to the synthesize of new strands. The cycles were repeated several times in order to obtain millions of the copies of the target DNA [15]. Preparation of Agarose Gel One gram (1 g) of agarose for DNA was measured or 2 g of agarose powdered will be measured for PCR analysis. This done by mixing the agarose powder with 100 ml 1×TAE in a microwaveable flask and microwaved for 1-3 minutes until the agarose is completely dissolved (do not over boil the solution as some of the buffer will evaporate) and thus alter the final percentage of the agarose in the gel. Allow the agarose solution to cool down to about 50°c then after five minutes 10µL was added to EZ vision DNA stain. EZ vision binds to the DNA and allows one to easily visualize the DNA under ultra violet (UV) light. The agarose was poured into the gel tray with the well comb firmly in place and this was placed in newly poured gel at 4°c for 10-15 mins or it sit at room temperature for 20-30 mins, until it has completely solidified[16]. Loading and Running of samples on Agarose gel The agarose gel was placed into the chamber, and the process of electrophoresis commenced with running buffer introduced into the reservoir at the end of the chamber until it the buffer covered at least 2millimeter of the gel. It is advisable to place samples to be loaded in the correct order according to the lanes they are assigned to be running. When loading the samples keep the pipette tip perpendicular to the row of the wells as by supporting your accustomed hand with the second hand; this will reduce the risk of accidentally puncturing the wells with the tip. Lower the tip of the pipette until it breaks the surface of the buffer and is located just above the well. Once all the samples have been loaded it is advised to always avoid any movement of the gel chamber. This might result in the sample spilling into adjacent well. Place the lid on the gel chamber with the terminal correctly positioned to the matching electrodes on the gel chamber black to black and red to red. Remember that DNA is negatively charged hence the movement of the electric current from negatively charged to the positively charged depending on the bandwidth in Kilobytes. Once the electrode is connected to the power supply, switch ON the power supply then set the correct constant voltage (100) and stopwatch for proper time. Press the start button to begin the flow of current that will separate the DNA fragment.After few minutes the samples begins to migrate from the wells into the gel. As the DNA runs, the diaphragm moves from the negative electrode towards the positive electrode [17]. PCR mix Components and Sanger Sequencing This is made up of primers which is both Forward and Reverse, the polymerase enzyme (Taq), a template DNA and the pieces of nucleotides which include: ddNTP, ddATP, ddGTP and ddTTP. Note that the specific Primer’s sequences for bacterial identification is: 785F 5' (GGA TTA GAT ACC CTG GTA) 3', 27F 5' (AGA GTT TGA TCM TGG CTC AG) 3', 907R 5' (CCG TCA ATT CMT TTR AGT TT) 3', 1492R 5' (TAC GGY TAC CTT GTT ACG ACT T) 3' in Sanger Sequencing techniques. BLAST The resulting genomic sequence were assembled and submitted in GenBank at NCBI for assignment of accession numbers. The resultant assertion numbers were subjected to homology search by using Basic Local Alignment Search Tool (BLAST) as NCBI with the assertion number MW362290, MW362291, MW362292, MW362293, MW362294 and MW362295 respectively. Whereas, the other isolates’ accession numbers were retrieved from NCBI GenBank which are:AB 738796.1, JH792136.1, MW 015768.1 and MG745385.1.MEGA 5.2 software was used for the construction of phylogenetic tree and phylogenetic analysis. All the organisms possess 100% identities, 0% gaps and 0.0% E.value which indicated that the organisms are closely related to the existing organisms. The use of 16S rRNA is the best identification process for bacteria because 16S rRNA gene has a distinguishing size of about 500 bases until 1500bp. Rather than using 23S rRNA which is of higher variation, The 16S rRNA is adopted in prokaryotes. 18S rRNA is used for identification in Eukaryotes Results The results of both the conventional morphological and cultural identification was correlated with the molecular sequencing results. Six isolates were confirmed B. cereus species while the other four isolates were. B. wiedmannii, B. thuringiensis, B. toyonensis and B. pseudomycoides.The 16S rRNA sequence of six isolates MW 362290.1- MW362295.1 were assigned accession numbers and deposited in the GenBank while the other four sequences were aligned to those available in the NCBI database. The alignment results showed closely relatedness to LT844650.1with an identity of 100% to 92.2% as above. The six isolates of Bacillus cereus great evolutionary relatedness as shown in the phylogenetic tree constructed using MEGA X software. Results The results of both the conventional morphological and cultural identification was correlated with the molecular sequencing results. Six isolates were confirmed B. cereus species while the other four isolates were. B. wiedmannii, B. thuringiensis, B. toyonensis and B. pseudomycoides.The 16S rRNA sequence of six isolates MW 362290.1- MW362295.1 were assigned accession numbers and deposited in the GenBank while the other four sequences were aligned to those available in the NCBI database. The alignment results showed closely relatedness to LT844650.1with an identity of 100% to 92.2% as above. The six isolates of Bacillus cereus great evolutionary relatedness as shown in the phylogenetic treeconstructed using MEGA X software. Discussion The results obtained in this study is consistent with the previous studies in other countries22,23 The results of the phylogenetic analysis of the 16S rRNA isolate of in this study was similar to the housekeeping genes proposed by [18, 19]. In comparing this study with the earlier study, B. cereus group comprising other species of Bacillus was hypothesized to be considered to form a single species with different ecotypes and pathotype. This study was able to phenotypically differentiated B. thuringiensis, B. pseudomycoides, B. toyonensis, B. wiedmannii and B. cereus sensu strito. Despite differences at the colonial appearance level, the 16S rRNA sequences have homology ranging from 100% to 92% providing insufficient resolution at the species level [6, 7, 18].After analysis through various methods, the strain was identified as Gram-positive bacteria of Bacillus cereus with a homology of 99.4%. Cohan [20] demonstrated that 95–99% of the similarity of 16S rRNA gene sequence between two bacteria hints towards a similar species while >99% indicates the same bacteria.The phylogenetic tree showed that B. toyonensis, B. thuringiensis and B. wiedmanniiare the outgroups of B. cereus group while B. pseudomycoides are most closely related to B. cereus group [19, 21, 22]. Conclusion In the area of molecular epidemiology, genotypic typing method has greatly increased our ability to differentiate between micro-organisms at the intra and interspecies levels and have become an essential and powerful tool. Phenotypic method will still remain important in diagnostic microbiology and genotypic method will become increasingly popular. After analysis through various methods, the strain was identified as Gram-positive bacteria of Bacillus cereus with a homology of between 100% and 92.3%. Acknowledgments Collate acknowledgments in a separate section at the end of the article before the references, not as a footnote to the title. Use the unnumbered Acknowledgements Head style for the Acknowledgments heading. List here those individuals who provided help during the research. Conflicts of interest The Authors declare that there is no conflict of interest. References: Simpkins Meyer F.; Paarmann D.; D’Souza M.; Olson R.; Glass EM.; Kubal M.; Paczian T.; Rodriguez A.; Stevens R. Wilke A The metagenomics rast server–a public resource for the automatic phylogenetic and functional analysis of metagenomes. BMC Bioinformatics. 2008, 9(1), 386. Segata N.; Waldron L.; Ballarini A.; Narasimhan V.; Jousson O.; Huttenhower C. Metagenomic microbial community profiling using unique clade-specific marker genes. Nature methods. 