195 research outputs found
FaCE: a tool for Three Body Faddeev calculations with core excitation
FaCE is a self contained programme, with namelist input, that solves the
three body Faddeev equations. It enables the inclusion of excitation of one of
the three bodies, whilst the other two remain inert. It is particularly useful
for obtaining the binding energies and bound state structure compositions of
light exotic nuclei treated as three-body systems, given the three effective
two body interactions. A large variety of forms for these interactions may be
defined, and supersymmetric transformations of these potentials may be
calculated whenever two body states need to be removed due to Pauli blocking.Comment: 19 pg, 3 figs, program available for download from
ftp://ftp.ph.surrey.ac.uk/pub/thompson/face
Effect of Preheating on the Permeability of Neonatal Rat Stratum Corneum to Alkanols
We heated flat sheets of neonatal rat stratum corneum for various times at temperatures between 40 and 90°C before determining the permeability coefficient (Kp) of propanol and/or hexanol from water. Below 70°C, Kp remained constant; at 75°C, Kp increased linearly with exposure time; at 80°C and above, there was a large increase in under 2 h, with no further increase on longer heating. There was a 15-fold increase in 6-h Kp between 70°C and 80°C, values being constant above 80°C but at a figure less than for lipid-extracted stratum corneum. Thermal analysis showed that the increase in Kp corresponds to changes in the 80°C lipid endotherm, suggesting that the increased Kp is due to a disordering of the lipid structures. The effect of treating preheated stratum corneum with dimethylsulfoxide (DMSO) vapor for 16h was also studied. Below 70°C, Kp was increased five-fold, but between 70 and 80°C this difference was eliminated, so that above 80°C the Kp was the same as with heat treatment alone. We concluded that both heat and DMSO affect the lipid structures of stratum corneum. DMSO produced a small, reversible structural change, while the effect of heat is irreversible and produces a greater degree of disorder in the lipid structures, but the lipid still contributed to the barrier effect of stratum corneum
Transfer to the continuum and Breakup reactions
Reaction theory is an essential ingredient when performing studies of nuclei
far from stability. One approach for the calculation of breakup reactions of
exotic nuclei into two fragments is to consider inelastic excitations into the
single particle continuum of the projectile. Alternatively one can also
consider the transfer to the continuum of a system composed of the light
fragment and the target. In this work we make a comparative study of the two
approaches, underline the different inputs, and identify the advantages and
disadvantages of each approach. Our test cases consist of the breakup of
Be on a proton target at intermediate energies, and the breakup of B
on Ni at energies around the Coulomb barrier. We find that, in practice
the results obtained in both schemes are in semiquantitative agreement. We
suggest a simple condition that can select between the two approaches.Comment: 10 pages, 12 figures. Replaced by accepted version. To appear in
Nucl. Phys.
A large gastrointestinal stromal tumor of the duodenum: a case report
<p>Abstract</p> <p>Introduction</p> <p>Gastrointestinal stromal tumors of the duodenum are uncommon. They can reach a large size. Diagnosis can be elusive and managing them can be difficult. Our case report aims to increase awareness and highlight some issues related to the diagnosis and management of duodenal gastrointestinal stromal tumors.</p> <p>Case presentation</p> <p>We present the case of a 38-year-old Middle Eastern woman with a large, slowly-growing gastrointestinal stromal tumor of the duodenum. Her complaints were minor epigastric discomfort and swelling. A pancreaticoduodenectomy with complete tumor excision was performed. She was doing very well with no evidence of disease recurrence when she was last seen 34 months after her operation.</p> <p>Conclusion</p> <p>Gastrointestinal stromal tumors of the duodenum should be suspected in any patient with a duodenal wall mass. Extramural growth and central ulceration with or without bleeding should alert the endoscopist to the possibility of a duodenal gastrointestinal stromal tumor diagnosis. There is more than one surgical approach available; however, complete surgical excision, with negative margins, is the absolute requirement. Preoperative imatinib mesylate can be considered in unresectable or borderline resectable cases.</p
Single-neutron transfer from 11Be gs via the (p,d) reaction with a radioactive beam
The 11Be(p,d)10Be reaction has been performed in inverse kinematics with a
radioactive 11Be beam of E/A = 35.3 MeV. Angular distributions for the 0+
ground state, the 2+, 3.37 MeV state and the multiplet of states around 6 MeV
in 10Be were measured at angles up to 16 deg CM by detecting the 10Be in a
dispersion-matched spectrometer and the coincident deuterons in a silicon
array. Distorted wave and coupled-channels calculations have been performed to
investigate the amount of 2+ core excitation in 11Be gs. The use of "realistic"
11Be wave functions is emphasised and bound state form factors have been
obtained by solving the particle-vibration coupling equations. This calculation
gives a dominant 2s component in the 11Be gs wave function with a 16% [2+ x 1d]
core excitation admixture. Cross sections calculated with these form factors
are in good agreement with the present data. The Separation Energy prescription
for the bound state wave function also gives satisfactory fits to the data, but
leads to a significantly larger [2 x 1d] component in 11Be gs.Comment: 39 pages, 12 figures. Accepted for publication in Nuclear Physics A.
