1,479 research outputs found
Recovery of cobalt sulfate from spent lithium ion batteries by reductive leaching and solvent extraction with Cyanex 272
Cobalt sulfate was recovered from crushed and screened prismatic type spent lithium ion batteries (LIBs) containing 5-20% Co, 5-7% Li, 5-10% Ni, 15% organic chemicals, and 7% plastics together with Cu, Al, Fe, and Mn. Cobalt was reductively leached from the - 16 mesh fraction in 1 h by stirring with 2 M H2SO4 and 6 vol.% H2O2, at 60 °C and 300 rpm using a solid/liquid ratio of 100 g/L to give a cobalt concentration of 28 g/L, corresponding to a leaching efficiency of > 99%. Metal ion impurities such as copper, iron, and aluminium were precipitated as hydroxides from solution by adjusting pH to 6.5. Cobalt was then selectively extracted from the purified aqueous phase by equilibrating with 50% saponified 0.4 M Cyanex 272 at an equilibrium pH ∼ 6. The McCabe-Thiele plot predicted 99.9% cobalt extraction in a 2 stage counter-current operation with A/O ratio of 1/2. Separation factors for the extraction of Co/Li and Co/Ni at pH 6 were close to 750. The stripping of the loaded organic phase with 2 M H2SO4 produced a solution of 96 g/L Co from which pure pigment grade cobalt sulfate could be recovered by evaporation/recrystallisation. Overall, 92% cobalt could be recovered from the spent lithium ion batteries
Cholesterol granuloma in the wall of a mandibular dentigerous cyst: a rare case report
Cholesterol granuloma is an inflammatory reaction to cholesterol crystals deposition. It may develop in a variety of
sites including the middle ear, mastoid process or even paranasal sinuses. Very few cases of cholesterol granuloma
occurring in the jaws were reported. This report presents a rare case of cholesterol granuloma that developed in
the wall of a large mandibular dentigerous cyst. The condition was treated with hemimandibulectomy followed by
reconstruction with a free fibular flap
Is bi-maximal mixing compatible with the large angle MSW solution of the solar neutrino problem?
It is shown that the large angle MSW solution of the solar neutrino problem
with a bi-maximal neutrino mixing matrix implies an energy-independent
suppression of the solar nu_e flux. The present solar neutrino data exclude
this solution of the solar neutrino problem at 99.6% CL.Comment: 6 pages. No figure
Spin Fluctuation and Persistent Current in a Mesoscopic Ring Coupled to a Quantum Dot
We investigate the persistent current influenced by the spin fluctuations in
a mesoscopic ring weakly coupled to a quantum dot. It is shown that the Kondo
effect gives rise to some unusual features of the persistent current in the
limit where the charge transfer between two subsystems is suppressed. Various
aspects of the crossover from a delocalized to a localized dot limit are
discussed in relation with the effect of the coherent response of the Kondo
cloud to the Aharonov-Bohm flux.Comment: 4 pages, 2 figure
Human monoclonal antibodies that neutralize anthrax toxin by inhibiting heptamer assembly
A panel of human anti-anthrax protective antigen IgG1 monoclonal antibodies were evaluated to determine the mechanism of toxin neutralization. AVP-22G12, AVP-1C6 and AVP-21D9 bound to the protective antigen with picomolar affinities to distinct non-overlapping linear epitopes. Two of the antibodies neutralized the anthrax toxin by completely inhibiting the protective antigen oligomer assembly process in vitro
Development of wirelessly-powered, extracranial brain activator (ECBA) in a large animal model for the future non-invasive human neuromodulation
As transcranial electrical stimulation (tES) is an emerging and promising technique for neuromodulation, we developed a novel device; wirelessly-powered, extracranial brain activator (ECBA), which is mounted subcutaneously, and its neuromodulation effect was investigated. The oscillatory changes in electrocorticography (EcoG) were analyzed from two types of stimulation. Two weeks prior to the recording experiment, we underwent surgery for implantation of subdural strips and ECBA module over centroparietal regions of anesthetized beagles. Low-frequency stimulation (LFS) and subsequent high-frequency stimulation (HFS) protocols (600 pulses respectively) were applied. Then, the power changes before and after each stimulation in five different bands were compared. A significantly larger voltage difference with subcutaneous than transcutaneous stimulation measured at EcoG channels indicated a substantial current attenuation between the skin and skull. Compared with the baseline, all subjects showed consistently decreased delta power and increased gamma power after HFS. LFS also induced a similar, but opposite, pattern of power change in four beagles. The results from this study indicate that LFS and HFS with our novel ECBA can consistently and effectively modulate neural activity of the cortex, inducing neural inhibition and facilitation functions, respectively. Future studies are necessary to further ensuring a consistent efficacy and long-term safety.11Ysciescopu
Equations for filling factor estimation in opal matrix
We consider two equations for the filling factor estimation of infiltrated
zinc oxide (ZnO) in silica (SiO_2) opal and gallium nitride in ZnO opal. The
first equation is based on the effective medium approximation, while the second
one - on Maxwell-Garnett approximation. The comparison between two filling
factors shows that both equations can be equally used for the estimation of the
quantity of infiltrated nanocrystals inside opal matrix.Comment: 14 pages, 7 figures, 1 table. Addendum to the article:
http://arxiv.org/abs/physics/050815
Magnetic circular dichroism in X-ray fluorescence of Heusler alloys at threshold excitation
The results of fluorescence measurements of magnetic circular dichroism (MCD)
in Mn L_2,L_3 X-ray emission and absorption for Heusler alloys NiMnSb and
Co2MnSb are presented. Very intense resonance Mn L_3 emission is found at the
Mn 2p_3/2 threshold and is attributed to a peculiarity of the threshold
excitation in materials with the half-metallic character of the electronic
structure. A theoretical model for the description of resonance scattering of
polarized x-rays is suggested.Comment: 3 pages, 2 figures. Discussed at conferences, submitting process in
progres
Summer pruning effect on tree growth and fruit production of persimmon
This paper reviews the effect of summer pruning in persimmon (Diospyros kaki Thunb.) with regard to its positive and negative aspects on tree growth and fruit production. In order for this practice to be of a significant value, a clear understanding is needed to appreciate the fact that so many variables are involved and much remains to be substantiated. Major reasons for summer pruning of persimmon are to improve fruit quality by enhancing light penetration into the tree canopy and to restrict vegetative shoot growth. Summer pruning generally suppresses tree growth even though it elevates leaf activity. Positive effects of summer pruning on skin color, soluble solids, and appearance of fruits are observed mainly in those orchards where the trees are heavily dormant-pruned to lower tree height and to secure space in high density plantings. Secondary shoot pruning and topping could also improve fruit quality, increasing flower bud formation of remaining shoots. Summer-pruning effects are highly dependent on its severity and timing to affect tree growth, shoot regrowth, reserve accumulation, and fruit quality
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