2012, 9(8), 811–814. Brady A.; Salzberg SL. Phymm and phymmbl: metagenomic phylogenetic classification with interpolated markov models. 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DNA Extraction from a bacterial cell. A video on Experimental Biotechnology. 2020. Quick biochemistry. A YouTube video on polymerase chain reaction. 2018. Bio-Rad laboratories. A YouTube video on loading and running of samples on Agarose gel. 2012. Saitou N. and Nei, M. The neighbor-joining method: a new method for reconstructing phylogenetic trees. Biol. Evol. 1987, 4, 406-425. Doi: 101093/oxfordjournals. Lazarte N.J.; Lopez R.P.; Ghiringhelli P.D.; Beron C.M. Bacillus wiedmannii biovar thuringiensis: A specialized Mosquitocidal pathogen with plasmid from diverse origins Genome. Evol. 2018, 10(10), 2823-2833. Doi.1093/gbe/evy211 Cohan, F.M. What are bacterial species? Rev. Microbiol. 2002, 56, 457-487 Abiola C.; Oyetayo V.O. Isolation and Biochemical Characterization of Microorganisms Associated with the Fermentation of Kersting’s Groundnut (Macrotyloma geocarpum). Research Journal of Microbiology, 2016, 11: 47- 55.DOI:10.3923/jm.2016.47.55 Adeoti O.M.; Usman T.A. Molecular Characterization of Rhizobacteria Isolates from Saki, Nigeria. Eur. Of Bio. Biotech. 2021, 2(2), 159. Doi 10.24018/ejbio.2021

Lentil (Lens culinaris Medik.) is a traditional crop in Sicily, Italy. Near Villalba (Caltanissetta), a local lentil landrace, “Lenticchia di Villalba”, is commonly grown. From 2002 to 2004, wilt was observed in five lentil fields (≈1 ha each) at rates from 5 to 20%. Affected plants were yellow and stunted with discoloration in the vascular tissue of stems and crowns. Pieces of brown vascular tissue from stems were disinfested in 2% sodium hypochlorite for 2 min, rinsed with sterile distilled water, placed on potato dextrose agar, and incubated at 23°C. Isolates with morphological characteristics of Fusarium oxysporum Schlecht.:Fr. (2) were consistently recovered from affected plants. For molecular identification of five isolates, the rDNA internal transcribed spacer (ITS) region and a portion of the elongation factor EF-1α were sequenced using ITS5/4 and EF1/2 primers, respectively (1). Two sequences of the ITS region were obtained: a 468-bp sequence from isolates ER1259, ER1260, and ER1275 (submitted as GenBank Accession No. EU159118) and a 483-bp sequence from isolates ER1274 and ER1276 (submitted as GenBank Accession No. EU281661). The two sequences shared 93% similarity. A sequence homology search using the NCBI BLAST program revealed that the first sequence had 100% homology with the ITS sequences of more than 50 F. oxysporum isolates of various formae speciales in GenBank and the second shared 100% homology with the ITS sequences of five isolates of F. redolens Wollenw. (e.g., GenBank Accession No. X94169 of the strain CBS 360.87). Amplification of the EF-1α produced a sequence from isolates ER1274 and ER1276 (submitted as GenBank Accession No. EU281660) with 99 to 100% homology to sequences of F. redolens and a sequence from strains ER1259, ER1275, and ER1260 (submitted as GenBank Accession No. EU281659) with 100% homology to that of more than 50 F. oxysporum strains in GenBank. Although F. redolens and F. oxysporum are morphologically similar, recent molecular studies have shown that they are distinct and phylogenetically distant species (3). On the basis of genetic sequences, isolates ER1274 and ER1276 were identified as F. redolens. These isolates were evaluated for pathogenicity on lentil. For each isolate, 10 2-week-old seedlings of “Lenticchia di Villalba” were inoculated by submerging roots in a suspension of 2.5 × 106 conidia/ml for 10 min. Plants were put into separate tubes containing 70 ml of a nutritional liquid medium (7 ml of HydroPlus Olikani per liter; Yara, Nanterre, France) and incubated in a growth chamber at 20°C with 12 h of light per day. Seedlings dipped in sterile water served as the control treatment. The pathogenicity test was repeated twice. Inoculated seedlings started to wilt 1 week after inoculation and developed root rot and vascular discoloration. After 2 weeks, 70% of the inoculated plants were affected by both isolates and 40 and 10% died when inoculated with ER1274 and ER1276 isolates, respectively. F. redolens was consistently reisolated from the stems of wilted plants. Noninoculated plants remained healthy. Currently, only F. oxysporum f. sp. lentis Vasud. and Sriniv. has been reported as the cause of Fusarium wilt of lentil. To our knowledge, this is the first report of F. redolens as a pathogen on lentil. References: (1) R. P. Baayen et al. Phytopathology 91:1037, 2001. (2) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. The Pennsylvania State University Press, University Park, 1983. (3) K. O'Donnell et al. Mycologia 90:465, 1998.

During a survey of potato scab pathogens in China from 2003 to 2012, a new pathogen was found in Shanxi and Neimenggu provinces. The incidence was approximately 20% of all recovered strains. The lesions caused by the pathogen were slightly raised and similar to those caused by Streptomyces scabies (3). Lesions were excised (approximately 10 mm3) from 40 infected tubers, surface-disinfested with 0.3% NaOCl for 30 s, rinsed in sterile water three times, cut into 5 mm3, then sliced into 1-mm pieces, and plated on water agar amended with ampicillin (50 μg/ml). Plates were incubated at 28°C in the dark for 4 days. The spores of Streptomyces sp. strains growing from the tuber pieces were collected from single bacterial colonies and cultured on oatmeal agar. To fulfill Koch's postulates, one strain, CPS-2, was grown at 28°C for 10 days and the spores were washed from the plates as inoculum. One hundred milliliters of inoculum (1 × 105 CFU/ml) was mixed with autoclaved soil and vermiculite (1:1) in each pot (15 cm in diameter). Cut tubers were planted in the pots (potato cv. Favorita, one plant per pot, five replicates) and grown under greenhouse conditions (22 ± 5°C). Typical common scab symptoms consisting of small, brown, raised lesions developed on potato tubers 12 weeks after planting. The same strain was re-isolated from the lesions of the new scabby tubers. Non-inoculated plants, treated as described above, but without strain CPS-2, remained healthy. The CPS-2 strain was identified based on morphological and physiological characterization and 16S rDNA sequence. On yeast-malt extract agar, the test strain produced grayish-white aerial hypha, reddish brown substrate mycelium and pigments, and loose spiral spore chains. Spores were smooth and were 0.8 to 0.9 × 1.1 to 1.2 μm in size (diameter and length). The ability of the strain to use single sources of carbon and nitrogen was verified according to the International Streptomyces project (4). The strain grew in media supplemented with L-arabinose, D-fructose, D-glucose, rhamnose, raffinose, meso-inositol, sucrose, and D-xylose, but not D-mannitol. It used L-hydroxyproline, L-methionine, and L-histidine, and produced melanin on tyrosine and peptone yeast extract agar. The strain did not grow at a pH less than 5.0 and was sensitive to streptomycin (20 μg/ml), phenol (0.1%), and crystal violet (0.5 μg/mL), but not to penicillin (10 IU/ml). The strain also produced hydrogen sulfide. The biological characteristics of strain CPS-2 were in accord with Streptomyces galilaeus. CPS-2 produced thaxtomin A in oatmeal liquid medium and the txt AB gene fragment was successfully amplified using specific primers (2). The 16S rDNA sequence of CPS-2 was amplified by PCR with primers 16S1-F: 5′-CATTCACGGAGAGTTTGATCC-3′ and 16S1-R: 5′-AGAAAGGAGGTGATCCAGCC-3′ (1) and sequenced. A BLAST search of the 16S rDNA sequence for CPS-2 was conducted using the NCBI GenBank database, resulting in 99.8% similarity to S. galilaeus (NR_040857). The 16S rDNA sequence for CPS-2 (1,388 bp) was deposited in GenBank (AY621378). To our knowledge, this is the first report of S. galilaeus causing common scab of potato in China. References: (1) R. A. Bukhalid et al. Appl. Environ. Microbiol. 68:738, 2002. (2) R. Flores-González et al. Plant Pathol. 57:162, 2008. (3) D. H. Lambert and R. Loria. Int. J. Syst. Bacteriol. 39:387, 1989. (4) E. B. Shirling and D. Gottlieb. Int. J. Syst. Bacteriol. 16:313, 1966.

