193 research outputs found
High-grade iron ores of KMA as a raw material for metalization
Mineralogical composition of rich iron ores of KMA deposits is considered in the work, with the aim of potential obtaining high-quality iron ore products, as a raw material for metallizatio
Eardrum perforation treatment blood plasma enriched with platelet growth factors
Introduction. The problem of the development of acute post-traumatic otitis media has not lost its relevance. Long-term preservation of the defect of the tympanic membrane contributes to the development of chronic inflammation in the middle ear and a deterioration in the quality of life of patients.Objective. To study the effect of blood plasma enriched with platelet growth factors on the regeneration of the tympanic membrane tissues in patients with acute post-traumatic perforation.Materials and methods. Patients with acute post-traumatic perforation of the tympanic membrane were divided into the main (24 people) and control (19 people) groups. Patients of the main group in the area of perforation of the tympanic membrane were injected once by application with a clot of autoplasma, enriched with platelet growth factors. The control group patients underwent dynamic observation of the processes of natural regeneration of the tympanic membrane tissues. On the 5, 10 and 15th days, the tissue regeneration of the tympanic membranes was assessed subjectively (patient complaints, audiometry) and objectively (otoscopy with the calculation of the dynamics of the relative perforation area, otoacoustic emission).Results. A single application of blood plasma enriched with platelet growth factors to the perforation area was significantly more often accompanied by closure of the tympanic membrane perforation (p ≤ 0.01) and a decrease in the average relative area of the tympanic membrane perforation on days 10 and 15 of the study (p ≤ 0.01). The dynamics of the average relative area of the tympanic membrane perforation reflected a high rate of closure of the tympanic membrane defect in the main group. Better healing of the tympanic membrane in patients of the main group was accompanied by an improvement in the auditory function of the affected ear. The quality of hearing was, on average, significantly better in the patients of the main group than in the patients of the control group, both on the 10th and 15th days of observation (p ≤ 0.01).Conclusion. Clinical use of blood plasma enriched with platelet growth factors has a beneficial effect on the rate, intensity of closure of the tympanic membrane perforation and hearing
Small x behavior of parton distributions. A study of higher twist effects
Higher twist corrections to the structure function F_2 at small x are studied
for the case of a flat initial condition for the twist-two QCD evolution in the
next-to-leading order approximation. We present an analytical parameterization
of the contributions from the twist-two and higher twist operators of the
Wilson operator product expansion. Higher twist terms are evaluated using two
different approaches, one motivated by BFKL and the other motivated by the
renormalon formalism. The results of the latter approach are in very good
agreement with deep inelastic scattering data from HERA.Comment: 46 pages, 9 figures, typeset using REVTeX. Misprints corrected, new
results, discussions, references and acknowledgements added, 2 pictures
replaced. The conclusions remain unchange
Monte Carlo simulation for jet fragmentation in SUSY-QCD
We present results from a new Monte Carlo simulation for jet fragmentation in
QCD and SUSY QCD for large primary energies up to GeV. In
the case of SUSY QCD the simulation takes into account not only gluons and
quarks as cascading particles, but also their supersymmetric partners. A new
model-independent hadronization scheme is developed, in which the hadronization
functions are found from LEP data. An interesting feature of SUSY QCD is the
prediction of a sizeable flux of the lightest supersymmetric particles (LSPs),
if R-parity is conserved. About 10% of the jet energy is transferred to LSPs
which, owing to their harder spectra, constitute an important part of the
spectra for large . Spectra of protons and of secondary particles,
photons and neutrinos, are also calculated. These results have implications for
the decay of superheavy particles with masses up to the GUT scale, which have
been suggested as a source of ultrahigh energy cosmic rays.Comment: latex, 25 pages with 17 eps figure
Giant optical anisotropy in transition metal dichalcogenides for next-generation photonics
Large optical anisotropy observed in a broad spectral range is of paramount
importance for efficient light manipulation in countless devices. Although a
giant anisotropy was recently observed in the mid-infrared wavelength range,
for visible and near-infrared spectral intervals, the problem remains acute
with the highest reported birefringence values of 0.8 in BaTiS3 and h-BN
crystals. This inspired an intensive search for giant optical anisotropy among
natural and artificial materials. Here, we demonstrate that layered transition
metal dichalcogenides (TMDCs) provide an answer to this quest owing to their
fundamental differences between intralayer strong covalent bonding and weak
interlayer van der Walls interaction. To do this, we carried out a correlative
far- and near-field characterization validated by first-principle calculations
that reveals an unprecedented birefringence of 1.5 in the infrared and 3 in the
visible light for MoS2. Our findings demonstrate that this outstanding
anisotropy allows for tackling the diffraction limit enabling an avenue for
on-chip next-generation photonics.Comment: 20 pages, 5 figure
Theoretical issues of small physics
The perturbative QCD predictions concerning deep inelastic scattering at low
are summarized. The theoretical framework based on the leading log
resummation and factorization theorem is described and some recent
developments concerning the BFKL equation and its generalization are discussed.
The QCD expectations concerning the small behaviour of the spin dependent
structure function are briefly summarized and the importance of
the double logarithmic terms which sum contributions containing the leading
powers of is emphasised. The role of studying final states
in deep inelastic scattering for revealing the details of the underlying
dynamics at low is pointed out and some dedicated measurements, like deep
inelastic scattering accompanied by an energetic jet, the measurement of the
transverse energy flow etc., are briefly discussed.Comment: 17 pages, LATEX, 7 uuencoded eps figures include
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