Added minor corrections made in proof to pages 26 and 3
Microalgae as substrate in low cost terracotta-based microbial fuel cells: Novel application of the catholyte produced
© 2016 Elsevier Ltd. In this work, the by-product generated during the operation of cylindrical MFCs, made out of terracotta material, is investigated as a feasible means of degrading live microalgae for the first time. In addition to the low cost materials of this design, the reuse of the solution produced in the cathode renders the technology truly green and capable of generating bioenergy. In this study, the effect of a light/dark cycle or dark conditions only on the digestion of live microalgae with the catholyte is investigated. The results show that a combination of light/dark improves degradation and allows algae to be used as substrate in the anode. The addition of 12.5 mL of a 1:1 mix of catholyte and microalgae (pre-digested over 5 days under light/dark) to the anode, increases the power generation from 7 ΌW to 44 ΌW once all the organic matter in the anode had been depleted
Coulomb and nuclear breakup effects in the single neutron removal reaction 197Au(17C,16C gamma)X
We analyze the recently obtained new data on the partial cross sections and
parallel momentum distributions for transitions to ground as well as excited
states of the 16C core, in the one-neutron removal reaction 197Au(17C,16C
gamma)X at the beam energy of 61 MeV/nucleon. The Coulomb and nuclear breakup
components of the one-neutron removal cross sections have been calculated
within a finite range distorted wave Born approximation theory and an eikonal
model, respectively. The nuclear contributions dominate the partial cross
sections for the core excited states. By adding the nuclear and Coulomb cross
sections together, a reasonable agreement is obtained with the data for these
states. The shapes of the experimental parallel momentum distributions of the
core states are described well by the theory.Comment: Revtex format, two figures included, to appear in Phys. Rev. C.
(Rapid communications
Recreational fisheries in the UK: natural capital, ecosystem services, threats, and management
Dynamic biospeckle analysis, a new tool for the fast screening of plant nematicide selectivity
From the lab to the field: Self-stratifying microbial fuel cells stacks directly powering lights
The microbial fuel cell (MFC) technology relies on energy storage and harvesting circuitry to deliver stable power outputs. This increases costs, and for wider deployment into society, these should be kept minimal. The present study reports how a MFC system was developed to continuously power public toilet lighting, with for the first time no energy storage nor harvesting circuitry. Two different stacks, one consisting of 15 and the other 18 membrane-less MFC modules, were operated for 6 days and fuelled by the urine of festival goers at the 2019 Glastonbury Music Festival. The 15-module stack was directly connected to 2 spotlights each comprising 6 LEDs. The 18-module stack was connected to 2 identical LED spotlights but going through 2 LED electronic controller/drivers. Twenty hours after inoculation the stacks were able to directly power the bespoke lighting system. The electrical energy produced by the 15-module stack evolved with usage from â280 mW (â2.650 V at â105 mA) at the beginning to â860 mW (â2.750 V at â300 mA) by the end of the festival. The electrical energy produced by the LED-driven 18-module stack increased from â490 mW at the beginning to â680 mW toward the end of the festival. During this period, illumination was above the legal standards for outdoor public areas, with the 15-module stack reaching a maximum of â89 Lx at 220 cm. These results demonstrate for the first time that the MFC technology can be deployed as a direct energy source in decentralised area (e.g. refugee camps)
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