Occurrence and Toxicity of Hydrocarbon Residues in Crab (Callinectes sapidus) from Contaminated Site

To elucidate seasonal changes in hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) due to oil spill, tissues of blue crab (Callinectes sapidus) were investigated. Total petroleum hydrocarbons (n-alkanes) concentrations ranged from 0.17-0.32ìg/gdw and 0.28-0.62ìg/gdw during the dry and wet seasons respectively. Thetissues accumulate a complex spectrum dominated by heavier hydrocarbons, alkylsubstituted and PAHs. The impact of biogenic contribution through dietary uptake was related to the elevated levels, particularly of the PAHs. Studies of other site specific, resident organism are recommended in order to be able to establish the extent of toxicit

Seasonal Metal Distribution in Ondo Coastal Sediment, Nigeria

The distribution of heavy metals in streambed sediment from an oil-producing region in Nigeria has been examined between the two distinct seasons (dry and wet). The highest mean concentration duringthe dry season (wet season in brackets) was 2083.3±355.5 (2264.2±347.3)mg/kg Cu and 0.16±0.06 (0.19±0.09)mg/kg Zn respectively. With similar patterns at both seasons, the order of increasing concentration was Z

Seasonal Metal Distribution in Ondo Coastal Sediment, Nigeria

The distribution of heavy metals in streambed sediment from an oil-producing region in Nigeria has been examined between the two distinct seasons (dry and wet). The highest mean concentration duringthe dry season (wet season in brackets) was 2083.3±355.5 (2264.2±347.3)mg/kg Cu and 0.16±0.06 (0.19±0.09)mg/kg Zn respectively. With similar patterns at both seasons, the order of increasing concentration was Z

Action for the eleven dimensional multiple M-wave system

We present the covariant supersymmetric and kappa-symmetric action for a system of N nearly coincident M-waves (multiple M0-brane system) in flat eleven dimensional superspace.Comment: 4+ pages, RevTeX4, no figures. V2: misprints corrected, discussion extended, references added, LaTeX, 10 pages. V3: misprints corrected. V4, extended version, 1+13 pages, to appear in JHE

Neoadjuvant chemotherapy in Albinos with locally advanced skin cancer at a Blantyre Hospital: - Case Series

Albinism in Africa remains a public health concern with increasing numbers of advanced skin cancer in this population at presentation. There are challenges with availability of Radiotherapy (RT) units in Africa which is an important modality for controlling loco-regional disease alone or in combination with surgery. Proposed chemotherapy  regimens have not been well validated through Randomized Controlled Trials thus posing difficulties for standard of care for units that do not have access to functional RT facilities. Malawi is one such country without radiotherapy.Case summarySeven patients with locally advanced skin cancer were seen in the adult oncology unit at Queen Elizabeth Central Hospital in Blantyre (QECH), Malawi between 2010 and 2013. QECH is one of the teaching hospitals in the country. All were subjected to neo-adjuvant chemotherapy. The primary treatment aim was cyto-reduction followed by surgery whilst the secondary outcome was general symptom control. Three patients achieved complete responses of which two underwent resection and a pectoralis major myocutaneous flap. One had a near complete response and threeshowed partial responses.ConclusionNeo-adjuvant chemotherapy may be a possible

Three-body collisions in Boltzmann-Uehling-Uhlenbeck theory

Aiming at a microscopic description of heavy ion collisions in the beam energy region of about 10 A GeV, we extend the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model by including a relativistic mean field, in-medium baryon-baryon cross sections and three-body collisions. The model is then compared with experimental data for central Au+Au collisions at 2-10 A GeV and central Pb+Pb collisions at 30 and 40 A GeV on the proton rapidity spectra, the midrapidity yields of $\pi^+$, $K^\pm$ and $(\Lambda+\Sigma^0)$, and the transverse mass spectra of $\pi^\pm$ and $K^\pm$. The three-body collisions increase the inverse slope parameters of the hadron $m_\perp$-spectra to a good agreement with the data.Comment: 26 pages, 9 figures, figures added, discussion extended, results not changed, version accepted in Phys. Rev.

Hartree-Fock ground state of the two-dimensional electron gas with Rashba spin-orbit interaction

We search for the uniform Hartree-Fock ground state of the two-dimensional electron gas formed in semiconductor heterostructures including the Rashba spin-orbit interaction. We identify two competing quantum phases: a ferromagnetic one with partial spin polarization in the perpendicular direction and a paramagnetic one with in-plane spin. We present a phase diagram in terms of the relative strengths of the Rashba to the Coulomb interaction and the electron density. We compare our theoretical description with existing experimental results obtained in GaAs-AlGaAs heterostructures.Comment: 5 pages, 2 figure

Anisotropic swelling of elastomers filled with aligned 2D materials

A comprehensive study has been undertaken on the dimensional swelling of graphene-reinforced elastomers in liquids. Anisotropic swelling was observed for samples reinforced with graphene nanoplatelets (GNPs), induced by the in-plane orientation of the GNPs. Upon the addition of the GNPs, the diameter swelling ratio of the nanocomposites was significantly reduced, whereas the thickness swelling ratio increased and was even greater than that of the unfilled elastomers. The swelling phenomenon has been analyzed in terms of a modification of the Flory-Rhener theory. The newly-derived equations proposed herein, can accurately predict the dependence of dimensional swelling (diameter and thickness) on volume swelling, independent of the type of elastomer and solvent. The anisotropic swelling of the samples was also studied in combination with the evaluation of the tensile properties of the filled elastomers. A novel theory that enables the assessment of volume swelling for GNP-reinforced elastomers, based on the filler geometry and volume fraction has been developed. It was found that the swelling of rubber nanocomposites induces a biaxial constraint from the graphene flakes

EXPERIMENTAL STRESS CONCENTRATION FACTOR IN CONCRETE-FILLED STEEL TUBULAR T-JOINTS

© 2018 Elsevier Ltd An experimental investigation of stress concentration factor (SCF) in Steel circular hollow section brace welded to concrete-filled circular hollow section chord (CHS-to-CFCHS) T-joints has been performed under axial tension, axial compression, in-plane bending and out-of-plane bending. The distribution of SCF around the welded brace-to-chord intersection on both the brace and chord has been investigated using three CHS-to-CFCHS T-joint specimens. The experimental SCF results have been compared with the predicted SCF in empty T-joints. The relationship between the maximum SCF in relation to parameter β, with fixed other geometrical parameters, has been investigated for the basic load conditions. The experimental maximum SCF under axial tension has been compared with the predicted maximum SCF from parametric equations for CHS-to-CFCHS T-joints previously developed by the authors. The results show that the concrete has a significant effect in reducing the SCF, mostly under axial tension and the parametric equations for predicting SCFs in empty T-joints are not suitable for CHS-to-CFCHS T-joints. The effect of parameter β on the maximum SCF in CHS-to-CFCHS T-joints is significant under axial tension and out-of-plane bending moment