Environments containing significant concentration of NaCl such as salt lakes harbor extremophiles microorganisms which have a great biotechnology interest. To explore the diversity of Bacteria in Chott Tinsilt (Algeria), an isolation program was performed. Water samples were collected from the saltern during the pre-salt harvesting phase. This Chott is high in salt (22.47% (w/v). Seven halophiles Bacteria were selected for further characterization. The isolated strains were able to grow optimally in media with 10–25% (w/v) total salts. Molecular identification of the isolates was performed by sequencing the 16S rRNA gene. It showed that these cultured isolates included members belonging to the Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus genera with less than 98% of similarity with their closest phylogenetic relative. The halophilic bacterial isolates were also characterized for the production of biosurfactant and industrially important enzymes. Most isolates produced hydrolases and biosurfactants at high salt concentration. In fact, this is the first report on bacterial strains (A4 and B4) which were a good biosurfactant and coagulase producer at 20% and 25% ((w/v)) NaCl. In addition, the biosurfactant produced by the strain B4 at high salinity (25%) was also stable at high temperature (30-100°C) and high alkalinity (pH 11).Key word: Salt Lake, Bacteria, biosurfactant, Chott, halophiles, hydrolases, 16S rRNAINTRODUCTIONSaline lakes cover approximately 10% of the Earth’s surface area. The microbial populations of many hypersaline environments have already been studied in different geographical regions such as Great Salt Lake (USA), Dead Sea (Israel), Wadi Natrun Lake (Egypt), Lake Magadi (Kenya), Soda Lake (Antarctica) and Big Soda Lake and Mono Lake (California). Hypersaline regions differ from each other in terms of geographical location, salt concentration and chemical composition, which determine the nature of inhabitant microorganisms (Gupta et al., 2015). Then low taxonomic diversity is common to all these saline environments (Oren et al., 1993). Halophiles are found in nearly all major microbial clades, including prokaryotic (Bacteria and Archaea) and eukaryotic forms (DasSarma and Arora, 2001). They are classified as slight halophiles when they grow optimally at 0.2–0.85 M (2–5%) NaCl, as moderate halophiles when they grow at 0.85–3.4 M (5–20%) NaCl, and as extreme halophiles when they grow at 3.4–5.1 M (20–30%) NaCl. Hyper saline environments are inhabited by extremely halophilic and halotolerant microorganisms such as Halobacillus sp, Halobacterium sp., Haloarcula sp., Salinibacter ruber , Haloferax sp and Bacillus spp. (Solomon and Viswalingam, 2013). There is a tremendous demand for halophilic bacteria due to their biotechnological importance as sources of halophilic enzymes. Enzymes derived from halophiles are endowed with unique structural features and catalytic power to sustain the metabolic and physiological processes under high salt conditions. Some of these enzymes have been reported to be active and stable under more than one extreme condition (Karan and Khare, 2010). Applications are being considered in a range of industries such as food processing, washing, biosynthetic processes and environmental bioremediation. Halophilic proteases are widely used in the detergent and food industries (DasSarma and Arora, 2001). However, esterases and lipases have also been useful in laundry detergents for the removal of oil stains and are widely used as biocatalysts because of their ability to produce pure compounds. Likewise, amylases are used industrially in the first step of the production of high fructose corn syrup (hydrolysis of corn starch). They are also used in the textile industry in the de-sizing process and added to laundry detergents. Furthermore, for the environmental applications, the use of halophiles for bioremediation and biodegradation of various materials from industrial effluents to soil contaminants and accidental spills are being widely explored. In addition to enzymes, halophilic / halotolerants microorganisms living in saline environments, offer another potential applications in various fields of biotechnology like the production of biosurfactant. Biosurfactants are amphiphilic compounds synthesized from plants and microorganisms. They reduce surface tension and interfacial tension between individual molecules at the surface and interface respectively (Akbari et al., 2018). Comparing to the chemical surfactant, biosurfactant are promising alternative molecules due to their low toxicity, high biodegradability, environmental capability, mild production conditions, lower critical micelle concentration, higher selectivity, availability of resources and ability to function in wide ranges of pH, temperature and salinity (Rocha et al., 1992). They are used in various industries which include pharmaceuticals, petroleum, food, detergents, cosmetics, paints, paper products and water treatment (Akbari et al., 2018). The search for biosurfactants in extremophiles is particularly promising since these biomolecules can adapt and be stable in the harsh environments in which they are to be applied in biotechnology.OBJECTIVESEastern Algeria features numerous ecosystems including hypersaline environments, which are an important source of salt for food. The microbial diversity in Chott Tinsilt, a shallow Salt Lake with more than 200g/L salt concentration and a superficies of 2.154 Ha, has never yet been studied. The purpose of this research was to chemically analyse water samples collected from the Chott, isolate novel extremely or moderate halophilic Bacteria, and examine their phenotypic and phylogenetic characteristics with a view to screening for biosurfactants and enzymes of industrial interest.MATERIALS AND METHODSStudy area: The area is at 5 km of the Commune of Souk-Naâmane and 17 km in the South of the town of Aïn-Melila. This area skirts the trunk road 3 serving Constantine and Batna and the railway Constantine-Biskra. It is part the administrative jurisdiction of the Wilaya of Oum El Bouaghi. The Chott belongs to the wetlands of the High Plains of Constantine with a depth varying rather regularly without never exceeding 0.5 meter. Its length extends on 4 km with a width of 2.5 km (figure 1).Water samples and physico-chemical analysis: In February 2013, water samples were collected from various places at the Chott Tinsilt using Global Positioning System (GPS) coordinates of 35°53’14” N lat. and 06°28’44”E long. Samples were collected randomly in sterile polythene bags and transported immediately to the laboratory for isolation of halophilic microorganisms. All samples were treated within 24 h after collection. Temperature, pH and salinity were measured in situ using a multi-parameter probe (Hanna Instruments, Smithfield, RI, USA). The analytical methods used in this study to measure ions concentration (Ca2+, Mg2+, Fe2+, Na+, K+, Cl−, HCO3−, SO42−) were based on 4500-S-2 F standard methods described elsewhere (Association et al., 1920).Isolation of halophilic bacteria from water sample: The media (M1) used in the present study contain (g/L): 2.0 g of KCl, 100.0/200.0 g of NaCl, 1.0 g of MgSO4.7HO2, 3.0 g of Sodium Citrate, 0.36 g of MnCl2, 10.0 g of yeast extract and 15.0 g agar. The pH was adjusted to 8.0. Different dilutions of water samples were added to the above medium and incubated at 30°C during 2–7 days or more depending on growth. Appearance and growth of halophilic bacteria were monitored regularly. The growth was diluted 10 times and plated on complete medium agar (g/L): glucose 10.0; peptone 5.0; yeast extract 5.0; KH2PO4 5.0; agar 30.0; and NaCl 100.0/200.0. Resultant colonies were purified by repeated streaking on complete media agar. The pure cultures were preserved in 