273 research outputs found
Algae bioaccumulation capacity for metals in acid mine drainage (AMD)-a case study in Frongoch Mine, the UK
Algae living in the AMD water around the Frongoch Mine, the UK, were collected
and identified by microscope. Metals’ concentration was evaluated in AMD water
and algae in two seasons (June and October) in 2019 to assess the bioaccumulation
capacity of algae. Two types of algae, Ulothrix sp. and Oedogonium sp., were found to
be the main species at the Frongoch mine, and they revealed a high capacity of metals
bioaccumulation. Concentrations of metals in AMD water from higher to lower were
Zn>>Pb>Cd>Fe>Cu. Study results identified the bioaccumulated metals concentrations
in algae from higher to lower were Fe>Pb>Cu>Cd>Zn
Sorption of Metaldehyde using granular activated carbon
In this work the ability of granular activated carbon (GAC) to sorb metaldehyde was evaluated. The kinetic data could be described by an intra-particle diffusion model which indicated that the porosity of the sorbent strongly influenced the rate of sorption. The analysis of the equilibrium sorption data revealed that ionic strength and temperature did not play any significant role in the metaldehyde uptake. The sorption isotherms were successfully predicted by the Freundlich model. The GAC used in this paper exhibited a higher affinity and sorption capacity for metaldehyde with respect to other GACs studied in previous works, probably as a result of its higher specific surface area
"Square Root" of the Proca Equation: Spin-3/2 Field Equation
New equations describing particles with spin 3/2 are derived. The non-local
equation with the unique mass can be considered as "square root" of the Proca
equation in the same sense as the Dirac equation is related to the
Klein-Gordon-Fock equation. The local equation describes spin 3/2 particles
with three mass states. The equations considered involve fields with spin-3/2
and spin-1/2, i.e. multi-spin 1/2, 3/2. The projection operators extracting
states with definite energy, spin, and spin projections are obtained. All
independent solutions of the local equation are expressed through projection
matrices. The first order relativistic wave equation in the 20-dimensional
matrix form, the relativistically invariant bilinear form and the corresponding
Lagrangian are given. Two parameters characterizing non-minimal electromagnetic
interactions of fermions are introduced, and the quantum-mechanical Hamiltonian
is found. It is proved that there is only causal propagation of waves in the
approach considered.Comment: 17 pages, corrections in Eqs. (50), (51
Solutions of Podolsky's Electrodynamics Equation in the First-Order Formalism
The Podolsky generalized electrodynamics with higher derivatives is
formulated in the first-order formalism. The first-order relativistic wave
equation in the 20-dimensional matrix form is derived. We prove that the
matrices of the equation obey the Petiau-Duffin-Kemmer algebra. The
Hermitianizing matrix and Lagrangian in the first-order formalism are given.
The projection operators extracting solutions of field equations for states
with definite energy-momentum and spin projections are obtained, and we find
the density matrix for the massive state. The -matrix Schrodinger
form of the equation is derived, and the Hamiltonian is obtained. Projection
operators extracting the physical eigenvalues of the Hamiltonian are found.Comment: 17 pages, minor corrections, published versio
Two-body quantum mechanical problem on spheres
The quantum mechanical two-body problem with a central interaction on the
sphere is considered. Using recent results in representation
theory an ordinary differential equation for some energy levels is found. For
several interactive potentials these energy levels are calculated in explicit
form.Comment: 41 pages, no figures, typos corrected; appendix D was adde
The Coulomb-Oscillator Relation on n-Dimensional Spheres and Hyperboloids
In this paper we establish a relation between Coulomb and oscillator systems
on -dimensional spheres and hyperboloids for . We show that, as in
Euclidean space, the quasiradial equation for the dimensional Coulomb
problem coincides with the -dimensional quasiradial oscillator equation on
spheres and hyperboloids. Using the solution of the Schr\"odinger equation for
the oscillator system, we construct the energy spectrum and wave functions for
the Coulomb problem.Comment: 15 pages, LaTe
CLINICAL AND IMMUNOLOGICAL FEATURES OF KIDNEY TRANSPLANT RECIPIENTS WITH CYTOMEGALOVIRUS INFECTION MANIFESTATION IN THE EARLY POSTOPERATIVE PERIOD
Aim. To optimize the management of postoperative renal allograft recipients through the introduction of methods for predicting risk of manifestation of cytomegalovirus infection on the basis of a comprehensive assessment of the clinical and immunological status. Materials and methods. We retrospectively analyzed the medical records of 303 patients with end-stage renal disease, among them – were the recipients of renal allograft – 136, among whom 29 within 2 months after the operation had clinical signs of CMV infection. Assessable "CMV syndrome", laboratory evidence of CMV infection, the incidence of antigens (genes) of HLA A, B and DRB *1, calculated goodness of fit χ2 and relative risk RR, changes MCP-1 in urine. Results. In renal allograft recipients with clinical and laboratory evidence of CMV infection in the early postoperative period, significantly more (χ2 > 3,8) met antigen B35. A positive association with CMV infection was detected also for DRB1 * 08, B21, B22, B41, A24 (9), B51 (5), DRB1*14 and DRB1*15. Protective effects possessed antigens / alleles of genes A26 (10), B14, B38 (16) B61 (40) and DRB1*16. MCP-1 levels in this group of recipients were raised to 2174,7 ± 296,3 pg/ml with a strong negative correlation with the levels of urea and creatinine in serum (r = 0,9, p < 0.001). Conclusion. Immunological markers of risk manifestation of CMV infection in recipients of kidneys in the early postoperative period are: the carriage of В35 и В55,56(22), В49(21), В41, DRB1*08 и DRB1*15, an increase of levels of MCP-1 in urine without increasing the levels of urea and creatinine in the serum
Anisotropic inharmonic Higgs oscillator and related (MICZ-)Kepler-like systems
We propose the integrable (pseudo)spherical generalization of the
four-dimensional anisotropic oscillator with additional nonlinear potential.
Performing its Kustaanheimo-Stiefel transformation we then obtain the
pseudospherical generalization of the MICZ-Kepler system with linear and
potential terms. We also present the generalization of the
parabolic coordinates, in which this system admits the separation of variables.
Finally, we get the spherical analog of the presented MICZ-Kepler-like system.Comment: 7 page
Facile control of silica nanoparticles using a novel solvent varying method for the fabrication of artificial opal photonic crystals
In this work, the Stöber process was applied to produce uniform silica nanoparticles (SNPs) in the meso-scale size range. The novel aspect of this work was to control the produced silica particle size by only varying the volume of the solvent ethanol used, whilst fixing the other reaction conditions. Using this one-step Stöber-based solvent varying (SV) method, seven batches of SNPs with target diameters ranging from 70 to 400 nm were repeatedly reproduced, and the size distribution in terms of the polydispersity index (PDI) was well maintained (within 0.1). An exponential equation was used to fit the relationship between the particle diameter and ethanol volume. This equation allows the prediction of the amount of ethanol required in order to produce particles of any target diameter within this size range. In addition, it was found that the reaction was completed in approximately 2 h for all batches regardless of the volume of ethanol. Structurally coloured artificial opal photonic crystals (PCs) were fabricated from the prepared SNPs by self-assembly under gravity sedimentation
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