Saccharification of delignified sawdust from 20 different trees in the Lagos area of Nigeria

Sawdust produced during the chopping of trees is a major waste product causing pollution of air as well as of the Lagos Lagoon in Nigeria. Sawdust from 20 different trees processed in the wood industry has been delignified successively by the Kraft process and hydrogen peroxide followed by Trichoderma viride cellulose catalyzed bioconversion into glucose, a fermentable sugar. Sugars are also released from sawdust during each delignification procedure prior to enzymatic catalyzed bioconversion. A 654% increase in sugar formation was observed from Entada gigas and 422% increase from Nauclea diderrichii when exposed to both delignification procedures compared to the amount of sugar released during Kraft pretreatment only. Relative high amounts of glucose were released during bioconversion of these waste celluloses when subjected to both delignification procedures compared to the bioconversion of Kraft delignified sawdust. Both delignification procedures resulted in a 175% increase in sugar formation for both Erythrophleum suaveolens and Milicia excels wood species. Different glucose concentrations were released during biodegradation with the highest at 9.23 mg.ml-1 released from Lophira alata after Kraft pretreatment and 14.28 mg.ml-1 from E. suaveolens after both delignification procedures. The concentration of sugar produced during the cellulase catalyzed bioconversion of delignified sawdust was many folds higher than the amount of sugars released during the delignification procedures.Key words: Bioenergy, sawdust, Trichoderma viride cellulase, delignification, saccharification

Measurement of the nuclear modification factor for muons from charm and bottom hadrons in Pb+Pb collisions at 5.02 TeV with the ATLAS detector

Heavy-flavour hadron production provides information about the transport properties and microscopic structure of the quark-gluon plasma created in ultra-relativistic heavy-ion collisions. A measurement of the muons from semileptonic decays of charm and bottom hadrons produced in Pb+Pb and pp collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV with the ATLAS detector at the Large Hadron Collider is presented. The Pb+Pb data were collected in 2015 and 2018 with sampled integrated luminosities of 208 mu b(-1) and 38 mu b(-1), respectively, and pp data with a sampled integrated luminosity of 1.17 pb(-1) were collected in 2017. Muons from heavy-flavour semileptonic decays are separated from the light-flavour hadronic background using the momentum imbalance between the inner detector and muon spectrometer measurements, and muons originating from charm and bottom decays are further separated via the muon track's transverse impact parameter. Differential yields in Pb+Pb collisions and differential cross sections in pp collisions for such muons are measured as a function of muon transverse momentum from 4 GeV to 30 GeV in the absolute pseudorapidity interval vertical bar eta vertical bar < 2. Nuclear modification factors for charm and bottom muons are presented as a function of muon transverse momentum in intervals of Pb+Pb collision centrality. The bottom muon results are the most precise measurement of b quark nuclear modification at low transverse momentum where reconstruction of B hadrons is challenging. The measured nuclear modification factors quantify a significant suppression of the yields of muons from decays of charm and bottom hadrons, with stronger effects for muons from charm hadron decays

A search for an unexpected asymmetry in the production of e+μ− and e−μ+ pairs in proton-proton collisions recorded by the ATLAS detector at root s = 13 TeV

This search, a type not previously performed at ATLAS, uses a comparison of the production cross sections for e(+)mu(-) and e(-)mu(+) pairs to constrain physics processes beyond the Standard Model. It uses 139 fb(-1) of proton-proton collision data recorded at root s = 13 TeV at the LHC. Targeting sources of new physics which prefer final states containing e(+)mu(-) and e(-)mu(+), the search contains two broad signal regions which are used to provide model-independent constraints on the ratio of cross sections at the 2% level. The search also has two special selections targeting supersymmetric models and leptoquark signatures. Observations using one of these selections are able to exclude, at 95% confidence level, singly produced smuons with masses up to 640 GeV in a model in which the only other light sparticle is a neutralino when the R-parity-violating coupling lambda(23)(1)' is close to unity. Observations using the other selection exclude scalar leptoquarks with masses below 1880 GeV when g(1R)(eu) = g(1R)(mu c) = 1, at 95% confidence level. The limit on the coupling reduces to g(1R)(eu) = g(1R)(mu c) = 0.46 for a mass of 1420 GeV