20% glycerol vials and stored at −80°C for long-term preservation.Biochemical characterisation of halophilic bacterial isolates: Bacterial isolates were studied for Gram’s reaction, cell morphology and pigmentation. Enzymatic assays (catalase, oxidase, nitrate reductase and urease), and assays for fermentation of lactose and mannitol were done as described by Smibert (1994).Optimization of growth conditions: Temperature, pH, and salt concentration were optimized for the growth of halophilic bacterial isolates. These growth parameters were studied quantitatively by growing the bacterial isolates in M1 medium with shaking at 200 rpm and measuring the cell density at 600 nm after 8 days of incubation. To study the effect of NaCl on the growth, bacterial isolates were inoculated on M1 medium supplemented with different concentration of NaCl: 1%-35% (w/v). The effect of pH on the growth of halophilic bacterial strains was studied by inoculating isolates on above described growth media containing NaCl and adjusted to acidic pH of 5 and 6 by using 1N HCl and alkaline pH of 8, 9, 10, 11 and 12 using 5N NaOH. The effect of temperature was studied by culturing the bacterial isolates in M1 medium at different temperatures of incubation (4°C–55°C).Screening of halophilic bacteria for hydrolytic enzymes: Hydrolase producing bacteria among the isolates were screened by plate assay on starch, tributyrin, gelatin and DNA agar plates respectively for amylase, lipase, protease and DNAse activities. Amylolytic activity of the cultures was screened on starch nutrient agar plates containing g/L: starch 10.0; peptone 5.0; yeast extract 3.0; agar 30.0; NaCl 100.0/250.0. The pH was 7.0. After incubation at 30 ºC for 7 days, the zone of clearance was determined by flooding the plates with iodine solution. The potential amylase producers were selected based on ratio of zone of clearance diameter to colony diameter. Lipase activity of the cultures was screened on tributyrin nutrient agar plates containing 1% (v/v) of tributyrin. Isolates that showed clear zones of tributyrin hydrolysis were identified as lipase producing bacteria. Proteolytic activity of the isolates was similarly screened on gelatin nutrient agar plates containing 10.0 g/L of gelatin. The isolates showing zones of gelatin clearance upon treatment with acidic mercuric chloride were selected and designated as protease producing bacteria. The presence of DNAse activity on plates was determined on DNAse test agar (BBL) containing 10%-25% (w/v) total salt. After incubation for 7days, the plates were flooded with 1N HCl solution. Clear halos around the colonies indicated DNAse activity (Jeffries et al., 1957).Milk clotting activity (coagulase activity) of the isolates was also determined following the procedure described (Berridge, 1952). Skim milk powder was reconstituted in 10 mM aqueous CaCl2 (pH 6.5) to a final concentration of 0.12 kg/L. Enzyme extracts were added at a rate of 0.1 mL per mL of milk. The coagulation point was determined by manual rotating of the test tube periodically, at short time intervals, and checking for visible clot formation.Screening of halophilic bacteria for biosurfactant production. Oil spread Assay: The Petridis base was filled with 50 mL of distilled water. On the water surface, 20μL of diesel and 10μl of culture were added respectively. The culture was introduced at different spots on the diesel, which is coated on the water surface. The occurrence of a clear zone was an indicator of positive result (Morikawa et al., 2000). The diameter of the oil expelling circles was measured by slide caliber (with a degree of accuracy of 0.02 mm).Surface tension and emulsification index (E24): Isolates were cultivated at 30 °C for 7 days on the enrichment medium containing 10-25% NaCl and diesel oil as the sole carbon source. The medium was centrifuged (7000 rpm for 20 min) and the surface tension of the cell-free culture broth was measured with a TS90000 surface tensiometer (Nima, Coventry, England) as a qualitative indicator of biosurfactant production. The culture broth was collected with a Pasteur pipette to remove the non-emulsified hydrocarbons. The emulsifying capacity was evaluated by an emulsification index (E24). The E24 of culture samples was determined by adding 2 mL of diesel oil to the same amount of culture, mixed for 2 min with a vortex, and allowed to stand for 24 h. E24 index is defined as the percentage of height of emulsified layer (mm) divided by the total height of the liquid column (mm).Biosurfactant stability studies : After growth on diesel oil as sole source of carbone, cultures supernatant obtained after centrifugation at 6,000 rpm for 15 min were considered as the source of crude biosurfactant. Its stability was determined by subjecting the culture supernatant to various temperature ranges (30, 40, 50, 60, 70, 80 and 100 °C) for 30 min then cooled to room temperature. Similarly, the effect of different pH (2–11) on the activity of the biosurfactant was tested. The activity of the biosurfactant was investigated by measuring the emulsification index (El-Sersy, 2012).Molecular identification of potential strains. DNA extraction and PCR amplification of 16S rDNA: Total cellular DNA was extracted from strains and purified as described by Sambrook et al. (1989). DNA was purified using Geneclean® Turbo (Q-BIO gene, Carlsbad, CA, USA) before use as a template in polymerase chain reaction (PCR) amplification. For the 16S rDNA gene sequence, the purified DNA was amplified using a universal primer set, forward primer (27f; 5′-AGA GTT TGA TCM TGG CTC AG) and a reverse primer (1492r; 5′-TAC GGY TAC CTT GTT ACG ACT T) (Lane, 1991). Agarose gel electrophoresis confirmed the amplification product as a 1400-bp DNA fragment.16S rDNA sequencing and Phylogenic analysis: Amplicons generated using primer pair 27f-1492r was sequenced using an automatic sequencer system at Macrogene Company (Seoul, Korea). The sequences were compared with those of the NCBI BLAST GenBank nucleotide sequence databases. Phylogenetic trees were constructed by the neighbor-joining method using MEGA version 5.05 software (Tamura et al., 2011). Bootstrap resembling analysis for 1,000 replicates was performed to estimate the confidence of tree topologies.Nucleotide sequence accession numbers: The nucleotide sequences reported in this work have been deposited in the EMBL Nucleotide Sequence Database. The accession numbers are represented in table 5.Statistics: All experiments were conducted in triplicates. Results were evaluated for statistical significance using ANOVA.RESULTSPhysico-chemical parameters of the collected water samples: The physicochemical properties of the collected water samples are reported in table 1. At the time of sampling, the temperature was 10.6°C and pH 7.89. The salinity of the sample, as determined in situ, was 224.70 g/L (22,47% (w/v)). Chemical analysis of water sample indicated that Na +and Cl- were the most abundant ions (table 1). SO4-2 and Mg+2 was present in much smaller amounts compared to Na +and Cl- concentration. Low levels of calcium, potassium and bicarbonate were also detected, often at less than 1 g/L.Characterization of isolates. Morphological and biochemical characteristic feature of halophilic bacterial isolates: Among 52 strains isolated from water of Chott Tinsilt, seven distinct bacteria (A1, A2, A3, A4, B1, B4 and B5) were chosen for further characterization (table 2). The colour of the isolates varied from beige, pale yellow, yellowish and orange. The bacterial isolates A1, A2, A4, B1 and B5 were rod shaped and gram negative (except B5), whereas A3 and B4 were cocci and gram positive. All strains were oxidase and catalase positive except for B1. Nitrate reductase and urease activities were observed in all the bacterial isolates, except