277 research outputs found

    Comparative Studies on the Biosurfactant Production Capacity of Bacillus Subtilis and Pseudomonas Aeruginosa Using Engine Oil and Diesel Respectively as Substrate

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    The study was carried out to compare the the production capabilities and the biosurfactant activity of the bacteria, Bacillus subtilis and Pseudomonas aeruginosa using engine oil and diesel as the substrates respectively. The test organisms were isolated from engine oil contaminated soil as in the case of the Bacillus subtilis, which was collected from an automobile workshop in Samaru, Zaria and hydrocarboncontaminated water in the case of the Pseudomonas aeruginosa. The medium used for the experiment was a mineral medium supplemented with 2% engine oil and 2% diesel as the sole source of carbon and energy for Bacillus subtilis and Pseudomonas aeruginosa respectively. Production of biosurfactant was assayed by monitoring the increase in cell concentration, biosurfactant concentration, emulsification index and decrease in surface tension. Highest level of cell concentration and biosurfactant concentration (3.3 x 108 CFU/ml and 0.0106mg/ml respectively) were obtained at 144 h for the Pseudomonas aeruginosa using diesel as source of carbon and energy while the highest level of cell concentration and biosurfactant concentration (3.2 x 108 CFU/ml and 0.0096mg/ml respectively) were obtained at 120hrs for the Bacillus subtilis using engine oil as source of carbon and energy. The research show that Pseudomonas aeruginosa using diesel as the sole source of carbon and energy is better for the production of biosurfactant than Bacillus subtilis using engine oil as the sole source of carbon and energy.Key words: Biosurfactant, engine oil, diesel, Pseudomonas aeruginosa, Bacillus subtilis

    Isolation and characterization of Pseudomonas aeruginosa and Brevibacillus species and their potential to biodegrade polyethylene material

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    This study was conducted to screen for Pseudomonas aeruginosa and Brevibacillus species from soil and investigate their ability to biodegrade low density polyethylene materials. The organisms were isolated using phenotypic characterization and molecular identification by polymerase chain reaction (PCR). The PCR confirmed the presence of two different strains of Pseudomonas aeruginosa and absence of Brevibacillus specie from the soil sample. The bacteria were inoculated in a nutrient broth to which 2% polyethylene was amended for a period of three weeks in a shaker incubator at 180rpm. Effect of temperature, pH and concentration of polyethylene on the biodegradation process was also studied. The initial and final dry weights of the polyethylene were recorded and the % degraded was calculated. It was found that both strains of Pseudomonas aeruginosa were capable of degrading the polyethylene. Strain C3 produced a maximum degradation of 20% at 37°C and pH 6. Strain B3 achieved a maximum degradation of 15% at 37°C at pH 6 and 7. In addition, it was found that both strains of Pseudomonas aeruginosa were able to survive up to 6% of polyethylene producing a maximum degradation of 55%. Therefore strains B3 and C3 of Pseudomonas aeruginosa can be effective in biodegradation of polyethylene in dump sites if their potentials are well exploited

    Effect of weeding status and tapping date on the yield of gum Arabic (Acacia Senegal) in Jigawa state, Nigeria

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    The study examined the Effect of Weeding Status and Tapping Date on the yield of gum Arabic (Acacia senegal) in Jigawa State, Nigeria. The said task has been accomplished by employing a two factorial experiment of complete randomized block design with three replicates which involves the weeding status and tapping dates conducted in 2014 season at two different locations; Kadoma and Kwanar duhuwa. The weeding status experiment comprises of three 100% weeded plots; and three Unwweded plots; while the tapping date investigation was tested at six levels (1st and 15th September, 1st and 5th October and 1st and 15th November). In each of these treatments three (3) trees were tapped making a total number of two hundred and sixteen trees in the two locations and one hundred and eight (108) trees at kadoma and Kwanar duhuwa respectively. The first picking of the gum yield took place 45day after tapping and each consecutive picking was collected after 15 days from the previous one. The gum from each picking was weighed after air drying with sensitive balance JY2002 model. SAS statistical package used for the data analysis thus DUNCAN multiple range test were employed in establishing the relationships between the variable investigated.Thus, the finding has revealed that gum Arabic tapping conducted on the 15th of October gave higher yield of gum Arabic when compared with the rest dates of tapping; the unweeded plots gave superior yield than the weeded plot.Therefore gum Arabic farmers were advised not to weed gum Arabic field when they are matured enough for harvest at the same time tapping should be carried out when the gum Arabic tree lost at least 50% of their leaves.Keywords; Gum Arabic, Jigawa State, Tapping and Weeding

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

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    The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

    Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

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    A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO

    Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

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    Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

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    Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

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