Studies on Industrial Pollution in Nigeria: The effect of Textile effluents on the quality of Groundwater in some parts of Lagos

The textile industry is one of the industries in Nigeria that pollute the environment by the indiscriminate discharge of untreated effluents. Until recently little attention was given to groundwater pollution studies in the industrial estates. We report herein, the effect of the effluents discharged from two textile industries on the well waters from around the Estates investigated. The results showed that the effluents had high values of BOD5 (100–390 mg/l), COD (204–2000 mg/l), pH and were highly coloured. These values were higher than the efffluent limits stipulated by the Federal Ministry of Environment for textile industries. The effect of depth and distance of well from the point of effluent discharge on the quality of well water was also investigated and the results showed that of the fifteen tube wells around Company A, the well that was closest to point of discharge (a shallow well) showed the highest BOD5 (107 mg/l) and total dissolved solids (TDS) while all the other wells together with those around Company B showed acceptable results. KEYWORDS: Textile effluents, groundwater, pollution. Nig. Jnl Health & Biomed. Sciences Vol.3(1) 2004: 44-5

Correlation studies of heavy metals concentration with sediment properties of some rivers surrounding the Lagos lagoon

Lagos lagoon is a highly polluted water body, which receives enormous amount of domestic and industrial wastes from rivers and streams. In this study, two main Lagos urban rivers Odo-Iyaalaro and Shasha rivers that receive industrial effluents and empty into the Lagos Lagoon were examined. The sediments at the bottom of waters play a role in the study of pollution in the rivers. Upstream of Odo-Iyaalaro River (Point 1) receives the largest volume of effluents and showed the highest level of heavy metals in sediments with concentrations of 108.3mg/l for Pb, 805mg/l for Zn, 94.5mg/l for Cu, 31mg/l for Cr and 42.1 mg/l for Cd. Down the river, the levels decreased to 25mg/l for Pb, 64.5 mg/l for Zn, 22mg/l for Cu, 15.9 mg/l for Cr and 1.9 mg/l for Cd. A good correlation was found to exist between the level of Zn in water and sediment, and also between the CEC and %silt-clay of sediments. Shasha River receives relatively fewer amounts of industrial effluents, but is relatively the main receptacle for municipal and land-based waste. The levels of heavy metals in Shasha River were lower compared with that of Odo-Iyaalaro River, with the upstream points showing concentrations of 20.5mg/l for Pb, 25.3mg/l for Zn, 7.9mg/l for Cu, 30.8 mg/l for Cr and 1.5mg/l for Cd. A good correlation exists between the CEC and all the metals determined, and between the %organic carbon and all the metals determined. Compared with literature data, the results of heavy metals gave an indication of pollution. KEYWORDS: correlation, heavy metals, sediments, caution exchange capacity, rivers, lagoon Nigerian Journal of Health and Biomedical Sciences Vol. 5(1) 2006: 118-12

Search for neutral long-lived particles in pp collisions at s \sqrt{s} = 13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter

A search for decays of pair-produced neutral long-lived particles (LLPs) is presented using 139 fb(-1) of proton-proton collision data collected by the ATLAS detector at the LHC in 2015-2018 at a centre-of-mass energy of 13 TeV. Dedicated techniques were developed for the reconstruction of displaced jets produced by LLPs decaying hadronically in the ATLAS hadronic calorimeter. Two search regions are defined for different LLP kinematic regimes. The observed numbers of events are consistent with the expected background, and limits for several benchmark signals are determined. For a SM Higgs boson with a mass of 125 GeV, branching ratios above 10% are excluded at 95% confidence level for values of c times LLP mean proper lifetime in the range between 20 mm and 10 m depending on the model. Upper limits are also set on the cross-section times branching ratio for scalars with a mass of 60 GeV and for masses between 200 GeV and 1 Tev