B4. All the bacterial isolates were negative for H2S formation. B5 was the only strain positive for mannitol fermentation (table 2).We isolated halophilic bacteria on growth medium with NaCl supplementation at pH 7 and temperature of 30°C. We studied the effect of NaCl, temperature and pH on the growth of bacterial isolates. All the isolates exhibited growth only in the presence of NaCl indicating that these strains are halophilic. The optimum growth of isolates A3 and B1 was observed in the presence of 10% NaCl, whereas it was 15% NaCl for A1, A2 and B5. A4 and B4 showed optimum growth in the presence of 20% and 25% NaCl respectively. A4, B4 and B5 strains can tolerate up to 35% NaCl.The isolate B1 showed growth in medium supplemented with 10% NaCl and pH range of 7–10. The optimum pH for the growth B1 was 9 and they did not show any detectable growth at or below pH 6 (table 2), which indicates the alkaliphilic nature of B1 isolate. The bacterial isolates A1, A2 and A4 exhibited growth in the range of pH 6–10, while A3 and B4 did not show any growth at pH greater than 8. The optimum pH for growth of all strains (except B1) was pH 7.0 (table 2). These results indicate that A1, A2, A3, A4, B4 and B5 are neutrophilic in nature. All the bacterial isolates exhibited optimal growth at 30°C and no detectable growth at 55°C. Also, detectable growth of isolates A1, A2 and A4 was observed at 4°C. However, none of the bacterial strains could grow below 4°C and above 50°C (table 2).Screening of the halophilic enzymes: To characterize the diversity of halophiles able to produce hydrolytic enzymes among the population of microorganisms inhabiting the hypersaline habitats of East Algeria (Chott Tinsilt), a screening was performed. As described in Materials and Methods, samples were plated on solid media containing 10%-25% (w/v) of total salts and different substrates for the detection of amylase, protease, lipase and DNAse activities. However, coagulase activity was determined in liquid medium using milk as substrate (figure 3). Distributions of hydrolytic activity among the isolates are summarized in table 4.From the seven bacterial isolates, four strains A1, A2, A4 and B5 showed combined hydrolytic activities. They were positive for gelatinase, lipase and coagulase. A3 strain showed gelatinase and lipase activities. DNAse activities were detected with A1, A4, B1 and B5 isolates. B4 presented lipase and coagulase activity. Surprisingly, no amylase activity was detected among all the isolates.Screening for biosurfactant producing isolates: Oil spread assay: The results showed that all the strains could produce notable (>4 cm diameter) oil expelling circles (ranging from 4.11 cm to 4.67 cm). The average diameter for strain B5 was 4.67 cm, significantly (P < 0.05) higher than for the other strains.Surface tension and emulsification index (E24): The assimilation of hydrocarbons as the sole sources of carbon by the isolate strains led to the production of biosurfactants indicated by the emulsification index and the lowering of the surface tension of cell-free supernatant. Based on rapid growth on media containing diesel oil as sole carbon source, the seven isolates were tested for biosurfactant production and emulsification activity. The obtained values of the surface tension measurements as well as the emulsification index (E24) are shown in table 3. The highest reduction of surface tension was achieved with B5 and A3 isolates with values of 25.3 mN m−1 and 28.1 mN m−1 respectively. The emulsifying capacity evaluated by the E24 emulsification index was highest in the culture of isolate B4 (78%), B5 (77%) and A3 (76%) as shown in table 3 and figure 2. These emulsions were stable even after 4 months. The bacteria with emulsification indices higher than 50 % and/or reduction in the surface tension (under 30 mN/m) have been defined as potential biosurfactant producers. Based on surface tension and the E24 index results, isolates B5, B4, A3 and A4 are the best candidates for biosurfactant production. It is important to note that, strains B4 and A4 produce biosurfactant in medium containing respectively 25% and 20% (w/v) NaCl.Stability of biosurfactant activities: The applicability of biosurfactants in several biotechnological fields depends on their stability at different environmental conditions (temperatures, pH and NaCl). For this study, the strain B4 appear very interesting (It can produce biosurfactant at 25 % NaCl) and was choosen for futher analysis for biosurfactant stability. The effects of temperature and pH on the biosurfactant production by the strain B4 are shown in figure 4.biosurfactant in medium containing respectively 25% and 20% (w/v) NaCl.Stability of biosurfactant activities: The applicability of biosurfactants in several biotechnological fields depends on their stability at different environmental conditions (temperatures, pH and NaCl). For this study, the strain B4 appear very interesting (It can produce biosurfactant at 25 % NaCl) and was chosen for further analysis for biosurfactant stability. The effects of temperature and pH on the biosurfactant production by the strain B4 are shown in figure 4. The biosurfactant produced by this strain was shown to be thermostable giving an E-24 Index value greater than 78% (figure 4A). Heating of the biosurfactant to 100 °C caused no significant effect on the biosurfactant performance. Therefore, the surface activity of the crude biosurfactant supernatant remained relatively stable to pH changes between pH 6 and 11. At pH 11, the value of E24 showed almost 76% activity, whereas below pH 6 the activity was decreased up to 40% (figure 4A). The decreases of the emulsification activity by decreasing the pH value from basic to an acidic region; may be due to partial precipitation of the biosurfactant. This result indicated that biosurfactant produced by strain B4 show higher stability at alkaline than in acidic conditions.Molecular identification and phylogenies of potential isolates: To identify halophilic bacterial isolates, the 16S rDNA gene was amplified using gene-specific primers. A PCR product of ≈ 1.3 kb was detected in all the seven isolates. The 16S rDNA amplicons of each bacterial isolate was sequenced on both strands using 27F and 1492R primers. The complete nucleotide sequence of 1336,1374, 1377,1313, 1305,1308 and 1273 bp sequences were obtained from A1, A2, A3, A4, B1, B4 and B5 isolates respectively, and subjected to BLAST analysis. The 16S rDNA sequence analysis showed that the isolated strains belong to the genera Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus as shown in table 5. The halophilic isolates A2 and A4 showed 97% similarity with the Halomonas variabilis strain GSP3 (accession no. AY505527) and the Halomonas sp. M59 (accession no. AM229319), respectively. As for A1, it showed 96% similarity with the Halomonas venusta strain GSP24 (accession no. AY553074). B1 and B4 showed for their part 96% similarity with the Salinivibrio costicola subsp. alcaliphilus strain 18AG DSM4743 (accession no. NR_042255) and the Planococcus citreus (accession no. JX122551), respectively. The bacterial isolate B5 showed 98% sequence similarity with the Halobacillus trueperi (accession no. HG931926), As for A3, it showed only 95% similarity with the Staphylococcus arlettae (accession no. KR047785). The 16S rDNA nucleotide sequences of all the seven halophilic bacterial strains have been submitted to the NCBI GenBank database under the accession number presented in table 5. The phylogenetic association of the isolates is shown in figure 5.DICUSSIONThe physicochemical properties of the collected water samples indicated that this water was relatively neutral (pH 7.89) similar to the Dead Sea and the Great Salt Lake (USA) and in contrast to the more basic lakes such as Lake Wadi Natrun (Egypt) (pH 11) and El Golea Salt Lake (Algeria) (pH 9). The salinity of the sample was 224.70 g/L (22,47% (w/v). This range of salinity (20-30%) for Chott Tinsilt is comparable to a number of well characterized hypersaline ecosystems including both natural and man-made habitats, such as the Great Salt Lake (USA) and solar salterns of Puerto Rico. Thus, Chott Tinsilt is a hypersaline environment, i.e. environments with salt concentrations well above that of seawater. Chemical analysis of water sample indicated that Na +and Cl- were the most abundant ions, as in most hypersaline ecosystems (with some exceptions such as the Dead Sea). These chemical water characteristics were consistent with the previously reported data in other hypersaline ecosystems (DasSarma and Arora, 2001; Oren, 2002; Hacěne et al., 2004). Among 52 strains isolated from this Chott, seven distinct bacteria (A1, A2, A3, A4, B1, B4 and B5) were chosen for phenotypique, genotypique and phylogenetique characterization.The 16S rDNA sequence analysis showed that the isolated strains belong to the genera Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus. Genera obtained in the present study are commonly occurring in various saline habitats across the globe. Staphylococci have the ability to grow in a wide range of salt concentrations (Graham and Wilkinson, 1992; Morikawa et al., 2009; Roohi et al., 2014). For example, in Pakistan, Staphylococcus strains were isolated from various salt samples during the study conducted by Roohi et al. (2014) and these results agreed with previous reports. Halomonas, halophilic and/or halotolerant Gram-negative bacteria are typically found in saline environments (Kim et al., 2013). The presence of Planococcus and Halobacillus has been reported in studies about hypersaline lakes; like La Sal del Rey (USA) (Phillips et al., 2012) and Great Salt Lake (Spring et al., 1996), respectively. The Salinivibrio costicola was a representative model for studies on osmoregulatory and other physiological mechanisms of moderately halophilic bacteria (Oren, 2006).However, it is interesting to note that all strains shared less than 98.7% identity (the usual species cut-off proposed by Yarza et al. (2014) with their closest phylogenetic relative, suggesting that they could be considered as new species. Phenotypic, genetic and phylogenetic analyses have been suggested for the complete identification of these strains. Theses bacterial strains were tested for the production of industrially important enzymes (Amylase, protease, lipase, DNAse and coagulase). These isolates are good candidates as sources of novel enzymes with biotechnological potential as they can be used in different industrial processes at high salt concentration (up to 25% NaCl for B4). Prominent amylase, lipase, protease and DNAase activities have been reported from different hypersaline environments across the globe; e.g., Spain (Sánchez‐Porro et al., 2003), Iran (Rohban et al., 2009), Tunisia (Baati et al., 2010) and India (Gupta et al., 2016). However, to the best of our knowledge, the coagulase activity has never been detected in extreme halophilic bacteria. Isolation and characterization of crude enzymes (especially coagulase) to investigate their properties and stability are in progress.The finding of novel enzymes with optimal activities at various ranges of salt concentrations is of great importance. Besides being intrinsically stable and active at high salt concentrations, halophilic and halotolerant enzymes offer great opportunities in biotechnological applications, such as environmental bioremediation (marine, oilfiel) and food processing. The bacterial isolates were also characterized for production of biosurfactants by oil-spread assay, measurement of surface tension and emulsification index (E24). There are few reports on biosurfactant producers in hypersaline environments and in recent years, there has been a greater increase in interest and importance in halophilic bacteria for biomolecules (Donio et al., 2013; Sarafin et al., 2014). Halophiles, which have a unique lipid composition, may have an important role to play as surface-active agents. The archae bacterial ether-linked phytanyl membrane lipid of the extremely halophilic bacteria has been shown to have surfactant properties (Post and Collins, 1982). Yakimov et al. (1995) reported the production of biosurfactant by a halotolerant Bacillus licheniformis strain BAS 50 which was able to produce a lipopeptide surfactant when cultured at salinities up to 13% NaCl. From solar salt, Halomonas sp. BS4 and Kocuria marina BS-15 were found to be able to produce biosurfactant when cultured at salinities of 8% and 10% NaCl respectively (Donio et al., 2013; Sarafin et al., 2014). In the present work, strains B4 and A4 produce biosurfactant in medium containing respectively 25% and 20% NaCl. To our knowledge, this is the first report on biosurfactant production by bacteria under such salt concentration. Biosurfactants have a wide variety of industrial and environmental applications (Akbari et al., 2018) but their applicability depends on their stability at different environmental conditions. The strain B4 which can produce biosurfactant at 25% NaCl showed good stability in alkaline pH and at a temperature range of 30°C-100°C. Due to the enormous utilization of biosurfactant in detergent manufacture the choice of alkaline biosurfactant is researched (Elazzazy et al., 2015). On the other hand, the interesting finding was the thermostability of the produced biosurfactant even after heat treatment (100°C for 30 min) which suggests the use of this biosurfactant in industries where heating is of a paramount importance (Khopade et al., 2012). To date, more attention has been focused on biosurfactant producing bacteria under extreme conditions for industrial and commercial usefulness. In fact, the biosurfactant produce by strain B4 have promising usefulness in pharmaceutical, cosmetics and food industries and for bioremediation in marine environment and Microbial enhanced oil recovery (MEOR) where the salinity, temperature and pH are high.CONCLUSIONThis is the first study on the culturable halophilic bacteria community inhabiting Chott Tinsilt in Eastern Algeria. Different genera of halotolerant bacteria with different phylogeneticaly characteristics have been isolated from this Chott. Culturing of bacteria and their molecular analysis provides an opportunity to have a wide range of cultured microorganisms from extreme habitats like hypersaline environments. Enzymes produced by halophilic bacteria show interesting properties like their ability to remain functional in extreme conditions, such as high temperatures, wide range of pH, and high salt concentrations. These enzymes have great economical potential in industrial, agricultural, chemical, pharmaceutical, and biotechnological applications. Thus, the halophiles isolated from Chott Tinsilt offer an important potential for application in microbial and enzyme biotechnology. In addition, these halo bacterial biosurfactants producers isolated from this Chott will help to develop more valuable eco-friendly products to the pharmacological and food industries and will be usefulness for bioremediation in marine environment and petroleum industry.ACKNOWLEDGMENTSOur thanks to Professor Abdelhamid Zoubir for proofreading the English composition of the present paper.CONFLICT OF INTERESTThe authors declare that they have no conflict of interest.Akbari, S., N. H. Abdurahman, R. M. Yunus, F. Fayaz and O. R. Alara, 2018. Biosurfactants—a new frontier for social and environmental safety: A mini review. Biotechnology research innovation, 2(1): 81-90.Association, A. P. H., A. W. W. Association, W. P. C. 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A Boiling Liquid Expanding Vapour Explosion (BLEVE) is a physical explosion caused by the sudden bursting of a vessel containing a superheated liquid. The scientific community describes the BLEVE as a physical explosion and is trying to develop models to predict the strength of the shock waves generated. Taking into account the data provided by the experimental campaign on the BLEVE water, this paper focuses on the causes that may lead to the formation of the second external pressure peak. Many authors assume that this peak is influenced by the liquid/vapour phase transition that occurs in the tank after the sudden pressure drop. Using Scilab, a numerical model is created that can solve Euler's equations for the shock tube problem, simulating only the behavior of the vapour phase. The quality of the model is tested taking into account data obtained experimentally in laboratory-scale tests. Then, based on the EVUT (equal-velocity-unequal-temperature) model proposed in the literature, the boiling phenomenon caused by the sudden pressure drop is analysed. The "relaxation time model" is discussed for modelling the source terms. Using the developed model, the effects of boiling on the density, velocity and internal pressure profiles are investigated. Finally, the model is discussed by comparing it with the experimental data from the E27 test of the water BLEVE campaign

Abstract In the recent past, with an increasing number of terrorist activities, blast related research has focused on conducting careful experiments to develop newer protection strategies. As field experiments using explosives themselves are very cumbersome and expensive, shock tubes are increasingly being employed to study these air-blast based phenomena as they can produce the instantaneous pressure rise that is associated with blast waves, minus the use of explosives. From the literature on shock tubes that are being used for blast loading, it was observed that no experiments have been reported in the sub-millisecond loading duration (near-field) regime as no extant facility has the capability to simulate the conditions in this regime. Even in reports on shock tubes being used to recreate far-field blast conditions (starting from _ 4 milliseconds), attention is not directed towards the shock tube experiment artefacts viz., repeated reflections inside the (closed) shock tube, and generation of a wave whose pressure remains steady for a time before dropping off like a blast wave. In this backdrop, shock tube experiments that pertain to the far-field conditions were first conducted and then quantified in terms of the equivalent TNT field explosion (’TNT equivalent’ in short). The decay time was brought down to 1:6 ms by using plastic diaphragms, and an insert to channel out the reflected shock pressure. Then, the role played by the artefacts of shock tube loading on plates was shown to erroneously increase the final deformation of metal plates by about 15%. While the effect of these artefacts on the micro-structure did not show a large difference, the frequency content of both pressure loadings (the artefact and the correct one), showed differences in the spectral content, which could potentially change the response of structures that are sensitive to the frequency content of the input pulse. These shock tube experiments were found to have a repeatability of 5.5% and the plate deformation experiments on this facility were in the dynamic regime of structural loading. Using a more repeatable diaphragm less shock tube (1%), experiments were then conducted with similar decay times but on a smaller shock tube to validate the digital image correlation (DIC) technique. This device was then used along with numerical computations on ABAQUS to try and explain a blast mitigation strategy that gave a reduction in deflection of up to 50% in the quasi-static regime. To generate even shorter decay times, experiments using a piston impacting a water column were conducted. While the blast pulses from this facility could be reported in terms of their TNT equivalent mass, a subsequent correlation with the explosion-based plate deflection data failed as the exact impulse that is imparted to the plate could not be correctly determined. A novel conical shock tube that can generate sub-millisecond decay times (the near field conditions) in air was then developed and experiments on different metal plates (mild steel, aluminium, copper) were conducted for the extreme case of structural loading, viz., impulsive loading. The plate deflection data from this facility compared very well with an empirical formula that is available for impulse loading of plates using explosives. Thus, the ability of this device to reproduce several features of a near-field air-blast loading - namely the elastic spring back, the impulsive loading of a plate, and a unique shape of the deformed plates - were all successfully demonstrated. The device was characterized at reduced pressures to have a repeatability of 5% and the spatial variation in the exit plane pressure was better than 7%. Using this device, a scaled equivalent of a possible explosion from an improvised explosive device (IED) was also administered to mice to explore the possibility of ultimately conducting controlled blast induced traumatic brain injury studies in the laboratory. Over the course of this work, the simulation capability of shock tubes over an extended range of air-blasts was demonstrated. In terms of TNT masses and stand-off distance, it is currently as follows: Far and mid-field range - using the diaphragm less shock tube (49 kg@5:3m –25 kg@8:4m), and using the vertical shock tube from (0:31 kg@0:86m–33 kg@6:4m); Near-field range: water shock tube (2 kg@0:63m) and the conical shock tube (0:04 kg@0:38m– 0:08 kg@0:56m).

A novel airblast injector is designed for gas turbine combustors. Unlike standard pressure swirl and prefilming/non-prefilming air blast atomizers, the novel injector is designed to improve the fuel injection delivery to the injector and improve atomization of the fuel by using a porous stainless steel tube. There are three swirling air streams in the injector. The liquid fuel is injected through the porous tube, with 7 micron porosity, between the swirling air streams, viz. an inner swirling air through the tube and the other two swirling air streams merging downstream of the tube. The swirl vane angles and the air split ratio are selected to increase the amount of air through the injector and facilitate the atomization process. The liquid fuel is injected through the outer surface of the porous tube, due to the permeability of the tube, produces a thin liquid sheet on the inner surface of the tube. The atomization occurs by surface stripping of the liquid sheet. The advantage of such an injector is that it produces a liquid sheet with uniform thickness around the circumference of the tube under all liquid loading. The porous tube also increases the surface area of contact between the fuel and air and produces a fine spray at engine idle conditions. An experimental approach is adopted in the present study to characterize the spray and aerodynamics of the injector for Jet-A and Gas-To-Liquid (GTL) fuels at atmospheric conditions. The effect of flare height on the Sauter Mean Diameter (SMD) is also studied. Spray characterization, droplet size and volume flux are investigated with PDI measurements. The effect of pressure drop and fuel properties on SMD distribution is analyzed. Velocity profiles at downstream of the injector are obtained from LDV measurements, and the velocity profile at the exit of the injector is also analyzed. A central toroidal recirculation zone (CTRZ) is observed at the exit of the injector. The effect of different configurations of the injector on spray characteristics is studied. A correlation for SMD is obtained.

DLR investigated forced combustion oscillations of two liquid fuel burners in a research combustion chamber at elevated pressures simulating idle conditions of aircraft engine combustors. The work was performed in collaboration with MTU Munich. An existing combustion chamber with optical access, capable to operate up to 20 bar, was upgraded with an air flow pulsator, that bypasses air from the combustor plenum to the exhaust with a sinusoidal massflow variation up to 700 Hz. Pressure transducers in the plenum and the flame tube monitored the forced disturbances. A photomultiplier recorded the OH* chemiluminescence of the flame. For the agreed operating conditions frequency scans of these values were registered. Additionally images of the OH* chemiluminescence were taken at selected frequencies and evaluated in a statistical manner, to separate turbulent and periodic behaviour. From the analysis of the pressure data, it can be concluded, that serious thermo-acoustic feedback was not observed for both burners. However burner 2 with the flame detached from the wall exhibited a higher fluctuation level as burner 1 with the wall attached flame. A resonant behaviour was observed near the characteristic frequency of the sound room comprised of plenum, flame tube and burner nozzle as connecting passage. The chemiluminescence images show different modes of spatial fluctuation for the burners and for burner 2 they also vary with the operating condition.

Injection of water into a combustor is a proven method for reducing emissions of particulate and nitrogen oxide emissions beyond what can be achieved by reducing firing temperature through fuel lean operation. However, the added complexity and cost associated with a standalone water injection circuit makes this method less desirable. A method for reducing the complexity of water injection is to premix the fuel with water as an emulsion and injecting this mixture through the existing liquid fuel circuit. In the present study, the gaseous fuel injectors of a commercial micro gas turbine generator were modified to operate on both water-in-oil emulsions and gas fuel. These injectors were installed in an otherwise unmodified engine. The original air-blast injector was modified by adding a central fuel tube and blocking the original gas fuel passages. Dual-fuel operation was achieved by injecting gaseous fuel through the annular passage surrounding the liquid fuel tube. This gas fuel passageway is used for both gas fuel delivery and for introduction of air that is used to assist in the liquid fuel atomization. The atomization behavior of these injectors has been characterized using laser diffraction and high speed video for water mass fractions of between zero and 0.5, and air-to-liquid ratios between zero and one. Additionally, pollutant emissions were measured from an engine equipped with these modified injectors and operated over the same range of water mass fraction and air-to-liquid ratio. The results confirmed viability of the modified injectors for introducing water in form of an emulsion. It was also observed that, while atomization performance was altered in a minor way, the complex interaction between evaporation and subsequent mixing resulted in non-monotonic impact on NOx emissions.

<div class="section abstract"><div class="htmlview paragraph">Enhanced protection against high speed crashes requires more aggressive passive safety countermeasures as compared to what are provided in vehicle structures today. Apart from such collision-related scenarios, high energy explosions, accidentally caused or otherwise, require superior energy-absorbing capability of vehicle body subsystems. A case in point is a passenger vehicle subjected to an underbody blast emanating shock wave energy of military standards. In the current study, assessment of the behavior of a “hollow” countermeasure in the form of a depressed steel false floor panel attached with spot-welds along flanges to a typical predominantly flat floor panel of a car is initially carried out with an explicit LS-DYNA solver. This is followed up with the evaluation of PU (polyurethane) foam-filled and liquid-filled false floor countermeasures. In all cases, a charge is detonated under the false floor subjecting it to a high-energy shock pressure loading. For the case of the liquid-filled countermeasure, a novel ALE (Arbitrary Lagrangian-Eulerian) formulation for fluid-structure interaction has been adopted with a Hybrid III dummy seating above the flat floor with a modified MIL-LX legform for injury prediction. In order to establish confidence on the ALE model, a drop-weight impact test on a liquid-filled square aluminum tube has been carried out and its behavior predicted, prior to the analysis of the countermeasures mentioned. It appears that the fluid-filled countermeasure is a promising solution in countering the effects of a shock pressure loading by greatly reducing the load transferred to the lower limb of an occupant sitting right above a detonated charge placed under the floor of a car.</div></div>

The present paper reports the results of an experimental investigation on the unsteady flow in a Lean Premixed Prevaporized (LPP) burner for aeronautical applications. The experiments were focused on two main aspects: understanding the effect of the fuel spray on the unsteady air flow field and characterizing the fuel spray under unsteady flow conditions in terms of velocity and spatial distribution of the fuel droplets. The experimental campaign was performed with laser-based instrumentation (LDV, PDA and PIV) on a large-scale model of the LPP burner with air preheating and fuel injection in order to allow detailed measurements of the two-phase unsteady flow. The gas flow field is dominated by a spiral vortex breakdown phenomenon, which results in a complex unsteady flow configuration and an extended recirculation zone near the axis of the burner. The fuel droplets flow field is strongly correlated to the gas flow field. By comparing the results of the present experimental campaign with results obtained without fuel spray, there is evidence of a positive effect of the spray on the air flow field. The spray effect results in a reduction of the recirculation phenomenon in the exit section of the LPP burner. At the LPP burner exit a general satisfactory degree of vaporization is obtained. However, at the periphery of the premixing duct outlet section, a significant concentration of larger droplets of not yet vaporized fuel is present, due to the secondary air blast disintegration of the liquid film formed on the internal surface of the premixer tube. This phenomenon is responsible for lack of homogeneity of the fuel distribution in time and space at the premixer duct exit.

The European Facility for Industrial Transmutation (EFIT) is developed to transmute long-lived actinides from spent fuel on an industrial scale. In this lead-cooled reactor an intermediate loop is eliminated for economic reasons. Within the framework of design and safety studies the impact of a steam generator tube rupture accident has been investigated. In this postulated event high-pressured liquid water blasts into the lead pool which could trigger various transients. As a major concern steam could be dragged into the core featuring a positive void worth. A thermal lead/water interaction could lead to in-core damage propagation; it could initiate a sloshing of the lead coolant and trigger voiding processes. Furthermore the pressurization of the cover gas needs to be considered. To prove the feasibility of the proposed design these risks are investigated and assessed. Numerical simulations are performed using the advanced safety analysis code SIMMER-III [2]. For the important issue of thermal lead/water interactions the SIMMER code has been validated against Japanese heavy-liquid/water injection experiments.